Subpoblaciones de linfocitos T en adultos mayores cubanos con leucemia linfoide crónica / Subpopulations of T lymphocytes in Cuban older adults with chronic lymphoid leukemia

Introducción: la inmunosenescencia está asociada con un mayor riesgo de desarrollo de cáncer. Dentro de las hemopatías malignas que afectan a este grupo de edad, está la leucemia linfoide crónica (LLC), caracterizada por trastornos en la inmunidad adaptativa que incluye las subpoblaciones de linfocitos T. Objetivo: Determinar la frecuencia de las subpoblaciones de linfocitos T en los pacientes adultos mayores con leucemia linfoide crónica evaluados en el Instituto de Hematología e Inmunología de Cuba. Métodos: Se realizó un estudio transversal en 30 adultos mayores con leucemia linfoide crónica. Se cuantificaron los linfocitos TCD3+CD4+ y TCD3+CD8+ en sangre periférica por citometría de flujo. Para la lectura y el análisis de los datos se empleó un citómetro de flujo Beckman Coulter Gallios. Se utilizaron los valores porcentuales, la media y la desviación estándar. Se consideró estadísticamente significativo si p≤0.05. Resultados: Hubo un predominio de hombres que representaron el 56,7 por ciento y del grupo de 70-79 años de edad. No se reportó ningún adulto mayor con LLC con valores altos ni normales de linfocitos TCD3+CD4+. Predominaron los hombres con valores bajos porcentuales de linfocitos TCD3+CD4+, TCD3+CD8+ e inversión del índice CD4/CD8 en relación con las mujeres. Conclusiones: Los adultos mayores con LLC presentan alteraciones en el número de las subpoblaciones de linfocitos T. La acción de estas células en relación al crecimiento de células B malignas aún es desconocido y resulta importante determinar si esto puede reflejar un intento de evasión de las células tumorales al control inmunológico(AU)

Introduction: Immunosenescence is associated with an increased risk of cancer development. Among the malignant hemopathies that affect this age group, it is chronic lymphoid leukemia (CLL), characterized by disorders in adaptive immunity, which include subpopulations of T lymphocytes. Objective: To determine frequency of T lymphocyte subpopulations in older adult patients with chronic lymphoid leukemia evaluated at the Institute of Hematology and Immunology of Cuba. Methods: A cross-sectional study was conducted in 30 older adults with chronic lymphoid leukemia. TCD3+CD4+ and TCD3+CD8+ lymphocytes were quantified in peripheral blood by flow cytometry. A Beckman Coulter Gallios flow cytometer was used to read and analyze the data. The percentage values, the mean and the standard deviation were used. It was considered statistically significant if p≤0.05. Results: There was a predominance of men who represented 56.7 percent and the age group of 70-79 years. No older adults with CLL with high or normal values of TCD3+CD4+ lymphocytes were reported. Men predominated with low percentage values of TCD3+CD4+, TCD3+CD8+ lymphocytes and inversion of the CD4/CD8 ratio in relation to women. Conclusions: Older adult with CLL present alterations in the number of T lymphocyte subpopulations. The role of these cells in relation to the growth of malignant B cells it is unknown and it turns out important to determine if this may reflect an attempt to evade tumor cells from immune control(AU)

Humoral and Cellular Immunology in Human Prostate Cancer: Plasma Cells and T and B Lymphocytes / Inmunología Humoral y Celular en el Cáncer de Próstata Humano: Células Plasmáticas y Linfocitos T y B

SUMMARY: In solid and malignant tumors, innate and adaptive immunity are combined in antitumor responses. This study aimed to analyze the activation of plasma cells and the correlation between the infiltration of B and T lymphocytes with the degree of malignancy or Gleason grade in human prostate biopsies diagnosed with cancer. Prostate cancer biopsies were obtained from the Clinical Hospital of Universidad de Chile (n=70), according to the bioethical norms of the institution. Histological sections of 5µm thickness were processed for immunohistochemistry with primary antibodies against BL and total TL (HRP/DAB). Recognition and quantification were performed under a Leica DM750 optical microscope. Microsoft Excel and GraphPad software were used for the statistical study. Correlation coefficient (Pearson) and mean comparison tests (Kruskal-Wallis and Dunn) and p≤ 0.05 were developed. B and T lymphocyte populations were inversely interregulated in prostate cancer (Gleason) (r= -0.46). Their relationship with Gleason grade is variable according to lymphocyte type (LB vs. Gleason r= -0.0.47 and LT vs. Gleason r= -0.21). Histological diagnosis of prostate cancer correlates with a predominance of LT. The malignancy of the pathology correlates with a predominance of LTs, according to the Gleason grade. The increased knowledge of B and T lymphocyte infiltration and plasma cell activation could be used to better target clinical trials on treatments based on immune system responses. Immunotherapy could be a new paradigm to apply better antitumor therapy strategies.

En tumores sólidos y malignos, la inmunidad innata y adaptativa se combinan en respuestas antitumorales. Este estudio tuvo como objetivo analizar la activación de células plasmáticas y la correlación entre la infiltración de linfocitos B y T con el grado de malignidad o grado de Gleason en biopsias de próstata humana diagnosticadas con cáncer. Las biopsias de cáncer de próstata se obtuvieron del Hospital Clínico de la Universidad de Chile (n=70), de acuerdo con las normas bioéticas de la institución. Secciones histológicas de 5 µm de espesor fueron procesadas para inmunohistoquímica con anticuerpos primarios contra LB y LT total (HRP/DAB). El reconocimiento y las cuantificaciones se realizaron bajo un microscopio óptico Leica DM750. Para el estudio estadístico se utilizaron los programas Microsoft Excel y GraphPad. Se desarrollaron pruebas de coeficiente de correlación (Pearson) y comparación de medias (Kruskal-Wallis y Dunn) y p≤ 0.05. Los resultados muestran que las poblaciones de linfocitos B y T están inversamente interreguladas en el cáncer de próstata (r= -0,4578). Su relación con el grado de Gleason es variable según el tipo de linfocito (LB vs Gleason r= -0,47* y LT vs Gleason r= -0,21). Se concluye que la malignidad del cáncer de próstata se correlaciona con un predominio de LT, versus el grado de Gleason. El mayor conocimiento de la infiltración de linfocitos B y T y la activación de células plasmáticas podría aprovecharse para una mejor orientación de ensayos clínicos en tratamientos basados en las respuestas del sistema inmunitario. La inmunoterapia podría ser un nuevo paradigma para aplicar mejores estrategias de terapias antitumorales.

Inmunoterapia para el tratamiento del cáncer de cabeza y cuello ¿dónde estamos y hacia dónde vamos? / Immunotherapy for the treatment of head and neck cancer: where are we and where are we going?

El cáncer de cabeza y cuello comprende a todos aquellos tumores que se desarrollan en el tracto aerodigestivo superior, una de las características de éstos es su diversidad, que no es solo desde el punto de vista histológico y etiológico, sino que incluyen diversas formas de presentación, progresión y enfoques terapéuticos. Son de causa multifactorial, siendo el alcohol y el tabaco los principales factores de riesgo asociados; en los últimos años se ha relacionado a ciertos virus con potencial oncogénico con la génesis tumoral, entre ellos al Virus del Papiloma Humano, lo que ha permitido modificar el sistema de estadificación tumor primario-nodos linfáticos cancerosos-metástasis (TNM); presentándolo ahora en dos grandes grupos acorde a la Proteína supresora de tumores P16: P16+ y P16-,los cuales tienen características y manejo diferente. En vista de la heterogeneidad de la enfermedad, son diversos los tratamientos que se ha empleados para el manejo de la misma, entre ellos cirugía, radioterapia, quimioterapia e/o inmunoterapia; ésta última terapéutica, está dirigida hacia la estimulación del sistema inmune del paciente con la finalidad de generar la destrucción de las células tumorales, se realizan previo a una intervención quirúrgica para reducir el tamaño del tumor. Una forma destacable, es la del bloqueo de puntos de control inmunitarios, especialmente hacia proteínas de control inmune moduladoras de respuesta de células T, como los anti-PD-1 y los anti-CTLA-4. La inmunoterapia cada vez va tomando más protagonismo en oncología, en especial las formas de evasión de las reacciones inmunitarias por parte de las células cancerígenas(AU)

Head and neck cancer includes all those tumors that develop in the upper aerodigestive tract, one of the characteristics of these is their heterogeneity, which is not only from the histological and etiological, but also include various forms of presentation, progression and therapeutic approaches.They have a multifactorial cause, with alcohol and tobacco being the main associated risk factors, however, in recent year scertain viruses with oncogenic potential have been linked to tumor genesis, including HPV, which has made it possible tomodify the TNM staging system; now presenting it in two large groups, P16+ and P16-, which have different characteristics and management. In view of the heterogeneity of the disease, there are various treatments that have been used to manageit, including surgery, radiotherapy, chemotherapy and/ orimmunotherapy which will be determined taking into account the location and tumor extension. The latter treatment, is aimedat stimulating the patient's immune system in order to generate the destruction of tumor cells, are performed prior to a surgical intervention to reduce the size of the tumor. A remarkable therapy is that of blocking immune checkpoints, especially anti-PD-1 and anti-CTLA. Immunotherapy is becoming more and more prominent, however, there is still much to discover, so we believe that we should continue investigating the ways of evasion of immune reactions by cancer cells(AU)

Respuesta inmunitaria anti-SARS-CoV-2: Infección Naturalvs. Vacunación / Anti-SARS-CoV-2 immune response: natural infection vs vaccination

Este trabajo es una revisión bibliográfica que compara la inmunidad anti-SARS-CoV-2 inducida por la infección natural y la inducida por vacunación, para entenderlas particularidades de la respuesta en cada caso, así como sus ventajas y desventajas. Se escogieron artículos que reportaran la medición de concentración de anticuerpos séricos, determinantes de inmunidad celular y/o evolución clínica de los pacientes. Se encontró que: A) Los pacientes recuperados de una infección por SARS-CoV-2 presentaron una respuesta mayor y más heterogénea de anticuerpos y células B de memoria que los pacientes vacunados, con un mayor número de linfocitos TCD4+, que cooperan con la diferenciación de linfocitos B y con la producción de anticuerpos neutralizantes. B) La vacunación previene la tormenta de citocinas asociada a la infección natural. C) Dos dosis de una vacuna basada en ARN mensajero logran una concentración de anticuerpos de clase IgG prácticamente igual a la de los pacientes severamente enfermos, pero sin el daño a los nódulos linfáticos asociado a la infección natural. D) Se puede aumentar el número de linfocitos B administrando dosis de refuerzo de la vacuna. Si bien, tanto la vacunación como la infección natural generan respuestas anti-SARS-CoV-2 significativas, la vacunación es el método más seguro para proteger a la población, pues evita el riesgo a la inmunopatología y a la mortalidad asociados con la infección natural. Más aún, la inmunidad híbrida (aquella que adquieren los pacientes que superaron la infección natural y fueron después vacunados) induce una producción de anticuerpos capaces de neutralizar por completo al SARS-CoV-2(AU)

This work is a bibliographic review that comparesanti-SARS-CoV-2 inmmune response induced by natural infección with that induced by vaccination, to understand theparticularities of each response, as well as their advantages and disadvantages. Research articles that reported levels of antibodies in serum, determinants of cellular inmmunity and/or clinical evolution of patients were chosen. It was found that: A) Pacients previously infected with SARS-CoV-2 presented a larger and more heterogeneous response of antibodies and memory B cells than vaccined patients, with a larger number of CD4+T cells that cooperate with the differentiation of B cells and production of neutralizing antibodies. B) Vaccination prevents the cytokine storm associated with natural infection. C) Two doses of an mRNA vaccine induced an IgG concentration nearly equal to severe ill patients but without the damage to lymph nodes associated with natural infection. D) B cell levels can be increased by giving booster doses of the vaccine. Althought both vaccination and natural infection generate significant anti-SARS-CoV-2 immune responses, vaccination is the safest method to protect general population, because it avoids the risk of immunopathology and mortality associated with natural infection. Futhermore, hybrid immunity (thatadquired by patients who overcame the natural infection and were later vaccinated), induces production of antibodies capable of completely neutralizing SARS-CoV-2(AU)

Spleen regeneration after subcutaneous heterotopic autotransplantation in a mouse model

BACKGROUND: Splenectomy may lead to severe postoperative complications, including sepsis and cancers. A possible solution to this problem is heterotopic autotransplantation of the spleen. Splenic autografts rapidly restore the regular splenic microanatomy in model animals. However, the functional competence of such regenerated autografts in terms of lympho- and hematopoietic capacity remains uncertain. Therefore, this study aimed to monitor the dynamics of B and T lymphocyte populations, the monocyte-macrophage system, and megakaryocytopoiesis in murine splenic autografts. METHODS: The model of subcutaneous splenic engraftment was implemented in C57Bl male mice. Cell sources of functional recovery were studied using heterotopic transplantations from B10-GFP donors to C57Bl recipients. The cellular composition dynamics were studied by immunohistochemistry and flow cytometry. Expression of regulatory genes at mRNA and protein levels was assessed by real-time PCR and Western blot, respectively. RESULTS: Characteristic splenic architecture is restored within 30 days post-transplantation, consistent with other studies. The monocyte-macrophage system, megakaryocytes, and B lymphocytes show the highest rates, whereas the functional recovery of T cells takes longer. Cross-strain splenic engraftments using B10-GFP donors indicate the recipient-derived cell sources of the recovery. Transplantations of scaffolds populated with splenic stromal cells or without them afforded no restoration of the characteristic splenic architecture. CONCLUSIONS: Allogeneic subcutaneous transplantation of splenic fragments in a mouse model leads to their structural recovery within 30 days, with full reconstitution of the monocyte-macrophage, megakaryocyte and B lymphocyte populations. The circulating hematopoietic cells provide the likely source for the cell composition recovery.

Inibidores epigenéticos como reguladores de linfócitos T CD8+ humanos / Epigenetic inhibitors as regulators of human CD8 T lymphocytes

Linfócitos T CD8 são células chave na resposta antitumoral. Uma vez ativadas, sofrem mudanças epigenéticas, adquirem fenótipos distintos e sua função está ligada ao potencial citotóxico e produção de mediadores inflamatórios. Porém, na resposta antitumoral, tais células encontram-se disfuncionais. Assim, estratégias capazes de reprogramar as células TCD8 podem aumentar sua eficácia. Inibidores epigenéticos são capazes de modular o perfil de células T CD4, mas os efeitos em células T CD8 ainda não estão totalmente esclarecidos. Portanto, buscamos identificar possíveis inibidores epigenéticos que sejam capazes de modular a atividade e o perfil fenotípico de linfócitos T CD8. Para tal, células T CD8 foram isoladas por sorting a partir de PBMC de doadores saudáveis e cultivados em placas de 96 poços na presença de coquetel de ativação (DynaBeads anti-CD3/CD28, IFN- e IL-2 recombinantes) e 1µM de diferentes inibidores epigenéticos (MS023, A485, L-MOSES, A-196, GSKLSD1, A366). Linfócitos T CD8 não estimulados e linfócitos T CD8 ativados na ausência de inibidores epigenéticos foram utilizados como controles. Após 4 ou 8 dias de cultura, as células foram coletadas e analisadas por citometria de fluxo para avaliação de marcadores ligados à ativação (CD69), função (IFN- e granzima B), diferenciação (CCR7, CD45RA) e exaustão (PD-1, TIGIT). As células foram adquiridas no citômetro de fluxo BD FACSymphony A5, e a análise estatística foi feita através do software GraphPad Prism 9. Realizamos ensaios in vitro nos quais células T CD8 foram ativadas na presença ou não de diferentes inibidores, com um deles apresentando intenso potencial de modular células T CD8: o A485, um inibidor seletivo do bromodomínio p300/CBP. Os nossos dados mostram que o A485 aumentou a ativação celular, evidenciado pelo aumento da frequência de células TCD8+CD69+. Este inibidor também foi capaz de modular o fenótipo de memória das células T, polarizando-as para um perfil TN/TSCM, diferentemente do controle e dos outros inibidores, que induziram um perfil TEM (células T efetoras de memória). Após oito dias, o tratamento com o inibidor A485 resultou em menor frequência de células PD-1+ e de células TIGIT+ em comparação com o controle. De relevância clínica, o inibidor A485 foi capaz de modular células CAR-T anti-CD19 isoladas de produtos de infusão, aumentando a frequência do marcador CD69 e modulando seu perfil fenotípico, menos diferenciado, em comparação ao controle. Além disso, o inibidor A485 potencializou a ação antitumoral das células CAR-T anti-CD19 em ensaios de co-cultura com a linhagem celular Daudi CD19+. Em resumo, os nossos dados mostram que a inibição de p300/CBP induz um perfil TN/TSCM em células T CD8 ativadas e em células CAR-T, potencializando as suas atividades antitumorais. Posto que a retenção do perfil TN/TSCM favorece o controle tumoral, esses achados podem ter implicações clínicas para pacientes com doenças hematológicas e com tumores sólidos.

CD8 T lymphocytes are key cells for the induction of antitumor responses. Once activated, these cells undergo epigenetic changes, acquire distinct phenotypes, and their function is linked to the production of cytotoxic and inflammatory mediators. However, these cells are dysfunctional within the tumor microenvironment. Therefore, strategies capable of reprogramming CD8 T cells can enhance their antitumor efficacy. Previous studies have shown that epigenetic inhibitors can modulate the profile of CD4 T cells, but the effects on CD8 T cells are still to be clarified. Thus, we aimed to identify possible epigenetic inhibitors that can modulate the activity and phenotype of CD8 T lymphocytes. To do this, CD8 T lymphocytes were isolated by cell sorting from healthy blood samples and cultured in 96-well plates in the presence of a polyclonal stimulatory cocktail (i.e., anti-CD3/CD28 DynaBeads, recombinant (r)IFN-, and rIL-2) along with 1µM of different epigenetic inhibitors (i.e., MS023, A485, LMOSES, GSKLSD1, and A366). Unstimulated CD8 T lymphocytes and polyclonally-stimulated CD8 T lymphocytes in the absence of epigenetic inhibitors were used as controls. After 4 or 8 days of culture, the cells were analyzed by flow cytometry for the assessment of cell markers related to activation (CD69), function (IFN- and granzyme B), differentiation (CCR7 and CD45RA) and exhaustion (PD-1 and TIGIT). Cells were acquired by the BD FACSymphony A5 cytometer, and statistical analyses were done using the GraphPad Prism 9 software. First, we conducted in vitro assays in which CD8 T cells were activated in the presence or absence of different inhibitors. A485, a p300/CBP bromodomain inhibitor, showed a potent modulatory effect on CD8 T cells. The inhibitor A485 increased T cell activation, observed by the increased frequency of CD69+ CD8 T cells. This inhibitor could also modulate the T cell memory phenotype, polarizing them towards a TN/TSCM profile, unlike the control and the other inhibitors, which polarized them towards to the TEM (effector memory T cells) profile. When the analyses were conducted after eight days of culture, we observed that the treatment with the A485 inhibitor resulted in a lower frequency of PD-1+ and TIGIT+ T cells compared with CD8 T cells activated in the absence of the inhibitor. Of clinical relevance, A485 was able to modulate anti-CD19 CAR-T cells isolated from pre-infusion products by positively regulating the frequency of CD69+ CAR-T cells and modulating their memory phenotype, keeping these cells less differentiated. In addition, A485 potentiated the in vitro antitumor activity of antiCD19 CAR-T cells in co-culture assays with the CD19+ Daudi cell line. In summary, our data show that the p300/CBP inhibition induces the TN/TSCM profile in CD8 T cells and CAR-T cells, thus boosting their antitumor activitiesSince the TN/TSCM phenotype has been shown to be favorable for tumor control, these findings can be of clinical interest for patients with hematological malignancies and solid tumors.

Caracterização das infecções que acometem o usuário no momento do diagnóstico para o Hiv/Aids / Characterization of infections that affect the user at the moment of diagnosis for Hiv/Aids / Caracterización de las infecciones que afectan a los usuarios en el momento del diagnóstico del Vih/Sida

: O estado do Pará, de 2009 a 2019, apresentou um aumento de 46,5% na taxa de detecção de aids. O que destaca a importância de estudos para a avaliação e acompanhamento deste público. Objetivo: Analisar as infecções que acometem os usuários de um centro de referência no momento de seu diagnóstico para a infecção pelo HIV. Métodos: Estudo descritivo, realizado em um centro de referência da cidade de Santarém, Pará. A amostra foi de 332 prontuários de pacientes diagnosticados para o HIV nos anos de 2016 e 2017. A coleta de dados buscou informações sociodemográficas, clínicas e imunológicas dos pacientes no momento do diagnóstico para a infecção pelo HIV. Os dados foram organizados e analisados por estatística descritiva e inferencial, adotando- se p<0,05. Resultados: Observou-se prevalência do sexo masculino (67%), faixa etária de 15-24 anos (32,2%), solteiros (59%), com vínculo empregatício (64,5%), contagem de linfócitos T CD4+ ≥200 céls/mm3 (54,8%) e carga viral detectável (75,3%). A Candidíase (25%) e a Tuberculose (25%) predominaram como infecções oportunistas (IO), e a Sífilis (67,5%) como outras infecções. Conclusão: Conforme método proposto e os dados já informados, conclui-se que o diagnóstico para a Sífilis se associou ao sexo masculino, bem como a situação de contagem de linfócitos T CD4+ <200 céls/mm3 se associou com a presença de alguma infecção oportunista, da instalação da Candidíase e da Tuberculose.

Introduction: The state of Pará, from 2009 to 2019, showed a 46.5% increase in the AIDS detection rate. What stands out the importance of studies for the evaluation and monitoring of this public. Objective: Analyze the infections that affect the users of a reference center at the moment of diagnosis for HIV infection. Methods: Descriptive study, carried out in a reference center in the city of Santarém, Pará. The sample consisted of 332 records of patients diagnosed with HIV in the years 2016 and 2017. The data collection sought sociodemographic, clinical and immunological information of the patients at the moment diagnosis for HIV infection. The data were organized and analyzed using descriptive and inferential statistics, adopting p <0.05. Results: There was a prevalence of males (67%), aged 15-24 years (32.2%), single (59%), with employment (64.5%), CD4 + T lymphocyte count ≥200 cells/mm3 (54.8%) and detectable viral load (75.3%). Candidiasis (25%) and Tuberculosis (25%) predominated as opportunistic infections (IO), and Syphilis (67.5%) as other infections. Conclusion: According to the proposed method and the data already reported, it is concluded that the diagnosis for Syphilis was associated with the male gender, as well as the situation of CD4 + T lymphocyte count <200 cells/mm3 was associated with the presence of some opportunistic infection, of the installation of Candidiasis and Tuberculosis.

Introducción: El estado de Pará, de 2009 a 2019, presentó un aumento del 46,5% en la tasa de detección del SIDA. Lo que pone de manifiesto la importancia de los estudios para la evaluación y el seguimiento de este público. Objetivo: Analizar las infecciones que sufren los usuarios de un centro de referencia en el momento de su diagnóstico de infección por VIH. Métodos: Estudo descritivo, realizado em um centro de referência da cidade de Santarém, Pará. La muestra fue de 332 historias clínicas de pacientes diagnosticados de VIH en los años 2016 y 2017. La recogida de datos buscaba información sociodemográfica, clínica e inmunológica de los pacientes en el momento del diagnóstico de la infección por VIH. Los datos se organizaron y analizaron mediante estadísticas descriptivas e inferenciales, adoptando p<0,05. Resultados: Se observó la prevalencia del sexo masculino (67%), el grupo de edad de 15 a 24 años (32,2%), la soltería (59%), el empleo (64,5%), el recuento de linfocitos T CD4+ ≥200 células/mm3 (54,8%) y la carga viral detectable (75,3%). La candidiasis (25%) y la tuberculosis (25%) predominaron como infecciones oportunistas (IO), y la sífilis (67,5%) como otras infecciones. Conclusión: De acuerdo con el método propuesto y los datos ya informados, se concluye que el diagnóstico de Sífilis se asocia al sexo masculino, así como la situación de contagio de linfocitos T CD4+ <200 células/mm3 se asocia a la presencia de alguna infección oportunista, a la instauración de la Candidiasis y a la Tuberculosis.

Trasplante pulmonar: una perspectiva desde la inmunología / Lung transplantation: a perspective from immunology

Resumen El trasplante pulmonar implica una serie de desafíos, que como lo ha demostrado la historia, no sólo depende de un adecuado desarrollo de técnicas quirúrgicas, sino también de la comprensión de una serie de complejas interacciones inmunológicas celulares y humorales que serán las responsables del tipo de respuesta (innata y/o adquirida) fisiológica y que pudiesen desencadenar las complicaciones asociadas al trasplante (rechazo hiperagudo, agudo o crónico). Cada una de las cuales tiene su potencial prevención y/o tratamiento. El poder conocer esta serie de respuestas, permite al clínico anticiparse a algunos de estos eventos y evitar de mejor forma el daño y las consecuencias que pueden producir en los casos de trasplante pulmonar.

Lung transplantation involves a series of challenges, which as history has shown, depends not only on an adequate development of surgical techniques, but also on the understanding of a series of complex cellular and humoral immunological interactions that will be responsible for the type of physiological response (innate - acquired) and that could trigger the complications associated with transplantation (hyperacute, acute or chronic rejection). Each of which has its potential prevention and treatment. Being able to know this series of responses, allows the clinician to anticipate some of these events and to avoid in a better way the damage and the consequences that can occur in cases of lung transplantation.

Alergia alimentar não IgE mediada: proctocolite induzida por proteínas alimentares ­ Atualização / Non-IgE mediated food allergy: food protein-induced allergic proctocolitis ­ An update

Nas últimas décadas observa-se aumento na prevalência mundial de alergia alimentar, que já acomete aproximadamente 6% das crianças, atribuído à interação entre fatores genéticos, ambientais e alterações na resposta imunológica e pode envolver reações mediadas por IgE, não mediadas e mistas. As formas não IgE mediadas decorrem de reação de hipersensibilidade tardia, mediada por linfócitos T e afetam prioritariamente o trato gastrointestinal, como a Síndrome da enterocolite induzida por proteína alimentar (FPIES), Síndrome da proctocolite alérgica induzida por proteína alimentar (FPIAP), Síndrome da enteropatia induzida por proteína alimentar (FPE) e doença celíaca. As características destas reações podem ser diferenciadas por sua apresentação clínica, gravidade, idade de início e história natural. Entre as reações alérgicas aos alimentos não IgE mediadas, a proctocolite alérgica é a mais frequente. Geralmente ocorre no primeiro ano de vida e apresenta excelente prognóstico. Embora costume ter um curso benigno, traz grande preocupação aos cuidadores por frequentemente cursar com quadro de hematoquezia exigindo diagnóstico diferencial adequado. O conhecimento e manejo da proctocolite alérgica é de suma importância para a prática médica em Alergia e Imunologia. Seu diagnóstico é baseado na história clínica seguindo-se dieta de exclusão, especialmente do leite de vaca, com subsequente provocação oral, que geralmente pode ser realizada no domicílio. O diagnóstico preciso é importante, para se evitar dietas de exclusão desnecessárias. Nesta revisão foram utilizados artigos publicados nos últimos anos, com busca realizada através da base PubMed envolvendo revisões, diagnóstico e tratamento de alergias não IgE mediadas, com foco em proctocolite alérgica.

An increase in the worldwide prevalence of food allergies has been observed in the past decades, currently affecting 6% of children. This increase has been associated with the interaction between genetic, environmental, and immune response factors and can be observed in IgE, non-IgE, and mixed mediated reactions. Non-IgE mediated food allergies result from delayed-type hypersensitivity and mostly affect the gastrointestinal tract, such as food protein-induced enterocolitis syndrome (FPIES), food protein-induced allergic proctocolitis (FPIAP), food protein-induced enteropathy (FPE), and celiac disease. These reactions can be differentiated by their clinical presentation, severity, age at onset, and natural history. Among non-IgE-mediated allergic reactions to food, allergic proctocolitis is the most frequent. It usually develops in the first year of life and has excellent prognosis. Although it has a benign course, allergic proctocolitis is challenging for health care professionals because it often presents with hematochezia, requiring an accurate differential diagnosis. Knowledge and management of allergic proctocolitis is of paramount importance for medical practice in allergy and immunology. Its diagnosis is based on clinical history followed by elimination diet, especially cow's milk, with subsequent oral food challenge, which may usually be performed at home. Accurate diagnosis is important to avoid unnecessary elimination diets. For this review, PubMed database was searched for recently published literature reviews and studies on the diagnosis and treatment of non- IgE mediated allergies, with a focus on allergic proctocolitis.

Imunologia da tuberculose: uma revisão narrativa da literatura / Tuberculosis immunology: a narrative literature review

A resposta imune desenvolvida pelo hospedeiro contra o Mycobacterium tuberculosis é considerada de natureza complexa e multifacetada. Esta interação bacilo-hospedeiro resulta, na maioria das vezes, em uma infecção latente assintomática, podendo ou não evoluir para a forma ativa da tuberculose (TB). O presente estudo objetivou atualizar e sumarizar o conhecimento científico acerca dos mecanismos imunológicos associados à infecção e sua progressão para a TB ativa. Trata-se de uma revisão narrativa, realizada a partir do levantamento bibliográfico de artigos científicos indexados nas bases de dados PubMed/MEDLINE e SciELO, nos últimos 20 anos. Nas últimas décadas, a caracterização de linfócitos Tγδ, MAIT, iNKT e outra células T CD1 restritas proporcionaram um maior entendimento do papel da imunidade inata na infecção pelo bacilo. A migração de linfócitos T CD4+ produtores de IFN-g, TNF-α e de outras moléculas solúveis, promove o recrutamento e formação do granuloma, estrutura que beneficia tanto o hospedeiro quanto o bacilo. Eventualmente, um desequilíbrio nesta complexa rede de interação, resulta em uma resposta inflamatória exacerbada que contribui para o desenvolvimento de um granuloma necrótico. Por fim, a exaustão da resposta imune local frente à contínua exposição ao bacilo, associada ao perfil anti-inflamatório dos linfócitos Th2 e linfócitos Treg, favorecem a inativação funcional e, consequentemente, o desenvolvimento da doença ativa. A resposta imunológica é crucial para o desenvolvimento da infecção por M. tuberculosis. Portanto, estudos que possibilitem uma maior compreensão sobre a interação bacilohospedeiro podem viabilizar o desenvolvimento de novos métodos diagnósticos, estratégias terapêuticas e, sobretudo, avanços no desenvolvimento de imunobiológicos.

The immune response developed by the host against Mycobacterium tuberculosis is considered a complex and multifaceted nature. This host-bacillus interaction, which in most cases results in an asymptomatic latent infection that may or may not evolve to the development of active pulmonary tuberculosis (TB). The present study aimed to update and summarize the current scientific knowledge regarding the immunological mechanisms associated with infection and the development of active disease. This is a narrative review, based on scientific articles indexed in the PubMed/ MEDLINE and SciELO databases over the last 20 years. In recent decades, the characterization of Tγδ lymphocytes, MAIT, iNKT and CD1-restricted T cells has provided a better understanding of the role of innate immunity in bacilli infection. The migration of T CD4+ lymphocytes that produce IFN-γ, TNF-α and other soluble molecules, promotes the recruitment and formation of the granuloma, a structure that benefits both the host and the bacillus. Eventually, an imbalance in this complex interaction network results in an exacerbated inflammatory response that contributes to the development of a necrotic granuloma. Finally, exhaustion of the local immune response due to continuous exposure to the bacillus, associated with the anti-inflammatory profile of Th2 lymphocytes and Treg lymphocytes, favor functional inactivation and, consequently, the development of active disease. The immune response is crucial for the development of M. tuberculosis infection. Therefore, studies that enable a greater understanding of the hostbacillus interaction may enable the development of new diagnostic methods, therapeutic strategies and, above all, advances in the development of immunobiologicals.

Supervivencia en las personas que viven con VIH en el marco del sistema de salud colombiano 2011-2018 / Survival in people living with HIV in the framework the Colombian health system: 2011-2018

Resumen Objetivo: Describir la supervivencia a siete años y los principales factores asociados a esta, en las personas con VIH que fueron atendidas en el sistema de salud colombiano entre 2011 a 2018. Métodos: Análisis de supervivencia de una cohorte de 64 039 personas diagnosticadas con VIH en Colombia. Se aplicó el método de Kaplan-Meier para estimar la probabilidad de supervivencia a partir de la fecha del diagnóstico. Se ajustó un modelo de supervivencia paramétrico flexible de Royston Parmar. Resultados: La estimación de la supervivencia global a 7 años fue de 94,8% (IC 95%: 94,5-95,2). El mayor riesgo de muerte se presentó en los hombres (HR: 1,2; IC 95%: 1,1-1,4; p: 0,010); en personas ≥50 años de edad (HR: 3,1; IC 95%: 1,6-6,3; p: 0,002); en el régimen subsidiado (HR: 2,2; IC 95%: 1,9-2,5; p: <0,001); en la etapa sida (HR: 2,8; IC 95%: 2,1-3,7; p: <0,001); en quienes presentaron la última carga viral detectable (HR: 7,1; IC 95%: 6,0-8,3; p: <0,001); y en quienes mostraron conteo de linfocitos T CD4+ <350 células/μL (HR: 1,9; IC 95%: 1,4-2,4; p: <0,001). Conclusión: La probabilidad de la supervivencia de las personas que viven con VIH aumenta al ser diagnosticados en edades jóvenes, en quienes presenten un recuento de linfocitos T CD4+ ≥350 células/μL, una carga viral indetectable (< 50 copias/mL) y no se encuentren en etapa sida.

Summary Objective: to describe the seven-year survival and predictors of mortality among people with HIV who were treated in the Colombian health system between 2011 and 2018. Methods: 64 039 people diagnosed with HIV in Colombia were included. Kaplan-Meier analysis estimated the probability of survival from the date of diagnosis. A Royston Parmar flexible parametric survival model was fitted. Results: The overall survival at 7 years was 94.8% (95% CI: 94.5-95.2). Survival was related to sex (men, HR: 1.2; 95% CI: 1.1-1.4; p: 0.010); people ≥50 years of age (HR: 3.1; 95% CI: 1.6-6.3; p: 0.002); subsidized regime (HR: 2.2; 95% CI: 1.9-2.5; p: <0.001); AIDS stage (HR: 2.8; 95% CI: 2.1-3.7; p: <0.001); a detectable viral load (HR: 7.1; 95% CI: 6.0-8.3; p: <0.001); and a CD4+ Lymphocyte count <350 cells/μL (HR: 1.9; 95% CI: 1.4-2.4; p: <0.001). Conclusion: The probability of survival of people living with HIV increases when they are diagnosed at a young age, in those with a CD4+ T Lymphocyte count ≥350 cells/μL, an undetectable viral load (<50 copies/mL) and are not in the AIDS stage.

Polimorfismo genético del correceptor CCR5 en pacientes cubanos VIH/sida de la tercera edad / Genetic polymorphism of the CCR5 coreceptor in Cuban elderly HIV/AIDS patients

Introducción: El polimorfismo en algunos genes de quimiocinas se asocia con resistencia a la infección por VIH-1, en este sentido la presencia de la mutación Δ32 del correceptor CCR5 en homocigosis, se relaciona con resistencia a la infección y la mutación heterocigótica con un retraso en la progresión de la enfermedad. Objetivos: Identificar la frecuencia del polimorfismo genético del correceptor CCR5 en los pacientes bajo estudio, así como su relación con los niveles de linfocitos T CD4+, la carga viral y las enfermedades oportunistas. Métodos: Se realizó un estudio de corte transversal en 45 pacientes VIH/sida de la tercera edad, cubanos atendidos en el Centro Hospitalario Universitario del IPK durante los meses de enero a mayo de 2019 en el servicio de Medicina del Centro Hospitalario Universitario del IPK, a los que se les realizó la reacción en cadena de la polimerasa (PCR) para determinar el polimorfismo genético del correceptor CCR5. Resultados: El polimorfismo genético del correceptor CCR5 que predominó fue el homocigótico salvaje con 87 por ciento seguido del heterocigótico Δ32 con 13 por ciento. El 80 por ciento de los pacientes presentaron carga viral no detectable y el 56 por ciento niveles de linfocitos T CD4+ por encima de 350 cél/µL. La enfermedad oportunista que predominó fue la neumonía por Pneumocystis jirovecii en 32 por ciento de los sujetos estudiados. No se observaron diferencias estadísticamente significativas entre el polimorfismo genético del correceptor CCR5 y los niveles de linfocitos T CD4+, la carga viral y las enfermedades oportunistas presentes en los pacientes estudiados. Conclusiones: Los polimorfismos genéticos del correceptor CCR5 hallados fueron el homocigótico salvaje y el heterocigótico-∆32. Fue limitado el polimorfismo del gen en los pacientes estudiados(AU)

Introduction: Polymorphism in some chemokine genes is associated to resistance to HIV-1 infection. Homozygous Δ32 mutation of the CCR5 coreceptor is related to resistance to infection, whereas heterozygous mutation is related to a delay in the progress of the disease. Objectives: Identify the frequency of genetic polymorphism of the CCR5 coreceptor in the patients studied, as well as its relationship to CD4+ T lymphocyte levels, viral load and opportunistic diseases. Methods: A cross-sectional study was conducted of 45 Cuban elderly HIV/AIDS patients attending the Medicine Service of the University Hospital Center at IPK from January to May 2019. These patients underwent polymerase chain reaction testing (PCR) to determine genetic polymorphism of the CCR5 coreceptor. Results: A predominance was found of wild homozygotous genetic polymorphism of the CCR5 coreceptor with 87 percent, followed by heterozygotous Δ32 genetic polymorphism with 13 percent. In 80 percent of the patients studied the viral load was undetectable, whereas in 56 percent CD4+ T lymphocyte levels were above 350 cel/µl. The prevailing opportunistic disease was Pneumocystis jirovecii pneumonia in 32 percent of the subjects. Statistically significant differences were not found between genetic polymorphism of the CCR5 coreceptor and CD4+ T lymphocyte levels, viral load and the opportunistic diseases present in the patients studied. Conclusions: The genetic polymorphisms of the CCR5 coreceptor found in the study were of the wild homozygotous and heterozygotous Δ32 types. Gene polymorphism was limited in the patients studied(AU)

IL-17 E SUA RELAÇÃO COM AS LESÕES PERIRRADICULARES: REVISÃO DE LITERATURA / IL-17 AND ITS RELATIONSHIP TO PERIRRADICULAR INJURIES: LITERATURE REVIEW

A lesão perirradicular consiste em uma doença inflamatória de origem microbiana causada pelo desenvolvimento da infecção no sistema de canais radiculares. Citocinas pró-inflamatórias e imunoregulatórias são fundamentais para o desenvolvimento dessas lesões. No entanto, pouco se sabe sobre como e em que momento elas atuam nas diferentes fases de desenvolvimento da lesão. A presença de bactérias e seus subprodutos metabólicos evocam reações imunológicas do hospedeiro, como a chegada de diferentes células do sistema de defesa aos tecidos periapicais, bem como produção de mediadores inflamatórios. Diversos estudos vêm sendo realizados para identificar os mediadores envolvidos na atividade de reabsorção óssea, permitindo uma melhor compreensão sobre a etiopatogenia das periacopatias. Além disso, investigações prévias sugerem que os linfócitos T CD4+ são as célulasinflamatórias predominantes que se infiltram na patogênese das lesões periapicais e desempenham um papel importante no curso da doença. Células Th17, que compreendem uma subpopulação da T CD4+, cujo produto principal é a interleucina IL-17. A IL-17 é uma citocina pró-inflamatória que exerce efeitos potentes em diferentes tipos celulares da imunidade inata e é considerada uma ponte molecular entre o sistema imunológico inato e adaptativo. Ela também é responsável pelo início e propagação da inflamação, apresentando um papel importante na ligação da ativação da célula T para mobilização e ativação de neutrófilos. Neste contexto, a presente revisão da literatura discutiu o papel da IL-17 na formação e manutenção de lesões perirradiculares.

The periapical lesion is an inflammatory disease of microbial origin caused by infection development in the root canal system. Pro-inflammatory and immunoregulatory cytokines are essential for the development of these lesions. However, little is known about how and when they act in the different stages of injury development. The presence of bacteria and their metabolic products evoke host immune reactions, such as the arrival of different cells of the defense system in periapical tissues, as well as the production of inflammatory mediators. Several studies have been carried out to identify the mediators involved in bone resorption activity, allowing a better understanding of the etiopathogenesis of periapicopathies. In addition, previous investigations suggest that CD4 + T lymphocytes are the predominant inflammatory cells that infiltrate the pathogenesis of periapical lesions and play an important role in the course of the disease. Th17 cells, which comprise a subpopulation of CD4 + T, whose main product is interleukin IL-17. IL-17 is a pro-inflammatory cytokine that has potent effects on different cell types of innate immunity and is considered a molecular bridge between the innate and adaptive immune systems. It is also responsible for the onset and spread of inflammation, playing an important role in linking T cell activation to neutrophil mobilization and activation. In this context, the present literature review discussed the role of IL-17 in the formation and maintenance of periradicular lesions.

First report of expansion of CD4+/CD28 null T-helper lymphocytes in adult patients with idiopathic autoimmune hemolytic anemia

ABSTRACT CD28 null T helper (Th) cells are rare in healthy individuals, but they are increased in various inflammatory and immune-mediated diseases. In this study, we determined the size of the CD4+/CD28 null T lymphocyte compartment in the peripheral blood of 40 autoimmune hemolytic anemia (AIHA) patients (idiopathic and secondary) and 20 healthy control subjects, using tri-color flow cytometry. The frequency and absolute count of CD4+/CD28 null T helper (Th) cells was significantly higher in idiopathic AIHA patients, compared to healthy controls (p = 0.001 and 0.001, respectively) and to patients with secondary AIHA (p = 0.04 and 0.01, respectively). The percentage of CD4+/CD28 null Th cells was also negatively correlated to the hemoglobin (Hb) level (p = 0.03). These findings demonstrate, for the first time, the expansion of this phenotypically-defined population of T lymphocytes in patients with idiopathic AIHA and indicate that it likely plays an etiological role in the development of this disease. However, establishing the use of this marker for diagnosis or monitoring treatment of such patients needs further studies.

Reatividade cruzada entre betalactâmicos: uma abordagem prática / Cross-reactivity among beta-lactams: a practical approach

Os betalactâmicos são a classe de drogas que mais causam reações de hipersensibilidade envolvendo um mecanismo imunológico específico, e são os principais desencadeantes entre os antimicrobianos. São representados pelas penicilinas, cefalosporinas, carbapenêmicos, monobactâmicos e inibidores da betalactamase. A estrutura química básica destes fármacos consiste na presença dos seguintes componentes: anel betalactâmico, anel adjacente e cadeias laterais, sendo todos potenciais epítopos. Os anticorpos da classe IgE e linfócitos T estão frequentemente envolvidos no reconhecimento desses epítopos. A reatividade cruzada depende da estabilidade dos produtos intermediários (determinantes antigênicos) derivados da degradação dos anéis betalactâmicos, anéis adicionais e da semelhança estrutural das cadeias laterais entre as drogas. Classicamente acreditava-se num grande potencial de reatividade cruzada dentro de cada classe e até entre as classes, mas estudos da última década mostraram que indivíduos alérgicos à penicilina (com testes cutâneos positivos) reagiam às cefalosporinas em aproximadamente 3% dos casos, aos carbapenêmicos em cerca de 1%, e praticamente não reagiam aos monobactâmicos. Essa reatividade ou tolerância parece estar vinculada ao grau de similaridade entre as cadeias laterais desses antibióticos. Nesta revisão, ressaltamos a importância da investigação sistematizada na confirmação ou exclusão de alergia aos betalactâmicos, descrevemos a prevalência da reatividade cruzada entre estes fármacos e sugerimos um algoritmo de abordagem desses pacientes baseados em sua estrutura química e nos dados publicados na literatura.

Beta-lactams are the drugs most commonly involved in hypersensitivity reactions mediated by a specific immune mechanism and are the main triggers among antibiotics. They include penicillins, cephalosporins, carbapenems, monobactams and beta-lactam inhibitors. The basic chemical structure of these drugs consist on the presence of the following components: betalactam ring, an adjacent ring and side chains, all of which are potential epitopes. IgE antibodies and T lymphocytes are often involved in recognizing those epitopes. Cross-reactivity depends on the stability of intermediate products (antigenic determinants) derived from the degradation of the beta-lactam ring, on the adjacent rings, and on the structural similarity of the side chains between drugs. Classically, it was believed that there was a great potential for cross-reactivity within each class and even between classes, but studies from the last decade showed that individuals allergic to penicillin (with positive skin tests) reacted to cephalosporins in approximately 3% of cases, to carbapenems in about 1%, and rarely reacted to monobactams. This reactivity or tolerance seems to be linked to the degree of similarity between the side chains of these antibiotics. In this review, we emphasize the importance of systematic investigation to confirm or exclude allergy to beta-lactams, we describe the prevalence of crossreactivity between these drugs and we suggest an algorithm for approaching these patients based on their chemical structure and on data published in the literature.

Immune characterization of a Colombian family cluster with SARS-CoV-2 infection / Caracterización inmunológica de un grupo familiar colombiano con infección por SARS-CoV-2

Abstract | Introduction: Immunological markers have been described during COVID-19 and persist after recovery. These immune markers are associated with clinical features among SARS- CoV-2 infected individuals. Nevertheless, studies reporting a comprehensive analysis of the immune changes occurring during SARS-CoV-2 infection are still limited. Objective: To evaluate the production of proinflammatory cytokines, the antibody response, and the phenotype and function of NK cells and T cells in a Colombian family cluster with SARS-CoV-2 infection. Materials and methods: Proinflammatory cytokines were evaluated by RT-PCR and ELISA. The frequency, phenotype, and function of NK cells (cocultures with K562 cells) and T-cells (stimulated with spike/RdRp peptides) were assessed by flow cytometry. Anti-SARS-CoV-2 antibodies were determined using indirect immunofluorescence and plaque reduction neutralization assay. Results: During COVID-19, we observed a high proinflammatory-cytokine production and a reduced CD56bright-NK cell and cytotoxic response. Compared with healthy controls, infected individuals had a higher frequency of dysfunctional CD8+ T cells CD38+HLA-DR-. During the acute phase, CD8+ T cells stimulated with viral peptides exhibited a monofunctional response characterized by high IL-10 production. However, during recovery, we observed a bifunctional response characterized by the co-expression of CD107a and granzyme B or perforin. Conclusion: Although the proinflammatory response is a hallmark of SARS-CoV-2 infection, other phenotypic and functional alterations in NK cells and CD8+ T cells could be associated with the outcome of COVID-19. However, additional studies are required to understand these alterations and to guide future immunotherapy strategies.

Resumen | Introducción. Se han descrito diferentes marcadores inmunológicos durante la COVID-19, los cuales persisten incluso después de la convalecencia y se asocian con los estadios clínicos de la infección. Sin embargo, aún son pocos los estudios orientados al análisis exhaustivo de las alteraciones del sistema inmunológico en el curso de la infección. Objetivo. Evaluar la producción de citocinas proinflamatorias, la reacción de anticuerpos, y el fenotipo y la función de las células NK y los linfocitos T en una familia colombiana con infección por SARS-CoV-2. Materiales y métodos. Se evaluaron las citocinas proinflamatorias mediante RT-PCR y ELISA; la frecuencia, el fenotipo y la función de las células NK (en cocultivos con células K562) y linfocitos T CD8+ (estimulados con péptidos spike/RdRp) mediante citometría de flujo, y los anticuerpos anti-SARS-CoV-2, mediante inmunofluorescencia indirecta y prueba de neutralización por reducción de placa. Resultados. Durante la COVID-19 hubo una producción elevada de citocinas proinflamatorias, con disminución de las células NK CD56 bright y reacción citotóxica. Comparados con los controles sanos, los individuos infectados presentaron con gran frecuencia linfocitos T CD8+ disfuncionales CD38+HLA-DR-. Además, en los linfocitos T CD8+ estimulados con péptidos virales, predominó una reacción monofuncional con gran producción de IL-10 durante la fase aguda y una reacción bifuncional caracterizada por la coexpresión de CD107a y granzima B o perforina durante la convalecencia. Conclusión. Aunque la reacción inflamatoria caracteriza la infección por SARS-CoV-2, hay otras alteraciones fenotípicas y funcionales en células NK y linfocitos T CD8+ que podrían asociarse con la progresión de la infección. Se requieren estudios adicionales para entender estas alteraciones y guiar futuras estrategias de inmunoterapia.

COVID-T: una plataforma funcional para monitorear la respuesta de linfocitos t específicos de SARS-COV-2 en individuos vacunados y recuperados de COVID-19 / COVID-T: A functional platform to monitor SARS-CoV-2-specific T cell responses in vaccinated individuals and COVID-19 recovered patients

Resumen La rápida propagación del coronavirus SARS-CoV-2, agente causal de la enfermedad pandémica emergente COVID-19 y sus nuevas variantes, requiere del compromiso de la comunidad inmunológica para comprender la magnitud y naturaleza de la respuesta inmunológica adaptativa desarrollada por pacientes recuperados de COVID-19 e individuos vacunados con diferentes estrategias y protocolos, a los fines de imple mentar nuevas políticas sanitarias. En la actualidad, la determinación de la inmunidad contra SARS-CoV-2 se basa principalmente en la detección de anticuerpos específicos y la determinación de su actividad neutralizante. Sin embargo, a pesar de la alta sensibilidad de estos ensayos, un número considerable de pacientes e indivi duos vacunados carecen de respuesta humoral detectable, o evidencian una disminución rápida de la misma en el tiempo. Con el objetivo de estudiar la respuesta inmune celular desencadenada frente a SARS-CoV-2, en nuestro laboratorio desarrollamos la "Plataforma COVID-T" estrategia integral optimizada dirigida a caracte rizar y monitorear la respuesta de linfocitos T específicos de SARS-CoV-2 a partir de muestras de sangre de individuos vacunados y/o recuperados de COVID-19. Esta plataforma permite evaluar la naturaleza, magnitud y persistencia de la inmunidad celular T generada tanto por la infección con SARS-CoV-2, como por distintos esquemas y protocolos de vacunación en diferentes poblaciones de individuos. Asimismo, permite evaluar la respuesta inmunológica T generada frente a nuevas variantes del virus e identificar individuos sanos resistentes a SARS-CoV-2 con inmunidad pre-existente hacia coronavirus estacionales.

Abstract The rapid spread of the SARS-CoV-2, the caus ative agent of the emergent pandemic disease COVID-19, requires the urgent commitment of the immunology community to understand the adaptive immune response developed by COVID-19 convalescent patients and individuals vaccinated with different strategies and schemes, with the ultimate goal of implementing and optimizing health care and prevention policies. Currently, assessment of SARS-CoV-2-specific immunity is mainly focused on the measurement of the antibody titers and analysis of their neutralizing capacity. However, a considerable proportion of individuals lack humoral responses or show a progressive decline of SARS-CoV-2-specific neutral izing antibodies. In order to study the cellular response of convalescent patients and vaccinated individuals, we have developed the 'COVID-T Platform', an optimized strategy to study SARS-CoV-2-specific T cell responses. This platform allows assessment of the nature, magnitude and persistence of antigen-specific T-cell immunity in COVID-19-convalescent patients and vaccinated individuals. Moreover, it gives the opportunity to study cellular responses against emerging coronavirus variants and to identify individuals with cross-reactive immunity against seasonal coronaviruses.

Reduced naïve T cell numbers correlate with increased low-grade systemic inflammation during ageing and can be modulated by physical activity / Un número reducido de células T vírgenes se correlaciona con un aumento de la inflamación sistémica de bajo grado durante el envejecimiento y puede ser modulado por la actividad física

SUMMARY: Age-associated decline of immune system, termed immunosenescence, is characterized by low-grade systemic inflammation, known as inflammaging, together with T-cell functional dysregulation. Although affecting all individuals, different environmental as well genetic factors impinge on the individual´s susceptibility or resilience to immunosenescence. Physical activity has been shown to improve autonomy and functionality in older adults. However, if physical activity affects immunosenescence or inflammaging remains unknown. The purpose of this study was to analyze immunosenescence and inflammaging in elderly individuals by measuring peripheral naïve T cells and interleukin (IL) -6 from peripheral blood and evaluate the impact of physical activity on T cell dysregulation and inflammaging. Thirty (30) elderly volunteers (10 males and 20 females), and 7 young controls (2 males ad 7 females), were recruited for this study. A methodology questionnaire was used to evaluate different parameters such as physical activity, and peripheral naïve CD4+ and CD8+ T cells and serum IL-6 were measured by FACS and ELISA respectively. Our results shown that naïve T cells decline, and IL-6 levels increase as older people age. Interestingly, we observed strong negative correlation between naïve T cells numbers and IL-6 levels in older adults, suggesting a direct link between reduced naïve T cell pool and increased inflammaging. Continuous physical activity during youth did not affect immunosenescence and inflammaging in elderly, but physical activity during elderly increase naïve T cell numbers and reduce inflammaging in older subjects. Our results showed reduced number of naïve T cells and increased levels of IL-6 as elder people get older. Moreover, the strong negative correlation between these parameters suggest that naïve T cells can have a direct suppressive activity over innate immune components. Furthermore, physical activity during elderly can reduce immunosenescence and inflammaging in older subjects.

RESUMEN: El deterioro del sistema inmunológico asociado con la edad, denominado inmunosenescencia, se caracteriza por una inflamación sistémica de bajo grado, conocida como inflamaging, junto con una desregulación funcional de las células T. Aunque afectan a todos los individuos, diferentes factores ambientales y genéticos inciden en la susceptibilidad o resiliencia del individuo a la inmunosenescencia. Estudios anteriores han demostrado que la actividad física mejora la autonomía y la funcionalidad en los adultos mayores, aunque como la actividad física impacta a la inmunosenescencia e inflammaging es aún desconocido. El propósito de este estudio fue analizar la inmunosenescencia e inflammaging en personas de edad avanzada, midiendo las células T vírgenes y la interleucina (IL)-6 de sangre periférica, junto con evaluar el impacto de la actividad física sobre la inflamación basal y la inmunosenescencia. Treinta voluntarios ancianos (10 hombres y 20 mujeres) y 7 controles jóvenes (2 hombres y 5 mujeres) fueron incluidos en este estudio. Para medir actividad física, autonomía y dependencia se utilizó un cuestionario de metodología, junto con evaluar el número de células T CD4+ y CD8+ periféricas vírgenes e IL-6 sérica mediante FACS y ELISA, respectivamente. Nuestros resultados muestran que las células T vírgenes disminuyen y los niveles de IL-6 aumentan a medida que las personas mayores envejecen. Curiosamente, observamos una fuerte correlación negativa entre el número de células T vírgenes y los niveles de IL-6 en adultos mayores, lo que sugiere un vínculo directo entre la reducción de la reserva de células T vírgenes y el aumento de la inflamación. La actividad física durante la juventud no afectó la inmunosenescencia ni la inflamación en los ancianos, pero la actividad física durante la vejez aumenta el número de células T vírgenes y reduce la inflamación en los adultos mayores. Estos resultados sugieren que inmunosenescencia e inflammaging parecen estar directamente conectados, además de concluir que el desarrollo de actividad física durante la vejez reduce la inmunosenescencia y la inflamación basal en adultos mayores.

Enfermedad residual medible mediante reordenamientos de inmunoglobulinas y receptores de linfocitos-T / Measurable residual disease by rearrangements of immunoglobulins and T-lymphocyte receptors

Resumen Las leucemias agudas constituyen la neoplasia más frecuente en pacientes pediátricos. Actualmente, el 80% de los niños con leucemia linfoblástica aguda (LLA) logran curarse con quimioterapia con vencional pero el 20% de los mismos presentarán una reaparición de la enfermedad. La enfermedad residual medible (ERM) ha sido descripta como un importante factor pronóstico, que permite evaluar la respuesta de los pacientes al tratamiento. Una de las técnicas más sensibles par a estudiar ERM es la cuantificación de reordena mientos génicos de inmunoglobulinas (Ig) y receptores de linfocitos-T (TCR). Los objetivos del presente trabajo fueron describir los reordenamientos detectados de Ig/TCR, evaluar el efecto de la ERM en la supervivencia de niños con LLA y comparar la ERM por Ig/TCR con la cuantificada mediante citometría de flujo multiparamétrica (CFM). Del total de 455 pacientes estudiados, en el 96% fue posible caracterizar al menos un reordenamiento de Ig/TCR. El total de reordenamientos clonales detectados fue de 1550. La ERM pudo ser estudiada en forma exitosa en el 89% de los casos. El valor de ERM positiva combinada al día 33 y 78 de tratamiento, permitió identificar pacientes de alto riesgo, entre los previamente estratificados por la ERM mediante CFM al día 15. La comparación entre la determinación de ERM mediante reordenamientos Ig/TCR y CFM mostró una excelente correlación. El presente trabajo constituye un estudio de ERM mediante Ig/TCR realizado en un número muy significativo de pacientes diagnosticados en forma consecutiva, tratados en el marco de un protocolo homogéneo y con excelente seguimiento clínico.

Abstract Acute leukemias are the most common neoplasm in pediatric patients. Currently, 80% of children with diagnosis of acute lymphoblastic leukemia (ALL) are cured with conventional chemotherapy, but 20% of them will have a recurrence of the disease. Measurable Residual Disease (MRD) has been described as an important prognostic factor that allows evaluating the response of patients to treatment. One of the most sensitive techniques to study MRD is the quantification of immunoglobulins (Ig) and T-lymphocyte receptors (TCR) genes rearrangements. The aims of this study were to describe the detected Ig/TCR rearrangements, to evaluate the prognostic impact of MRD in our population of children with ALL and to compare the MRD values by Ig/TCR with those obtained by multiparametric flow cytometry (MFC). A total of 455 patients were studied. In 96% of the cases, it was possible to characterize at least one Ig/TCR rearrangement. The total number of Ig/TCR rear rangements detected was 1550. MRD was successfully applied in 89% of the cases. The combined positive MRD values at day 33 and 78 of treatment allow the identification of high-risk patients in cases previously stratified by MRD using flow cytometry at day 15. The comparison between MRD determination by Ig/TCR rearrangements and FC showed excellent correlation. The present work constitutes a study of MRD by Ig/TCR carried out in a very significant number of patients consecutively diagnosed, treated within a homogeneous protocol and with excellent clinical follow-up.