Enrichment of effector memory T cells in the CD4 and CD8 T cell compartment during chronic graft versus host disease in children.

BACKGROUND: During allogeneic Hematopoietic stem cell transplantation (HSCT), frequent pathological scenarios include graft versus host disease (GVHD) and viral infections. We hypothesized if exogenous stimulus as alloantigen and viral antigens might impact on central and effector memory T cells in pediatric recipients. PATIENTS AND METHODS: Subjects included 21 pediatric recipients and 20 healthy children (control group). Peripheral blood samples of patients were collected along the first 712 days post-HSCT. T cell phenotyping of naïve, central, and effector memory T cells (TCMs and TEMs, respectively) was conducted using flow cytometry. Viral nucleic acids were detected using real-time PCR. RESULTS: T cell reconstitution was not reached after 1 year post-HSCT. Chronic GVHD was associated with increased numbers of naïve CD4 T cells (p < 0.05) as well as an increase in TEM and TCM cells of the CD4 (p < 0.0001 and p < 0.05, respectively) and CD8 T cell TEM (p < 0.0001). and TCM (p < 0.001) populations too. Moreover, BK and Epstein-Barr viruses were the main viral pathogens detected (<104 copies), which were associated with a decrease in all T cell compartments. CONCLUSION: During chronic GVHD, alloantigen persistence generates TEM cell enrichment among CD4 and CD8 T cells, and viral infections are associated with deficient recovery of T cells after HSCT.

Presence of antibodies against HLA class I and class II molecules in children before and after allo-HSCT. Alloantibodies before and after HSCT.

A severe complication of allogeneic hematopoietic stem cell transplantation (HSCT) is graft failure (GF). Among others, donor-specific anti-HLA antibodies (DSA) are associated with graft rejection after allogeneic or haploidentical transplantation in adults. Knowledge of DSA and pediatric recipients is limited. Hence, we aimed to generate more information about the presence of DSA (pre- and post-HSCT) and the clinical outcomes (graft rejection and poor function) in children. We identified DSA in 27% of the patients. We observed a higher frequency (50%) of DSA-bearing patients with a benign disease diagnosis than those diagnosed with leukemia (16.66%). We observed graft rejection in one patient (with DSA against two alleles of HLA class I molecules) and poor function in three recipients during the first 30 days after HSCT in the absence of DSA. The presence of donor and nondonor HLA-specific antibodies decreased substantially after transplantation. After the transplant, we identified two patients with DSA specific for HLA class I molecules (independent of clinical relevance), and four recipients showed PGF in the absence of DSA. We were unable to establish any association between the presence of DSA and a clinical outcome: graft failure or prevalence of viral infection.

Herpesvirus Screening in Childhood Hematopoietic Transplant Reveals High Systemic Inflammation in Episodes of Multiple Viral Detection and an EBV Association with Elevated IL-1ß, IL-8 and Graft-Versus-Host Disease.

Infections remain a major cause of morbidity and mortality among hematopoietic stem cell transplant (HSCT) recipients. Unlike Epstein-Barr Virus (EBV) and Human Cytomegalovirus (HCMV), Human Herpesvirus (HHV) 6, HHV7 and HHV8 are not routinely monitored in many centers, especially in the pediatric population of low-medium income countries. We screened EBV, HCMV, HHV6, HHV7 and HHV8 in 412 leukocytes-plasma paired samples from 40 pediatric patients assisted in a tertiary hospital in Mexico. Thirty-two underwent allo-HSCT, whereas eight received auto-HSCT. Overall viral detection frequencies in allo- and auto-HSCT were: EBV = 43.7% and 30.0%, HCMV = 5.0% and 6.7%, HHV6 = 7.9% and 20.0% and HHV7 = 9.7% and 23.3%. HHV8 was not detected in any sample. Interestingly, HHV6 and HHV7 were more frequent in auto-HSCT, and HHV6 was observed in all episodes of multiple detection in auto-HSCT patients. We found EBV DNA in plasma samples, whereas HCMV, HHV6 and HHV7 DNA were predominantly observed in leukocytes, indicative of their expansion in cellular compartments. We also found that IL-1ß, IL-2, IL-6 and IL-8 were significantly increased in episodes in which multiple viruses were simultaneously detected, and samples positive for EBV DNA and graft-versus-host disease had a further increase of IL-1ß and IL-8. In conclusion, the EBV, HCMV, HHV6 and HHV7 burdens were frequently detected in allo- and auto-HSCT, and their presence associated with systemic inflammation.

Supervivencia de pacientes con leucemia aguda post trasplante de células hematopoyéticas: 8 años de experiencia de un centro único en México / Survival of patients with acute leukemia after hematopoietic cell transplantation: A 8-years single center study in Mexico

Introducción: El trasplante de células progenitoras hematopoyéticas (TCPH) es el trata-miento para la leucemia aguda en niños, el tipo de cáncer más común en edad pediátrica. El objetivo del presente estudio fue determinar la supervivencia global y libre de enferme-dad en un grupo de pacientes sometidos a TCPH y explorar los factores de riesgo pacientes pediátricos con leucemia aguda. Metodología: El presente estudio observacional incluye a pacientes pediátricos diagnosticados de leucemia mieloide aguda (LMA) o linfoide (LLA), sometidos a TCPH, de 2011 a 2018 presentados en el Hospital Infantil Federico Gómez. Se construyen curvas de Kaplan Meier para la supervivencia global, por subgrupos según tipo de leucemia y estado libre de enfermedad así como un estudio multivariable para medir factores de riesgo. Resultados: Se incluyeron 53 pacientes en el análisis. 5 pacientes (11%) tuvieron falla primaria del injerto. La supervivencia global fue del 28% a los 24 meses. Fallecieron 30 pacientes (67%). La mediana de supervivencia global fue de 11 meses. Para LMA fue de 8.9 meses y para LLA de 12.4 meses. Uno de los factores de riesgo constituyó la edad >10 años al momento del trasplante OR 5.2 (1.07-25.12), P=0.04 y el número de recaídas previas al trasplante OR 4.3 (1.2-15.07) P=0.025. Conclusión: Los pacientes que sobrevivieron un año libre de la enfermedad tenían un mejor pronóstico en general. En estudios relacionados a TCPH no se ha reportado que exista un rango de edad de los receptores de trasplante que esté relacionado a mayor mortalidad, por lo cual es un dato significativo como un factor de riesgo independiente.

Introduction: Hematopoietic stem cell transplantation (HSCT) is the treatment for acute leukemia in children, the most common type of cancer in children. The objective of the present study was to de-termine the overall and disease-free survival in a group of patients undergoing HSCT and to explore the risk factors for pediatric patients with acute leukemia. Methodology: This observational study includes all pediatric patients diagnosed with acute myeloid leukemia (AML) or lymphoid leukemia (ALL), undergoing HSCT from March 2011 to March 2018, presented at the Federico Gómez Children's Hospital. Kaplan Meier curves are constructed for overall survival by subgroups according to the type of leukemia and disease-free status, as well as a multivaria-ble study to measure risk factors. Results: 53 patients were included in the análisis. 5 patients (11%) had primary graft failure. Overall survival was 28% at 24 months. Thirty patients (67%) died. The median overall survival was 11 months. For AML, it was 8.9 months, and for ALL, it was 12.4 months. One of the risk factors was age >10 years at the time of transplant OR 5.2 (1.07-25.12) P=0.04 and the number of relapses prior to transplant OR 4.3 (1.2-15.07) P=0.025. Conclusión: Patients who survived one year free of the disease had a better prognosis. In studies relat-ed to HSCT, it has not been reported that there is an age range of transplant recipients that is related to higher mortality, which is why it is a significant and independent risk factor.

Natural killer cell reconstitution after hematopoietic stem-cell transplantation in children.

INTRODUCTION: After hematopoietic stem cell transplantation (HSCT), natural killer (NK) cells reconstitution is the main barrier against viral infections. OBJECTIVE: To determine that the knowledge on the kinetics of NK cell reconstitution after HSCT contributes to transplant efficient monitoring, which increases the possibility of its success. METHOD: Twenty-one patients undergoing HSCT were included, as well as a control group of clinically healthy individuals. At different time points after transplantation (range of 21 to 670 days), CD3- CD16+ CD56+ NK cells were quantified by flow cytometry in peripheral blood samples. RESULTS: NK cell recovery occurs at three to six months and 10 to 12 months post-transplantation; their number was significantly lower (in comparison with the control group) in the rest of the monitoring time. CONCLUSIONS: The first period of NK cell recovery occurs between three and six months after transplantation. Reconstitution is transient and the number of NK cells varies in the first years.

INTRODUCCIÓN: Después de un trasplante de células progenitoras hematopoyéticas (TCPH), la reconstitución de las células natural killer (NK) es la principal barrera contra las infecciones virales. OBJETIVO: Determinar que el conocimiento sobre la cinética de la reconstitución de las células NK posterior al TCPH contribuye a un eficiente monitoreo del trasplante, lo que incrementa la posibilidad de éxito de este. MÉTODO: Se incluyeron 21 pacientes sometidos a TCPH, así como un grupo control de individuos clínicamente sanos. En diferentes momentos después del trasplante (intervalo de 21 a 670 días), mediante citometría de flujo se cuantificaron las células NK CD3− CD16+ CD56+ en muestras de sangre periférica. RESULTADOS: La recuperación de las células NK ocurre a los tres a seis meses y a los 10 a 12 meses postrasplante; su número fue significativamente menor (en comparación con el grupo control) en el tiempo restante del monitoreo. CONCLUSIONES: El primer periodo de recuperación de las células NK ocurre entre los tres y seis meses posteriores al trasplante. La reconstitución es transitoria y el número de células NK varía en los primeros años.

Reconstitución de células natural killer después del trasplante de células progenitoras hematopoyéticas en niños / Natural killer cell reconstitution after hematopoietic stem-cell transplantation in children

Resumen Introducción: Después de un trasplante de células progenitoras hematopoyéticas (TCPH), la reconstitución de las células natural killer (NK) es la principal barrera contra las infecciones virales. Objetivo: Determinar que el conocimiento sobre la cinética de la reconstitución de las células NK posterior al TCPH contribuye a un eficiente monitoreo del trasplante, lo que incrementa la posibilidad de éxito de este. Método: Se incluyeron 21 pacientes sometidos a TCPH, así como un grupo control de individuos clínicamente sanos. En diferentes momentos después del trasplante (intervalo de 21 a 670 días), mediante citometría de flujo se cuantificaron las células NK CD3− CD16+ CD56+ en muestras de sangre periférica. Resultados: La recuperación de las células NK ocurre entre los tres y seis meses y entre los 10 y 12 meses postrasplante; su número fue significativamente menor (en comparación con el grupo control) en el tiempo restante del monitoreo. Conclusiones: El primer periodo de recuperación de las células NK ocurre entre los tres y seis meses posteriores al trasplante. La reconstitución es transitoria y el número de células NK varía en los primeros años.

Abstract Introduction: After hematopoietic stem cell transplantation (HSCT), natural killer (NK) cells reconstitution is the main barrier against viral infections. Objective: To determine that the knowledge on the kinetics of NK cell reconstitution after HSCT contributes to transplant efficient monitoring, which increases the possibility of its success. Method: Twenty-one patients undergoing HSCT were included, as well as a control group of clinically healthy individuals. At different time points after transplantation (range of 21 to 670 days), CD3- CD16+ CD56+ NK cells were quantified by flow cytometry in peripheral blood samples. Results: NK cell recovery occurs at three to six months and 10 to 12 months post-transplantation; their number was significantly lower (in comparison with the control group) in the rest of the monitoring time. Conclusions: The first period of NK cell recovery occurs between three and six months after transplantation. Reconstitution is transient and the number of NK cells varies in the first years.

Pediatric mature B-cell NHL, early referral and supportive care problems in a developing country.

OBJECTIVE: Mature B-cell non-Hodgkin lymphoma (B-NHL) comprises more than 50% of all non-Hodgkin lymphoma (NHL) in children and adolescents. An official report published by the Mexican National Center for the Control and Prevention of Cancer in the Pediatric and Adolescent Populations, reported a lymphoma OS of 71% (including all Hodgkin and NHL). The Mexican Association of Pediatric Oncology and Hematology conducted a retrospective study to analyze the clinical characteristics and outcomes of children with diagnosis of B-NHL in Mexico, in order to perceive the main areas of improvement in the health care. METHODS: From 1 January 2000 to 31 December 2016, 166 pediatric patients were diagnosed with B-cell NHL at the participant institutions. RESULTS: According to histology the outcomes were 5-year EFS 63%, for BL/BLL, and 80% DLBCL, (P = .051), 5-year PFS 81%, for BL/BLL, and 91% for DLBCL, (P = .126), and 5-year OS 71%, for BL/BLL, and 83% for DLBCL, (P = .095). DISCUSSION: Overall, 18 patients died due to acute treatment toxicity, resulting in a cumulative incidence of toxic death of 10.84% and an early death rate of 7.23%, defined as <30 days after initial treatment. In conclusion, there is an urgent need to establish an academic collaboration to create strategies to improve pediatric cancer care according to our resources, especially in diseases with expected excellent prognosis as B-NHL. These strategies must include comprehensive supportive care, early referral, and the creation of easy communication between pediatric and adults centers as well as late-effects clinics.