Effects of Cathepsin S Inhibition in the Age-Related Dry Eye Phenotype.

Purpose: Aged C57BL/6J (B6) mice have increased levels of cathepsin S, and aged cathepsin S (Ctss-/-) knockout mice are resistant to age-related dry eye. This study investigated the effects of cathepsin S inhibition on age-related dry eye disease. Methods: Female B6 mice aged 15.5 to 17 months were randomized to receive a medicated diet formulated by mixing the RO5461111 cathepsin S inhibitor or a standard diet for at least 12 weeks. Cornea mechanosensitivity was measured with a Cochet-Bonnet esthesiometer. Ocular draining lymph nodes and lacrimal glands (LGs) were excised and prepared for histology or assayed by flow cytometry to quantify infiltrating immune cells. The inflammatory foci (>50 cells) were counted under a 10× microscope lens and quantified using the focus score. Goblet cell density was investigated in periodic acid-Schiff stained sections. Ctss-/- mice were compared to age-matched wild-type mice. Results: Aged mice subjected to cathepsin S inhibition or Ctss-/- mice showed improved conjunctival goblet cell density and cornea mechanosensitivity. There was no change in total LG focus score in the diet or Ctss-/- mice, but there was a lower frequency of CD4+IFN-γ+ cell infiltration in the LGs. Furthermore, aged Ctss-/- LGs had an increase in T central memory, higher numbers of CD19+B220-, and fewer CD19+B220+ cells than wild-type LGs. Conclusions: Our results indicate that therapies aimed at decreasing cathepsin S can ameliorate age-related dry eye disease with a highly beneficial impact on the ocular surface. Further studies are needed to investigate the role of cathepsin S during aging.

Ectopic lymphoid structures in the aged lacrimal glands.

Aging is a complex biological process in which many organs are pathologically affected. We previously reported that aged C57BL/6J had increased lacrimal gland (LG) lymphoid infiltrates that suggest ectopic lymphoid structures. However, these ectopic lymphoid structures have not been fully investigated. Using C57BL/6J mice of different ages, we analyzed the transcriptome of aged murine LGs and characterized the B and T cell populations. Age-related changes in the LG include increased differentially expressed genes associated with B and T cell activation, germinal center formation, and infiltration by marginal zone-like B cells. We also identified an age-related increase in B1+ cells and CD19+B220+ cells. B220+CD19+ cells were GL7+ (germinal center-like) and marginal zone-like and progressively increased with age. There was an upregulation of transcripts related to T follicular helper cells, and the number of these cells also increased as mice aged. Compared to a mouse model of Sjögren syndrome, aged LGs have similar transcriptome responses but also unique ones. And lastly, the ectopic lymphoid structures in aged LGs are not exclusive to a specific mouse background as aged diverse outbred mice also have immune infiltration. Altogether, this study identifies a profound change in the immune landscape of aged LGs where B cells become predominant. Further studies are necessary to investigate the specific function of these B cells during the aged LGs.

Application of the diagnostic criteria for Common Variable Immunodeficiency in resource-limited settings.

INTRODUCTION: Common variable immunodeficiency (CVID) is the most prevalent symptomatic humoral deficiency; however, its heterogeneous presentation makes the diagnosis difficult. The present study is aimed to verify the CVID diagnostic criteria as established by the European Society for Immunodeficiencies in 42 CVID patients from our outpatient clinic. METHODS: Information was collected from their medical records and when needed, lymphocyte subpopulations in peripheral blood (PB) were performed by flow cytometry. RESULTS: All the patients fulfilled the clinical working definition for CVID and showed decreased serum IgG and IgA at diagnosis. Over two-thirds of the patients had decreased memory B cell percentages. However, the remaining patients exhibited other quantitative B cell defects in PB. Evaluation of vaccination responses was only found in 13 records and 69% were not responsive. None of the patients were subjected to vaccination studies to both, T-cell dependent and independent antigens. The two required tests to evaluate T cell responses were performed in 84.2% of the patients and reported normal. Without the support of third-party payers, only 34.2% of our patients would have completed the required evaluations. CONCLUSIONS: Further efforts are needed to speed up CVID diagnosis in low-resourced settings, increasing the availability of the required resources and optimizing the healthcare supply chain.

Gut Microbiota From Sjögren syndrome Patients Causes Decreased T Regulatory Cells in the Lymphoid Organs and Desiccation-Induced Corneal Barrier Disruption in Mice.

Sjögren syndrome (SS) is an autoimmune inflammatory disorder characterized by secretory dysfunction in the eye and mouth; in the eye, this results in tear film instability, reduced tear production, and corneal barrier disruption. A growing number of studies show that homeostasis of the ocular surface is impacted by the intestinal microbiome, and several 16S sequencing studies have demonstrated dysbiosis of the intestinal microbiota in SS patients. In this study, we utilized metagenomic sequencing to perform a deeper analysis of the intestinal microbiome using stools collected from sex- and age-matched healthy (n = 20), dry eye (n = 4) and SS (n = 7) subjects. The observed Operational Taxonomic Units (OTUs) and Shannon alpha diversity were significantly decreased in SS compared to healthy controls, and there was a significant inverse correlation between observed OTUs and ocular severity score. We also identified specific bacterial strains that are differentially modulated in SS vs. healthy subjects. To investigate if the differential composition of intestinal microbiome would have an impact on the immune and eye phenotype, we performed functional studies using germ-free mice colonized with human intestinal microbiota from SS patients and healthy controls. Flow cytometry analysis demonstrated reduced frequency of CD4+ FOXP3+ cells in ocular draining cervical lymph nodes (CLN) in mice colonized with SS patient intestinal microbiota 4 weeks post-colonization. We also found that offspring of SS-humanized mice also have fewer CD4+FOXP3+ cells in the CLN as well as spleen, demonstrating vertical transmission. SS-humanized mice subjected to desiccating stress exhibited greater corneal barrier disruption as compared to healthy control humanized mice under the same conditions. Taken together, these data support the hypothesis that the intestinal microbiota can modulate ocular surface health, possibly by influencing development of CD4+ FOXP3+ regulatory T cells (Tregs) in the ocular draining lymph nodes.

Immune phenotype of the CD4+ T cells in the aged lymphoid organs and lacrimal glands.

Aging is associated with a massive infiltration of T lymphocytes in the lacrimal gland. Here, we aimed to characterize the immune phenotype of aged CD4+ T cells in this tissue as compared with lymphoid organs. To perform this, we sorted regulatory T cells (Tregs, CD4+CD25+GITR+) and non-Tregs (CD4+CD25negGITRneg) in lymphoid organs from female C57BL/6J mice and subjected these cells to an immunology NanoString® panel. These results were confirmed by flow cytometry, live imaging, and tissue immunostaining in the lacrimal gland. Importantly, effector T helper 1 (Th1) genes were highly upregulated on aged Tregs, including the master regulator Tbx21. Among the non-Tregs, we also found a significant increase in the levels of EOMESmed/high, TbetnegIFN-γ+, and CD62L+CD44negCD4+ T cells with aging, which are associated with cell exhaustion, immunopathology, and the generation of tertiary lymphoid tissue. At the functional level, aged Tregs from lymphoid organs are less able to decrease proliferation and IFN-γ production of T responders at any age. More importantly, human lacrimal glands (age range 55-81 years) also showed the presence of CD4+Foxp3+ cells. Further studies are needed to propose potential molecular targets to avoid immune-mediated lacrimal gland dysfunction with aging.

Differentially Expressed Gene Pathways in the Conjunctiva of Sjögren Syndrome Keratoconjunctivitis Sicca.

Sjögren syndrome (SS) is an autoimmune condition that targets the salivary and lacrimal glands, with cardinal clinical signs of dry eye (keratoconjunctivitis sicca, KCS) and dry mouth. The conjunctiva of SS patients is often infiltrated by immune cells that participate in the induction and maintenance of local inflammation. The purpose of this study was to investigate immune-related molecular pathways activated in the conjunctiva of SS patients. Female SS patients (n=7) and controls (n=19) completed a series of oral, ocular surface exams. Symptom severity scores were evaluated using validated questionnaires (OSDI and SANDE). All patients fulfilled the ACR/EULAR criteria for SS and the criteria for KCS. Fluorescein and lissamine green dye staining evaluated tear-break-up time (TBUT), corneal and conjunctival disease, respectively. Impression cytology of the temporal bulbar conjunctiva was performed to collect cells lysed and subjected to gene expression analysis using the NanoString Immunology Panel. 53/594 differentially expressed genes (DEGs) were observed between SS and healthy controls; 49 DEGs were upregulated, and 4 were downregulated (TRAF5, TGFBI, KLRAP1, and CMKLRI). The top 10 DEGs in descending order were BST2, IFITM1, LAMP3, CXCL1, IL19, CFB, LY96, MX1, IL4R, CDKN1A. Twenty pathways had a global significance score greater or equal to 2. Spearman correlations showed that 29/49 upregulated DEGs correlated with either TBUT (inverse) or OSDI or conjunctival staining score (positive correlations). Venn diagrams identified that 26/29 DEGs correlated with TBUT, 5/26 DEGs correlated with OSDI, and 16/26 correlated with conjunctival staining scores. Five upregulated DEGs (CFB, CFI, IL1R1, IL2RG, IL4R) were uniquely negatively correlated with TBUT. These data indicate that the conjunctiva of SS patients exhibits a phenotype of immune activation, although some genes could be inhibitory. Some of the DEGs and pathways overlap with previous DEGs in salivary gland biopsies, but new DEGs were identified, and some of these correlated with symptoms and signs of dry eye. Our results indicate that gene analysis of conjunctiva imprints is a powerful tool to understand the pathogenesis of SS and develop new therapeutic targets.

Modulation of Oxidative Stress and Inflammation in the Aged Lacrimal Gland.

Inflammation and oxidative stress accompany aging. This study investigated the interplay between oxidative stress and inflammation in the lacrimal gland. C57BL/6 mice were used at 2 to 3, 12, and 24 months of age. Nuclear factor erythroid derived-2-related factor 2 (Nrf2)-/- and corresponding wild-type mice were used at 2 to 3 and 12 to 13 months of age. A separate group of 15.5 to 17 months of age C57BL/6 mice received a diet containing an Nrf2 inducer (Oltipraz) for 8 weeks. Aged C57BL/6 lacrimal glands showed significantly greater lymphocytic infiltration, higher levels of MHC II, IFN-γ, IL-1ß, TNF-α, and cathepsin S (Ctss) mRNA transcripts, and greater nitrotyrosine and 4-hydroxynonenal protein. Young Nrf2-/- mice showed an increase in IL-1ß, IFN-γ, MHC II, and Ctss mRNA transcripts compared with young wild-type mice and greater age-related changes at 12 to 13 months of age. Oltipraz diet significantly decreased nitrotyrosine and 4-hydroxynonenal and decreased the expression of IL-1ß and TNF-α mRNA transcripts, while decreasing the frequency of CD45+CD4+ cells in lacrimal glands and significantly increasing conjunctival goblet cell density compared with a standard diet. The findings provide novel insight into the development of chronic, low-grade inflammation and oxidative stress in age-related dry eye. New therapies targeting oxidative stress pathways will be valuable in treating age-related dry eye.

Rapamycin Eyedrops Increased CD4+Foxp3+ Cells and Prevented Goblet Cell Loss in the Aged Ocular Surface.

Dry eye disease (DED), one of the most prevalent conditions among the elderly, is a chronic inflammatory disorder that disrupts tear film stability and causes ocular surface damage. Aged C57BL/6J mice spontaneously develop DED. Rapamycin is a potent immunosuppressant that prolongs the lifespan of several species. Here, we compared the effects of daily instillation of eyedrops containing rapamycin or empty micelles for three months on the aged mice. Tear cytokine/chemokine profile showed a pronounced increase in vascular endothelial cell growth factor-A (VEGF-A) and a trend towards decreased concentration of Interferon gamma (IFN)-γ in rapamycin-treated groups. A significant decrease in inflammatory markers in the lacrimal gland was also evident (IFN-γ, IL-12, CIITA and Ctss); this was accompanied by slightly diminished Unc-51 Like Autophagy Activating Kinase 1 (ULK1) transcripts. In the lacrimal gland and draining lymph nodes, we also observed a significant increase in the CD45+CD4+Foxp3+ cells in the rapamycin-treated mice. More importantly, rapamycin eyedrops increased conjunctival goblet cell density and area compared to the empty micelles. Taken together, evidence from these studies indicates that topical rapamycin has therapeutic efficacy for age-associated ocular surface inflammation and goblet cell loss and opens the venue for new investigations on its role in the aging process of the eye.

Dissecting the localization of lipopolysaccharide-responsive and beige-like anchor protein (LRBA) in the endomembrane system

Introduction and objectives: LRBA deficiency is caused by loss of LRBA protein expression, due to either homozygous or compounds heterozygous mutations in LRBA. LRBA deficiency has been shown to affect vesicular trafficking and autophagy. To date, LRBA has been observed in the cytosol, Golgi apparatus and some lysosomes in LPS-stimulated murine macrophages. The objectives of the present study were to study the LRBA localization in organelles involved in vesicular traffic, phagocytosis, and autophagy in mononuclear phagocytes (MP). Materials and methods: We analyzed LRBA colocalization with different endosomes markets using confocal microscopy in MP. We used the autophagy inhibitors to determine the role of LRBA in formation, maturation or degradation of the autophagosome. Results: LRBA intracellular trafficking depends on the activity of the GTPase ADP ribosylation factor-1 (ARF) in MP. LRBA was identified in early, late endosomes but did not colocalize strongly with lysosomal markers. Although LRBA appears not to be recruited during the phagocytic cargo uptake, it greatly colocalized with the microtubule-associated protein 1A/1B-light chain 3 (LC3) under a steady state and this decreased after the induction of autophagy flux. Although the use of inhibitors of lysosome fusion did not restore the LRBA/LC3 colocalization, inhibitors of either early to late endosomes trafficking or PI3K pathway did. Conclusions: Taken together, our results show that LRBA is located in endomembrane system vesicles, mainly in the early and late endosomes. Although LRBA appears not to be involved in the phagocytic uptake, it is recruited in the early steps of the autophagy flux

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Defective glycosylation and multisystem abnormalities characterize the primary immunodeficiency XMEN disease.

X-linked immunodeficiency with magnesium defect, EBV infection, and neoplasia (XMEN) disease are caused by deficiency of the magnesium transporter 1 (MAGT1) gene. We studied 23 patients with XMEN, 8 of whom were EBV naive. We observed lymphadenopathy (LAD), cytopenias, liver disease, cavum septum pellucidum (CSP), and increased CD4-CD8-B220-TCRαß+ T cells (αßDNTs), in addition to the previously described features of an inverted CD4/CD8 ratio, CD4+ T lymphocytopenia, increased B cells, dysgammaglobulinemia, and decreased expression of the natural killer group 2, member D (NKG2D) receptor. EBV-associated B cell malignancies occurred frequently in EBV-infected patients. We studied patients with XMEN and patients with autoimmune lymphoproliferative syndrome (ALPS) by deep immunophenotyping (32 immune markers) using time-of-flight mass cytometry (CyTOF). Our analysis revealed that the abundance of 2 populations of naive B cells (CD20+CD27-CD22+IgM+HLA-DR+CXCR5+CXCR4++CD10+CD38+ and CD20+CD27-CD22+IgM+HLA-DR+CXCR5+CXCR4+CD10-CD38-) could differentially classify XMEN, ALPS, and healthy individuals. We also performed glycoproteomics analysis on T lymphocytes and show that XMEN disease is a congenital disorder of glycosylation that affects a restricted subset of glycoproteins. Transfection of MAGT1 mRNA enabled us to rescue proteins with defective glycosylation. Together, these data provide new clinical and pathophysiological foundations with important ramifications for the diagnosis and treatment of XMEN disease.

The gut-eye-lacrimal gland-microbiome axis in Sjögren Syndrome.

The bacterial communities that collectively inhabit our body are called the microbiome. Virtually all body surface harbors bacteria. Recent advances in next-generation sequencing that have provided insight into the diversity, composition of bacterial communities, and their interaction are discussed in this review, as well as the current knowledge of how the microbiome promotes ocular health. The ocular surface is a site of low bacterial load. Sjögren Syndrome is an autoimmune disease that affects the exocrine glands, causing dry mouth and dry eye. Systemic antibiotic treatment and germ-free mice have demonstrated that commensal bacteria have a protective role for the ocular surface and lacrimal gland. The existence of a gut-eye-lacrimal gland axis-microbiome is discussed.

Dissecting the localization of lipopolysaccharide-responsive and beige-like anchor protein (LRBA) in the endomembrane system.

INTRODUCTION AND OBJECTIVES: LRBA deficiency is caused by loss of LRBA protein expression, due to either homozygous or compounds heterozygous mutations in LRBA. LRBA deficiency has been shown to affect vesicular trafficking and autophagy. To date, LRBA has been observed in the cytosol, Golgi apparatus and some lysosomes in LPS-stimulated murine macrophages. The objectives of the present study were to study the LRBA localization in organelles involved in vesicular traffic, phagocytosis, and autophagy in mononuclear phagocytes (MP). MATERIALS AND METHODS: We analyzed LRBA colocalization with different endosomes markets using confocal microscopy in MP. We used the autophagy inhibitors to determine the role of LRBA in formation, maturation or degradation of the autophagosome. RESULTS: LRBA intracellular trafficking depends on the activity of the GTPase ADP ribosylation factor-1 (ARF) in MP. LRBA was identified in early, late endosomes but did not colocalize strongly with lysosomal markers. Although LRBA appears not to be recruited during the phagocytic cargo uptake, it greatly colocalized with the microtubule-associated protein 1A/1B-light chain 3 (LC3) under a steady state and this decreased after the induction of autophagy flux. Although the use of inhibitors of lysosome fusion did not restore the LRBA/LC3 colocalization, inhibitors of either early to late endosomes trafficking or PI3K pathway did. CONCLUSIONS: Taken together, our results show that LRBA is located in endomembrane system vesicles, mainly in the early and late endosomes. Although LRBA appears not to be involved in the phagocytic uptake, it is recruited in the early steps of the autophagy flux.

LRBA in the endomembrane system.

Bi-allelic mutations in LRBA (from Lipopolysaccharide-responsive and beige-like anchor protein) result in a primary immunodeficiency with clinical features ranging from hypogammaglobulinemia and lymphoproliferative syndrome to inflammatory bowel disease and heterogeneous autoimmune manifestations. LRBA deficiency has been shown to affect vesicular trafficking, autophagy and apoptosis, which may lead to alterations of several molecules and processes that play key roles for immunity. In this review, we will discuss the relationship of LRBA with the endovesicular system in the context of receptor trafficking, autophagy and apoptosis. Since these mechanisms of homeostasis are inherent to all living cells and not only limited to the immune system and also, because they are involved in physiological as well as pathological processes such as embryogenesis or tumoral transformation, we envisage advancing in the identification of potential pharmacological agents to manipulate these processes.

Las mutaciones bi-alélicas en LRBA (del inglés, Lipopolysaccharide-responsive and beige-like anchor protein) conllevan a una inmunodeficiencia primaria con características clínicas que abarcan desde hipogamaglubulinemia y síndrome linfoproliferativo hasta una enfermedad inflamatoria intestinal y manifestaciones autoinmunes heterogéneas. Se ha demostrado que la deficiencia de LRBA afecta el tráfico vesicular, la autofagia y la apoptosis pudiendo generar alteraciones en la regulación de varios procesos importantes para la inmunidad. En esta revisión discutiremos la relación de LRBA con el sistema endovesicular en el contexto del tráfico de receptores, la autofagia y la apoptosis. Estos mecanismos de homeostasis son inherentes a todas las células y no están limitados a las células del sistema inmune, están involucrados en procesos fisiológicos y patológicos, como la embriogénesis o la transformación tumoral. El entendimiento de la función de LRBA permitirá avanzar en la identificación de los posibles blancos farmacológicos para manipular estos procesos.

LRBA in the endomembrane system / LRBA en el sistema de endomembranas

Abstract Bi-allelic mutations in LRBA (from Lipopolysaccharide-responsive and beige-like anchor protein) result in a primary immunodeficiency with clinical features ranging from hypogammaglobulinemia and lymphoproliferative syndrome to inflammatory bowel disease and heterogeneous autoimmune manifestations. LRBA deficiency has been shown to affect vesicular trafficking, autophagy and apoptosis, which may lead to alterations of several molecules and processes that play key roles for immunity. In this review, we will discuss the relationship of LRBA with the endovesicular system in the context of receptor trafficking, autophagy and apoptosis. Since these mechanisms of homeostasis are inherent to all living cells and not only limited to the immune system and also, because they are involved in physiological as well as pathological processes such as embryogenesis or tumoral transformation, we envisage advancing in the identification of potential pharmacological agents to manipulate these processes.

Resumen Las mutaciones bi-alélicas en LRBA (del inglés, Lipopolysaccharide-responsive and beige-like anchor protein) conllevan a una inmunodeficiencia primaria con características clínicas que abarcan desde hipogamaglubulinemia y síndrome linfoproliferativo hasta una enfermedad inflamatoria intestinal y manifestaciones autoinmunes heterogéneas. Se ha demostrado que la deficiencia de LRBA afecta el tráfico vesicular, la autofagia y la apoptosis pudiendo generar alteraciones en la regulación de varios procesos importantes para la inmunidad. En esta revisión discutiremos la relación de LRBA con el sistema endovesicular en el contexto del tráfico de receptores, la autofagia y la apoptosis. Estos mecanismos de homeostasis son inherentes a todas las células y no están limitados a las células del sistema inmune, están involucrados en procesos fisiológicos y patológicos, como la embriogénesis o la transformación tumoral. El entendimiento de la función de LRBA permitirá avanzar en la identificación de los posibles blancos farmacológicos para manipular estos procesos.

Abordaje inmunológico del síndrome por deleción 22q11 / Immunological approaches to 22q11 deletion syndrome

El síndrome por deleción 22q11 (SD22q11) es el síndrome por deleción cromosómica más frecuente en humanos y se caracteriza por la tríada clínica que incluye cardiopatía congénita, hipocalcemia e inmunodeficiencia primaria. El 85-90% de los pacientes tienen microdeleciones en el cromosoma 22q11.2. Tomando como punto cardinal la cardiopatía congénita, se diseñó una estrategia para tamización y diagnóstico de SD22q11 con énfasis en la evaluación inmune. Es imprescindible realizar una historia clínica detallada y, posteriormente, un análisis cuantitativo y funcional de las subpoblaciones de linfocitos en sangre periférica para clasificarlo en SD22q11 completo (<1%) o parcial (95-99%) e instaurar las pautas de tratamiento en aspectos como: aislamiento del paciente, vacunación, profilaxis contra microorganismos oportunistas, uso de productos sanguíneos irradiados y reconstitución inmunológica. Sin embargo, el abordaje del paciente debe ser multidisciplinario para detectar y prevenir complicaciones a largo plazo que pueden ser graves, especialmente en los pacientes con SD22q11 completo.

In humans, 22q11 deletion syndrome (22q11DS) is considered the most common chromosome deletion syndrome. It is characterised by a clinical triad that includes congenital heart disease, hypocalcaemia and primary immunodeficiency. Approximately 85-90% of patients with this syndrome exhibit microdeletions in chromosome 22q11.2. Using congenital heart disease as a starting point, we designed a strategy for the screening and diagnosis of 22q11DS with an emphasis on immunological evaluation. A detailed clinical history and the subsequent quantitative and functional analyses of the lymphocyte subpopulations in the peripheral blood is crucial to classify as complete (<1%) or partial (95-99%) the disease and to guide clinicians in terms of patient isolation, vaccination, prophylaxis for opportunistic infections, use of irradiated blood products and immunological reconstitution. However, multidisciplinary care is necessary to detect and prevent long-term complications that could be severe, particularly in cases of complete 22q11DS.

Adverse events following immunization in patients with primary immunodeficiencies.

BACKGROUND: Adverse events following immunization (AEFI) requires special consideration in patients with primary immunodeficiency diseases (PID) because they may represent a "red flag" for the initial diagnosis and may cause disease complications. Therefore, the definition of appropriate vaccination schemes is a major issue in PID. The aim of this study is to describe the AEFI in a cohort of PID patients. METHODS: Medical records from 379 PID patients were included. AEFI severity was classified according to the WHO 1999 guidelines. Causality was assessed using the Clinical Immunization Safety Assessment (CISA) 2009 criteria. RESULTS: Evidence of AEFI was found in 26 medical records and represented a total of 29 reactions. Most of the AEFI were observed in patients with idiopathic hypogammaglobulinemia (IHG), chronic granulomatous disease (CGD) and severe combined immunodeficiency (SCID), representing 10, 4 and 4 cases, respectively. A total of 21 reactions were associated with replicative vaccines, 7 of which were serious cases related to Bacille Calmette-Guérin (BCG). BCG was also the vaccine more often associated with definitive AEFI in PID. In addition to BCG-related complications, seizures were the most serious AEFI among PID patients. CONCLUSIONS: Our study included a large cohort of PID patients and confirmed an increased risk of serious AEFI in these populations. The design and implementation of neonatal screening strategies for the early detection of congenital lymphopenias and other PID are urgently needed to avoid serious complications of the BCG vaccine usually applied immediately after birth. Our findings also support the use of the acellular pertussis vaccine to minimize the appearance of seizures in PID patients vaccinated with diphtheria, pertussis and tetanus (DPT).

[Variation in NK cell number and function in individuals with recurrent or severe infections]. / Variaciones en el número y función de los linfocitos asesinos naturales durante infecciones recurrentes o graves.

INTRODUCTION: The information about defects affecting natural killer cell (NK) development and activity in patients with an abnormal increase of recurrent infections is scarce. OBJECTIVE: To perform a systematic analysis of NK abnormalities in patients with recurrent infections. MATERIALS AND METHODS: Our study enrolled twenty patients with severe or recurrent viral infections. Natural killer cell subsets, surface receptors expression and cytotoxicity were analyzed. Results were compared with those from age- and sex-matched healthy controls. RESULTS: Transient alterations were observed in the percentages and absolute numbers of NK cells in patients with infection active episodes. We also described five patients with stable disturbances in the distribution of NK cell subpopulations. These defects are mainly due to a decrease in the CD56 dim CD16 bright cells in peripheral blood. In addition, NK cell function abnormalities were observed in some patients, however, those were always transient and mainly associated to active disease. CONCLUSIONS: These findings demonstrate transient alterations in the percentages and absolute numbers of NK cells in patients with recurrent or severe infection. Also, stable disturbances in CD56 dim CD16 bright NK cells are observed in these patients. Nevertheless, these parameters must be thoroughly studied to determine the mechanisms that entail these immune abnormalities and investigate how they alter the immune response.

Variaciones en el número y función de los linfocitos asesinos naturales durante infecciones recurrentes o graves / Variation in NK cell number and function in individuals with recurrent or severe infections

Introducción. Existen pocos datos sobre los defectos que afectan el desarrollo y función de los linfocitos asesinos naturales ( natural killers, NK) en pacientes con un incremento anormal en la recurrencia de infecciones. Objetivo. Realizar una evaluación sistemática de las diferentes subpoblaciones y la función de estas células en pacientes con infecciones recurrentes. Materiales y métodos. Se incluyeron 20 pacientes con infecciones graves o recurrentes y se analizaron las subpoblaciones y la respuesta citotóxica de los linfocitos NK en sangre periférica. Los resultados de los pacientes se compararon con controles sanos pareados por edad y sexo. Resultados. Los pacientes con episodios infecciosos activos presentaron anormalidades transitorias en el porcentaje o el número absoluto de linfocitos NK. Se caracterizaron, además, cinco pacientes con alteraciones persistentes en la distribución de las subpoblaciones de linfocitos NK. Estas alteraciones se debieron principalmente a la disminución de células CD56 dim CD16 bright . Se evidenciaron, también, defectos en la función de los linfocitos NK en algunos de nuestros pacientes; sin embargo, estas alteraciones fueron transitorias y se asociaron principalmente a la fase activa de la enfermedad. Conclusiones. Nuestros resultados evidencian defectos transitorios en el número y función de los linfocitos NK en pacientes con infecciones recurrentes o graves, además de alteraciones persistentes en los LNK CD56 dim CD16 bright en algunos individuos. Es necesario profundizar en los mecanismos que conllevan al desarrollo de estos defectos inmunes y estudiar cómo estas alteraciones influyen en la respuesta inmune.

Introduction: The information about defects affecting natural killer cell (NK) development and activity in patients with an abnormal increase of recurrent infections is scarce. Objective: To perform a systematic analysis of NK abnormalities in patients with recurrent infections. Materials and methods: Our study enrolled twenty patients with severe or recurrent viral infections. Natural killer cell subsets, surface receptors expression and cytotoxicity were analyzed. Results were compared with those from age- and sex-matched healthy controls. Results: Transient alterations were observed in the percentages and absolute numbers of NK cells in patients with infection active episodes. We also described five patients with stable disturbances in the distribution of NK cell subpopulations. These defects are mainly due to a decrease in the CD56 dim CD16 bright cells in peripheral blood. In addition, NK cell function abnormalities were observed in some patients, however, those were always transient and mainly associated to active disease. Conclusions: These findings demonstrate transient alterations in the percentages and absolute numbers of NK cells in patients with recurrent or severe infection. Also, stable disturbances in CD56 dim CD16 bright NK cells are observed in these patients. Nevertheless, these parameters must be thoroughly studied to determine the mechanisms that entail these immune abnormalities and investigate how they alter the immune response.