Antigen Drives Regulatory B10 Cell Development and Function

B cells mediate immune responses via the secretion of antibody and interactions with other immune cell populations through antigen presentation, costimulation, and cytokine secretion. Although B cells are primarily believed to promote immune responses using the mechanisms described above, some unique regulatory B cell populations that negatively influence inflammation have also been described. Among these is a rare interleukin (IL)-10-producing B lymphocyte subset termed “B10 cells.” B cell-derived IL-10 can inhibit various arms of the immune system, including polarization of Th1/Th2 cell subsets, antigen presentation and cytokine production by monocytes and macrophages, and activation of regulatory T cells. Further studies in numerous autoimmune and inflammatory models of disease have confirmed the ability of B10 cells to negatively regulate inflammation in an IL-10-dependent manner. Although IL-10 is indispensable to the effector functions of B10 cells, how this specialized B cell population is selected in vivo to produce IL-10 is unknown. Some studies have demonstrated a link between B cell receptor (BCR)-derived signals and the acquisition of IL-10 competence. Additionally, whether antigen-BCR interactions are required for B cell IL-10 production during homeostasis as well as active immune responses is a matter of debate. Therefore, the goal of this thesis is to determine the importance of antigen-driven signals during B10 cell development in vivo and during B10 cell-mediated immunosuppression.

Chapter 3 of the dissertation explored the BCR repertoire of spleen and peritoneal cavity B10 cells using single-cell sequencing to lay the foundation for studies to understand the full range of antigens that may be involved in B10 cell selection. In both the spleen and peritoneal cavity B10 cells studied, BCR gene utilization was diverse, and the expressed BCR transcripts were largely unmutated. Thus, B10 cells are likely capable of responding to a wide range of foreign and self-antigens in vivo.

Studies in Chapter 4 determined the predominant antigens that drive B cell IL-10 secretion during homeostasis. A novel in vitro B cell expansion system was used to isolate B cells actively expressing IL-10 in vivo and probe the reactivities of their secreted monoclonal antibodies. B10 cells were found to produce polyreactive antibodies that bound multiple self-antigens. Therefore, in the absence of overarching active immune responses, B cell IL-10 is secreted following interactions with self-antigens.

Chapter 5 of this dissertation investigated whether foreign antigens are capable of driving B10 cell expansion and effector activity during an active immune response. In a model of contact-induced hypersensitivity, in vitro B cell expansion was again used to isolate antigen-specific B10 clones, which were required for optimal immunosuppression.

The studies described in this dissertation shed light on the relative contributions of BCR-derived signals during B10 cell development and effector function. Furthermore, these investigations demonstrate that B10 cells respond to both foreign and self-antigens, which has important implications for the potential manipulation of B10 cells for human therapy. Therefore, B10 cells represent a polyreactive B cell population that provides antigen-specific regulation of immune responses via the production of IL-10.

Molecular characterization of immunoglobulin gene rearrangements in diffuse large B-cell lymphoma: antigen-driven origin and IGHV4-34 as a particular subgroup of the non-GCB subtype.

The pathogenesis of diffuse large B-cell lymphoma (DLBCL) remains partially unknown. The analysis of the B-cell receptor of the malignant cells could contribute to a better understanding of the DLBCL biology. We studied the molecular features of the immunoglobulin heavy chain (IGH) rearrangements in 165 patients diagnosed with DLBCL not otherwise specified. Clonal IGH rearrangements were amplified according to the BIOMED-2 protocol and PCR products were sequenced directly. We also analyzed the criteria for stereotyped patterns in all complete IGHV-IGHD-IGHJ (V-D-J) sequences. Complete V-D-J rearrangements were identified in 130 of 165 patients. Most cases (89%) were highly mutated, but 12 sequences were truly unmutated or minimally mutated. Three genes, IGHV4-34, IGHV3-23, and IGHV4-39, accounted for one third of the whole cohort, including an overrepresentation of IGHV4-34 (15.5% overall). Interestingly, all IGHV4-34 rearrangements and all unmutated sequences belonged to the nongerminal center B-cell-like (non-GCB) subtype. Overall, we found three cases following the current criteria for stereotyped heavy chain VH CDR3 sequences, two of them belonging to subsets previously described in CLL. IGHV gene repertoire is remarkably biased, implying an antigen-driven origin in DLBCL. The particular features in the sequence of the immunoglobulins suggest the existence of particular subgroups within the non-GCB subtype.

Lymphoepithelioma-like gastric carcinoma presenting as giant ulcer of the lesser curvature. Case report

Lymphoepithelioma-like gastric carcinoma (LELGC) has special clinicopathologic features that differentiate it from the common gastric adenocarcinoma. LELGC is a rare neoplasm of the stomach with an incidence of 1-4% of all gastric cancers and is characterized by desmoplastic stroma uniformaly infiltrated by abundant lymphocytes and plasma cells. LELGC is closely associated with the Epstein-Barr virus (EBV), with 80-100% of LELGC being EBV-positive. LELGC has a male predominance, occurs in elderly people and is usually located in the upper and middle portion of the stomach. We report a rare case of lymphoepithelioma-like gastric carcinoma located in the lesser curvature at the border of the gastric body to the pyloric antrum.

Regulatory T cells control strain specific resistance to Experimental Autoimmune Prostatitis

Susceptibility to autoimmune diseases results from the encounter of a complex and long evolved genetic context with a no less complex and changing environment. Major actors in maintaining health are regulatory T cells (Treg) that primarily dampen a large subset of autoreactive lymphocytes escaping thymic negative selection. Here, we directly asked whether Treg participate in defining susceptibility and resistance to Experimental Autoimmune Prostatitis (EAP). We analyzed three common laboratory strains of mice presenting with different susceptibility to autoimmune prostatitis upon immunization with prostate proteins. The NOD, the C57BL/6 and the BALB/c mice that can be classified along a disease score ranging from severe, mild and to undetectable, respectively. Upon mild and transient depletion of Treg at the induction phase of EAP, each model showed an increment along this score, most remarkably with the BALB/c mice switching from a resistant to a susceptible phenotype. We further show that disease associates with the upregulation of CXCR3 expression on effector T cells, a process requiring IFNγ. Together with recent advances on environmental factors affecting Treg, these findings provide a likely cellular and molecular explanation to the recent rise in autoimmune diseases incidence.

Evaluation of Adoptive T Cell Therapy and Oncolytic Virotherapy for Treatment of Brain Tumors

Adoptive immunotherapy and oncolytic virotherapy are two promising strategies for treating primary and metastatic malignant brain tumors. We demonstrate the ability of adoptively transferred tumor-specific T cells to rapidly mediate the clearance of established brain tumors in several mouse models. Similar to the clinical situation, tumor recurrences are frequent and result from immune editing of tumors. T cells can eliminate antigen-expressing tumor cells but are not effective against antigen loss variant (ALV) cancer cells that multiply and repopulate a tumor. We show that the level of tumor antigen present affects the success of adoptive T cell therapy. When high levels of antigen are present, tumor stromal cells such as microglia and macrophages present tumor peptide on their surface. As a result, T cells directly eliminate cancer cells and cross-presenting stromal cells and indirectly eliminate ALV cells. We were able to show the first direct evidence of tumor antigen cross-presentation by CD11b+ stromal cells in the brain using soluble, high-affinity T cell receptor monomers. Strategies that target brain tumor stroma or increase antigen shedding from tumor cells leading to increased crosspresentation by stromal cells may improve the clinical success of T cell adoptive therapies. We evaluated one potential strategy to complement adoptive T cell therapy by characterizing the oncolytic effects of myxoma virus (MYXV) in a syngeneic mouse brain tumor model of metastatic melanoma. MYXV is a rabbit poxvirus with strict species tropism for European rabbits. MYXV can also infect mouse and human cancer cell lines due to signaling defects in innate antiviral mechanisms and hyperphosphorylation of Akt. MYXV kills B16.SIY melanoma cells in vitro, and intratumoral injection of virus leads to robust, selective and transient infection of the tumor. We observed that virus treatment recruits innate immune cells iii to the tumor, induces TNFα and IFNβ production in the brain, and results in limited oncolytic effects in vivo. To overcome this, we evaluated the safety and efficacy of co-administering 2C T cells, MYXV, and neutralizing antibodies against IFNβ. Mice that received the triple combination therapy survived significantly longer with no apparent side effects, but eventually relapsed. Based on these findings, methods to enhance viral replication in the tumor and limit immune clearance of the virus will be pursued. We conclude that myxoma virus should be further explored as a vector for transient delivery of therapeutic genes to a tumor to enhance T cell responses.

Development of dendritic cells in the intestine

The intestinal tract is exposed to a large variety of antigens such as food proteins, commensal bacteria and pathogens and contains one of the largest arms of the immune system. The intestinal immune system has to discriminate between harmless and harmful antigens, inducing tolerance to harmless antigens and active immunity towards pathogens and other harmful materials. Dendritic cells (DC) in the mucosal lamina propria (LP) are central to this process, as they sample bacteria from the local environment and constitutively migrate to the draining mesenteric lymph nodes (MLN), where they present antigen to naïve T cells in order to direct an appropriate immune response. Despite their crucial role, understanding the function and phenotype of LP DC has been hampered by the fact that they share phenotypic markers with macrophages (mφ), which are the dominant population of mononuclear phagocyte (MP) in the LP. Recent work in our own and other laboratories has established gating strategies and phenotyping panels that allow precise discrimination between intestinal DC and mφ using the mφ specific markers CD64 and F4/80. In this way four bona fide DC subsets with distinct functions have been identified in adult LP based on their expression of CD11b and CD103 and a major aim of my project was to understand how these subsets might develop in the neonatal intestine. At the beginning of my PhD, the laboratory had used these new methods to show that signal regulatory protein α (SIRPα), an inhibitory receptor expressed by myeloid cells, was expressed by mφ and most DC in the intestine, except for those expressing CD103 alone. In addition, mice carrying a non-signalling mutation in SIRPα (SIRPα mt) had a selective reduction in CD103+CD11b+ DC, a subset which is unique to the intestinal LP. This was the basis for the initial experiments of my project, described in Chapter 3, where I investigated if the phenotype in SIRPα mt mice was intrinsic to haematopoietic cells or not. To explore this, I generated bone marrow (BM) chimeric mice by reconstituting irradiated WT mice with SIRPα mt BM, or SIRPα mt animals with WT BM. These experiments suggested that the defect in CD103+CD11b+ DC was not replicated in DC derived from BM of SIRPα origin. However as this seemed inconsistent with other data, I considered the possibility that 18 the phenotype may have been lost with age, as the BM chimeric mice were considerably older than those used in the original studies of SIRPα function. However a comparison of DC subsets in the intestine of WT and SIRPα mt mice as they aged provided no conclusive evidence to support this idea. As these experiments did show age-dependent effects on DC subsets, in Chapter 4, I went on to investigate how the DC populations appeared in the intestine and other tissues in the neonatal period. These experiments showed there were few CD103+CD11b+ DC present in the LP and migratory DC compartment of the MLN in the neonate and that as this population gradually increased in proportion with age, there was a reciprocal decrease in the relative proportion of CD103-CD11b+ DC. Interestingly, most of the changes in DC numbers in the intestine were found during the second or third week of life when the weaning process began. To validate my findings that there were few CD103+CD11b+ DC in the neonate and that this was not merely an absence of CD103 upregulation, I examined the expression of CD101 and Trem-1, markers that other work in the laboratory had suggested were specific to the CD103+CD11b+ DC lineage. My work showed that CD101 and Trem-1 were co- expressed by most CD103+CD11b+ DC in small intestine (SI) LP, as well as a small subset of CD103-CD11b+ DC in this tissue. Interestingly, Trem-1 was highly specific to the SI LP and migratory DC in the MLN, but absent from the colon and other tissues. CD101 expression was also only found on CD11b+ DC, but showed a less restricted pattern of distribution, being found in several tissues as well as the SI LP. The relative timing of their development suggested there might be a relationship between CD103+CD11b+ and CD103-CD11b+ DC and this was supported by microarray analysis. I hypothesised that the CD103-CD11b+ DC that co-expressed CD101 and Trem-1 may be the cells that developed into CD103+CD11b+ DC. To investigate this I analysed how CD101 and Trem-1 expression changed with age amongst the DC subsets in SI LP, colonic LP (CLP) and MLN. The proportion of CD101+Trem-1+ cells increased amongst CD103+CD11b+ DC in the SI LP and MLN with age, while amongst CD103+CD11b+ DC in the CLP this decreased. This was not the same in CD103-CD11b+ DC, where CD101 and Trem-1 expression was more varied with age in all tissues. CD101 and Trem-1 were not expressed to any great extent on CD103+CD11b- or CD103-CD11b- DC. The phenotypic development of the 19 intestinal DC subsets was paralleled by the gradual upregulation of CD103 expression, while the production of retinoic acid (RA), as assessed by the AldefluorTM assay, was low early in life and did not attain adult levels until after weaning. Thus DC in the neonatal intestine take some time to acquire the adult pattern of phenotypic subsets and are functionally immature compared with their adult counterparts. In Chapter 5, I used CD101 and Trem-1 to explore the ontogeny of intestinal DC subsets in CCR2-/- and SIRPα mt mice, both of which have selective defects in one particular group of DC. The selective defect seen amongst CD103+CD11b+ DC in adult SIRPα mt mice was more profound in mice at D7 and D14 of age, indicating that it may be intrinsic to this population and not highly dependent on environmental factors that change after birth. The expression of CD101 and Trem-1 by both CD103+CD11b+ and CD103-CD11b+ DC was reduced in SIRPα mt mice, again indicating that this entire lineage was affected by the lack of SIRPα signalling. However there was also a generalised defect in the numbers of all DC subsets in many tissues from early in life, suggesting there was compromised development, recruitment or survival of DC in the absence of SIRPα signalling. In contrast to the findings in SIRPα mt mice, more CD103+CD11b+ DC co-expressed CD101 and Trem-1 in CCR2-/- mice, while there were no differences in the expression of these molecules amongst CD103-CD11b+ DC. This may suggest that CCR2+ CD103-CD11b+ DC are not the cells that express CD101 and Trem-1 that are predicted to be the direct precursors of CD103+CD11b+ DC. I also examined the expression of DC growth factor receptors on DC subsets from mice of different ages, but no clear age or subset- related patterns of the expression of mRNA for Csf2ra, Irf4, Tgfbr1 and Rara could be observed. Next, I investigated whether Trem-1 played any role in DC development. Preliminary experiments in Trem-1-/- mice show no differences between any of the DC subsets, nor were there any selective effects on individual subsets when DC development from Trem-1-/- KO and WT BM was compared in competitive chimeras. However these experiments were difficult to interpret due to viability problems and because I found an unexpected defect in the ability of Trem-1-/- BM to generate all DC, irrespective of whether they expressed Trem-1 or not. 20 The final experiments I carried out were to examine the role of the microbiota in driving the differentiation of intestinal DC subsets, based on the hypothesis that this could be one of the environmental factors that might influence events in the developing intestine. To this end I performed experiments in both antibiotic treated and germ free adult mice, both of which showed no significant phenotypic differences amongst any of the DC subsets. However the study of germ free mice was compromised by recent contamination of the colony and may not be the conclusive answer. Together the data in this thesis have shown that the population of CD103+CD11b+ DC, which is unique to the intestine, is not present at birth. These cells gradually increase in frequency over time and as this occurs there is a reciprocal decrease in the frequency of CD103-CD11b+ DC. Along with other results, this leads to the idea that there may be a linear developmental pathway from CD103-CD11b+ DC to CD103+CD11b+ DC that is driven by non-microbial factors that are located preferentially in the small intestine. My project indicates that markers such as CD101 and Trem-1 may assist the dissection of this process and highlights the importance of the neonatal period for these events.

The interaction between Sertoli cells and luekemia inhibitory factor on the propagation and differentiation of spermatogonial stem cells in vitro

Background: Sertoli cells play a pivotal role in creating microenvironments essential for spermatogonial stem cells (SSCs) self-renewal and commitment to differentiation. Maintenance of SSCs and or induction of in vitro spermiogenesis may provide a therapeutic strategy to treat male infertility. Objective: This study investigated the role of luekemia inhibitory factor (LIF) on the propagation of SSCs and both functions of Sertoli cells on the proliferation and differentiation of these cells. Materials and Methods: SSCs were sorted from the testes of adult male mice by magnetic activated cell sorting and thymus cell antigen 1 antibody. On the other hand, isolated Sertoli cells were enriched using lectin coated plates. SSCs were cultured on Sertoli cells for 7 days in the absence or presence of LIF. The effects of these conditions were evaluated by microscopy and expression of meiotic and post meiotic transcripts by reverse transcriptase polymerase chain reaction. Results: Our data showed that SSCs co-cultured with Sertoli cells in the presence of LIF formed colonies on top of the Sertoli cells. These colonies had alkaline phosphatesase activity and expressed SSCs specific genes. SSCs were enjoyed limited development after the mere removal of LIF, and exhibiting expression of meiotic and postmeiotic transcript and loss of SSCs specific gene expression (p< 0.05). Conclusion: Our findings represent co-culture of SSCs with Sertoli cells provides conditions that may allow efficient proliferation and differentiation of SSCs for male infertility treatment.

Studies of MHC class I antigen presentation & the origins of the immunopeptidome

La présentation d'antigène par les molécules d'histocompatibilité majeure de classe I (CMHI) permet au système immunitaire adaptatif de détecter et éliminer les agents pathogènes intracellulaires et des cellules anormales. La surveillance immunitaire est effectuée par les lymphocytes T CD8 qui interagissent avec le répertoire de peptides associés au CMHI présentés à la surface de toutes cellules nucléées. Les principaux gènes humains de CMHI, HLA-A et HLA-B, sont très polymorphes et par conséquent montrent des différences dans la présentation des antigènes. Nous avons étudié les différences qualitatives et quantitatives dans l'expression et la liaison peptidique de plusieurs allotypes HLA. Utilisant la technique de cytométrie de flux quantitative nous avons établi une hiérarchie d'expression pour les quatre HLA-A, B allotypes enquête. Nos résultats sont compatibles avec une corrélation inverse entre l'expression allotypique et la diversité des peptides bien que d'autres études soient nécessaires pour consolider cette hypothèse. Les origines mondiales du répertoire de peptides associés au CMHI restent une question centrale à la fois fondamentalement et dans la recherche de cibles immunothérapeutiques. Utilisant des techniques protéogénomiques, nous avons identifié et analysé 25,172 peptides CMHI isolées à partir des lymphocytes B de 18 personnes qui exprime collectivement 27 allotypes HLA-A,B. Alors que 58% des gènes ont été la source de 1-64 peptides CMHI par gène, 42% des gènes ne sont pas représentés dans l'immunopeptidome. Dans l'ensemble, l’immunopeptidome présenté par 27 allotypes HLA-A,B ne couvrent que 17% des séquences exomiques exprimées dans les cellules des sujets. Nous avons identifié plusieurs caractéristiques des transcrits et des protéines qui améliorent la production des peptides CMHI. Avec ces données, nous avons construit un modèle de régression logistique qui prédit avec une grande précision si un gène de notre ensemble de données ou à partir d'ensembles de données indépendants génèrerait des peptides CMHI. Nos résultats montrent la sélection préférentielle des peptides CMHI à partir d'un répertoire limité de produits de gènes avec des caractéristiques distinctes. L'idée que le système immunitaire peut surveiller des peptides CMHI couvrant seulement une fraction du génome codant des protéines a des implications profondes dans l'auto-immunité et l'immunologie du cancer.

UTILIZING DIELECTROPHORESIS TO DETERMINE THE PHYSIOLOGICAL DIFFERENCES OF EUKARYOTIC CELLS

Type 1 diabetes affects over 108,000 children, and this number is steadily increasing. Current insulin therapies help manage the disease but are not a cure. Over a child’s lifetime they can develop kidney disease, blindness, cardiovascular disease and many other issues due to the complications of type 1 diabetes. This autoimmune disease destroys beta cells located in the pancreas, which are used to regulate glucose levels in the body. Because there is no cure and many children are affected by the disease there is a need for alternative therapeutic options that can lead to a cure. Human mesenchymal stem cells (hMSCs) are an important cell source for stem cell therapeutics due to their differentiation capacity, self-renewal, and trophic activity. hMSCs are readily available in the bone marrow, and act as an internal repair system within the body, and they have been shown to differentiate into insulin producing cells. However, after isolation hMSCs are a heterogeneous cell population, which requires secondary processing. To resolve the heterogeneity issue hMSCs are separated using fluorescent- and magnetic-activate cell sorting with antigen labeling. These techniques are efficient but reduce cell viability after separation due to the cell labeling. Therefore, to make hMSCs more readily available for type 1 diabetes therapeutics, they should be separated without diminishing there functional capabilities. Dielectrophoresis is an alternative separation technique that has the capability to separated hMSCs. This dissertation uses dielectrophoresis to characterize the dielectric properties of hMSCs. The goal is to use hMSCs dielectric signature as a separation criteria rather than the antigen labeling implemented with FACS and MACS. DEP has been used to characterize other cell systems, and is a viable separation technique for hMSCs.

Studies of MHC class I antigen presentation & the origins of the immunopeptidome

La présentation d'antigène par les molécules d'histocompatibilité majeure de classe I (CMHI) permet au système immunitaire adaptatif de détecter et éliminer les agents pathogènes intracellulaires et des cellules anormales. La surveillance immunitaire est effectuée par les lymphocytes T CD8 qui interagissent avec le répertoire de peptides associés au CMHI présentés à la surface de toutes cellules nucléées. Les principaux gènes humains de CMHI, HLA-A et HLA-B, sont très polymorphes et par conséquent montrent des différences dans la présentation des antigènes. Nous avons étudié les différences qualitatives et quantitatives dans l'expression et la liaison peptidique de plusieurs allotypes HLA. Utilisant la technique de cytométrie de flux quantitative nous avons établi une hiérarchie d'expression pour les quatre HLA-A, B allotypes enquête. Nos résultats sont compatibles avec une corrélation inverse entre l'expression allotypique et la diversité des peptides bien que d'autres études soient nécessaires pour consolider cette hypothèse. Les origines mondiales du répertoire de peptides associés au CMHI restent une question centrale à la fois fondamentalement et dans la recherche de cibles immunothérapeutiques. Utilisant des techniques protéogénomiques, nous avons identifié et analysé 25,172 peptides CMHI isolées à partir des lymphocytes B de 18 personnes qui exprime collectivement 27 allotypes HLA-A,B. Alors que 58% des gènes ont été la source de 1-64 peptides CMHI par gène, 42% des gènes ne sont pas représentés dans l'immunopeptidome. Dans l'ensemble, l’immunopeptidome présenté par 27 allotypes HLA-A,B ne couvrent que 17% des séquences exomiques exprimées dans les cellules des sujets. Nous avons identifié plusieurs caractéristiques des transcrits et des protéines qui améliorent la production des peptides CMHI. Avec ces données, nous avons construit un modèle de régression logistique qui prédit avec une grande précision si un gène de notre ensemble de données ou à partir d'ensembles de données indépendants génèrerait des peptides CMHI. Nos résultats montrent la sélection préférentielle des peptides CMHI à partir d'un répertoire limité de produits de gènes avec des caractéristiques distinctes. L'idée que le système immunitaire peut surveiller des peptides CMHI couvrant seulement une fraction du génome codant des protéines a des implications profondes dans l'auto-immunité et l'immunologie du cancer.

Infección por virus sincitial respiratorio y su relación con valores de IGG en niños críticos

Antecedente: La infección por el virus sincitial respiratorio (VSR) representa una elevada morbimortalidad, y en algunos casos necesidad de manejo en unidades de cuidado intensivo pediátrico (UCIP). La respuesta inmunológica influye de manera directa en la expresión de la severidad y pronóstico de los pacientes con infección respiratoria. Metodología: Estudio de una cohorte retrospectiva de pacientes con infección respiratoria grave secundaria a VSR, sin historia de inmunodeficiencia, atendidos en la UCIP del Hospital Universitario Clínica San Rafael. Se realizó análisis descriptivoglobaly de acuerdo a la categorización de las prueba de IgG. Resultados: De 188 pacientes que ingresaron a la UCIP, 13% presentaron infección por VSR (24), con una edad promedio de 7,3 (DE=3,6) meses. Pertenecían al sexo masculino79,83%. Se encontró que 12,5% tenían un valor de IgGbajo para su edad, 58,33% tenían valores en límite inferior y el 29,17% dentro de rangos normales para su edad. En los pacientes con IgG baja, fue mayor la presentación de choque séptico que no responde a líquidos (100 vs 92 vs 86%), la mediana de días de ventilación mecánica fue mayor (8 vs 6 vs 5 respectivamente), así como la mortalidad (67 vs 7,1 vs 0%). Conclusión: Nuestra serie encontró que aquellos pacientes con niveles bajos o valores en el límite inferior de IgG sérica tuvieron mayor compromiso sistémico, mayor duración de ventilación mecánica y mayor mortalidad. Se necesitan estudios prospectivos que relaciones niveles bajos de IgG con severidad y pronostico en estos pacientes con infección grave por VSR.

Caracterización y prevalencia del compromiso ocular en pacientes con enfermedad autoinmune y autoinflamatoria en un centro de referencia reumatológica en Colombia entre los años 2000 a 2015

RESUMEN Objetivo: Estimar la prevalencia de las diferentes enfermedades oftalmológicas que aparecen en el contexto de una enfermedad autoinmune (EAI) en pacientes de un centro de referencia reumatológica en Colombia, según características clínicas y sociodemográficas durante un período de 15 años, comprendido entre los años 2000 a 2015. Métodos: Se realizó un estudio descriptivo, observacional de prevalencia. El tipo de muestreo fue aleatorio estratificado con asignación proporcional en el programa Epidat 3.4. Los datos se analizaron en el programa SPSS v22.0 y se realizó análisis univariado de las variables categóricas, para las variables cuantitativas se realizaron medidas de tendencia central. Resultados: De 1640 historias clínicas revisadas, se encontraron 634 pacientes (38,65%) con compromiso ocular. Si excluimos los pacientes con SS, que por definición presentan ojo seco, 222 pacientes (13,53%) presentaron compromiso oftalmológico. Del total de pacientes, el 83,3% fueron mujeres. La AR fue la enfermedad autoinmune con mayor compromiso oftalmológico con 138 pacientes (62,2%), y en último lugar la sarcoidosis con 1 solo paciente afectado. La QCS fue la manifestación más común en todos los grupos diagnósticos de EAI, con 146 pacientes (63,5%). De 414 pacientes con Síndrome de Sjögren (SS) y QCS 8 presentaron compromiso ocular adicional, siendo la uveítis la segunda patología ocular asociada en pacientes con SS y la primera causa en las espondiloartropatias (71,4 %). Los pacientes con catarata (4,1%) presentaron la mayor prevalencia de uso de corticoide (88.8%). De 222 pacientes, 28 (12,6%) presentaron uveítis. Del total de pacientes, 16 (7,2%) presentaron maculopatía por antimalaráricos y 6 (18,75%) de los pacientes con LES. Los ANAS se presentaron en el 100% los pacientes con trastorno vascular de la retina. Los pacientes con epiescleritis presentaron la mayor proporción de positivización de anticuerpos anti-DNA. La EAI que más presentó epiescleritis fue LES con 4 pacientes (12,5%) El 22% de paciente con anticuerpos anti-RNP presentaron escleritis y 32,1% de los pacientes con uveítis presentaron HLA-B27 positivo. Las manifestaciones oftalmológicas precedieron a las sistémicas entre un 11,1% y un 33,3% de los pacientes. Conclusión: Las enfermedades oculares se presentan con frecuencia en los pacientes colombianos con EAI (38.65%), siendo la AR la enfermedad con mayor compromiso ocular (62,2%) y la QCS la enfermedad ocular con mayor prevalencia en todas las EAI (63,5%). La uveítis se presentó en 28 pacientes (12,6%). Las manifestaciones oftalmológicas pueden preceder a las sistémicas. El examen oftalmológico debe ser incluido en los pacientes con EAI, por ser la enfermedad ocular una comorbilidad frecuente. Adicionalmente, los efectos oftalmológicos de las medicaciones sistémicas utilizadas en EAI deben ser estrechamente monitorizados, durante el curso del tratamiento.