Helper T cell immunity in humans with inherited CD4 deficiency.

CD4+ T cells are vital for host defense and immune regulation. However, the fundamental role of CD4 itself remains enigmatic. We report seven patients aged 5-61 years from five families of four ancestries with autosomal recessive CD4 deficiency and a range of infections, including recalcitrant warts and Whipple's disease. All patients are homozygous for rare deleterious CD4 variants impacting expression of the canonical CD4 isoform. A shorter expressed isoform that interacts with LCK, but not HLA class II, is affected by only one variant. All patients lack CD4+ T cells and have increased numbers of TCRαß+CD4-CD8- T cells, which phenotypically and transcriptionally resemble conventional Th cells. Finally, patient CD4-CD8- αß T cells exhibit intact responses to HLA class II-restricted antigens and promote B cell differentiation in vitro. Thus, compensatory development of Th cells enables patients with inherited CD4 deficiency to acquire effective cellular and humoral immunity against an unexpectedly large range of pathogens. Nevertheless, CD4 is indispensable for protective immunity against at least human papillomaviruses and Trophyrema whipplei.

Autoantibodies against type I IFNs in humans with alternative NF-κB pathway deficiency.

Patients with autoimmune polyendocrinopathy syndrome type 1 (APS-1) caused by autosomal recessive AIRE deficiency produce autoantibodies that neutralize type I interferons (IFNs)1,2, conferring a predisposition to life-threatening COVID-19 pneumonia3. Here we report that patients with autosomal recessive NIK or RELB deficiency, or a specific type of autosomal-dominant NF-κB2 deficiency, also have neutralizing autoantibodies against type I IFNs and are at higher risk of getting life-threatening COVID-19 pneumonia. In patients with autosomal-dominant NF-κB2 deficiency, these autoantibodies are found only in individuals who are heterozygous for variants associated with both transcription (p52 activity) loss of function (LOF) due to impaired p100 processing to generate p52, and regulatory (IκBδ activity) gain of function (GOF) due to the accumulation of unprocessed p100, therefore increasing the inhibitory activity of IκBδ (hereafter, p52LOF/IκBδGOF). By contrast, neutralizing autoantibodies against type I IFNs are not found in individuals who are heterozygous for NFKB2 variants causing haploinsufficiency of p100 and p52 (hereafter, p52LOF/IκBδLOF) or gain-of-function of p52 (hereafter, p52GOF/IκBδLOF). In contrast to patients with APS-1, patients with disorders of NIK, RELB or NF-κB2 have very few tissue-specific autoantibodies. However, their thymuses have an abnormal structure, with few AIRE-expressing medullary thymic epithelial cells. Human inborn errors of the alternative NF-κB pathway impair the development of AIRE-expressing medullary thymic epithelial cells, thereby underlying the production of autoantibodies against type I IFNs and predisposition to viral diseases.

Anti-GM-CSF Neutralizing Autoantibodies in Colombian Patients with Disseminated Cryptococcosis.

BACKGROUND: Cryptococcosis is a potentially life-threatening fungal disease caused by encapsulated yeasts of the genus Cryptococcus, mostly C. neoformans or C. gattii. Cryptococcal meningitis is the most frequent clinical manifestation in humans. Neutralizing autoantibodies (auto-Abs) against granulocyte-macrophage colony-stimulating factor (GM-CSF) have recently been discovered in otherwise healthy adult patients with cryptococcal meningitis, mostly caused by C. gattii. We hypothesized that three Colombian patients with cryptococcal meningitis caused by C. neoformans in two of them would carry high plasma levels of neutralizing auto-Abs against GM-CSF. METHODS: We reviewed medical and laboratory records, performed immunological evaluations, and tested for anti-cytokine auto-Abs three previously healthy HIV-negative adults with disseminated cryptococcosis. RESULTS: Peripheral blood leukocyte subset levels and serum immunoglobulin concentrations were within the normal ranges. We detected high levels of neutralizing auto-Abs against GM-CSF in the plasma of all three patients. CONCLUSIONS: We report three Colombian patients with disseminated cryptococcosis associated with neutralizing auto-Abs against GM-CSF. Further studies should evaluate the genetic contribution to anti-GM-CSF autoantibody production and the role of the GM-CSF signaling pathway in the immune response to Cryptococcus spp.

Defective formation of IgA memory B cells, Th1 and Th17 cells in symptomatic patients with selective IgA deficiency.

OBJECTIVE: Selective IgA deficiency (sIgAD) is the most common primary immunodeficiency in Western countries. Patients can suffer from recurrent infections and autoimmune diseases because of a largely unknown aetiology. To increase insights into the pathophysiology of the disease, we studied memory B and T cells and cytokine concentrations in peripheral blood. METHODS: We analysed 30 sIgAD patients (12 children, 18 adults) through detailed phenotyping of peripheral B-cell, CD8+ T-cell and CD4+ T-cell subsets, sequence analysis of IGA and IGG transcripts, in vitro B-cell activation and blood cytokine measurements. RESULTS: All patients had significantly decreased numbers of T-cell-dependent (TD; CD27+) and T-cell-independent (TI; CD27-) IgA memory B cells and increased CD21low B-cell numbers. IgM+IgD- memory B cells were decreased in children and normal in adult patients. IGA and IGG transcripts contained normal SHM levels. In sIgAD children, IGA transcripts more frequently used IGA2 than controls (58.5% vs. 25.1%), but not in adult patients. B-cell activation after in vitro stimulation was normal. However, adult sIgAD patients exhibited increased blood levels of TGF-ß1, BAFF and APRIL, whereas they had decreased Th1 and Th17 cell numbers. CONCLUSION: Impaired IgA memory formation in sIgAD patients is not due to a B-cell activation defect. Instead, decreased Th1 and Th17 cell numbers and high blood levels of BAFF, APRIL and TGF-ß1 might reflect disturbed regulation of IgA responses in vivo.These insights into B-cell extrinsic immune defects suggest the need for a broader immunological focus on genomics and functional analyses to unravel the pathogenesis of sIgAD.

Early-Onset Invasive Infection Due to Corynespora cassiicola Associated with Compound Heterozygous CARD9 Mutations in a Colombian Patient.

PURPOSE: CARD9 deficiency is an inborn error of immunity that predisposes otherwise healthy humans to mucocutaneous and invasive fungal infections, mostly caused by Candida, but also by dermatophytes, Aspergillus, and other fungi. Phaeohyphomycosis are an emerging group of fungal infections caused by dematiaceous fungi (phaeohyphomycetes) and are being increasingly identified in patients with CARD9 deficiency. The Corynespora genus belongs to phaeohyphomycetes and only one adult patient with CARD9 deficiency has been reported to suffer from invasive disease caused by C. cassiicola. We identified a Colombian child with an early-onset, deep, and destructive mucocutaneous infection due to C. cassiicola and we searched for mutations in CARD9. METHODS: We reviewed the medical records and immunological findings in the patient. Microbiologic tests and biopsies were performed. Whole-exome sequencing (WES) was made and Sanger sequencing was used to confirm the CARD9 mutations in the patient and her family. Finally, CARD9 protein expression was evaluated in peripheral blood mononuclear cells (PBMC) by western blotting. RESULTS: The patient was affected by a large, indurated, foul-smelling, and verrucous ulcerated lesion on the left side of the face with extensive necrosis and crusting, due to a C. cassiicola infectious disease. WES led to the identification of compound heterozygous mutations in the patient consisting of the previously reported p.Q289* nonsense (c.865C > T, exon 6) mutation, and a novel deletion (c.23_29del; p.Asp8Alafs10*) leading to a frameshift and a premature stop codon in exon 2. CARD9 protein expression was absent in peripheral blood mononuclear cells from the patient. CONCLUSION: We describe here compound heterozygous loss-of-expression mutations in CARD9 leading to severe deep and destructive mucocutaneous phaeohyphomycosis due to C. cassiicola in a Colombian child.

[Colombian Guidelines of clinical practice for the use of immunoglobulins in the treatment of replacement and immunomodulation]. / Guía colombiana de práctica clínica para el uso de inmonuglobulinas en el tratamiento de reemplazo e inmunomodulación.

Immunoglobulins are heterodimeric proteins composed of 2 heavy chains and 2 light chains. Human immunoglobulin G (IgG) is a plasma derivative and contains more than 95% of IgG. The composition of IgG subclasses is similar to that of normal human plasma. Immunoglobulin therapy was first introduced more than 50 years ago, and its use has been described in numerous diseases. In Colombia, the importance of this immunomodulatory resource prompted the need for clinical practice guidelines to be available for its use. For this reason, a multidisciplinary group of experts was brought together and distributed in working groups, by specialties, in order to develop an initial manuscript. Systematic literature searches were undertaken; identified evidences were evaluated and classified to support a preliminary draft that was discussed, analyzed and amended. Recommendations were issued on the use of intravenous immunoglobulin in pathologies that include primary and secondary immunodeficiencies, autoimmune diseas es, neurological disorders, infections, transplants and miscellaneous conditions; grades were assigned to each one of them according to the GRADE system. The final result translated into recommendations that are put forth with the purpose to inform, guide and support on optimal use of this immunomodulatory resource.

Las inmunoglobulinas son proteínas heterodiméricas compuestas de 2 cadenas pesadas y 2 cadenas ligeras. La inmunoglobulina G humana es un derivado del plasma y contiene más de 95 % de IgG. La composición de las subclases de IgG es similar a la del plasma humano normal. El tratamiento con inmunoglobulina comenzó hace más de 50 años y su uso se ha descrito en numerosas enfermedades. En Colombia, la importancia de este recurso inmunomodulador condujo a la necesidad de contar con una guía de práctica clínica para su uso, para lo cual se reunió un grupo multidisciplinario de expertos, quienes se distribuyeron en mesas de trabajo, por especialidad, para redactar un texto base. Se llevaron a cabo búsquedas bibliográficas sistemáticas; las evidencias identificadas se valoraron y clasificaron para sustentar un texto preliminar que fue discutido, analizado y corregido. Se emitieron recomendaciones de uso de la inmunoglobulina intravenosa en patologías que abarcan inmunodeficiencias primarias y secundarias, enfermedades autoinmunes, alteraciones neurológicas, infecciones, trasplantes y enfermedades misceláneas; se asignaron calificaciones según el sistema GRADE para cada una. El resultado final se tradujo en las recomendaciones que se presentan con la finalidad de informar, orientar y apoyar en el uso óptimo de dicho recurso inmunomodulador.

Severe Enteropathy and Hypogammaglobulinemia Complicating Refractory Mycobacterium tuberculosis Complex Disseminated Disease in a Child with IL-12Rß1 Deficiency.

PURPOSE: Mendelian susceptibility to mycobacterial disease is a rare clinical condition characterized by a predisposition to infectious diseases caused by poorly virulent mycobacteria. Other infections such as salmonellosis and candidiasis are also reported. The purpose of this article is to describe a young boy affected with various infectious diseases caused by Mycobacterium tuberculosis complex, Salmonella sp, Klebsiella pneumonie, Citrobacter sp., and Candida sp, complicated with severe enteropathy and transient hypogammaglobulinemia. METHODS: We reviewed medical records and performed flow cytometry staining for lymphocyte populations, lymphocyte proliferation in response to PHA, and intracellular IFN-γ production in T cell PHA blasts in the patient and a healthy control. Sanger sequencing was used to confirm the genetic variants in the patient and relatives. RESULTS: Genetic analysis revealed a bi-allelic mutation in IL12RB1 (C291Y) resulting in complete IL-12Rß1 deficiency. Functional analysis demonstrated the lack of intracellular production of IFN-γ in CD3+ T lymphocytes from the patient in response to rhIL-12p70. CONCLUSIONS: To our knowledge, this is the third patient with MSMD due to IL-12Rß1 deficiency complicated with enteropathy and hypogammaglobulinemia and the first case of this disease to be described in Colombia.

Successful immune reconstitution by means of hematopoietic stem cell transplantation in a Colombian patient with chronic granulomatous disease.

INTRODUCTION: Chronic granulomatous disease is a primary immunodeficiency that results from mutations in proteins of the NADPH oxidase system that affect the microbicidal activity of phagocytes. Immune reconstitution by hematopoietic stem cell transplantation is currently the only curative therapy for this disease.  OBJECTIVE: To describe the clinical and molecular characterization of a patient with X-linked chronic granulomatous disease and the successful immune reconstitution by means of a hematopoietic stem cell transplantation.  METHODS: The respiratory burst was measured by flow cytometry using the dihydrorodamine 123 (DHR) oxidation test in neutrophils of peripheral blood. Mutational analysis of CYBB was performed by PCR amplification in complementary DNA, as well as sequencing and comparative genomic hybridization in genomic DNA. HLA-identical stem cells from the patient's younger brother were used for the transplantation and reduced intensity pre-transplantation conditioning was administered. Post-transplantation immune reconstitution was evaluated periodically by serial complete blood counts and DHR 123 in peripheral blood neutrophils.  RESULTS: The diagnosis of X-linked chronic granulomatous disease resulted from a hemizygous deletion affecting Xp21.1 that included the entire CYBB. Post-transplantation engraftment was documented in platelets and peripheral blood neutrophils at days 10 and 11, respectively. Total hematological reconstitution was achieved by day 30 post-transplantation and no complications or infections have been observed in the three years since the transplantation.  CONCLUSION: Hemopoietic stem cell transplantation allows for total reconstitution of the immune function related to microbicidal activity of phagocytic cells from patients with X-linked chronic granulomatous disease.

Reconstitución inmune exitosa mediante trasplante de células madre hematopoyéticas en un paciente colombiano afectado con enfermedad granulomatosa crónica / Successful immune reconstitution by means of hematopoietic stem cell transplantation in a Colombian patient with chronic granulomatous disease

Introducción. La enfermedad granulomatosa crónica es una inmunodeficiencia primaria causada por mutaciones en los genes que codifican para las proteínas del sistema de la oxidasa de NADPH ( Nicotinamide Adenine Dinucleotide Phosphate ) de las células fagocíticas, las cuales afectan la producción de especies reactivas del oxígeno y la actividad microbicida. Actualmente, la única terapia curativa para esta enfermedad es la reconstitución inmune mediante el trasplante de células madre hematopoyéticas. Objetivo. Reportar la caracterización clínica y molecular de un paciente con enfermedad granulomatosa crónica ligada al cromosoma X y su reconstitución inmunitaria exitosa mediante el trasplante de células madre hematopoyéticas. Materiales y métodos. El estallido respiratorio en neutrófilos de sangre periférica se midió por citometría de flujo mediante la prueba de oxidación de la dihidrorrodamina 123 (DHR 123). El análisis de las mutaciones del gen CYBB se hizo mediante reacción en cadena de la polimerasa (PCR) en el ADN complementario y la secuenciación e hibridación genómica comparativa en el ADN genómico. En el trasplante se emplearon células madre del hermano menor con HLA idéntico, y previamente se hizo un acondicionamiento de intensidad reducida. La reconstitución inmunitaria después del trasplante se evaluó periódicamente con hemoleucogramas y la prueba DHR 123 en neutrófilos de sangre periférica. Resultados. El diagnóstico de la enfermedad granulomatosa crónica ligada al cromosoma X se estableció como resultado de una deleción hemicigota en la banda Xp21.1 que implicó la deleción completa del CYBB . La toma de injerto postrasplante para plaquetas y neutrófilos fue en los días 10 y 11, respectivamente. En el día 30 después del trasplante se logró la reconstitución hematológica completa y en los tres años siguientes no se observaron complicaciones ni infecciones. Conclusión. El trasplante de células madre hematopoyéticas permite la reconstitución completa de la función inmunitaria relacionada con la actividad microbicida de las células fagocíticas de pacientes con enfermedad granulomatosa crónica ligada al cromosoma X.

Introduction: Chronic granulomatous disease is a primary immunodeficiency that results from mutations in proteins of the NADPH oxidase system that affect the microbicidal activity of phagocytes. Immune reconstitution by hematopoietic stem cell transplantation is currently the only curative therapy for this disease. Objective: To describe the clinical and molecular characterization of a patient with X-linked chronic granulomatous disease and the successful immune reconstitution by means of a hematopoietic stem cell transplantation. Materials and methods: The respiratory burst was measured by flow cytometry using the dihydrorodamine 123 (DHR) oxidation test in neutrophils of peripheral blood. Mutational analysis of CYBB was performed by PCR amplification in complementary DNA, as well as sequencing and comparative genomic hybridization in genomic DNA. HLA-identical stem cells from the patient´s younger brother were used for the transplantation and reduced intensity pre-transplantation conditioning was administered. Post-transplantation immune reconstitution was evaluated periodically by serial complete blood counts and DHR 123 in peripheral blood neutrophils. Results: The diagnosis of X-linked chronic granulomatous disease resulted from a hemizygous deletion affecting Xp21.1 that included the entire CYBB . Post-transplantation engraftment was documented in platelets and peripheral blood neutrophils at days 10 and 11, respectively. Total hematological reconstitution was achieved by day 30 post-transplantation and no complications or infections have been observed in the three years since the transplantation. Conclusion: Hemopoietic stem cell transplantation allows for total reconstitution of the immune function related to microbicidal activity of phagocytic cells from patients with X-linked chronic granulomatous disease.

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).

The Extended Clinical Phenotype of 26 Patients with Chronic Mucocutaneous Candidiasis due to Gain-of-Function Mutations in STAT1.

PURPOSE: Gain-of-function (GOF) mutations in the signal transducer and activator of transcription 1 (STAT1) result in unbalanced STAT signaling and cause immune dysregulation and immunodeficiency. The latter is often characterized by the susceptibility to recurrent Candida infections, resulting in the clinical picture of chronic mucocutaneous candidiasis (CMC). This study aims to assess the frequency of GOF STAT1 mutations in a large international cohort of CMC patients. METHODS: STAT1 was sequenced in genomic DNA from 57 CMC patients and 35 healthy family members. The functional relevance of nine different STAT1 variants was shown by flow cytometric analysis of STAT1 phosphorylation in patients' peripheral blood cells (PBMC) after stimulation with interferon (IFN)-α, IFN-γ or interleukin-27 respectively. Extended clinical data sets were collected and summarized for 26 patients. RESULTS: Heterozygous mutations within STAT1 were identified in 35 of 57 CMC patients (61%). Out of 39 familial cases from 11 families, 26 patients (67%) from 9 families and out of 18 sporadic cases, 9 patients (50%) were shown to have heterozygous mutations within STAT1. Thirteen distinct STAT1 mutations are reported in this paper. Eight of these mutations are known to cause CMC (p.M202V, p.A267V, p.R274W, p.R274Q, p.T385M, p.K388E, p.N397D, and p.F404Y). However, five STAT1 variants (p.F172L, p.Y287D, p.P293S, p.T385K and p.S466R) have not been reported before in CMC patients. CONCLUSION: STAT1 mutations are frequently observed in patients suffering from CMC. Thus, sequence analysis of STAT1 in CMC patients is advised. Measurement of IFN- or IL-induced STAT1 phosphorylation in PBMC provides a fast and reliable diagnostic tool and should be carried out in addition to genetic testing.

[Common variable immunodeficiency: Clinical and immunological characterization of patients and homogeneous subgroup definition by means of B lymphocyte subpopulation typing]. / Inmunodeficiencia común variable: caracterización clínica e inmunológica de pacientes e identificación de subgrupos homogéneos con base en la tipificación de subpoblaciones de linfocitos B.

INTRODUCTION: Common variable immunodeficiency is a heterogeneous syndrome characterized by recurrent infections, hypogammaglobulinemia and defective production of specific antibodies. Abnormalities in peripheral blood lymphocyte subpopulations, in particular of B lymphocytes, allow the classification of patients into homogeneous groups. OBJECTIVE: To perform a clinical and immunological characterization and to evaluate lymphocyte subpopulations of twelve Colombian patients with common variable immunodeficiency in order to define homogeneous groups. MATERIALS AND METHODS: We reviewed medical records and evaluated serum immunoglobulins (Ig), lymphoproliferation, delayed hypersensitivity and used flow cytometry to quantify peripheral blood total lymphocyte and B cell populations. RESULTS: All patients had recurrent respiratory and/or gastrointestinal infections, while some also had infections affecting other systems. All patients had abnormally low serum IgG levels, while IgA and IgM levels were reduced in nine and ten patients, respectively. Lymphoproliferation to mitogen was lower in patients than in healthy controls but lymphoproliferation to specific antigen was normal in all. Flow cytometry revealed high numbers of T cells in three patients, while seven had a low CD4+/CD8+ ratio and four had reduced NK cells . Eleven patients had normal B cell counts, and eight of them also showed decreased memory B lymphocytes, and four had increased transitional or CD21 low B lymphocytes. CONCLUSION: Lymphocyte typing allowed assigning all but one patient to homogeneous groups according to international classification schemes, indicating the necessity of including more criteria until an ideal classification is achieved. This study will lead to a better medical monitoring of common variable immunodeficiency patients in groups at high risk of developing clinical complications.

Inmunodeficiencia común variable: caracterización clínica e inmunológica de pacientes e identificación de subgrupos homogéneos con base en la tipificación de subpoblaciones de linfocitos B / Common variable immunodeficiency: Clinical and immunological characterization of patients and homogeneous subgroup definition by means of B lymphocyte subpopulation typing

Introducción. La inmunodeficiencia común variable es un síndrome heterogéneo caracterizado por infecciones recurrentes, hipogammaglobulinemia y producción deficiente de anticuerpos específicos. Las anormalidades en subpoblaciones de linfocitos en sangre periférica, particularmente de linfocitos B, permiten la clasificación de los pacientes en grupos homogéneos. Objetivo. Caracterizar clínica e inmunológicamente los linfocitos B y tipificar sus subpoblaciones en doce pacientes colombianos con inmunodeficiencia común variable, para clasificarlos en grupos homogéneos. Materiales y métodos. Se revisaron las historias clínicas de los pacientes y se evaluaron las inmunoglobulinas séricas, la proliferación de linfocitos y la hipersensibilidad retardada, así como las subpoblaciones de linfocitos y de linfocitos B mediante citometría de flujo. Resultados. Todos los pacientes presentaron infecciones respiratorias o gastrointestinales recurrentes y, algunos, infecciones en otros sistemas. Además, todos presentaban disminución de la IgG, en tanto que la IgA y la IgM fueron bajas en nueve y diez pacientes, respectivamente. En todos hubo disminución de la proliferación de linfocitos inducida por mitógenos, pero fue normal frente a antígenos específicos. La tipificación de subpoblaciones reveló valores elevados de linfocitos T en tres pacientes; siete presentaron disminución en la relación CD4+/CD8+ y, cuatro, linfocitos NK bajos. El conteo de linfocitos B fue normal en once pacientes, ocho de los cuales presentaron linfocitos B de memoria bajos, en tanto que cuatro presentaron aumento de linfocitos B de transición o de linfocitos B CD21 low . Conclusión. La tipificación de subpoblaciones de linfocitos solo permitió asignar a 11 de los pacientes a grupos homogéneos según los esquemas de clasificación internacionales, lo que indica la necesidad de agregar más criterios hasta lograr una clasificación ideal. Este estudio permitirá establecer mejores seguimientos médicos para pacientes con inmunodeficiencia común variable en grupos con alto riesgo de desarrollar complicaciones clínicas.

Introduction: Common variable immunodeficiency is a heterogeneous syndrome characterized by recurrent infections, hypogammaglobulinemia and defective production of specific antibodies. Abnormalities in peripheral blood lymphocyte subpopulations, in particular of B lymphocytes, allow the classification of patients into homogeneous groups. Objective: To perform a clinical and immunological characterization and to evaluate lymphocyte subpopulations of twelve Colombian patients with common variable immunodeficiency in order to define homogeneous groups. Materials and methods: We reviewed medical records and evaluated serum immunoglobulins (Ig), lymphoproliferation, delayed hypersensitivity and used flow cytometry to quantify peripheral blood total lymphocyte and B cell populations. Results: All patients had recurrent respiratory and/or gastrointestinal infections, while some also had infections affecting other systems. All patients had abnormally low serum IgG levels, while IgA and IgM levels were reduced in nine and ten patients, respectively. Lymphoproliferation to mitogen was lower in patients than in healthy controls but lymphoproliferation to specific antigen was normal in all. Flow cytometry revealed high numbers of T cells in three patients, while seven had a low CD4+/CD8+ ratio and four had reduced NK cells . Eleven patients had normal B cell counts, and eight of them also showed decreased memory B lymphocytes, and four had increased transitional or CD21 low B lymphocytes. Conclusion: Lymphocyte typing allowed assigning all but one patient to homogeneous groups according to international classification schemes, indicating the necessity of including more criteria until an ideal classification is achieved. This study will lead to a better medical monitoring of common variable immunodeficiency patients in groups at high risk of developing clinical complications.

Analyses of the PRF1 gene in individuals with hemophagocytic lymphohystiocytosis reveal the common haplotype R54C/A91V in Colombian unrelated families associated with late onset disease.

Familial hemophagocytic lymphohistiocytosis (FHL), is a rare autosomal recessive disorder characterized by an impairment of cytotoxic cells and uncontrolled activation of macrophages. This study presents the first description of four patients with FHL type 2 in Latin America. Patient 1 fulfilled the disease diagnostic criteria since 2 months of age, whereas patients 2, 3 and 4 exhibited the typical manifestations of the disease only later in their childhood. The PRF1 genetic analysis in these patients revealed two previously reported mutations: L17fsx50 and R54C. Interestingly, seven out of the 8 alleles evaluated here in patients carried the haplotype R54C/A91V, suggesting that this is a highly frequent FHL type 2 allele in Colombia. This haplotype confers residual cytotoxic function leading to late onset disease. Therefore, this report highlights the remarkable complexity of FHL diagnostic, emphasizing the importance of the genetic characterization of the disease.

Evaluación de algunos parámetros inmunológicos y epidemiológicos / pacientes con poliposis nasal de localización etmoidal / Evaluation of some immunological and epidemiological parameters in patients with ethmoidal nasal polyposis

La poliposis nasal es una enfermedad crónica inflamatoria de la mucosa rinosinusal que afecta entre 1 por ciento a 5 por ciento de la población general. Si bien se han encontrado varias citocinas implicadas en la patogénesis de la poliposis, el mecanismo fisiopatológico permanece por esclarecer. En este trabajo se determinó la presencia de Interleucina 13 (IL-13) tanto en secreción como en tejido de mucosa sana y polipoide, y se relacionó este hallazgo con la reactividad alérgica de los pacientes y el grado de infiltración por células CD4+ y CD8+ Métodos: Se estudiaron 27 pacientes con poliposis diagnosticada por TAC, de los cuales se obtuvo historia clínica completa, muestra de secreción mucosa y biopsia de tejido polipoide y de mucosa sana. Mediante ELISA se detectó la presencia de IL-13 en las secreciones del tejido nasal sano o afectado por pólipos y por inmunohistoquímica se detectaron células IL-13 + y linfocitos T CD4+ y CD8+, tanto en tejido sano como afectado. Además se realizaron pruebas cutáneas para aeroalergenos. Resultados: En todos los pólipos se encontraron células IL13 +. En todos los casos se detectaron células CD4+ y CD8+, tanto en la mucosa normal como en el tejido polipoide. Sin embargo, el grado de infiltración fue mayor en este último. No se encontró asociación entre el grado de infiltración de células IL13+, CD4+ y CD8+ con la reactividad a las pruebas cutáneas. No hubo diferencia significativa en la concentración de IL-13 en secreción mucosa de pólipo respecto a mucosa sana. No hubo correlación entre los datos demográficos y los antecedentes familiares con el grado de infiltración de células IL13+, CD4+ y CD8+. Conclusiones: Se encontró en las biopsias estudiadas una alta densidad de células positivas para IL-13. En 14/27 casos las concentraciones de IL-13 fueron mayores que las del tejido nasal normal con niveles de hasta 120 pg/ul. No se demostró asociación entre el estado alérgico con la expresión de células IL-13+, ni con el grado de infiltración de linfocitos T CD4+ y CD8.

Nasal Polyposis is a chronic inflammatory disease of the rhinosinusal mucosa that affects 1% to 5% of the general population. Several cytokines have been detected in high concentrations in polyp tissues, but the mechanisms implicated remains to be clarified. In this work the presence of Interleukine 13 (IL-13) was determined as much in secretion as in healthy mucous membrane and polyp tissue, relating this finding with the allergic reactivity of the patients and the infiltration grade for cellsCD4 + and CD8 +. Methods: We studied 27 patients with diagnosed ethmoidal nasal polyposis confirmed by computerized tomography. Secretions and biopsy specimens were taken from both polyp and healthy turbinate tissues. IL-13 ELISA technique was done in secretion samples and an immunohistochemical procedure was realized to detect IL-13+, CD4+ and CD8+ cells in biopsy specimens. Additionally, skin tests for air allergens were done. Results: IL-13+ cells were detected in all nasal polyp samples. CD4+ and CD8+ cells were found in both polyp and healthy turbinate tissues; however, the infiltration degree was higher in the nasal polyp specimens. No association was found between the degree of infiltration of IL-13+, CD4+ and CD8+ cells with the skin test reactivity. Equally concentrations of IL-13 were detected in both polyp and turbinate mucosa secretions. There was no association between the demographic data and the family history with the degree of infiltration of IL-13+, CD4+, CD8+ cells. Conclusion: Our findings confirm the presence of and increase number of IL-13+ cells in all nasal polyp specimens. In 14/27 studied cases they had concentrations of IL-13 higher than those of the nasal normal mucosa with levels of up to 120 pg / ul. There is no association between the allergic state with the IL-13+cell expression, nor with the degree of infiltration of CD4+ and CD8+ T cells.

Caracterización epidemiológica, clínica y de algunos parámetros inmunológicos del síndrome de infección recurrente en niños y adolescentes desplazados a la ciudad de Cúcuta / Epidemiological, clinical and immunological characteristics of recurrent infection syndrome in individuals from low income neighborhoods from Cúcuta

Objetivo:Caracterizar desde el punto de vista epidemiológico, clínico e inmunológico el síndrome de infección recurrente en niños y adolescentes desplazados a cuatro barrios de Cúcuta. Metodología: Estudio descriptivo de corte transverso, de noviembre de 2003 a enero de 2004. Se realizó una encuesta a todos los individuos entre 0 y 15 años de edad y se clasificaron en síndrome de infección recurrente normal o en casos sospechosos de infección recurrente anormal de acuerdo con criterios previamente establecidos. Los pacientes con sospecha de síndrome de infección recurrente anormal fueron evaluados en consulta médica y con estudios básicos de laboratorio para definir su causa. Resultados: Se encuestaron 328 individuos, con edad promedio de 6,1 años; el 50,3 por ciento eran masculinos y 49,7 por ciento femeninos. Setenta (21,3 por ciento) fueron clasificados como síndrome de infección recurrente y 19 (5,8 por ciento) como sospechosos de síndrome de infección recurrente anormal. De estos úlimos doce presentaron síndrome de infección recurrente anormal no inmunológico (10 casos por alergias y dos por cardiopatía congénita), cinco, síndrome de infección recurrente anormal inmunológico, con un posible caso de deficiencia selectiva de lg A y dos fueron reclasificados como síndrome de infección recurrente normal después del análisis tanto clínico de laboratorio. Discusión: En la población desplazada estudiada la mayoría de los casos de síndrome de infección recurrente anormal son causados por enfermedades alérgicas. La encuesta probada fue útil para realizar tamización para la detección del síndrome de infección recurrente anormal.

Epidemiological assessment of mucocutaneous infections in patients with recurrent infection syndrome.

BACKGROUND: Recurrent infection syndrome (RIS) results from repeated interactions between hosts and environmental infectious agents and is considered normal (NRIS) because of its benign evolution and positive effects in the development of normal immune responses. Abnormal RIS (ARIS) is characterized by the unusually high frequency of severe infections, either as a result of anatomical or functional abnormalities or due to primary or secondary immunodeficiencies (PIDs and SIDs, respectively). Recurrent mucocutaneous infections (MCIs) can be manifestations of RIS or ARIS and could be more frequent in primary immunodeficiencies. Similarly, etiologic agents might vary from what is observed in the general population. METHODS: We carried out a descriptive study to determine the prevalence of aerobic bacterial and fungal mucocutaneous infections in 452 patients with recurrent infections, using clinical records to establish immunological status associated with the presence and characteristics of the infections. Microbiological analyses from mucocutaneous lesions were used to confirm the etiology. RESULTS: We found mucocutaneous infections in 50 patients for a total of 62 episodes (bacterial or fungal infections in 38 vs. 12 patients, respectively). Mucocutaneous infections were more frequent (21.8% vs. 9.1%; OR = 2.8) and recurrent (8.7% vs. 0.2%; P = 0.000) in primary immunodeficient patients. Furthermore, those with defects in phagocytic cells presented more mucocutaneous infections (56.2%) than patients with other primary immunodeficiencies (11.3%; OR = 10.1). CONCLUSIONS: Bacterial and fungal mucocutaneous infections are more frequent and severe in primary immunodeficient patients, particularly those with defective phagocytosis. Early and adequate assessment of the nature of mucocutaneous infections in ARIS should impact the ability of physicians to treat promptly, avoid complications and reduce the costs of medical assistance.

Micromatices de ADN en el estudio del sistema inmune / DNA microshades in the study of the inmune system

Las micromatrices de ADN son una de las tecnologías más recientes para el estudio de la expresión global de genes. Esta muestra, en un solo experimento los genes que están siendo activados y expresados en forma de ARNm, en un grupo celular determinado y bajo diferentes estímulos. Son múltiples las aplicaciones que se le han encontrado a esta metodología en el estudio celular permitiendo avanzar en campos tales como: el reconocimiento de los perfiles de respuesta celular ante estímulos determinados, la expresión de los factores reguladores de diferenciación y crecimiento celular, la determinación de los componentes y la cinética de activación de las diferentes vías de transducción, entre otros. En el campo clínico, las micromatrices han facilitado la comprensión de los mecanismos moleculares de carcinogénesis, conocer nuevos marcadores tumorales, clasificar neoplasias de difícil diferenciación, identificar patrones de expresión diferencial de genes involucrados en la génesis de metástasis, así como determinar los genes involucrados en las respuestas inmunes en diferentes enfermedades o en la respuesta a diferentes microorganismos. En el futuro se espera que el conocimiento del genoma de cada individuo permita dilucidar la predisposición a sufrir determinadas enfermedades y de esta manera desarrollar terapias específicas para cada persona. Las micromatrices son uno de los instrumentos que harán posible este anhelo médico.