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.

Classical HLA alleles tag SNP in families from Antioquia with type 1 diabetes mellitus

Introduction: The HLA region strongly associates with autoimmune diseases, such as type 1 diabetes. An alternative way to test classical HLA alleles is by using tag SNP. A set of tag SNP for several classical HLA alleles has been reported as associated with susceptibility or resistance to this disease in Europeans. Objective: We aimed at validating the methodology based on tag SNP focused on the inference of classical HLA alleles, and at evaluating their association with type 1 diabetes mellitus in a sample of 200 families from Antioquia. Materials and methods: We studied a sample of 200 families from Antioquia. Each family had one or two children with T1D. We genotyped 13 SNPs using tetra-primer ARMS-PCR or PCRRFLP. In addition, we tested the validity of the tag SNP reported for Europeans in 60 individuals from a population of Colombians living in Medellín (CLM) from the 1000 Genomes Project database. Statistical analyses included the Hardy-Weinberg equilibrium, the transmission disequilibrium and the linkage disequilibrium tests. Results: The linkage disequilibrium was low in reported tag SNP and classical HLA alleles in this CLM population. Association analyses revealed both risk and protection factors to develop type 1 diabetes mellitus. Appropriate tag SNPs for the CLM population were determined by using the genotype information available in the 1000 Genome Project database. Conclusions: Although linkage disequilibrium patterns in this CLM population were different from those reported in Europeans, we did find strong evidence of the role of HLA in the development of type 1 diabetes mellitus in the study population.

Polimorfismos de un solo nucleótido representativos para los alelos clásicos del antígeno leucocitario humano en familias antioqueñas con diabetes mellitus tipo 1 / Classical HLA alleles tag SNP in families from Antioquia with type 1 diabetes mellitus

Resumen Introducción. La región del antígeno leucocitario humano (Human Leukocyte Antigen, HLA) se ha asociado claramente con enfermedades autoinmunitarias, como la diabetes mellitus de tipo 1. Los polimorfismos representativos de un solo nucleótido (tag Single Nucleotide Polymorphism, tag SNP) constituyen una forma alternativa de evaluar los alelos clásicos del HLA. En la población europea se ha reportado un grupo de tag SNP para múltiples alelos clásicos relacionados con la predisposición o la resistencia frente a dicha enfermedad. Objetivo. Validar la metodología basada en los tag SNP enfocada en la inferencia de alelos HLA clásicos, y evaluar su asociación con la diabetes mellitus de tipo 1 en una muestra de familias antioqueñas. Materiales y métodos. Se estudió una muestra de 200 familias antioqueñas con uno a dos hijos afectados por diabetes mellitus de tipo 1. Se genotipificaron 13 SNP mediante el ARMS-PCR (Amplification Refractory Mutation System-Polymerase Chain Reaction) con cuatro iniciadores, o mediante la PCR-RFLP (PCR-Restriction Fragment Length Polymorphism). Además, se evaluó la validez de los tag SNP de 1.000 genomas reportados en europeos en una muestra de 60 individuos de la población colombiana de Medellín. Se hicieron las pruebas de desequilibrio de la transmisión, de desequilibrio de ligamiento y de equilibrio de Hardy-Weinberg. Resultados. En la población de estudio no se encontró suficiente desequilibrio de ligamiento entre los SNP y los alelos clásicos evaluados, por lo cual no fue posible inferir los alelos clásicos del HLA para el conjunto de familias con diabetes mellitus de tipo 1. El estudio de asociación evidenció que esta región aporta factores tanto de riesgo como de protección para el desarrollo de la enfermedad. Los tag SNP apropiados para la muestra de estudio se determinaron usando los SNP ubicados en la región HLA en la base de datos del 1000 Genomes Project en la mencionada población. Conclusiones. Los patrones de desequilibrio de ligamiento en la población estudiada fueron diferentes a los reportados para la población europea. A pesar de esto, se encontró evidencia clara sobre el papel de la región HLA en el riesgo de padecer diabetes mellitus de tipo 1 en la población de estudio.

abstract Introduction: The HLA region strongly associates with autoimmune diseases, such as type 1 diabetes. An alternative way to test classical HLA alleles is by using tag SNP. A set of tag SNP for several classical HLA alleles has been reported as associated with susceptibility or resistance to this disease in Europeans. Objective: We aimed at validating the methodology based on tag SNP focused on the inference of classical HLA alleles, and at evaluating their association with type 1 diabetes mellitus in a sample of 200 families from Antioquia. Materials and methods: We studied a sample of 200 families from Antioquia. Each family had one or two children with T1D. We genotyped 13 SNPs using tetra-primer ARMS-PCR or PCRRFLP. In addition, we tested the validity of the tag SNP reported for Europeans in 60 individuals from a population of Colombians living in Medellín (CLM) from the 1000 Genomes Project database. Statistical analyses included the Hardy-Weinberg equilibrium, the transmission disequilibrium and the linkage disequilibrium tests. Results: The linkage disequilibrium was low in reported tag SNP and classical HLA alleles in this CLM population. Association analyses revealed both risk and protection factors to develop type 1 diabetes mellitus. Appropriate tag SNPs for the CLM population were determined by using the genotype information available in the 1000 Genome Project database. Conclusions: Although linkage disequilibrium patterns in this CLM population were different from those reported in Europeans, we did find strong evidence of the role of HLA in the development of type 1 diabetes mellitus in the study population.

[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.

Tratamiento integral con prótesis parcial fija y cirugía maxilofacial en paciente con bruxismo / Comprehensive treatment with fixed partial prosthetic restoration and maxillofacial surgery in patients with bruxism

El propósito de este caso clínico es mostrar la relación que se puede generar entre tratamientos protésicos y cirugía maxilofacial sin ortodoncia previa, en un paciente bruxómano severo, con micrognatismo mandibular, desarmonía oclusal, pobre estética, patología articular y desgastes dentarios severos. Un año después de terminada la rehabilitación se encuentra un resultado óptimo, estable y biológicamente aceptable...