T cell receptor V-segment frequencies in peripheral CD8+ T cells in aging.

Infections are a major cause of illness and death amongst elderly people. Peripheral blood CD8+ T lymphocytes --which play a crucial role in host defence against viral infections--, are divided in subsets based upon the expression of several cell and activation markers. In senescence changes and variations in peripheral CD8+ T lymphocyte compartment have been described, and such a decrease in the CD8+CD45RA+ lymphocytes. In this report the T V alpha and Vbeta cell specificities repertoire usage in aging subjects were studied by the use of seven different monoclonal antibodies specific for defined regions of the TCR. Except for the Vbeta6subfamily, no differences between old and control subjects in frequency of T cells bearing selected V alphabeta epitopes, were observed.

[High- and low-risk molecular sequences in autoimmune diseases. An analysis of type I diabetes in Latin America]. / Secuencias moleculares de alto y bajo riesgo en enfermedades autoinmunes. Un análisis de la diabetes tipo I en Latinoamérica.

Type I diabetes is an autoimmune and a polygenic disease, in which MHC-class II genes contribute to 48% of the disease. The aim of the present study, is to provide a guideline to understanding the molecular association of these genes, through the immunogenetic analysis of 3 Latin american mestizo populations. We included 606 individuals, 349 patients with DMDI and 257 healthy controls coming from 3 geographical areas: Mexico City, Mexico; Caracas, Venezuela and Medellin, Colombia. The results clearly indicate that in mestizo groups, the diabetogenic haplotypes are from mediterranean ancestry, while protection is due to Amerindian genes. It was demonstrated that the relevant sequences for IDDM expression are located to DRB1 and DQB1 loci with a minimal contribution of DQA1 residues. The sequences determining peptide recognition and the induction of TH1 cells mediating the cellular autoimmune response are in positions DRB1-57 and 74 (an aspartic acid and a glutamic acid respectively, confer protection), modulated by D-57 in the DQ, 8 chain. These data show that DRB1-DQB1 haplotypes are central for IDDM expression and open new pathways for the disease management.

Secuencias moleculares de alto y bajo riesgo en enfermedades autoinmunes. Un análisis de la diabetes tipo I en Latinoamérica / High and low risk molecular sequences in autoinmmune diseases. An analysis of type I diabetes in Latin America

La diabetes tipo I es una enfermedad autoinmune, poligénica con una contribución del 48 por ciento de los genes MHC Case II. El objeto de este trabajo es proveer una explicación para las asociaciones moleculares de dichos genes, mediante el análisis de la inmunogenética de 3 poblaciones mestizas de Latinoamérica. Se estudiaron un total de 606 individuos, 349 pacientes con DMDI y 257 sujetos sanos de tres localidades México DF, Caracas, Venezuela, Medellín, Colombia. Los resultados indican que en los grupos mestizos, los haplotipos diabetogénicos son de contribución mediterránea y que la mayoría de los hoplatipos de protección son de origen indígena. Se demostró que las secuencias relevantes en la expresión de la enfermedad están en los loci DRB1 y DQB1, con un aporte mínimo de DQA1 y que las secuencias relevantes en el reconocimiento del péptido y en la inducción de las células Th1 mediadoras de la activación de la respuesta celular, están localizadas en DRB1-57 y 74 (la presencia de ac. aspártico y ac. glutámico confieren resistencia), moduladas por la presencia de D-57 en DQp del antígeno DQ. Estos datos demuestran la participación de DRB1-DQB1 en la enfermedad y abren caminos para un nuevo manejo de la DMDI

Neutrophil function in elderly persons assessed by flow cytometry.

It is well known that the immune response declines with senescence and it is suggested that these changes render an individual susceptible to infection, autoimmune phenomena and cancer. Bacterial and viral infections are a major cause of illness and death amongst aged subjects, and once infection is established, the elderly also have a diminished capacity to prevent its spread (1). The cellular and molecular basis for this age-related decline in immunocompetence are still unknown and, possibly, are related to an alteration in cell transduction mechanisms (2).

T cell receptor V-segment frequencies in aged individuals.

The T V alpha and V beta cell specificities repertoire usage in aging subjects was studied by the use of seven different monoclonal antibodies specific for defined regions of the T cell receptor (TCR). Except for the V beta 8 subfamily, no differences were observed in the frequency of T cells bearing selected V alpha beta epitopes, between old and control subjects.

CD8+ T cell subsets in aging.

Infections are major cause of illness and death amongst elderly people. Peripheral blood CD8+ T lymphocytes -which play a crucial role in host defence against viral infections-. are divided in subsets based upon the expression of several cell and activation markers. Since in senescence changes in peripheral blood CD8+ T lymphocyte compartment have been described, studies were performed to determine whether in aging there are variations in the peripheral blood CD8+CD38+, CD8+CD57+, CD8+HLA-DR+, CD8+CD45RA+ and CD8+CD45RO+ cell subset. A decrease in the CD8+CD45RA+ lymphocytes was observed, indicating that variations in the CD8+ compartment can take place with ageing.

Distribution of the HLA-DQA1 polymorphism in the population of the Basque Country (Spain).

Allele and genotype frequencies at the HLA-DQA1 locus were determined in Basque Country populations using PCR methodology and a dot-blot assay with ASO probes. The results showed no deviation from the Hardy-Weinberg equilibrium. No differences were found between the three Basque Provinces, but gene frequencies were significantly different from those of some other Spanish and world populations.

HTLV-I/II infections in Spain. The HTLV-I/II Spanish Study Group.

Antibodies to HTLV-I/II were investigated in sera from 7521 individuals living in Spain. They were classified in four major groups: a) subjects at high risk of retroviral infections e.g. parenteral drug addicts, homosexuals, prostitutes, and multiple-transfused individuals; b) patients suffering illness associated with HTLV-I in endemic regions; c) immigrants from endemic areas; and d) blood donors. Sera were collected from 1984 to December 1991. Repeatedly reactive ELISA was found in 211 samples (2.8%), but Western blot only confirmed the presence of HTLV-I/II antibodies in 23 samples (0.30%), corresponding to eight (0.25%) out of 3207 drug abusers, six (0.72%) out of 894 immigrants (five Africans and one South American), three (0.41%) out of 727 patients with HTLV-related diseases (one woman with HTLV-I associated myelopathy had received blood transfusions in an endemic area), four (0.54%) out of 793 prostitutes, one multiple-transfused native woman, and one (0.16%) out of 603 native seamen. The Western blot antibody pattern confirmed HTLV-II infection instead of HTLV-I in nine (39%) subjects. The remaining 14 (61%) HTLV-reactive samples were interpreted as HTLV-I seropositive, most of which were from immigrants. None of 857 blood donors analysed was reactive for HTLV antibody. These results suggest that both HTLV-I and HTLV-II are present in Spain, although at a low rate and mostly restricted to individuals coming from endemic areas, drug addicts, and prostitutes. Furthermore, diseases related to HTLV-I (particularly lymphoproliferative disorders, and subacute myelopathies) seem to be rarely associated with these viruses in Spain, a non-endemic area.

Epidemiology and inmunogenetics in recently diagnosed Venezuelan children with insulin-dependent diabetes mellitus.

Genetic and immunological markers in children with Type I diabetes have not been studied previously in Venezuela. We evaluated 91 newly diagnosed IDDM children mean age 7.8 +/- 4.5 (range 0.8-20.8 years), 51 females and 40 males. Eleven percent of first degree relatives had a family history of Type I IDDM; 56.7% had had upper respiratory infection prior to diagnosis and 12.7% had had either mumps or varicella. Peak incidence of disease was found in February and March and August to October. Eighty seven percent had HLA-DR3 and/or DR4 vs 36% of the Venezuelan general population; 81.6% were HLA-DQW2 and/or HLA-DQW8. We found 55.9% to have positive islet cell antibodies (ICA) with 4 of these having a positive complement fixation test. Three patients (7.9%) were found to have positive insulin autoantibodies. Only 3 out of 11 HLA-identical siblings had positive ICAs, while none had positive insulin autoantibodies. One of them also had a positive complement fixation test; this subject developed IDDM. No positive serotypes for enterovirus (Coxsackie-B) were found in our patients, but we detected 11 cases with elevated titers for cytomegalovirus antibodies and positive antibodies for measles, mumps, herpes and varicella were found in some children. These data confirm that most of our Type I diabetics carry HLA-DR3 or DR4 and that the heterozygous DR3/DR4 phenotype is markedly increased in this population; they also indicate that DR3QW2 and DR4QW8 are associated with increased risk in our population.

[Human immunodeficiency virus infection in the Spanish population. Review of the literature]. / Infección por el virus de la inmunodeficiencia humana en la población española. Revisión de la literatura.

The epidemiological aspects of the infection by the human immunodeficiency virus, HIV, in the Spanish population as described in the literature are reviewed. From the published studies is evident that HIV infection is limited to the population risk groups established in the epidemiological world reports, heroin addicts, homosexuals, heterosexuals with sexual contacts with infected persons and blood and hemoderivates receptors. The observed frequencies in these risk groups are similar to that described in other countries.

[Human immunodeficiency virus (HIV) infection in País Vasco, Spain]. / Infección por el virus de inmunodeficiencia humana (VIH) en el País Vasco, España.

An analysis of the epidemiology of the human immunodeficiency virus infection in the Basque Country, Spain is presented. The infection by this virus is mainly detected in intravenous drug addicts. In homosexuals the seropositivity frequency detected was moderate, and infection was also detected in sexual partners of drug addicts.

[Diseases in heroin addiction]. / Patologías médicas en la adicción a la heroína.

An analysis of the medical pathologies seen in heroin addicts heroin addicts hospitalized in the Provincia de Vizcaya, Basque Country, Spain, from 1982 to 1987, and its possible association to the infection by the human immunodeficiency virus, HIV, is presented. An increasing of hospitalized addicts per year was observed, being infectious diseases the main pathology detected. HIV infection was present in more than 90% of individuals with non opportunistic acquired infections. Significant annual increase in the number of tuberculosis and candida infections was present. The possible association of HIV infection with increased susceptibility to commonly acquired non opportunistic infections is discussed.

[Epidemiologic aspects of acquired immunodeficiency syndrome (AIDS). Review]. / Aspectos epidemiológicos del sindrome de immunodeficiencia adquirida (SIDA). Revisión.

A revision of the World current epidemiological aspects of the acquired immunodeficiency syndrome is presented. It was observed that near 70% of all the world cases occurred in the United States of America and 12% in Europe. There is an increase tendency of the number of cases. However, the analysis of the inter-annual percentage increase showed a tendency to stabilization in Europe and in the United States of North America.