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.

[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.

[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.

[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.

[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.

Specificity of lymphocytotoxic antibodies in AIDS and pre-AIDS patients.

The number of T helper and T suppressor cells (determined with monoclonal antibodies) and the presence of serum lymphocytotoxic antibodies with T helper and T suppressor specificities were determined in 3 AIDS and 10 pre-AIDS patients and in 6 healthy homosexual and 17 healthy heterosexual controls. The 13 patients were 8 homosexuals and 5 drug addicts. Lymphocytotoxic antibodies were detected in all of the symptomatic individuals (AIDS and pre-AIDS) but in only 1 (6%) of the healthy heterosexual controls. Lymphocytotoxic antibodies in the patients ranged in titer from 125 to 625. The antibodies were detected at 15, 20, and 37 degrees C, but the reactivity at 37 degrees C was 20 to 40% lower than at 15 degrees C. All of the patients' antibodies reacted with both T helper and T suppressor cells, but in 9 sera the reaction was higher with the T helper and T (p less than 0.05). No correlation could be found between the patients' level of T helper lymphocytes or T helper/T suppressor cell ratios and their levels of lymphocytotoxic antibodies (p greater than 0.1). Sera of 7 patients and 3 of 9 healthy heterosexual controls reacted with non-T mononuclear cells (B cells plus monocytes). The degree of cytotoxicity with these cells did not correlate with the levels of lymphocytotoxic antibodies to T cells.

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).

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.

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.

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.

[Changes in the serum immunoglobulin levels in mice with methylcholanthrene-induced fibrosarcoma]. / Cambios en los niveles séricos de immunoglobulinas en ratones con fibrosarcoma por metil-colantreno.

The serum immunoglobulin levels in mice with methylcholanthrene-induced sarcomas are studied. The results differ in the several groups of mice according to the localization of the tumor, and to the presence or absence of spleen.

[Gradually diminishing tumor protection caused by reimplants]. / Bradifilaxia tumoral por reimplantes.

Mice from which a MCA-induced sarcoma has been removed and which are exposed to repeated (every three months) tumoral cell transplants, gradually lose their protection against a certain threshold number of cells. Although the survival period after each transplant is longer than in non-protected animals (those that never received a primary tumor) it is seen that while some of them survive for three months (these are the ones to be re-inoculated with tumoral cells) others die. The proportion of mice which die rises with the number of inoculations received; and among those which die, the proportion of mice without localized tumor or neoplastic dissemination is also progressively higher. We do not know why these mice die at a later and cachectic stage without tumor but in a situation resembling a GVH (graft versus host) reaction. Repeated challenge through re-inoculation induces "bradyphylaxis" (progressively diminishing protection). On histopathological examination intense congestion is found, with haemorrhages in the lungs, liver, spleen and kidneys.

Antibodies to acquired immune deficiency syndrome (AIDS)-associated virus (HTLV-III/LAV) in Venezuelan populations.

Serum samples from 850 individuals from Venezuela were tested for the presence of antibodies to HTLV-III/LAV virus, the probable etiological agent of acquired immune deficiency syndrome (AIDS). At the time of the study, none of the individuals tested had symptoms indicative of AIDS or related disorders. Viral antibodies were assayed by indirect immunofluorescence (IF) assay, using a chronically infected, HTLV-III/LAV producer cell line CEM/LAV-NIT established in our laboratory. Twenty individuals (2.5%), 8 of them (40%) female, were seropositive by IF and by confirmatory Western blotting and radioimmunoprecipitation assays. The seropositivity rate ranged from 2.4% (11 of 465) in the general healthy population, 4% (2 of 50) among patients with Chagas' disease, and up to 29.2% (7 of 24) among patients with acute malaria infection. The titers of HTLV-III/LAV antibodies ranged from 1:40 to 1:640. In addition, 2 of 36 patients with hemophilia A (5.5%) also had antibodies to HTLV-III/LAV. Two of 7 patients with acute malaria had specific antibodies both to HTLV-III/LAV and HTLV-I, as determined by IF and Western blotting. None of over 169 randomly chosen, healthy blood donors from seven major Venezuelan cities, as well as none of 99 patients with leukemia/lymphoma, had antibodies to HTLV-III/LAV. The presence of specific antibodies among various Venezuelan populations indicates that HTLV-III/LAV, or a closely related cross-reactive virus, is indigenous in Latin American subjects as was previously indicated for tropical populations of central Africa. Isolation and characterization of this virus will help to understand the origin and etiology of AIDS.