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V Monteón

Publications and source records attributed to V Monteón.

6 recordsLinked to original sources
PubMed1997

Circulating lymphocyte subpopulations and activated T and B cells in patients with chagasic and non-chagasic myocardiopathy.

Trypanosoma cruzi causes a profound immune depression in the infected host, and a small proportion of chagasic patients will develop a chronic disease characterized by myocardiopathy. There is evidence suggesting that dilated non-chagasic cardiomyopathy may be mediated by an immunological mechanism. In an attempt to distinguish abnormal immunoregulatory cell patterns in both dilated myocardiopathies, total and activated T and B lymphocyte subpopulations were measured by flow cytometry and double-labeling in whole blood samples from patients with dilated myocardiopathy, 10 with positive serological tests for T. cruzi and 9 with different non-chagasic cardiomyopathies. Several significant differences were found between both groups of patients and 13 sex- and age-matched apparently healthy controls. Chagasic patients besides showing clear decrease in absolute numbers of CD3+/CD71+ and CD8+/CD25+ cell populations also had a significant increase in CD19+, CD10+, and CD19+/HLA-DR+ cell subsets, as well as high helper/ suppressor cell ratio. These findings suggest that concurrently with T cell diminution, which involved activated T lymphocytes displaying suppressor/cytotoxic immunophenotype, chronic chagasic patients with myocardiopathy showed elevated numbers of total and activated B lymphocytes. Patients with dilated non-chagasic myocardiopathy had significantly increased numbers of activated T cells (CD3+/CD25+, CD8+/CD25+, and CD8+/HLA-DR+) and total and activated B lymphocytes (CD10+, CD19+, CD19+HLA-DR+). These data support the notion that dilated myocardiopathies other than the chagasics may be associated with immunological abnormalities.

Adult↗
PubMed1997

Analysis of IgG subclasses of human antitopoisomerase I autoantibodies suggests chronic B cell stimulation.

Antitopoisomerase I autoantibodies are highly specific of scleroderma and are mainly IgG. The present study was designed to evaluate the prevalence of each IgG antitopoisomerase I subclass. An ELISA for the detection of IgG antitopoisomerase I subclasses was standardized and used to study the antibodies from 49 antitopoisomerase I-positive patients identified from a total of 541 patients. Correlations and multivariate analysis were performed to determine the frequency of associations between the IgG antitopoisomerase I subclasses. All IgG antitopoisomerase I subclasses were found. Twelve patients (24.5%) had all four IgG antitopoisomerase I subclasses, 13 (26.5%) had three, 16 (32.7%) had two, and 7 (14.3%) had only one antitopoisomerase I subclass. The presence of all four IgG antitopoisomerase I subclasses suggests that this specific B-cell is the target of multiple activation pathways which indicate that there is a complex T-cell-cytokine-driven process. Together with the absence of other autoantibodies in these sera, our results support the concept of a multiple but highly selected and chronic B-cell activation in scleroderma patients with antitopoisomerase I.

Adult↗
PubMed1996

Organ-specific circulating heart autoantibodies in Chagas' cardiomyopathy: exploratory study.

Chagas' disease can evolve to a chronic phase with cardiomyopathy that may include autoimmune mechanisms, among others. Recently an organ-specific anti-heart muscle antibody was detected in idiopathic cardiomyopathy, using human heart muscle as antigen. We decide to standardize an indirect immunofluorescence assay using rat organs in order to evaluate frequency of organ-specific anti-heart antibodies in chagasic cardiomyopathy. We tested 18 patients with chagasic cardiomyopathy for serum organ-specific anti-heart muscle antibodies. Nine patients were positive for organ-specific anti-heart antibodies (positive in heart muscle but negative in tongue muscle) and one was positive for non-organ-specific anti-heart muscle antibodies (positive in both heart and tongue muscle). We conclude that organ-specific anti-heart muscle antibodies can be detected using rat organs as antigens. Organ-specific anti-heart muscle antibodies are present in patients with chagasic cardiomyopathy.

Adult↗
PubMedDate not supplied

Standardization of micro-enzyme-linked immunosorbent assay (ELISA) and Western blot for detection of Trypanosoma cruzi antibodies using extracts from Mexican strains as antigens.

BACKGROUND: This report describes two assays for the detection of anti-Trypanosoma cruzi antibodies using Mexican strains of the parasite and the concordance with two assays previously evaluated at the Instituto Nacional de Cardiología Ignacio Chávez in Mexico City. METHODS: Micro-enzyme-linked immunosorbent assay (ELISA) and Western blot were used for the detection of T. cruzi antibodies with a total extract of epimastigote from Ninoa and Queretaro, which are Mexican strains of T. cruzi. To standardize these methods, a total of 246 serum samples was used. In addition, sera from six confirmed Mexican chronic individuals in the asymptomatic phase were also used for comparison with the Argentinean antigen. RESULTS: ELISA was 100% specific in that no false positive results were found with sera of both healthy individuals and non-Chagasic cardiopaths. Sera from individuals infected with Leishmania sp. showed approximately 16% of cross-reaction with ELISA. The test showed a positive predictive value of 90% and a negative predictive value of 100%. Western blot was also a highly sensitive test for detecting chronic Chagasic symptomatic patients from Mexico because no false negative results were obtained. Furthermore, it was possible to use Western blot to detect seven immunodominant antigens of approximately 30, 32, 40, 42, 65, 70, and 83 kDa. Concordance with two previous standardized tests at the Instituto Nacional de Cardiología showed a Kappa index of 0.96, indicating high concordance between the results obtained at these two laboratories. Finally, ELISA using Ninoa antigen extract was more sensitive than ELISA with an Argentinean extract, which failed to detect individuals in the chronic asymptomatic phase (undetermined phase) of infection. CONCLUSIONS: This study indicates that ELISA and Western blot using Ninoa and/or Queretaro extracts of T. cruzi as antigens are useful tools in the detection of individuals who have been exposed to T. cruzi both in the undetermined/asymptomatic and symptomatic phases. More concordance studies such as this are recommended to obtain an accurate Chagas diagnostic test and to determine the real prevalence of this disease in Mexico.

Animals↗