Asociación de la tuberculosis pulmonar con los antígenos del sistema HLA en el Noreste de México / Association of pulmonar tuberculosis with HLA system antigens in Northeastern Mexico

Antecedentes: La susceptibilidad genética a tuberculosis pulmonar (TbP) ha sido asociada al sistema HLA (antígenos de los leucocitos humanos) del MHC (complejo mayor de histocompatibilidad), principalmente con los antígenos HLA-DR y -DQ. Dado lo anterior, el objetivo de este estudio caso-control no pareado, fue determinar la asociación de TbP con los antígenos HLA-DR y -DQ en pacientes que asistían a una unidad médica del IMSS. Métodos: Los fenotipos del sistema HLA de casos (n=50) y controles (n=417), se definieron serológicamente por la técnica de microlinfocitotoxicidad dependiente de complemento. Los linfocitos B fueron obtenidos utilizando inmunoperlas. Las frecuencias alélicas y haplotípicas, equilibrio de Hardy-Weinberg y el desequilibrio de ligamiento, se determinaron mediante el programa computacional Arlequín versión 3.01, y el riesgo relativo (RR) mediante el programa Epimax Table Calculator. Resultados: Los alelos HLA-DR11(5), -DR16(2) y -DQ7(3) y los haplotipos /DR11(5)-DQ7(3), /DR14(6)-DQ5(1) y /DR16(2)-DQ7(3) fueron más frecuentes en casos que en controles (RR>1, p<0.05). Los alelos HLA-DR17(3) y DQ8(3) y los haplotipos /DR17(3)-DQ2 y /DR4-DQ8(3) fueron más frecuentes en controles que en casos (RR<1, p<0.05). Conclusiones: Estos resultados sugieren asociación entre TbP y HLA-DR y -DQ en esta población mestiza mexicana y son similares a los encontrados en otros estudios caso-control no pareados a nivel mundial.

BACKGROUND: Genetic susceptibility to pulmonary tuberculosis (PTb) has been associated with the HLA (Antigens of the Human Leukocytes) system of the MHC (Major Histocompatibility Complex), mainly with HLA-DR and-DQ antigens. Based on this assumption we carried out a case control study to determine the association of PTb with the HLA-DR and-DQ antigens among a sample of patients attending a medical unit belonging to the Mexican Social Security System (IMSS). METHODS: HLA system phenotypes from cases (n=50) and controls (n=417), were defined serologically using a complement dependent microlymphocytotoxic assay. B lymphocytes were obtained using immunobeads. The allele and haplotype frequencies were determined using the Arlequin version 3.01 computer software. Relative risk (RR) was calculated with the Epimax Table Calculator. RESULTS: The alelles HLA-DR11(5), -DR16(2) and -DQ7(3) and haplotypes /DR11(5)-DQ7(3), /DR14(6)-DQS(1) and /DR16(2)-DQ7(3) had a higher frequency in cases than in controls (RR>1, p<0.05). The HLA-DR17(3) and DQ8(3) alelles and /DR17(3)-DQ2 and /DR4-DQ8(3) haplotypes had a higher frequency among controls than among cases (RR<1, p<.05). CONCLUSIONS: These results indicate an association between PTb with the HLA-DR and -DQ antigens in a Mexican sample. Our results are similar to those found in the international literature.

Seroprevalence of HTLV-I/II in blood donors in Monterrey, México

The prevalence of antibiodies against human T-cell lymphotrophic virus (HTLV-I/II) in blood donors from the city of Monterrey, Mexico was investigated. We found that 4 out of 1017 sera (0.39 percent) reacted against HTLV-I/II, as determined by a passive agglutination test (PA). However, none of PA-positive sere reacted to HTLV-I/II specific polypeptides as demostrated by Western blot. These findings indicate that the population of Monterry has very low or no seroprevalence for HTLV-I/II