RESUMO
Objective To evaluate Mycobacterium tuberculosis (M. tuberculosis)-specific cellular immunity in individuals with latent or active tuberculosis and human immunodeficiency virus (HIV) coinfection. Methods One hundred HIV-infected individuals in Yunnan Province were enrolled. The enzyme-linked immunospot (ELISPOT) assay using early secreted antigenic target (ESAT)-6 and culture filtrate protein (CFP)-10 was employed to detect M. tuberculosis-specific T cells in the peripheral blood. The absolute number of CD3+ CD4+and CD3+ CD8+ T cells in the peripheral blood from the enrolled subjects were determined by flow cytometry. Data were analyzed using nonparametric Mann-Whitney test. Results The prevalence of latent tuberculosis co-infection in HIV-infected individuals without any clinical evidence of active tuberculosis was 67.6%. The absolute numbers of CD3+ CD4+ (532 × 106/L) and CD3+ CD8+ (473 × 106×/L) T cell in HIV-infected individuals with latent tuberculosis co-infection were similar to those of only HIV-infeeted individuals (406 ×106×/L and 504 × 106/L). While those in HIV-infected individuals with active tuberculosis co-infection were 189 × 106/L and 293 × 106/L, respectively, which were both significantly lower than those in other two groups (U=168. 0,U=163. 0,U= 374. 0,U=147. 0, all P<0. 01). Furthermore, ESAT-6 (31/106 cells) and CFP-10 (82/106 cells) specific spot-forming cells in HIV-infected individuals with active tuberculosis co-infection were significantly less than those in HIV-infected individuals with latent tuberculosis co-infection (92 × 106 cells and 109 × 106 cells, U= 507. 0,U= 529. 5, both P<0. 01). Conclusions The prevalence of latent tuberculosis in HIV-positive individuals without any clinical evidence of active tuberculosis is high in China. Both overall cellular immunity and M. tuberculosis-specific immune response in HIV-positive individuals with active tuberculosis co-infection are severely impaired.
RESUMO
Objective To investigate the genotypic characteristics of hepatitis B virus(HBV) in Tibet.Methods Serum samples from 60 cases of hepatitis B in Tibet Autonomous Region were collected from January 2000 to March 2004.HBV genotypes were analyzed by sequencing S region and precore/core region.Results HBV isolated from 60 cases were all found to be D genotype by S region sequencing.Dc mixture was found in 59 cases,showing the recombination between their precore/core gene and genotype B virus at 1804-2299 nucleotide.The other one case showed Dbc mixture genotype,showing recombination between its precore/core gene and genotype B and C genes.Conclusions All Tibet cases in this study show mixture genotype D with recombination with genotvpe C or both genotype B and C at precore/core region.No case of pure genotype D is found.