The relationship between CD4+ T lymphocyte count and Mycobacterium tuberculosis coinfection in human immunodeficiency virus-infected patients / 中华传染病杂志

ABSTRACT

Objective To evaluate the relationship between CD4+ T lymphocyte count and results of enzyme-linked immunospot (ELISPOT) assay in human immunodeficiency virus (HIV)-Mycobacterium tuberculosis (M.tb) coinfected patients.Methods A total of 193 HIV-infected individuals in Yunnan Province and Shanghai were enrolled.T-SPOT.TB assay was employed to detect M.tb specific T lymphocyte in the peripheral blood mononuclear cells (PBMC).CD4+ T lymphocyte in PBMC from the enrolled subjects was detected by flow cytometry.Data were analyzed using t test.ResultsThe incidence of latent tuberculosis in HIV-infected individuals was 30.6％.The CD4+ T lymphocyte counts in HIV-infected individuals with active tuberculosis were 190×106/L,which were significantly lower than those in HIV-infected individuals with latent tuberculosis (484×106/L; t=6.665,P＜0.01).The HIV-infected individuals were stratified according to CD4+ T lymphocyte counts of ＞500×106/L,200×106-500×106/L,and ＜200×106/L and the constituent ratios of active tuberculosis/latent tuberculosis were 1∶16.2,1∶1.3 and 5.6∶1,respectively.Among 79 subjects with positive T-SPOT.TB results,20 were coinfected with active tuberculosis,in which 14 had CD4+ T lymphocyte counts of ＜200 ×106/L,5 had 200×105-500×106/L and 1 had ＞500×106/L.Fifty-two in 59 HIV/latent tuberculosis patients individuals had CD4+ T lymphocyte counts of ＞200×106/L.ConclusionsThe prevalence of latent tuberculosis in HIV-infected individuals is high in China.Cellular immunity in HIV-infected individuals with active tuberculosis is severely impaired.With the decrease of CD4 ′ T lymphocyte counts,patients with latent tuberculosis are prone to develop active tuberculosis in HIV-infected individuals.The negative predictive value of T-SPOT.TB is significantly diminished in patient with low CD4+ T lymphocyte counts,especially less than 200×106/L.