Objective To characterize CD4+CD8+double-positive T ( DPT) cells in PBMCs from patients with tuberculosis(TB).Methods PBMCs were isolated from peripheral blood samples collected from patients with TB and healthy subjects.The subsets and percentages of CD4+T, CD8+T and DPT cells in PBMCs were determined by flow cytometry.Cell surface markers ( CD45RO, CCR7 and CD25 ) and intracellular cytokines ( IFN-γand TNF-α) were detected directly and after ESAT-6/PPD stimulation.Re-sults Patients with TB showed a significantly increased DPT cells as compared with the cured individuals and healthy subjects (P<0.005).The levels of DPT cells were gradually decreased down to normal upon the treatment of pharmacotherapy.DPT cells expressed higher levet of CD25 than CD4+T and CD8+T cells ( P<0.005 ) . DPT cells could express more IFN-γand TNF-αupon the stimulation of ESAT-6/PPD (P<0.005).The analysis of memory phenotype indicated that DPT cells were memory T cells.Conclusion DPT cells in peripheral blood of the patients with tuberculosis played a critical role in protective immunity against tuberculosis.The alterations of DPT cells in PBMCs during the period of pharmacotherapy might be a potential indicator for the prognosis of pulmonary tuberculosis.

Objective To study the relationship between HLA allele frequencies in peripheral blood mononuclear cells (PBMCs) and the susceptibility to tuberculosis in southern Chinese population. Methods The polymorphisms of HLA-A and HLA-DRB1 loci in the PBMCs were analyzed in 294 patients with active tuberculosis using polymerase chain reaction-sequence based typing (PCT-SBT). The allele frequencies in the patients were compared with the data from 644 control southern Chinese subjects obtained from the online database Allele Frequencies in Worldwide Population. Results The frequencies of HLA-A*0101 and HLA-DRB1*1454 alleles in the patient cohort with pulmonary tuberculosis were significantly higher than those in the control group (2.4％vs 0.6％,χ2=10.788, P=0.001, Pc=0.016;7.5％vs 0％,χ2=69.850, P<0.0001);the frequencies of HLA-DRB1*1202 and HLA-DRB1*1401 alleles were significantly lower in this patient cohort than in the control group (10.4％vs 16.1％,χ2=9.845, P=0.002, Pc=0.044;0％vs 3.1％,χ2=18.520, P<0.001). Conclusion The frequencies of HLA-A and HLA-DRB1 alleles are correlated with the susceptibility to active tuberculosis in this southern Chinese population. HLA-A*0101, HLA-DRB1*1454 and the other 3 alleles are likely susceptible genes to tuberculosis, while HLA-DRB1*1202, HLA-DRB1*1401 and the other 4 alleles can be protective genes in this population.

Objective To study the relationship between HLA allele frequencies in peripheral blood mononuclear cells (PBMCs) and the susceptibility to tuberculosis in southern Chinese population. Methods The polymorphisms of HLA-A and HLA-DRB1 loci in the PBMCs were analyzed in 294 patients with active tuberculosis using polymerase chain reaction-sequence based typing (PCT-SBT). The allele frequencies in the patients were compared with the data from 644 control southern Chinese subjects obtained from the online database Allele Frequencies in Worldwide Population. Results The frequencies of HLA-A*0101 and HLA-DRB1*1454 alleles in the patient cohort with pulmonary tuberculosis were significantly higher than those in the control group (2.4％vs 0.6％,χ2=10.788, P=0.001, Pc=0.016;7.5％vs 0％,χ2=69.850, P<0.0001);the frequencies of HLA-DRB1*1202 and HLA-DRB1*1401 alleles were significantly lower in this patient cohort than in the control group (10.4％vs 16.1％,χ2=9.845, P=0.002, Pc=0.044;0％vs 3.1％,χ2=18.520, P<0.001). Conclusion The frequencies of HLA-A and HLA-DRB1 alleles are correlated with the susceptibility to active tuberculosis in this southern Chinese population. HLA-A*0101, HLA-DRB1*1454 and the other 3 alleles are likely susceptible genes to tuberculosis, while HLA-DRB1*1202, HLA-DRB1*1401 and the other 4 alleles can be protective genes in this population.