Can immune parameters be used as predictors to distinguish between pulmonary multidrug-resistant and drug-sensitive tuberculosis?

INTRODUCTION: Despite the development and wide implementation of Directly Observed Therapy Strategies (DOTS), multidrug-resistant tuberculosis (MDR-TB) remains a serious global health threat. In this study, the role of host immune response in patients with MDR-TB is investigated and compared with that of patients with smear-positive drug-sensitive tuberculosis (SP-TB). MATERIAL AND METHODS: 27 patients with SP-TB, 20 patients with MDR-TB, and 20 healthy controls were included in the study. Immune parameters were determined by flow cytometry using monoclonal antibodies in order to compare the percentage values of these markers in the two study groups and the control group. RESULTS: The levels of lymphocyte subgroups in the gate of CD45(+)/CD14(–) lymphocyte: CD45(+), CD3(+), CD4(+), NK, CD3/HLA-DR, CD 95(+) cells were significantly lower; by contrast CD23(+), CD25(+), CD19(+), CD4(+)/CD8(+), HLA-DR cells were found to be lower, but not significantly so in patients with MDR-TB, compared to levels in patients in the SP-TB and control groups. Besides these findings, the levels of NKT cells and (γ)δ TCR(+) cells were significantly higher in the MDR-TB than in the healthy control and SP-TB group. CONCLUSIONS: The lower levels of CD3/ HLA-DR, CD4 (+), Fas (+), and NK, and the higher level of NKT together with (γ)δ T cells in patients with MDR-TB compared to those in SP-TB may indicate a profound immune suppression in MDR-TB patients and thereby may denote an accumulation in the bacterial load. Our findings may shed light on the pathogenesis and prognosis of MDR tuberculosis, and may point towards the use of flow cytometry findings as an aid to early diagnosis in MDR-TB patients.