Association of mycobacterial antigen-specific CD4+ memory T cell subsets with outcome of pulmonary tuberculosis

Objectives: Memory T cells are hallmark of acquired immunological responses. The relationship of mycobacterial antigen-specific CD4(+) memory T cell subsets with pulmonary tuberculosis was investigated. Methods: The mycobacterial antigen-specific CD4(+) T cells were detected based on CD154 expression and phenotypes of memory T cell were analyzed by surface staining of CD45RA and CCR7 and flow cytometrical analysis in patients with pulmonary tuberculosis and in tuberculin-positive healthy controls. The association of antigen-specific CD4(+) memory T cell subsets with disease severity and anti-TB treatment was analyzed in patients with pulmonary tuberculosis. Results: Patients with pulmonary tuberculosis had significantly lower frequencies of antigen-specific central memory T cells (T-CM) (p = 0.019) and higher frequencies of effector memory T cells (T-EM) (p = 0.022) compared with tuberculin-positive healthy controls without tuberculosis. Patients with smear/culture positive results showed lower population frequencies of T-CM and significantly higher frequencies of T-EM (p = 0.015) than those with smear/culture negative results. Treatment of TB patients with standard antibiotic regimens for more than one month led to significantly increased frequencies of T-CM (p = 0.031). Conclusions: The frequencies of mycobacterial antigen-specific T-CM and T-EM are associated with disease severity of pulmonary tuberculosis and T-CM are associated with short-term effects of anti-TB chemotherapy. (C) 2009 The British Infection Society. Published by Elsevier Ltd. All rights reserved.