Interleukin-12B & interleukin-10 gene polymorphisms in pulmonary tuberculosis

Background & objectives: Cytokines play an important role in anti-tuberculosis immune response. Skewing of immunity from protective to pathogenic may involve a shift in Th1-Th2 paradigm. Cytokine gene polymorphism is known to be associated with functional differences in cytokine regulation and altered clinical performance in a variety of diseases. The aim of this study was to know whether Interleukin-12B 3’ UTR (Taq1) (A/C) and Interleukin-10 (-1082 G/A) gene polymorphisms were associated with susceptibility to pulmonary tuberculosis. Methods: IL -10 (-1,082 G/A) and IL-12B gene polymorphisms were studied in132 pulmonary TB (PTB) patients and 143 normal healthy subjects (NHS), using DNA based polymerase chain reaction (PCR) with sequence specific primers and restriction digestion. Results: The allelic as well as genotypic frequencies of Interleukin -10 (-1082) and Interleukin -12B (3’UTR Taq 1) did not differ significantly between the patients and controls. Interpretation & conclusion: Our findings suggested that IL -10 (-1082 G/A) and IL -12B 3’UTR (Taq I) (A/C) gene polymorphisms were not associated either with susceptibility or resistance to pulmonary tuberculosis in the south Indian population

Elevated percentage of perforin positive cells in active pulmonary tuberculosis

Background & objectives: Perforin is one of the major effector molecules of cytotoxic cells associated with killing of cells harbouring intracellular bacterial infection. The precise role of perforin positive cells in tuberculosis still remains controversial. The present study was done to determine the number of circulating CD4+ and CD8+ perforin positive cells to assess the level of cytotoxic response against Mycobacterium tuberculosis in patients with pulmonary tuberculosis. Methods: Intracellular perforin and surface CD4 and CD8 staining of peripheral blood lymphocytes was done using specific monoclonal antibodies and enumerated using flowcytometry. Results: A significantly decreased total lymphocytes (P<0.01), CD4 (P<0.001) and CD8 (P<0.01) lymphocyte counts in PTB patients was observed compared to normal healthy individuals (NHS). Intracellular perforin staining showed significantly elevated percentages of total (P<0.05) and CD8 (P<0.01) perforin positive cells in PTB patients compared to NHS. However, the absolute counts of total, CD4 and CD8 cells positive for perforin were similar in patients and NHS. Interpretation & conclusion: Our results suggest that during active stage of pulmonary tuberculosis there was an increased percentage of CD8 cells positive for perforin, irrespective of their absolute counts. Further, CD8+ perforin positive cells ma