Cytokine gene polymorphisms and cytokine levels in pulmonary tuberculosis.

Selvaraj, P.; Alagarasu, K.; Harishankar, M.; Vidyarani, M.; Rajeswari, D.N.; Narayanan, P.R.

Cytokine; 2008; 43; 26-33.

Abstract: Polymorphisms in the cytokine genes are known to influence cytokine levels and may be associated with outcome of infections. We investigated the polymorphisms in the cytokine genes namely IFN- g (+874 and +5644), IL-2 (-330 and +160), IL-4 (VNTR), IL-6 (-174), IL-10 (-1082 and -819) and IL-12B (+1188) in 188 normal healthy subjects (NHS) and 166 pulmonary tuberculosis patients (PTB) using polymerase chain reaction-based methods. To study the influence of cytokine gene polymorphisms on cytokine levels, phytohaemagglutinin and culture filtrate antigen of Mycobacterium tuberculosis -induced cytokine levels were measured by ELISA from 72-h-old peripheral blood mononuclear cell culture supernatants. Significantly decreased frequency of TT genotype of IL-2 -330 polymorphism ( p = 0.024, odds ratio (OR) 0.53, 95% CI 0.31–0.92) was observed in patients compared to NHS. The genotype frequencies of other polymorphisms were not different between patients and NHS. IL-12p40 levels were significantly decreased among NHS with AA genotype of IL-12B gene polymorphism compared to NHS with AC genotype ( p < 0.05). Increased levels of IL-12p40 were observed among patients with CC genotype of IL-12B gene compared to patients with other genotypes ( p < 0.01). The present study suggests that the TT genotype of IL-2 -330 polymorphism may be associated with the protection to PTB in south India. Further, +1188 polymorphism of IL-12B gene either alone or in combination with closely linked genes may regulate IL-12p40 production and may play a major role on acquired immunity to tuberculosis.

Keywords: Tuberculosis, Gene polymorphsims, cytokines

Back to List of publications / Home