Association of Cytokine Gene Polymorphisms in Patients with Tuberculosis and Their Household Contacts

Cytokine gene polymorphisms are known to be associated with functional differences in cytokine regulation and may affect host susceptibility to tuberculosis (TB). Contacts are important group in developing tuberculosis infection and are 10–60 times more likely to develop TB than general population. The present study was carried out in patients with TB (N = 176), their household contacts (HHC; N = 155) from Free Chest TB Clinic PPM DOTS (1TU) covering 500,000 population at Mahavir Hospital and Research Centre, Hyderabad, and healthy controls (HC; N = 170) also included. The association of single‐nucleotide polymorphisms (SNPs) in the promoter region of TNF‐α (−308G/A), IL‐2 (−330T/G), IL‐4 (−589C/T) and in exon region of TGF‐β1 (+869T/C) genes was assessed by ARMS & PCR‐RFLP using specific primers in the above‐mentioned subjects. The differences in allelic or genotypic frequencies of TNF‐α (−308G/A) between patients, their HHC and HC were not statistically significant (P > 0.05). IL‐2 (−330T/G) TG genotype was significantly different between patients, HHC compared to HC (P