Polymorphisms of the interferon gamma and interleukin 10 genes in human brucellosis

We genotyped 83 patients with brucellosis and 101 controls to determine the influence of polymorphisms of the interferon gamma (IFNG) and interleukin 10 (IL10) genes on protection against, or susceptibility to, human brucellosis and its complications. The results showed a significant increase in the IFNG +874A/A genotype in patients compared with controls (34% vs. 19%) (P = 0.023, odds ratio = 2.17, 95% confidence interval 1.05-4.51). No significant differences were detected in the frequency distribution of the IL10 genotypes between patients and controls. Similarly, no significant differences were observed in the genotype frequencies of either of the two cytokines between complicated and non-complicated forms of brucellosis. Persons who are homozygous for the IFNG +874A allele may have a higher risk of contracting brucellosis.