Protein tyrosine phosphatase nonreceptor type 22 (PTPN22) gene polymorphism in pulmonary tuberculosis in the Indian population.

A variant of the protein tyrosine phosphatase nonreceptor type 22 (PTPN22) gene is known to be associated with susceptibility to autoimmune diseases and bacterial infections as it acts as an important regulator of T-cell activation. The objective of this study was to evaluate whether PTPN22-C1858T polymorphism is associated with the resistance to pulmonary tuberculosis (PTB). Single-nucleotide polymorphism of PTPN22-C1858T (rs2476601) was genotyped in 124 patients with PTB and 130 healthy controls from India using restriction fragment length polymorphism and direct sequencing of the amplified DNA. The frequencies of genotypes CC, CT, and TT were 100%, 0%, and 0%, respectively, in PTB; and 99.2%, 0.8% and 0%, respectively, in healthy control individuals. These values did not differ significantly between the patients and controls. The mutant allele C1858T was found to be a rare allele in Indian population.