BACKGROUND: The PTPN22 gene encodes Lyp, a phosphatase involved in downregulating T-cell receptor signaling and modulating immune homeostasis. Although PTPN22 polymorphisms rs2476601 (R620W) and rs33996649 (R263Q) are associated with autoimmune diseases, their role in infectious diseases such as tuberculosis susceptibility remains unclear. OBJECTIVE: To evaluate the association of PTPN22 polymorphisms with TB susceptibility and assess their functional relevance through gene expression profiling in a South Asian cohort. METHODOLOGY: PTPN22 polymorphisms and expression in 111 TB patients and 85 controls were analyzed by ARMS-PCR and RT-qPCR, with association and predictive analyses performed using logistic regression, ROC, LD (Haploview), and SPSS v26. RESULTS: A significant association was observed between the rs33996649 C/T genotype and increased TB susceptibility (p 0.05), possibly reflecting compensatory immune regulation in variant carriers. CONCLUSION: The PTPN22 rs33996649 (R263Q) variant shows a significant independent association with TB susceptibility, highlighting its role as a genetic risk factor and potential target for immunogenetic research.
Ain et al. (Fri,) studied this question.