SLC11A1 and VDR gene variants and susceptibility to tuberculosis and disease progression in East India

SETTING: Despite efforts at disease control, the incidence of tuberculosis (TB) remains high in India. OBJECTIVE: To assess the role of VDR and SLC11A1 gene polymorphisms in the development of pulmonary TB (PTB) in an ethnically matched population of India. DESIGN: In this case-control study, five variants (INT4/rs3731865, 823C/T/rs17221959, D543N/rs17235409, 577G/A/rs1059823 and TGTG deletion-3'UTR/rs172 35416) of SLC11A1 and three (BsmI/rs1544410, FokI/rs10735810 and TaqI/rs731236) of the VDR gene were studied in 101 TB patients and 225 controls from Kolkata, India. RESULTS: Statistically significant associations were observed for INT4: GC (OR 4.54 95%CI 2.38-8.68), CC (OR 35.20, 95%CI 9.15-135.38), 3'UTR (TGTG+/-, OR 2.96, 95%CI 1.52-5.78), TGTG-/- (OR 3.52, 95%CI 1.62-7.61) and 823C/T (CT, OR 0.31, 95%CI 0.17-0.58) variants of the SLC11A1 gene. Significantly different genotype frequencies between different groups of patients elucidated the role of the INT4 (P = 0.031), 577G/A (P = 0.033) and Fold (P = 0.02) variants in disease progression and the development of cavitary disease. Five haplotypes were also identified as having a significant association with PTB. CONCLUSION: This study, the first to include evidence on 577G/A and INT4, reports a significant association between SLC11A1 gene variants and PTB with respect to susceptibility and subsequent disease progression in East India.