Objective: To investigate association between the natural-resistance-associated macrophage protein 1 (NRAMP1) gene polymorphisms and susceptibility to pulmonary tuberculosis (TB) in Chinese Han population.
Methods: Hospital-based case-control study design was adopted. Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) technique were used to type three NRAMP1 polymorphisms (INT4, D543N and 3'UTR). Information on related factors of tuberculosis was collected using a pre-tested standard questionnaire. Univariate and multivariate unconditional logistic analyses were conducted using SPSS for window software package. Totally, 110 cases of TB were selected during April 2001 to June 2002, with an average age of (27.7 +/- 12.7) years. Also, 180 cases of healthy control were selected, aged (27.3 +/- 9.2) years in average. Locus of NRAMP1 polymorphism was analysed with univariate method.
Results: Univariate analysis demonstrated that the D543N G/A and 3'UTR TGTG+/del genotype occurred more frequently in the cases than in the controls, with crude odds ratios (OR) (95% CI) of 2.22 (1.03 - 4.78) and 1.93 (1.14 - 3.26), respectively. No significant association was observed between TB and INT4 polymorphisms. In multivariate analysis, associations of TB and D543N G/A and 3'UTR TGTG+/del genotypes remained, adjusted for exposure history and bacille Camette-Guérin immunization. Adjusted OR (95% CI) was 3.04 (1.12 - 8.27) and 2.36 (1.20 - 4.64), respectively. Still, no significant association between INT4 polymorphisms and TB was found.
Conclusion: Polymorphisms of D543N and 3'UTR locus in NRAMP1 gene might affect their susceptibility to TB in Chinese Han population.