Correlation analysis between single nucleotide polymorphisms of pulmonary surfactant protein A gene and pulmonary tuberculosis in the Han population in China

SummaryObjectiveTo investigate the correlation of single nucleotide polymorphisms (SNPs) in SFTPA1 and SFTPA2 genes encoding pulmonary surfactant protein A (SP-A) with the susceptibility to pulmonary tuberculosis (PTB) in the Han population in China.MethodsThis study included 248 patients with active PTB (case group) and 124 normal individuals (control group). SNPs at loci aa19, aa50, aa62, aa133, and aa219 of SFTPA1, and at loci aa9, aa91, aa140, and aa223 of SFTPA2 were analyzed with PCR. Multivariate logistic regression analysis was used to identify the correlation of age, sex, and SNPs with PTB.ResultsThe frequencies of the G allele at aa91 and T allele at aa140 in SFTPA2 were significantly higher in the case group than in the control group (p = 0.0002 and p = 0.045). The distribution of haplotype CGAAC in SFTPA1 was significantly lower in the case group than in the control group (p = 0.025). In SFTPA2, the distributions of haplotypes 1A6, 1A10, 1A9, and 1A2 were higher (all p < 0.05), but the distributions of haplotypes 1A13, 1A5, and 1A12 were lower in the case group than in the control group (all p < 0.05). When SFTPA1 and SFTPA2 were combined and analyzed, haplotype 6A11–1A8 was only found in the case group (4.1%, p = 0.001 compared with the control group), but the distribution of haplotype CGAAC-1A0 or 6A4–1A12 was significantly lower in the case group than in the control group (all p < 0.05).ConclusionsSNP in SP-A is associated with PTB in the Han population in China. The G allele at aa91, T allele at aa140, and haplotype 6A11–1A8 are risk factors for PTB, but haplotype CGAAC–1A0 and 6A4–1A12 are protective factors for PTB.