A prospective study on associations between superoxide dismutase gene polymorphisms and antituberculosis drug-induced liver injury in a Chinese Han population.

Background: Antituberculosis drug-induced liver injury (ATDILI) is increasing globally and, hence, it is crucial to predict its risk in the clinical management of antituberculosis therapy. As a major antioxidant, superoxide dismutase (SOD) is mainly responsible for providing defence against oxidative stress, which is involved in ATDILI. The present study aimed to investigate the associations between polymorphisms in SOD genes, including Cu/ZnSOD (SOD1), mitochondrial manganese SOD (MnSOD or SOD2) and extracellular SOD (SOD3), as well as the susceptibility to ATDILI in a Chinese Han population.

Methods: In total, 1060 Chinese Han subjects highly suspected to have tuberculosis (TB) were prospectively enrolled from West China Hospital of Sichuan University. Overall, 746 subjects comprising 118 ATDILI and 628 ATD-tolerant TB patients were eligible and were genotyped for seven single-nucleotide polymorphisms in three SOD genes (SOD1: rs4816407 and rs1041740; SOD2: rs4880; SOD3: rs699473, rs2536512, rs2855262 and rs8192290).

Results: Logistic regression analysis showed that none of the seven genetic variants in the three SOD genes were significantly associated with susceptibility to ATDILI in the Chinese Han population after Bonferroni correction, except for a potential association for the SOD2 rs4880 A>G (G allele, p = 0.190, odds ratio = 1.53, 95% confidence interval = 1.05-2.23; GG genotype, p = 0.155).

Conclusions: The promising application of single-nucleotide polymorphisms in the SOD1, SOD2 and SOD3 genes as genetic markers for ATDILI is challenged, and further studies are needed with larger sample sizes and different ethnicities, especially for SOD2 rs4880.