Combined effects of nucleotide-binding domain-like receptor protein 3 polymorphisms and environmental metals exposure on chronic kidney disease

Chronic inflammation is the cause of chronic kidney disease (CKD). The nucleotide-binding domain-like receptor protein 3 (NLRP3) inflammasome plays a vital role in the inflammation process and is associated with the regulatory effects of NLRP3 gene polymorphisms. This study evaluated the association between NLRP3 gene polymorphisms and CKD, and further explored whether the association of environmental metals with CKD varied by the NLRP3 genotypes. A total of 218 CKD patients and 427 age- and sex-matched healthy controls were recruited in this clinic-based case–control study. Patients were identified as having CKD if their estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m(2) and stage 3–5 for at least 3 months. We examined the genotypes of fifteen common ssingle-nucleotide polymorphisms in NLRP3 genes. Concentrations of total urinary arsenic were examined by summing of urinary inorganic arsenic species. Concentrations of selenium, cadmium, and lead were measured from blood samples. Associations between NLRP3 polymorphisms, environmental metals exposure, and CKD were evaluated using multivariable logistic regression while controlling for confounders. We observed that the odds of carrying NLRP3 rs4925650 GA/AA genotypes, NLRP3 rs1539019 CA/AA genotypes, and NLRP3 rs10157379 CT/TT genotypes were significantly higher among CKD cases compared to controls, with the adjusted odds ratio (95% confidence interval) were 1.54 (1.01–2.36), 1.56 (1.04–2.33), and 1.59 (1.05–2.38), respectively. The significant multiplicative interactions were identified between high levels of blood lead and NLRP3 rs4925650 GA/AA genotypes; high levels of blood cadmium or low levels of plasma selenium and the NLRP3 haplotype (rs4925648, rs4925650, rs12048215, and rs10754555) C-A-A-C multiplicatively interacted to increase the risk of CKD. Our results imply that NLRP3 polymorphisms may play an important role in the development of environmental metals exposure related CKD.