Role of MTHFR 677C>T and 1298A>C gene polymorphisms on renal toxicity caused by lead exposure in wastewater treatment plant workers

Environmental and occupational lead (Pb) exposures continue to pose major public health problems. Wastewater treatment plant (WWTP) workers proved are exposing to high Pb concentrations in sludge departments. The aim of the work was to investigate the role of MTHFR C677T and MTHFR A1298C gene polymorphisms on alteration of oxidative stress and homocysteine levels in WWTP workers exposed to high Pb concentrations, and study its relations with renal functions. The study included 90 WWTP workers from Abu-Rawash WWTP. Homocysteine, creatinine, urea, malondialdehyde (MDA), and total antioxidant capacity (TAC) were measured. Polymorphisms of MTHFR C677CT and MTHFR A1298C genes were studied using PCR/RFLP. Urine Pb concentrations were also measured. About 32.2% of the workers were with detectable Pb levels. Pb, homocysteine, and MDA levels were significantly higher among workers carrying TT polymorphism compared to other MTHFR C677T gene polymorphisms, while TAC was significantly lower among them compared to other polymorphisms. The same results were found among workers carrying CC compared to other MTHFR A1298C gene polymorphisms. WWTP workers carrying MTHFR 677TT and MTHFR 1298CC are more susceptible to elevation of homocysteine and the urinary Pb compared to the workers with the other polymorphisms. Furthermore, those workers were found to have increase in urea and creatinine. Therefore, MTHFR C677T and MTHFR A1298C gene polymorphisms could be used for prediction of the susceptibility to the risk of kidney impairments among WWTP workers in the sludge departments caused by their exposure to high Pb in their workplace.