Relationship between the GSTP1 gene polymorphism and its expression and hemoglobin levels in workers of a secondary lead smelter

Introduction. Working conditions in lead production are known to be associated with exposure to various harmful chemicals in the workplace air. Erythrocytes are constantly exposed to various stress factors causing irreversible damage and leading to the cell death. Thus, the antioxidant system, capable of inactivating reactive oxygen species (ROS) and eliminating the associated damage, plays an important role in protecting this type of cells. Glutathione is a significant part of this system, while glutathione-S-transferase Pi (GSTP1-1) is present in many mammalian tissues and the most common intraerythrocytic isoenzyme, representing 95 % of the total pool of glutathione-S-transferases.The purpose of the study was to establish the effect of GSTP1 gene polymorphism and its expression on the hemoglobin level in workers engaged in secondary lead processing.Materials and methods. To find the relationship between the rs1695 polymorphism of the GSTP1 gene and the blood hemoglobin level, three hundred twenty nine male workers of a secondary lead smelter were included in the study. DNA was isolated from whole blood samples by the salt method according to the standard technique, the rs1695 polymorphism of the GSTP1 gene was determined using real-time PCR with fluorescent probes. In 54 smelters of the refining department, we isolated RNA using the ExtractRNA reagent and determined the gene expression level using real-time PCR.Results. The analysis of the effect of the GSTP1 genotype on the hemoglobin level among the workers of various departments demonstrated the mutant genotype (G/G) to be associated with lower hemoglobin levels in workers in the refining department. The study of the GSTP1 gene expression level in workers of the refining department (refiners) and the comparison group in 2022 revealed that the expression level was statistically lower in the exposed workers.Limitations. Ethnicity was not determined in this study.Conclusions. We established a relationship between the GSTP1 gene polymorphism and the hemoglobin level in the refiners of the secondary lead smelter. We also found a decrease in the level of GSTP1 gene expression in the blood of workers exposed to occupational risk factors, indicating additional inhibition of detoxification processes at the level of gene expression.Compliance with ethical standards. The study was conducted in accordance with ethical principles of the WMA Declaration of Helsinki and approved by the Ethics Committee of the Yekaterinburg Medical Research Center for Prophylaxis and Health Protection in Industrial Workers (protocol No. 1 of February 26, 2021). All participants gave informed voluntary written consent to participate in the study.Contribution: Shaikhova D.R. — data processing, statistical analysis, draft manuscript preparation, editing; Kikot A.M., Bereza I.A. — data collection and processing, editing; Sutunkova M.P. — study conception and design. All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version.Conflict of interest. The authors declare no conflict of interest.Funding. The study had no sponsorship.Received: November 5, 2025 / Revised: November 18, 2025 / Accepted: December 2, 2025 / Published: January 15, 2026