CYP2E1-DEPENDENT VARIATIONS IN HEPATOCYTES DAMAGE DURING TREATMENT OF TUBERCULOSIS

Abstract

Relevance. Investigation of polymorphism in a locus of CYP2E1 as the prognostic factor of drug-induced hepatotoxicity at anti-TB therapy is significant due to the influence of CYP2E1 on drug metabolism.
 The objective of the investigation is to analyze the association of rs2070676 СYP2E1 gene polymorphism with drug-induced hepatotoxicity by means of the clinical-laboratory values of serum transaminases at anti-TB treatment.
 Materials and methods. The study involved 47 patients with drug-susceptible tuberculosis first time discovered. 58 healthy volunteers comprised a control group. Laboratory indices were determined in venous blood three times: before the treatment as baseline; in 2 months of intensive therapy (isoniazid, rifampicin, ethambutol, pyrazinamide), then in 4 months of maintenance therapy (isoniazid, rifampicin). Serum activities of enzymes ALT, AST, and GGT were measured by standard algorithm on automatic analyzer BS-300. Analysis of rs2070676 polymorphism of CYP2E1 gene was performed by polymerase chain reaction using standard PureLink® Genomic DNA Kit for Purification of Genomic DNA; Manufacturer of INVITROGEN (USA). For statistical processing, IBM SPSS Statistics 23 was applied.
 Results. Investigation of serum ALT and AST in patients with major genotype CYP2E1 (C/C) showed the lower baseline ALT and AST levels comparing to the control group, which might be caused by suppression of hepatocytes functions at the development of the disease. Anti-TB treatment caused an increase in ALT and AST levels comparing to the baseline in patients with major CYP2E1 (C/C) genotype. In the group with C/G polymorphism, the baseline ALT level didn’t differ much from the baseline of the control group; it showed a decrease after intensive therapy and returned back to the initial level at maintenance therapy. This might be related to the certain protective property of СYP2E1 gene polymorphism. The AST level was increased after intensive therapy (to a smaller extent than for the patients with major C/C genotype) and remained on the same level at maintenance therapy. A study of GGT showed a gradual increase regardless of genotype.
 Conclusion. According to the data of the experiment, the status of hepatocytes in patients with tuberculosis at baseline and during treatment was different depending on the CYP2E1 genotype. The results of the experiment indicate that the CYP2E1 gene polymorphism has a certain protecting role. It reduces the level of drug metabolites and hepatotoxicity which causes mitochondrial dysfunction.