Monitoring of cytogenetic effects in tick-borne encephalitis patients with type 2 diabetes mellitus, depending on polymorphism of glutathione-S-transferase genes

Abstract

BACKGROUND: Tick-borne encephalitis (TBE) is an acute viral disease with activation of oxidative stress and increasing in cytogenetic instability. Clinical symptoms of infectious diseases usually more severe in patients with type 2 diabetes mellitus (DM2), especially in the case of burden in the genotype of mutant variants of glutathione-S-transferase genes GSTM1 and GSTT1.
 AIMS: The aim of this study was to study the dynamics of the frequency of micronucleated cells in patients with acute TBE with concomitant DM2, depending on the burden of active and inactive variants of glutathione-S-transferase genes (GSTM1 and GSTT1) in the patients genotype.
 MATERIALS AND METHODS: Totally, samples to make micronucleus assay were obtained from 138 patients with febrile illness of acute TBE, 64 of whom were diagnosed with concomitant DM2 (groups 3 and 4). As control groups, 57 healthy individuals (control 1) and 61 patients with DM2 (control 2) were examined. The samples of buccal cells for the micronucleus assay were repeatedly obtained from the individuals on the first day of admission, and also after 1 week, 1, 3 and 6 months. Polymerase chain reaction was used to analyze the variants of the GSTM1 and GSTT1 genes.
 RESULTS: On the first days of the disease, significant increases in the frequency of micronucleated buccal cells were determined in all TBE patients as compared to controls 1 and 2 (P0.001). Significant increases in the frequency of micronucleated buccal cells was revealed in groups 3 and 4 of the TBE patients who were carriers of inactive variants of the GSTM1(0) and GSTT1(0) genes, as compared to the subgroup of TBE patients with active variants of these genes (P0.001). In all subgroups of TBE patients with concomitant DM2, the frequencies of micronucleated cells were significantly higher than in the subgroups of TBE patients without DM2 (P0.001). Study of the dynamics of the frequency of micronucleated buccal cells, as compared to the control, demonstrated that the highest and long-lasting (within 6 months) cytogenetical effects were maintained in the group of TBE patients with genotype GSTM1(0)/GSTT1 (0) and concomitant DM2.
 CONCLUSION: The most prolonged and highest increases in the frequencies of cytogenetically instable cells were determined in the group of acute TBE patients with concomitant DM2 who were carriers of the genotype with inactive variants of both GSTM1(0) and GSTT1(0) glutathione-S-transferase genes.