Blood MAIT cells phenotype in patients with Opisthorchis felineus invasion depending on the severity of liver fibrosis

Introduction. MAIT cells are a new subpopulation of T cells that protect mucous barriers against penetration of foreign substances. There are practically no studies devoted to the participation of these cells in the pathogenesis of parasitic diseases. Aim. To study the phenotype of blood MAIT cells in patients with Opisthorchis felineus ( O. felineus ) invasion depending on the severity of liver fibrosis. Materials and methods. A total of 78 patients with O. felineus invasion (42 men and 36 women) and 26 control group individuals (14 men and 12 women) were examined. Opisthorchiasis was diagnosed using coproovoscopy and duodenal contents microscopy. All patients underwent liver elastometry using Aixplorer (France) or Siemens Acuson S2000 (Germany) systems with determination of the liver fibrosis degree according to METAVIR. The phenotype composition of lymphocytes was investigated using a Navios flow cytometer (Beckman Coulter, USA). T cells, T helpers, and T cytotoxic lymphocytes were isolated and the presence of NCR Va7.2 and CD161 on the surface of these cells was assessed. Results. The content of MAIT T-helpers was decreased in patients with O. felineus invasion compared to healthy individuals (p < 0.001). In MAIT T-cytotoxic cells, a similar pattern was not detected (p = 0.5). In patients with liver fibrosis F2 according to METAVIR compared to individuals with F0 according to METAVIR, a decrease in the total number of T-cells, T-helpers and T-cytotoxic cells, as well as MAIT T-helpers and MAIT T-cytotoxic cells was observed. Thus, the content of CD161 + NCR Va7.2 + T-helpers was 0.020% [0.004–0.042%] in patients with opisthorchiasis with F0 according to METAVIR and 0.0% [0.0–0.003%] in individuals with liver fibrosis F2 according to METAVIR (p = 0.001). For CD161 + NCR Va7.2 + T-cytotoxic cells, these indicators were, respectively, 1.47% [0.41–2.49%] and 0.12% [0.07–0.31%] (p < 0.001). Conclusion. Further study of MAIT cells in patients with liver pathology has undoubted prospects for the creation of new therapeutic and diagnostic technologies.