CHARACTERISTICS OF PIGMENT METABOLISM FOLLOWING THE ADMINISTRATION OF ACELLULAR CRYOPRESERVED BIOLOGICAL AGENTS IN A MODEL OF AUTOIMMUNE HEPATITIS

Autoimmune hepatitis (AIH) is an immune-mediated inflammatory disease of the liver caused by a loss of tolerance to the liver's own hepatocyte antigens, leading to autoimmune liver damage. The aim of this study was to characterize the effects of acellular cryopreserved biological agents – conditioned medium from mesenchymal stem cells (MSC-СM), cryoextract of placenta (CEP), and cryoextract of spleen (CES) on the state of pigment metabolism in a rat model of AIH. Assessment of pigment metabolism showed that, in the context of developing AIH, there was a statistically significant (p < 0.001) increase in total bilirubin levels in the blood of rats by 148.9% compared to the values of intact rats, which were 33.4 μmol/L. The increase in total bilirubin in the control group animals was mainly due to an increase in direct bilirubin – its concentration rose significantly (p < 0.001) by 240.0%, reaching 17.0 μmol/L, while the level of indirect bilirubin increased (p < 0.001) by only 98.3% compared to the values of intact rats. In terms of the ability to normalize pigment metabolism in the context of AIH, the studied biological agents can be ranked in the following order (by % decrease in total bilirubin compared to control group values): MSC-СM (52.6%; p < 0.001) > CEP (49.6%; p < 0.001) > CES (40.2%; p < 0.001). Keywords: autoimmune hepatitis, Freund's adjuvant, bilirubin, pigment metabolism, autoimmune diseases, conditioned medium from mesenchymal stem cells, cryoextract of placenta, cryoextract of spleen.