Dyslipidemia and its features in primary biliary cholangitis

Abstract

Primary biliary cholangitis, previously known as primary biliary cirrhosis, is a rare autoimmune liver disease that mostly affects women. Disorder of biliary excretion and enterohepatic circulation of bile acids in patients with primary biliary cholangitis in the early stages of the disease leads to their insufficient flow into the intestine and ingestion of bile acids into the general bloodstream. Insufficient intake of bile acids into the duodenum contributes to malabsorption, energetic malnutrition, and a slowly progressing weight loss. Pathophysiological mechanisms of the development of weight loss are related to impaired emulsification of fats and decreased absorption of hydrolyzed products - fatty acids and monoglycerides, steatorrhea in patients with primary biliary cholangitis as well as to dysbiosis of intestinal microflora. Already in the early stages of the disease, this leads to accelerated ß-oxidation of fatty acids, which is aimed at compensating for the developing nutritional energy deficiency. Entry of bile acids into the general bloodstream in primary biliary cholangitis is accompanied by dyslipidemia. The mechanism of hyperlipidemia in patients with primary biliary cholangitis differs from that in other conditions because along with the increase in total cholesterol, there is an increase in high-density lipoproteins and the appearance of unusual lipoprotein X (Lp-X). The appearance of the latter is most likely a protective reaction of the body aimed at the inactivation of bile acids detergent action on membrane structures of blood-forming elements and vascular endotheliocytes. Exactly bile acids, but not the content of total cholesterol, correlates with the level of lipoprotein X and determine its formation. Concomitant hypercholesterolemia in patients with primary biliary cholangitis is also aimed at neutralizing the detergent action of bile acids that entered the general bloodstream and is most likely a compensatory reaction of the body. “Abnormal” hypercholesterolemia in primary biliary cholangitis can serve as a model system to search for and develop new ways of dyslipidemia treatment, as it proceeds without increasing the frequency of cardiovascular events.