The Activity of Alcohol Dehydrogenase Isoenzymes and Aldehyde Dehydrogenase in the Sera of Patients with Autoimmune Hepatitis.

Background: Autoimmune hepatitis (AIH) is a progressive inflammatory hepatopathy and an important cause of end-stage liver. The liver cells' destruction is reflected by increased activity of different enzymes in the serum. These enzymes include alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH), which play a significant role in the metabolism of many biological substances and exist mainly in the liver. In this study we investigated the activity of alcohol dehydrogenase and its isoenzymes and the total activity of ALDH in the sera of patients with autoimmune hepatitis.

Methods: Serum samples were taken for routine biochemical investigation from 32 patients with autoimmune hepatitis and from 40 healthy subjects. Class I and II of ADH and ALDH activity was measured by the spectrofluorometric method. For measurement of class III ADH and total ADH activity we employed the photometric methods.

Results: The activity of the class I ADH isoenzyme was significantly higher in the sera of patients with autoimmune hepatitis. The median activity of this isoenzyme in the patients group was approximately 63% (3.94 mU/L) higher than the control level (1.46 mU/L). For this reason, the total ADH activity was also significantly increased. The activities of other ADH isoenzymes and ALDH tested were unchanged.

Conclusions: The activity of total ADH and class I isoenzymes in the sera of patients with autoimmune hepatitis is increased, and it seems to be caused by the release of alcohol dehydrogenase from damaged liver cells.