Serum class I and II alcohol dehydrogenase activity during the course of viral hepatitis

We examined the activities of class I and II alcohol dehydrogenase isoenzymes in the sera of patients with viral hepatitis using the fluorogenic substrates 4-methoxy-1-naphthaldehyde for class I and 6-methoxy-2-naphthaldehyde for class II. It was found that serum activities of class I and II alcohol dehydrogenase isoenzymes over the course of five weeks of hospitalisation were higher than those of controls. The greatest increase in activities was found at the onset of disease, exceeding the mean control value by about 30 fold for class I and 4 fold for class II. These activities were lower than that of aminotransferase but higher than those for lactate dehydrogenase, alkaline phosphatase and gamma-glutamyltransferase. Thereafter, the activity of alcohol dehydrogenase isoenzymes gradually decreased, but did not reach the values of the control groups in the last period of the study. Activities of class I and II alcohol dehydrogenase isoenzymes correlated well with those of alanine and aspartate aminotransferase and lactate dehydrogenase in the first weeks of illness. These results clearly demonstrate that especially the activity of class I alcohol dehydrogenase isoenzyme measured by a fluorimetric method can be a useful marker of liver cell damage in the course of viral hepatitis.