The activity of gamma-glutamyl transferase in the serum of multiple sclerosis and other neurological diseases.

1. In the sera of 142 neurological patients, including 35 cases with multiple sclerosis (MS), and 20 normal controls the gamma-glutamyltransferase (gamma-GT) activity was determined. The result of this investigation was compared with the "combined hippuric acid test" formely often used in MS patients. 2. The MS patients are the only group which significantly differs from the normal controls. There are also small differences between them and some of the other neurological patient groups. About one-third of the MS patients show moderately pathological serum activities. On the other hand, patients with a definite liver affection, especially chronic alcoholics, regularly show an even more important elevation of the values, which makes this test a sensitive tool for the screening of alcohol-induced liver intoxications. 3. Although the gamma-GT test in not quite as sensitive in indicating organic defects in MS patients, it seems to reflected a disturbed liver function in the same way as the more complicated "combined hippuric acid test". It may therefore be used as a simple tool of finding and following up organic defects in MS patients.