[Pathogenesis-screening tests for liver dysfunction in the asymptomatic patients with elevated ALT values and their diagnostic efficacies in primary care medicine].

We have evaluated the diagnostic efficacies of ultrasonography and hepatitis C virus (HCV) antibody measurement to differentiate pathogenesis of liver dysfunction in the asymptomatic adults with elevated ALT value. Among 4256 visitors to PL Tokyo Health Control Center for their health examination, 463 cases (11%) showed abnormal liver function including elevation of ALT value. Ultrasonography and HCV antibody measurement using the second generation reagent had been applied to 362 cases in order to screen the etiology of liver dysfunction. The ultrasonography succeeded to establish the diagnosis of fatty liver in 137 cases (38%) and 41 cases (11%) demonstrated positive HCV antibody. There were 4 cases with positive HBs antigen, however, it was found that their abnormal liver function was attributed to other etiology such as fatty liver and alcoholic liver dysfunction rather than chronic type B hepatitis. HCV antibody-positive cases showed higher levels of total protein, ZTT, AST, ALT, and lower levels of albumin, A/G, total cholesterol, triglyceride, gamma-GT and cholinesterase value than other cases. HCV antibody titers were not correlated to hepatic parenchymal damage estimated by ALT or cholinesterase value. Only a little correlation was observed between HCV antibody titers and HCV-RNA amounts determined by the competitive reverse transcription-polymerase chain reaction (RT-PCR) method. These results indicate sufficient diagnostic efficacies of ultrasonography and HCV antibody measurement for a pathogenesis differentiation in the asymptomatic patients with liver dysfunction, and these examinations should be employed as the first-step screening tests for the etiology determination of liver diseases in the primary care medicine.