Is serum alanine transaminase level a reliable marker of histological disease in chronic hepatitis C infection

Background: Approximately 20–30% of patients chronically infected with hepatitis C virus (HCV) have persistently normal alanine transaminase (PNALT) levels. These patients are described to have a mild degree of histological liver damage. We aimed to assess the histological liver changes in HCV patients with PNALT.Patients and methods: Sixty-five patients with HCV and PNALT (group A) underwent a liver biopsy. PNALT was defined as three or more determinations identified to be within the normal range over 6 months or longer. The demographical features and histological changes were compared with 66 consecutive patients with chronic HCV infection and elevated ALT (group B). All patients had a detectable HCV RNA. Histological disease was scored according to the METAVIR system. Results: Females were more likely to have normal ALT levels (65%). The mean ALT level in Group A and B was 30 and 105 IU/L respectively. No patient in either group had normal histology. The mean necro-inflammatory scores in groups A and B (2.0 0.68 vs 2.09 0.67) and the mean fibrosis scores (2.11 0.87 vs 2.24 1.04) were not significantly different. Bridging fibrosis in groups A and B was seen in 24.6 and 37.9% patients, respectively, while cirrhosis was seen in 6.2 and 7.6% patients respectively. Hepatic steatosis in groups A and B (0.94 0.86 vs 1.0 1.02 respectively) was also not significantly different and did not show any association with the fibrosis scores across the two groups. In group A, the necroinflammatory and fibrosis scores of patients with and without steatosis were not statistically significant. Age was the only predictor of normal ALT levels. However, increasing age did not show a significant increase in histological activity in either group beyond a certain age. Conclusion: This study demonstrates that ALT is a poor surrogate marker for inflammation and fibrosis in HCV patients. Given the presence of significant necro-inflammation in PNALT patients, the risk/benefit ratio justifies treatment without the need for a liver biopsy.