Clinical Significance of Persistently Normal ALT in Chronic Hepatitis B Patients

Liver disease in patients with chronic hepatitis B virus (HBV) infection is due to both necroinflammation and active viral replication in liver cells. The role of alanine aminotransferase (ALT) level -- a marker for liver inflammation -- as a predictor of liver injury is unclear.

As reported in the September 24, 2007 advance online issue of the Journal of Hepatology, researchers conducted a study to determine whether normal ALT is associated with liver injury in a cohort of hepatitis B patients undergoing liver biopsy.

In this retrospective review, 192 individuals with chronic HBV were divided into 3 groups:

·         Persistently normal ALT (n = 59);

·         High-normal ALT: 1-1.5 x the upper limit of normal (ULN) (n = 26);

·         High ALT: > 1.5 x ULN (n = 107).

Results

·         Increasing age, higher ALT, higher grade of inflammation on biopsy, and hepatitis B “e” antigen (HBeAg) positivity predicted more extensive fibrosis.

·         18% of patients with persistently normal ALT had stage 2 or higher fibrosis and 34% had grade 2 or 3 liver inflammation.

·         Overall, 37% of patients with persistently normal ALT had significant fibrosis or inflammation.

·         Subgroup analysis showed that the majority of subjects with fibrosis belonged to the high-normal ALT group.

·         Among these patients, only a minority who were young and immune tolerant had significant findings on biopsy.

Conclusion

Based on these findings, the study authors wrote, “There is significant fibrosis and inflammation in 37% of patients with persistently normal ALT and a liver biopsy should be considered in patients older than 40 with high normal ALT.”

10/23/07

Reference  
M Lai, BJ Hyatt, I Nasser, and others. The clinical significance of persistently normal ALT in chronic hepatitis B infection. Journal of Hepatology. September 24, 2007 [Epub ahead of print].