Changes in antipyrine clearance and platelet count, but not conventional liver tests, correlate with fibrotic change in chronic hepatitis C: value for predicting fibrotic progression.

Objective: We tested whether fibrotic progression in chronic hepatitis C could be predicted by liver tests, antipyrine clearance, or platelet count.

Methods: In 58 patients (6 untreated, 52 interferon-treated), a second liver biopsy was taken median 4.5 yr after first histologic diagnosis. We used receiver operating characteristic curves to determine whether changes in conventional liver tests, antipyrine clearance, or platelet count were predictive of altered hepatic fibrosis score.

Results: Apart from a weak association with change in ALT, conventional liver tests (albumin, bilirubin, prothrombin time) failed to correlate with changes (Delta) in hepatic fibrosis, but there were significant correlations between deltaantipyrine clearance or deltaplatelet count and deltafibrosis score (p < 0.01). As indicated by areas under the receiver operating characteristic curves, the diagnostic accuracy of deltaantipyrine clearance for fibrotic progression was 68%; for Deltaplatelet count it was 80%. With defined cut-off values (-0.05 ml/min/kg for deltaantipyrine clearance; -41 x 10(9)/L for deltaplatelet count), the negative predictive values for fibrotic progression were 85% with antipyrine clearance and 89% with platelet count. Corresponding positive predictive values were 48% and 91%, respectively.

Conclusions: Changes in antipyrine clearance and platelet count are more sensitive than conventional tests for indicating fibrotic change in chronic hepatitis C. Both could be used to reliably identify those who do not have fibrotic progression, and platelet count also has a high positive predictive value for disease progression.