Updated thresholds for alanine aminotransferase do not exclude significant histological disease in chronic hepatitis C

Abstract

Background and aim: Histological changes in hepatitis C virus (HCV)-infected patients with persistently normal alanine aminotransferase (PNALT) have not been evaluated for updated upper limits of normal (ULN; ≤19/30U/L for females/males). We assessed significant fibrosis (≥F2, METAVIR) in patients with PNALT and persistently elevated alanine aminotransferase (PEALT). Patients and methods: Nine hundred and twenty consecutive, unselected HCV patients were stratified into four groups: Group I: (n=124) PNALT within the updated ULN [0.5 × ULN (corresponding to ≤19U/L) for females; 0.75 × ULN (corresponding to ≤30U/L) for males]; Group II (n=173): PNALT≤1 × ULN but greater than Group I; Group III (n=313): PEALT 1-2 × ULN; and Group IV (n=310): PEALT>2 × ULN. PNALT was defined as ≥3 determinations within the normal range over ≥6 months. Results: Advanced ≥F3 and ≥F2 fibrosis increased incrementally across Groups I; II; III; and IV: 24.2 and 45.2%; 25.4 and 56.1%; 36.1 and 64.2%; and 50 and 77.1% respectively (P<0.0001 for both). Multivariable logistic regression analysis identified age [odds ratio (OR), 1.05; 95% confidence intervals (CI): 1.02-1.08; P<0.0001], alanine aminotransferase (ALT) groups (OR 1.38; 95% CI: 1.03-1.83; P=0.030), presence of moderate-severe steatosis (OR 2.70; 95% CI: 1.19-6.15; P=0.018) and ≥A2 necroinflammation (OR 17.9; 95% CI: 8.88-36.20; P<0.0001) as independent predictors of ≥F2 fibrosis. Updated ULN for ALT were better at excluding ≥F2 fibrosis compared with traditional ULN (90.6 vs. 74.2%, P=0.0041) but less specific (20.8 vs. 44%, P=0.0007) with similar positive/negative predictive values. Conclusions: HCV patients with 'updated' normal ALT have the lowest prevalence of significant fibrosis, although utilizing these levels without resorting to biopsy would miss significant fibrosis in almost one-half of such patients. © 2011 John Wiley & Sons A/S.