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

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; ≤ 19/30 U/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 ≤ 19 U/L) for females; 0.75 × ULN (corresponding to ≤ 30 U/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.