Morphology of non A-non B hepatitis (HNANB). A study of 104 cases.

A series of 104 liver biopsies from patients with clinical HNANB were classified under code into established histologic groups. Activity and basic features were semiquantitatively assessed using a score system. In 23/104 cases non viral lesions were diagnosed. After breaking the code the remaining 81 hepatic biopsies were ranged into three groups: post-transfusional cases (PT) (n. 20), sporadic cases with clinically documented initial "acute hepatitis" (SP1) (n. 44), sporadic cases without determined onset of disease (SP2) (n. 17). There were no statistically significant features discriminating histologically PT group from SP 1 + 2 group. However, aggressive forms of hepatitis (acute hepatitis with piecemeal necrosis [AVH+PMN] and chronic aggressive hepatitis [CAH]) were more frequent in PT group (11/20 = 55% in PT versus 28/61 = 45.9% in SP 1+2 groups). No statistical significant differences were detected for the scored basic pattern (i.e. acidophilic body type, mononucleosis-like bead file pattern, etc.). Bile duct lesions were observed approximately with the same frequency in PT and SP1 groups. Prevalence of fatty change was striking: 55% in PT group and 54.1% in SP1 group.