[Delta superinfection of hepatitis B in Switzerland: histology and serology of 28 patients].

A series of 610 consecutive liver biopsies collected from Jan. 1980 to Oct. 1983 in two Swiss gastro-enterological centers was studied by immunohistology for the presence of delta-antigen, HBsAg and HBcAg in frozen sections. This led to the identification of 46 tissue and 45 serum samples of 28 patients, including 5 with follow-up biopsies. All had ongoing hepatitis B (HB) with delta-superinfection, representing 13.3% of all patients with HB. The sera were studied for HBsAg, anti-HBs, anti-HBc and HBe-markers by RIA, for anti-delta by indirect immunofluorescence on delta-positive test sections and for Dane particles by immune electromicroscopy. 18 of the 21 native Swiss patients were i.v. drug users between 20 and 28 years of age (30% of all drug users in this series). The other patients were residents from Mediterranean countries (n = 5), Eastern Europe (n = 1) and Asia (n = 1). Female patients (n = 5) were seen only among i.v. drug users. The most frequent histological type of HB was chronic active (aggressive) hepatitis (CAH) (26 of 46 biopsies or 13 of 28 patients, respectively), followed by acute HB with histological signs of possible transition to chronicity (8 of 46 biopsies or 6 of 28 patients), and acute lobular HB (6 of 46 biopsies or 5 of 28 patients). Chronic persistent HB (CPH) was rare (5 of 46 biopsies, final diagnosis in 3 patients). The delta-infection was found to persist in sequential biopsies when a chronic HB was established, the longest documented period being 72 months.(ABSTRACT TRUNCATED AT 250 WORDS)