Treatment with peginterferon alfa-2a for 48 weeks, with or without adefovir, resulted in sustained HDV RNA clearance in about one quarter of patients with HDV infection. (Current Controlled Trials number, ISRCTN83587695.).

(i) HBsAg levels correlated with HDV viraemia in chronic HDV. (ii) Biochemical parameters did not accurately indicate the stage and grade of liver disease in chronic HDV and thus liver biopsy seems to remain the major tool for the evaluation of delta hepatitis patients.

Despite the decrease of its prevalence in Turkey, DH remains a significant health problem in parts of the country with low socio-economic level.

High dose interferon treatment for 1 year is the only established treatment for chronic hepatitis D, but it is associated with a high relapse rate after treatment discontinuation. In this study, patients were treated with 10 MU interferon alpha 2b, thrice weekly for 2 years. Twenty-three patients were recruited and 15 completed the 2-year treatment and 6 months follow-up periods. Treatment response was assessed biochemically [normal alanine aminotransferase (ALT)], virologically (undetectable hepatitis D virus RNA) and histologically (at least 2 point decrease in the Knodell score) at the end of treatment (EOT) and at the end of follow-up. Out of 15 patients who finished the 2-year treatment period, seven patients (47%) had a biochemical response but only two (13%) had a normal ALT after follow-up. ALT decreased from the baseline value of 143.1 +/- 121.7 (mean +/- SD) to 39.7 +/- 20.6 (P < 0.01) at EOT. Virological response was observed in six patients at EOT and in two patients at follow-up. Two patients lost hepatitis B surface antigen. Of the 12 patients with paired liver biopsies, a histological improvement was observed in eight patients. Interferon treatment leads to a complete or partial response in a substantial number of patients but 2 years of treatment does not appear to increase sustained response rates over 1 year treatment.

In the present study we could not find any association between genotype D and distinct clinical phenotypes. Genotype D is the predominant type among hepatitis B carriers residing in our region and is not associated with more severe liver diseases. This genotype did not influence clinical manifestations in carriers with chronic hepatitis B virus infection. However, additional large-scale longitudinal studies are needed to find the relationship of HBV genotypes to liver disease severity and clinical outcomes.