The prevalence of hepatitis B infection in population in Poland is low and averages 1-1.5%. However, it means that about 380000 Poles constantly or temporarily replicate HBV. Chronic HBV infection is associated with increased risk of serious liver diseases and it is estimated that 25-40% of patients with chronic hepatitis B will die prematurely of cirrhosis or primary liver cancer. Up to the present, interferon-alpha (IFN-a), with low response rate between 25-55% and some limitations of therapy, has been the only available treatment for chronic hepatitis B. A favorable outcome of IFN-a therapy is associated with some prognostic factors, not accepted by all investigators, such as low level of HBV-DNA in serum. The aim of this study was to assess the efficacy of therapy with IFN-a2b (Intron A), administered sc. 5 MU ´ 3/week for 16 weeks, in 65 patients with chronic hepatitis B, divided into groups according to the baseline HBV-DNA level. Except for serum HBVDNA level, there were no demographical and biochemical differences between all the treated groups. The patients were followed-up for 12 months. Sustained response (SR) to the therapy (defined as ALAT normalization, loss of detectable HBV-DNA, seroconversion HBeAg to anti-HBeAg and improvement in liver histology) was observed in 16 (57.14%) of patients in the group with HBVDNA level 5000pg/ml. We conclude that IFN-a is particularly useful in therapy of patients with chronic hepatitis B with low levels of HBV-DNA. The baseline HBVDNA level <1000 pg/ml, in 6 (37.5%) with HBV-DNA level of 1001-3000 pg/ml, in 4 (28.57%) with HBV-DNA level of 3001-5000 pg/ml and only in 2 (28.57%) of patients in group with HBVDNA level >5000pg/ml. We conclude that IFN-α is particularly useful in therapy of patients with chronic hepatitis B with low levels of HBV-DNA. The baseline HBVDNA level <1000 pg/ml in serum is the predictor of good response to IFN-α therapy.

Keywords: response rate, HBV-DNA, interferon alpha-2b, chronic hepatitis B