A coordinated antibody and cellular immune response is required for an efficient clearance of HBV infection. Progression to chronic HBV infection occurs, therefore, in patients with an impaired or incompetent cell-mediated immune system. Levamisole is an immunocorrective drug. To evaluate the efficacy of Levamisole in preventing progression from prolonged viral hepatitis B to a chronic process a placebo controlled trial in 54 patients with prolonged viral hepatitis B was performed. This clinical trial was divided into two stages: Stage I lasted - the first six months of the disease. Levamisole, or Placebo, was administered in two cycles: three times a day 50 mg for 3 successive days, during the fifth and sixth week of hospitalization. Stage II was terminated after the next 18 months of observation. Levamisole was administered in 6 successive cycles separated by an 11-day interval, undertaking the treatment from the beginning of Stage II. Patients were evaluated during the therapy for biochemical, virological and immunological response and followed for at least 15 months after therapy to assess long-term efficacy. Altogether out of 33 patients treated with Levamisole at both observation stages, 31 persons recovered (93.9%). Recovery rate in the Placebo/Levamisole group was 66.7% - out of 21 patients 14 recovered. The comparative statistical analysis of the treatment results obtained in Group I (Levamisole/Levamisole) and Group II (Placebo/Levamisole) at both stages has shown statistically significant results. These results were much more beneficial in Group I (p < 0,05) than in Group II, and were dependent on the applied treatment (Q=0,78). These results indicate that Levamisole is a drug preventing the development of chronic hepatitis B in a relationship to its immunocorrective properties.

Keywords: Hepatitis B virus, prolonged viral hepatitis B, chronic hepatitis B, Levamisole, immunocorrection, cellular immunity