Natural human interferon alpha may act differently when given parenterally or orally to patients chronically infected with hepatitis B virus.

A literature review of patients chronically infected with hepatitis B virus (HBV) treated with natural human interferon alpha (nHuIFN-alpha) given parenterally every day for 28 days revelated that even the daily dose of (5 x 10(6)IU) of IFN-alpha inhibits cellular metabolism. As a result of metabolic block, the number of blood elements were diminished. Furthermore treated patients recorded several different adverse reactions. In contrast, among patients treated with the oral form of nHuIFN-alpha non metabolic block occurred and no adverse reactions were seen, even though the therapy lasted much longer. Two years after initiation of parenteral IFN-alpha therapy, the loss of HBV-BeAg was 53.8% and 28.8% of the patients had undergone seroconversion. In contrast, 77% of patients on oral interferon lost HBV-BeAg and 74% serconverted and normalized their biochemical liver function. The results suggest that the nHuIFN-alpha given orally and parenterally activate two different mechanisms responsible for virus elimination.