Serum levels of soluble interferon alfa/beta receptor as an inhibitory factor of interferon in the patients with chronic hepatitis C

Human serum contains a soluble form of interferon alfa/beta (sIFN alpha/bet a) receptors, the functional and clinical significance of which has not bee n investigated in patients with chronic hepatitis C. In the present study, serum levels of sIFN alpha/beta receptor were assessed in 81 patients with chronic hepatitis C and correlated with the effectiveness of IFN therapy in these patients. Serum levels of sIFN alpha/beta receptor were significantl y higher in patients with chronic hepatitis C than in healthy control patie nts (P < .0001). In these patients, scram levels of sIFN alpha/beta recepto r were correlated with those of alanine transaminase (ALT) (P < .05), (2'-5 ')serum oligo(A) synthetase (2-5AS) (P < .0001), and pathological stages of liver fibrosis (P < .01). In 55 patients with chronic hepatitis C who unde rwent IFN therapy, there was an inverse correlation between the pretherapeu tic serum levels of sIFN alpha/beta receptor and the rate of increase in se rum levels of 2-5AS after the start of IFN (P < .01). Pretherapeutic serum levels of sIFN alpha/beta receptor were significantly lower in patients who showed sustained response to IFN therapy compared with those who did not r espond to the therapy (P < .05). Multi variate analysis showed that low lev els of serum sIFN alpha/beta receptor (less than or equal to 4.0 ng/mL) (P < .05) and serological hepatitis C virus genotype II (P < .05) were indepen dent variables contributing to sustained response to IFN therapy. Thus, pre therapeutic serum levels of sIFN alpha/beta receptor were correlated with t he effectiveness of IFN therapy, suggesting that sIFN alpha/beta receptor s uppresses the effectiveness of IFN therapy in patients with chronic hepatit is C.