PREDICTION OF SUSTAINED RESPONSE TO INTERFERON-ALPHA THERAPY WITH SERUM-SOLUBLE INTERLEUKIN-2 RECEPTOR LEVELS IN PATIENTS WITH CHRONIC HEPATITIS-C

It is difficult to predict sustained response to interferon alpha ther apy for patients with chronic hepatitis C. Loss of serum hepatitis C v iral RNA (HCV-RNA) and normal serum alanine aminotransferase (ALT) lev el at the end of treatment do not necessarily mean sustained response, Relapses are very common, In this study, serum levels of soluble inte rleukin 2 receptor (sIL-2R, an indicator of immune response) were inve stigated to see if they are helpful to predict sustained response. We studied consecutive twenty patients with chronic hepatitis C who had H CV-RNA negativity and normal ALT levels at the end of interferon alpha therapy. Total doses of interferon ranged from 288 million units (MU) to 480MU. Serum HCV-RNA sequences were examined before and at the end of treatment by nested polymerase chain reaction (PCR) using primers to the 5' noncoding region. Serum sIL-2R levels were also measured bef ore and at the end of treatment using enzyme-linked immunoassay. Eight of twenty (40%) patients were sustained responders and the rest of th e patients (60%) relapsed (partial responders), Serum sIL-2R levels in sustained responders decreased (-96.2 +/- 45.2 IU/1), whereas partial responders showed increase in serum sIL-2R levels (81.3 +/- 50.5 IU/1 ). The difference in sIL-2R changes between sustained responders and p artial responders was significant (P < 0.01), In particular, six of si x (100%) patients who showed more than 50 IU/1 increase in sIL-2R leve ls were partial responders. In conclusion, monitoring serum sIL-2R lev els with HCV-RNA and ALT is useful to predict sustained response to in terferon.