Behavior of soluble HLA class I antigens in patients with chronic hepatitis C during interferon therapy: An early predictor marker of response?

Soluble HLA class I antigens (sHLA-I),β2-microglobulin (β2-μ.) and alanine aminotransferase (ALT) serum levels have been evaluated in 16 patients affected by chronic hepatitis C treated for six months with recombinant interferon-α (rIFN-α, 3 MU three times a week). The predictor role of sHLA-I and ALT modifications with respect to the response to rIFN-α therapy was also evaluated. Six patients responded (group 1), five patients relapsed following an initial response (group 2), and five did not respond to rIFN-α treatment (group 3). The baseline serum levels of sHLA-I andβ2-μ were significantly higher in all three groups of HCV-positive patients with respect to HCV-negative controls (P<0.05). A significant increase of sHLA-I serum level with respect to baseline value (P<0.001) was observed in group 1 patients after two weeks of rIFN-α treatment. sHLA-I serum level then decreased, although remaining steadily and significantly increased with respect to baseline (P values ranging from 0.05 to 0.01) in the following five months and then returned to baseline one month after the end of rIFN-α administration. No significant variations ofβ2-μ serum levels were detected throughout the observation period. In group 1 patients ALT serum levels significantly decreased after two weeks of rIFN-α treatment (P<0.001) and then remained in the normal range throughout the observation period. In the other two groups of patients no relevant variations of sHLA-I andβ2-μ serum levels were found during and after rIFN-α therapy. The modifications of sHLA-I serum levels discriminate, as a single marker, group 1 patients from group 2 and 3 patients after two weeks of rIFN-α treatment (P<0.003). The association of sHLA-I and ALT modifications improves the discriminant power and leads to a complete differentiation of the three groups of patients after four weeks of rIFN-α treatment (P<0.0001). If confirmed in a larger series of patients, these results will provide a useful marker to predict which patients affected by chronic hepatitis C will respond to treatment and will help to avoid their ineffective treatment with an expensive and potentially harmful drug.