Serum Levels of Classical HLA Class I Antigen in HIV-Infected patients during antiretroviral therapy. Correlation with the clinical outcome

Aim. Human major histocompatibility complex class I antigens (HLA-A, -B, and -C) are heterodimetric molecules composed of a heavy chain non covalently associated with an invariant protein known as B2-microglobulin. Besides being expressed on the membrane of the large majority of nucleated cells, HLA class I antigens are found in serum (sHLA-I). We have previously detected a significant increase in the serum level of B2-microglobulin-associated HLA-I antigens in HIV-infected patients as compared to HIV-negative controls. Materials and methods. The introduction of the Highly Active Antiretroviral Theraphy (HAART) has modified the clinical course of the disease and decreased the AIDS-related morbidity and mortality. Therefore, we measured the levels of sHLA-I antigens in 64 HIV-infected patients before and during HAART treatment and correlated them with the imunological and virological response to the antiretroviral treatment. Result and conclusions. Serum sHLA-I antigen level was elevaed in all HIV-infected subjects before and significantly decreased after 36 months of HAART treatment correlated with the decrease of plasma HIV-RNA level and with the increased od CD4+ T-lymphocyte number. These results suggest that the measurement of sHLA-I antigens serum level might represent a useful surrogate marker to monitor HIV-positive subjects undergoing HAART treatment.