[Protective role of HLA-B27 in HIV and hepatitis C virus infection].

The human leukocyte antigen (HLA) B27 has been linked to rheumatic diseases such as ankylosing spondylitis nearly 40 years ago, but its role in pathogenesis remains unclear. Apart from this association, HLA-B27 has a positive effect in two of the most threatening human viral infections: in HIV infection, HLA-B27 positive patients have low viral loads, CD4+ T cell counts decline slowly and AIDS progresses slowly. In acute hepatitis C virus (HCV) infection, HLA-B27 is associated with a very high rate of spontaneous viral clearance. The mechanisms of protection by HLA-B27 in HIV and HCV infection have been characterized in the recent years and will be discussed in this article.