[Spondylarthritis ankylopoietica and HLA-B27]

There is a strict association between HLA-B27 and a group of spondylarthropathies, especially with ankylosing spondylarthritis (AS). The causes of the association remain obscure, different hypotheses are regarded. There is an interaction between B27 and bacteria. However, the etiological and pathogenetic roles played by any of them in AS cannot be regarded as proved. B27 is an important genetic factor in the disease expression. It is implicated in the pathogenesis, being undoubtedly a risk factor. At the same time it cannot be excluded that B27 is only one of the genes, predisposed to the disease. From the practical standpoint, it is important that the I degree kinship relatives of AS patients, males in particular, having HLA-B27 may be subjected to prophylactic medical examinations.