Enteric bacteria and HLA-B27 associated cell surface modification in patients with seronegative spondarthritis.

Cytotoxic studies indicate cross-reactivity between some enteric organisms and cells obtained from the majority of patients with ankylosing spondylitis. Preliminary studies suggest that the factor responsible for cross-reactivity may be generated by a bacterial plasmid. However, the mechanism mediating the interaction between the HLA-B27 positive cell and the bacterial antigen is at present unknown.