B7-CREG and ankylosing spondylitis.

The distribution of HLA alleles in B27 negative AS and Reiter's syndrome patients is reviewed. Some groups have reported an increased incidence of B7-CREG antigens (B7, B22 and B40) in B27 negative Caucasian AS patients, but we could not confirm these results, although an increased incidence of B7 was found in our B27 negative American Black patients with AS. Studies with larger numbers of B27 negative AS patients of various racial groups are needed to establish clearly if there is an association with B7-CREG antigens.