TAP polymorphism is not associated with ankylosing spondylitis and complications with acute anterior uveitis in HLA-B27-positive Japanese

HLA-B27 is associated with the etiology of ankylosing spondylitis (AS) and acute anterior uveitis (AP;Cl). Transporter associated with antigen process ing (TAP) 1 and TAP2 polymorphism influences the range of peptide presented by HLA class I molecules. In this report, contribution of TAP polymorphism to the susceptibility to AS and AAU was studied in HLA-B27-positive Japane se individuals. Patients were classified into three groups: 16 AS patients, 14 AAU patients and 22 patients with both AS and AAU. Twelve HLA-Bn-positi ve healthy individuals were included as a control. TAP polymorphism was det ected by PCR-RFLP methods. Significant differences in frequencies of TAP1 a lleles were not found between patient groups None of the TAP2 frequencies s howed increased or decreased frequencies compared with HLA-B27-positive hea lthy controls. In comparison with a random Japanese control, TAP2D allele f requency was significantly increased in the AAU group, but failed to reach a significant level in a group consisting of the AAU-only patients and the patients with both AS and AAU. All of the patient groups were noted to have a significantly increased prevalence of the TAP2H allele as compared to ra ndom controls; however, the higher frequency of this allele was detected in HLA-B27 healthy controls as well. These observations suggest a linkage dis equilibrium between TAP2D, TAP2H and HLA-B27 in Japanese.