ALLELIC VARIATION AT THE TAP-1 LOCUS INFLUENCES DISEASE PHENOTYPE IN HLA-B27 POSITIVE INDIVIDUALS WITH ANKYLOSING-SPONDYLITIS

The objective was to determine the role of the TAP 1 gene in influenci ng the phenotype of disease in adult patients with ankylosing spondyli tis (AS). The distribution of TAP 1 gene alleles was determined using the PCR RFLP method and restriction enzymes Bcl I and Ace I. The study population included 115 HLA-B27 positive patients with well-documente d AS and 41 HLA-B27 positive normal controls. No significant differenc e in distribution of TAP 1 alleles was noted in comparisons of all AS patients with normal controls. However, AS patients with extraspinal d isease were noted to have a significantly increased prevalence of the TAP 1B allele (17.0%) as compared to AS patients without extraspinal d isease (2.9%) (P=0.005) or normal controls (1.9%) (P= 0.005). Polymorp hism at the TAP 1 locus may influence disease outcome in patients with AS.