The demographic and clinical spectrum of Arab versus Asian patients with ankylosing spondylitis in the UAE.

Ankylosing spondylitis is a rather uncommon condition in the UAE. Over a period of 10 years. 28 hospital-based patients diagnosed as having AS were retrospectively studied. They included 17 Arabs and 11 Asians. The onset of AS in most patients in this study was in adulthood (mean age at onset was 27.7 years in Arabs and 28.75 years in Asians). HLA B27 was positive in 56 and 81% in these two populations, respectively (P > 0.05). Analysis of these figures, however, along with previous relevant published data, could indicate that Arabs with AS are less likely to be B27-positive than Asians. Among the Arab patients there was not a single case from the local community, which could be attributed to the extremely low rate of B27 phenotype in their normal population. The interracial variations in the frequency of clinical features were statistically insignificant, therefore indicating some degree of similarity in the form and disease expression in both groups. AS is characterized as being predominantly axial in the majority of our patients. Extraspinal (oligo-poly) arthropathy involved mainly hips and knees, and there have been fewer extra-articular manifestations compared with other series published.