AB0549 Comparison between hla b27 prevalence among arabs and some european and american populations

Background HLA-B27 antigen is the strongest genetic risk factor associated with ankylosing spondylitis (AS) contributing to around thirty percent of its total genetic risk factors. HLA-B27 inclusion into the new ASAS classification criteria for spondyloarthropathies has led to earlier detection of the disease especially for the Arab populations where the diagnosis is often delayed. Data about HLA-B27 prevalence among these populations are very limited. Some data suggest that they had a much lower prevalence of HLA B27 among both healthy and AS patients when compared to Western populations. Objectives To Assess HLA-B27 prevalence among healthy and AS patients of the Arab populations and to compare it with some large studies done among European and American populations. Methods We divided Arab populations into three parts: A) Levant which includes Jordan, Iraq, Syria, Lebanon, and Palestine, B) Arabian Peninsula which includes Saudi Arabia, UAE, Kuwait, Qatar, Oman, Yemen and Bahrain, and C) North Africa which includes Egypt, Libya, Algeria, Tunis and Morocco. We looked up all the articles from PubMed and Medline addressing HLA-B27 prevalence among all these areas on AS patients and healthy individuals. HLA typing was performed by standard 2-stage micro-lymphocytotoxicity method in most of the studies. We also searched for large studies conducted on Western populations over the last ten years for comparison. Results Six studies were conducted in the Levant area, eight in the Arabian Peninsula and ten in North Africa. The prevalence of HLA B27 over these three regions was found to be highly variable ranging between 26.3 and 94% among AS patients and 0.3 to 5.7% among healthy individuals. Studies over some European and American populations revealed also highly variable results, but the number of subjects was much larger. Conclusions We have huge lack of data among Arabs in different regions in comparison to Europe and America. The studies conducted are few with small number of subjects. No data was found related to Libya, Yemen or Sudan. The total number of AS patients over 21 studies was found to be 1,535 only. Conclusions regarding HLA B27 prevalence among Arab subjects whether healthy or having AS cannot be drawn. More wide based population studies are needed to prevent delays in diagnosis and to start the treatment earlier for better disease outcome. Disclosure of Interest None Declared