Spondyloarthropathies in sub-Saharan Africa

HLA-B27 is virtually absent in most of the sub-Saharan Africa populations, and ankylosing spondylitis is rare; only a few patients have been reported from central and southern Africa. HLA-B27 was present in only one of 17 pat ients (6%). The disease shows clinical features that are similar to those o bserved in white HLA-B27-negative patients with ankylosing spondylitis; ie, the disease onset is later compared with HLA-B27-positive patients, the pa tients rarely get acute anterior uveitis as one of the extra-articular mani festations, and familial occurrence of ankylosing spondylitis is rarely obs erved. There is a virtual absence of ankylosing spondylitis even in the wes t African countries of Gambia and Senegal, where 3% to 6% of the general po pulation has HLA-B27. The epidemic of HIV infection in sub-Saharan Africa i n recent years, however, has been associated with a dramatic upsurge in the prevalence of spondyloarthropathies other than ankylosing spondylitis, pri marily reactive arthritis and undifferentiated forms of the disease, and le ss often psoriatic arthritis. HLA-B27, because of its rarity and virtual la ck of association with the observed cases of spondyloarthropathy in this po pulation, cannot be used as an aid to diagnosis of spondyloarthropathy in b lack Africans. Conversely, HIV infection is increasingly showing such a str ong association with reactive arthritis, psoriatic arthritis, and undiffere ntiated spondyloarthropathies in sub-Saharan African populations that any p atient with acute or chronic inflammatory arthritis may need to be tested f or possible HIV infection. More research is needed on the evaluation of ris k and protective factors in sub-Saharan African populations to better delin eate the relative importance of genetic and environmental factors in the pa thogenesis of spondyloarthropathies. (C) 2000 Lippincott Williams & Wilkins , Inc.