GOUT IN BLACK SOUTH-AFRICANS - A CLINICAL AND GENETIC-STUDY

Objective-To define the clinical characteristics of gout and determine if there were any genetic associations with gout in black South Africans. Methods-The records of 107 patients with gout seen over a five year period were retrospectively analysed. The HLA class I and class II antigens were studied in a prospective survey of 46 patients. Results-The male to female ratio was 6.6:1. The diagnosis of gout was based on identification of monosodium urate crystals from the synovial fluid, synovial tissue or tophaceous material in 62 patients (58%) and on clinical criteria in the remaining 45 patients (42%). The mode of presentation was monoarthritis in 40 patients (37.4%), pauciarthritis in 30 (28%) and polyarthritis in 37 (34.6%). The joints which were most frequently involved were the knee in 91 patients (85%), the first metatarsophalangeal in 80 (74.8%) and the ankle in 66 (61.7%). A secondary cause was identified in 52 patients (48.6%) (diuretic therapy in 48 patients and chronic renal impairment in four); 55 patients (51.4%) had primary gout, The genetic study showed an increased frequency of HLA-B14 in patients with primary gout compared with controls. Conclusions-Gout is more common in black Africans than previously recognised and frequently presents with involvement of more than one joint. There was an increased frequency of HLA-B14 in patients with primary gout but the clinical significance of this is uncertain.