Objective: To compare the clinical, serologic and radiologic expression of rheumatoid arthritis (RA) in UK Caucasian and ethnic black patients from Zimbabwe.
Methods: Standardized protocols and assessment criteria were used to study 84 black patients with no non-Bantu antecedents and 84 UK Caucasian patients with RA (matched for disease duration, sex and age).
Results: Articular manifestations of RA were less severe in the black patients with RA from Zimbabwe as shown by less early morning stiffness (p = 0.001), fewer patients with > or = 3 active joints (p = 0.01), fewer joint deformities (p = 0.004) and better grip strength (p = 0.001) in comparison to the white patients with RA from the UK. Caucasian patients had a higher frequency of extraarticular manifestations (p = 1 x 10(-6)) including rheumatoid nodules (p = 0.0001), Raynaud's (p = 0.01) and Sicca syndrome (p = 0.001). Toxic effects from disease modifying antirheumatic drugs occurred less frequently in black patients (p = 0.0002). More white patients had Ro and La antibodies. The radiologic changes in the black patients were less severe than those in the white patients. The distribution of erosions in hands and feet were different in the 2 groups of patients studied. There were no differences between the urban and rural black patients but a more detailed study involving a large number of patients is required to confirm this observation.
Conclusion: Black patients with RA from Zimbabwe have a disease that is clinically and radiologically less severe with fewer extraarticular features when compared to UK white patients.