Gout is more frequent in sickle cell disease than in haemoglobin AA among sub-Saharan Africans

Abstract

Background: Sickle Cell Disease (SCD) is a common autosomal recessive disorder worldwide that mostly affects Africans. Hyperuricemia, a common biochemical finding, occurs in up to 41% of SCD patients. Although hyperuricaemia is the most important risk factor for gout, the
latter is uncommonly reported in SCD.
Objective: To determine the frequency and factors associated with hyperuricaemia and gout among patients with Sickle Cell Disease  (SCD).
Design: This was a cross sectional study.
Methods: The study involved 104 SCD patients and 104 haemoglobin AA (HbAA) controls. The diagnosis of gout was based on the  demonstration of monosodium urate crystals in the synovial fluid of symptomatic individuals. Hyperuricaemia was found in 28 (26.9%) and 2 (1.9%) of SCD and control participants respectively (p<0.001). The median (range) Serum Uric Acid (SUA) was higher among patients (330 μmol/L [146 to 702 μmol/]) than in controls (232 μmol/L [143 to 440 μmol/L]), (p<0.01). Six (5.8%) cases of gout were found among the patients and none among the controls (p=0.029). The pattern of articular involvement was monoarticular in 2 (33.3%), oligoarticular in 3 (50%) and polyarticular in 1 (16.7%). One (16.7%) patient had subcutaneous tophi. Factors associated with gout in SCD were age, hyperuricaemia, more than two SCD crises in the past year and more than two hospital admissions in the past year.
Conclusion: Gout as is hyperuricaemia, is more frequent in persons with SCD than in the general population. It is mostly oligoarticular and older patients with multiple attacks of painful joint swelling as well as frequent hospital admissions may be at higher risk of gout.