Objectives: As populations with sickle cell disease (SCD) live longer, it is likely that the burden of renal dysfunction will be an increasing challenge for patients. In this study, we aim to determine the prevalence of renal dysfunction and its possible predictors in persons with SCD.
Methods: Ninety-eight patients with the homozygous SCD (SS disease;55 females, 43 males; mean age 34 ± 2.3 years) in their steady state had measurements of glomerular filtration rate (GFR) using 99mTc-DTPA nuclear renal scan, serum creatinine, and urinary albumin: creatinine ratio. Other haematological and biochemical measurements and data on clinical events were completed for each individual.
Results: Chronic kidney disease (CKD) stages 3 and above was present in 6% of the study population, and 65.3% had albuminuria. Hyperfiltration occurred in 24.5% patients with two-thirds having albuminuria as well. Serum creatinine was an insensitive marker of renal dysfunction as started rising after measured GFR fell below 50 mls/min/1.73 m(2). Multiple regression modelling showed serum creatinine and height to be significantly associated with GFR. Serum creatinine was also significantly associated with albuminuria, and age was not a predictor in any of the models. There was no association with markers of haemolysis.
Conclusion: We conclude that the burden of renal dysfunction is quite high in this young cohort with SS disease. Serum creatinine is a late and insensitive marker of worsening glomerular function, and screening for albuminuria could begin early in life. Longitudinal studies will continue to increase our understanding of pathophysiological mechanisms that lead to CKD in this specific population.
Keywords: Albuminuria; Chronic kidney disease; Glomerular filtration rate; Hyperfiltration; SS disease.