Kidney function, urinalysis abnormalities and correlates in equatorial Africans with sickle cell disease

BACKGROUND Little is known about the renal profiles of individuals with sickle cell disease (SCD) in equatorial Africa, the global epicenter of SCD. We evaluated the kidney function, urinalysis abnormalities and their correlates in a group of Cameroonians homozygous for SCD. METHODS This was a cross-sectional study of 4-month duration involving 72 homozygous SCD patients (39 men, 54%), recruited during routine visit or vaso-occlusive crisis at the Yaoundé Central Hospital in Cameroon. Clinical and laboratory data were used to evaluate the renal and urinalysis parameters, and potential effects of SCD-related clinical and hematological variables on those parameters investigated through linear and logistic regression models. RESULTS The mean serum creatinine increased with increasing age, translating into a decreasing estimated glomerular filtration rate (eGFR) with age (P < 0.001). One patient (1.4%) had an eGFR of <60 mL/min and nine others (12.5%) had 60 ≤ eGFR ≤ 90 mL/min. The eGFR was lower in women and decreased with increasing systolic blood pressure. The prevalence of proteinuria (>200 mg/g) was 93% and the main urinalysis abnormalities were leukocyturia (77.8%), albuminuria (40.3%), hematuria (13.9%) and cristalluria (9.7%). None of the predictive clinical, hematological and urinary factors studied was associated with proteinuria or albuminuria, while hematuria and leukocyturia were associated with increasing age and male gender. CONCLUSIONS Cameroonians homozygous for SCD present a high prevalence of proteinuria and urinalysis abnormalities, and a slight renal impairment. Age, blood pressure variables and gender seem to be the main determinants. Urinalysis abnormalities and kidney function assessment should be an active pursuit in women with SCD.