Proteinuria in adults with sickle-cell disease: the role of hydroxycarbamide(hydroxyurea) as a protective agent.

BACKGROUND: Renal abnormalities are often seen in sickle cell disease (SCD). OBJECTIVE: To investigate the role of hydroxycarbamide as a protective agent in sickle cell nephropathy. SETTING: Patients with SCD followed at a Hematology outpatients clinic. METHODS: Prospective study with 26 SCD patients. Renal function evaluation was performed and a comparison between patients and control group was done. Patients using hydroxycarbamide were compared to those not taking this drug. MAIN OUTCOME MEASURE: Effect of hydroxycarbamide on renal function. RESULTS: Patients mean age was 32.1 ± 9.9 years, and 16 (61 %) were males. Glomerular hyperfiltration was found in nine patients with SCD (34.6 %). GFR < 60 mL/min/1.73 m² was observed in three cases (11.5 %). Microalbuminuria (30-300 mg/day) was found in seven cases (27 %) and macroalbuminuria (>300 mg/dia) in one patient (3.8 %). All patients had urinary concentrating deficit, and inability to acidify urine was found in ten cases (38.4 %). The comparison of patients according to the use of hydroxycarbamide showed lower levels of serum creatinine in those using the drug (0.6 ± 0.1 vs. 0.8 ± 0.3 mg/dL, p = 0.03), as well as lower levels of 24 h-proteinuria (226 ± 16 vs. 414 ± 76 mg/dL, p = 0.0001), but not microalbuminuria (79 ± 15 vs. 55 ± 86 mg/dL, p = 0.35). CONCLUSION: SCD is associated with important renal abnormalities. Hydroxycarbamide seems to protect kidney function in SCD by decreasing proteinuria but not microalbuminuria.