['To evaluate the effects of enalapril, an angiotensin-converting enzyme inhibitor, on albuminuria associated with sickle cell anemia.', 'Two males and 6 females, mean age 22.8 +/- 5.5 years, with sickle cell anemia and albuminuria, received enalapril for 6 months. Before entry into the study, all had a urinary albumin concentration above 30 mg/L as determined by radioimmunoassay documented on three separate occasions at intervals of 15 to 30 days. Samples were collected before 10 AM after an oral water load of 10 mL/kg.', "Enalapril reduced 6 patients' pretreatment hyperalbuminuria to normal. One patient whose levels did not reach normal values experienced a reduction of 70%. Fractional excretion of sodium, potassium, and lithium did not change during the treatment. Mean arterial pressure decreased by 8.6 +/- 0.42 mm Hg. Two years after enalapril was discontinued, there were no changes in sodium, potassium, or creatinine levels of 7 patients who had received enalapril or in their mean arterial pressures. Urinary albumin concentration increased relative to pretreatment levels in 2 individuals, returned to pretreatment levels in 2, and remained below 30 mg/L in 2."] Does enalapril reduce the albuminuria of patients with sickle cell disease?