Microalbuminuria in sickle cell disease.

The kidney is involved in virtually all individuals who inherit the sickle cell form of hemoglobin. Though asymptomatic and relatively common, proteinuria in patients with sickle cell anemia (SS) over 40 years old is associated with reduced creatinine clearance. The subclinical increase in urinary albumin is termed microalbuminuria and is a marker of preclinical glomerular damage. The aim of the present study was to determine the presence of microalbuminuria measured by radioimmunoassay in patients with sickle cell disease. The study included 41 patients with SS, 11 patients with hemoglobin SC disease, 4 subjects with S beta-thalassemia and 10 normal controls. All subjects were teenagers or adults. Sixteen SS patients (40%) and 1 SC (9%) and 1 S beta (25%) patient presented mean urinary albumin excretion (UAE) above normal values (30 mg/l. No correlation was observed between UAE and age, creatinine clearance, hemoglobin level or %HbF. These parameters, as well as the presence of leg ulcers, were not significantly different between SS patients with and without UAE above 30 mg/dl. The high prevalence of microalbuminuria in patients with sickle cell anemia indicates that glomerular damage is common. The connection between microalbuminuria and clinical nephropathy has been demonstrated in diabetes and may indicate a sign of early disease rather than a marker for susceptibility. Thus, microalbuminuria may be an early indicator of glomerular damage for patients with sickle cell disease.