Sickle hemoglobinopathy and the kidney.

Individuals with sickle cell anemia manifest various functional and anatomic renal aberrations. Function of the renal medulla is uniformly affected as reflected in impaired urinary concentrating and acidifying ability. Disruption of normal blood flow patterns in the medulla with impairment of function of the loop of Henle (functional papillectomy), presumably because of sickling in the hyperosmolar and anoxic environment of the renal medulla, may mediate these abnormalities. Hematuria and frank papillary necrosis may result through the same mechanism. Nephrotic syndrome, glomerulonephritis, and progressive renal failure occur on occasion in sickle cell disease. Recent evidence strongly suggests an immune complex glomerulonephritis due to tubular injury with release of renal tubular antigen into the circulation of such individuals. Hemodialysis and renal transplantation appear to be reasonable modes of therapy for sickle cell patients in chronic renal failure.