Renal Complications of Sickle Cell Disease

A broad spectrum of renal changes is observed in patients with sickle cell anemia, and ideal therapeutic measures for the management of these alterations are still being studied. Affected patients have deficient urinary concentration and potassium excretion. Perhaps owing to a compensatory mechanism, the proximal tubules are in a condition of ‘hyperfunction’, with increased sodium and phosphorus reabsorption and greater creatinine and uric acid secretion. Mild tubular acidosis may be present. No treatment has been reported for these tubular changes, except for care in the maintenance of hydration. The use of anti-inflammatory drugs is being studied in order to inhibit the prostaglandins involved in the process. Increased renal blood flow, glomerular filtration rate, and filtration fraction are frequent findings.

Hematuria commonly occurs as a consequence of red blood cell sickling in the renal medulla, papillary necrosis, or even renal medullary carcinoma. Measures such as increased fluid ingestion, urine alkalinization and, if necessary, administration of epsilon-aminocaproic acid and certain invasive procedures have been proposed to treat hematuria.

Nephropathy in patients with sickle cell anemia can be manifested by proteinuria and, more rarely, nephrotic syndrome. Drugs such as prednisone and cyclophosphamide are ineffective for the treatment of patients with nephrotic syndrome. Angiotensin converting enzyme inhibitors decrease proteinuria, but their long-term effect in preventing the progression of glomerular disease has not been established. Chronic renal failure, although infrequent, may be one of the manifestations of this disease. Hemodialysis and transplantation are satisfactory therapeutic options for patients with end-stage renal disease.