Chapter 514 Hematologic Diseases Causing Hematuria

514.1 Sickle Cell Nephropathy

Craig C. Porter, Ellis D. Avner


Gross or microscopic hematuria may be seen in children with sickle cell disease or sickle trait and tends to resolve spontaneously in the majority of children (Chapter 456.1). With the exception of the associated renal cell carcinoma, clinically apparent renal involvement occurs more commonly in patients with sickle cell disease than those with sickle cell trait.

Etiology

The renal manifestations of sickle cell nephropathy are generally related to microthrombosis secondary to sickling in the relatively hypoxic, acidic, hypertonic renal medulla where vascular stasis is present. Analgesic use, volume depletion with consequent prerenal failure, infectious complications, and iron-related hepatic disease are independent contributing factors.

Pathology

Ischemia, papillary necrosis, and interstitial fibrosis are present in the kidneys of these patients.

Clinical Manifestations

Clinical manifestations of sickle cell nephropathy include polyuria caused by a urinary concentrating defect, renal tubular acidosis, and proteinuria associated with glomerular lesions resembling focal segmental glomerulosclerosis or membranoproliferative glomerulonephritis.

Approximately 20-30% of patients with sickle cell disease develop proteinuria. Nephrotic range proteinuria with or without clinically apparent nephrotic syndrome occurs less commonly and is often associated with progressive renal failure.

Treatment

Angiotensin-converting enzyme inhibitors, such as enalapril, can be used to achieve a significant reduction in urine protein excretion in patients with daily urine protein excretion exceeding 500 mg. Hydroxyurea can also be beneficial in reducing urinary protein excretion.

Prognosis

Sickle cell nephropathy can eventually lead to hypertension, renal insufficiency, and progressive kidney failure. Dialysis and eventual kidney transplantation are successful treatment modalities when kidney failure is irreversible.

Bibliography

Fitzhugh CD, Wigfall DR, Ware RE. Enalapril and hydroxyurea therapy for children with sickle nephropathy. Pediatr Blood Cancer. 2005;45:982-985.

McKie KT, Hanevold CD, Hernandez C, et al. Prevalence, presentation, and treatment of microalbuminuria and proteinuria in children with sickle cell disease. Pediatr Hematol Oncol. 2007;29:140-144.

Pham PT, Pham PC, Wilkinson AH, et al. Renal abnormalities in sickle cell disease. Kidney Int. 2000;57:1-8.

Scheinman JI. Sickle cell nephropathy. In: Avner ED, Harmon WE, Niaudet P, et al, editors. Pediatric nephrology. ed 6. Heidelburg, Germany: Springer-Verlag; 2009:1181-1198.

514.2 Coagulopathies and Thrombocytopenia

Craig C. Porter and Ellis D. Avner

Gross or microscopic hematuria may be associated with inherited or acquired disorders of coagulation (hemophilia, disseminated intravascular coagulation, thrombocytopenia). In these cases, however, hematuria is not usually the presenting complaint but develops after other manifestations (Chapters 469-478).