Hematologic aspects of renal insufficiency

Renal dysfunction gives rise to a variety of hematologic disturbances, including anemia, leukocyte dysfunction, and coagulopathy. The anemia of renal failure has been attributed to a relative deficiency of erythropoietin, but contributing factors include an absolute deficiency of iron or folate. Other contributing factors include heavy metal toxicity, blood loss, and hemolysis. The treatment of the anemia of renal disease has advanced with the development of recombinant human erythropoietin. At doses from 15-500 micrograms/kg triweekly in selected patients, normalization of hemoglobin is presently possible. Transfusion may still have a role in patients with renal disease, although more as preconditioning for renal transplantation. In non-HLA matched transplantation, donor-specific transfusion, as well as immunosuppressives, may exert some benefit in graft survival. The coagulopathy of renal disease consists of an acquired qualitative platelet defect best remedied by dialysis but also treated successfully by cryoprecipitate or DDAVP. Infectious complications of uremia include diminished leukocyte chemotaxis, phagocytosis, and bactericidal activity. Cell-mediated immune defects and hypogammaglobulinemia have also been described. The pathophysiology involved in the protean hematologic manifestations of uremia are discussed; additionally, we describe therapeutic recommendations to deal with anemia, bleeding and infectious complications of renal failure.