Resistance to erythropoietin: immunohemolytic anemia induced by residual formaldehyde in dialyzers.

Because of inadequate renal synthesis of erythropoietin, the anemia associated with chronic renal failure has been treated successfully in most patients on hemodialysis with recombinant human erythropoietin. Hemolysis due to anti-Nform antibody in dialysis patients with the reused dialyzer may be one of the factors that cause refractoriness to erythropoietin therapy. Patients who do not respond to erythropoietin administration should be screened for anti-Nform antibody.