title: Prevalence of anti-erythropoietin antibodies in hemodialysis patients without clinical signs of pure red cell aplasia. Comparison between hypo- and normoresponsive patients treated with epoetins for renal anemia.
abstract: OBJECTIVE
  The prevalence of anti-erythropoietin antibodies in renal patients without clinical evidence of pure red cell aplasia (PRCA) who respond poorly to epoetin is unknown. This study tested for anti-erythropoietin antibodies in hemodialysis patients who were either hypo- or normoresponsive to epoetin treatment.
  
  
  METHODS
  Epoetin hyporesponsiveness (hemoglobin < or =10.5 g/dl and epoetin > or =9,000 IU/week) and normoresponsiveness (hemoglobin >10.5 g/dl and epoetin <7,000 IU/week) were arbitrarily defined. Prevalence of anti-erythropoietin antibodies in hemodialysis patients without symptoms of PRCA was determined by screening sera of 536 patients from 35 German KfH dialysis units, using enzyme-linked immunosorbent assay (ELISA). Positive results were verified by radioimmunoprecipitation assay (RIP) and neutralizing activity was determined by bioassay.
  
  
  RESULTS
  Anti-erythropoietin antibodies were detected in 3 hyporesponsive and 3 normoresponsive patients using ELISA. One patient per group was verified as borderline by RIP testing; the other 4 were negative. The bioassay was negative for 1 patient; the other died unrelated to PRCA before testing. Follow-up with RIP testing after 15 months under continuous epoetin treatment was negative (4 patients, 2 deceased).
  
  
  CONCLUSIONS
  This survey did not identify anti-erythropoietin antibodies in hemodialysis patient's hyporesponsive to epoetin and does not support presumptive antibody screening as a routine work-up in these patients.
authors.affiliation: Department of Internal Medicine, Division of Nephrology, University Hospital of Cologne, Cologne, Germany. drmstoffel@yahoo.de
authors.forename: Markus P
authors.initials: MP
authors.lastname: Stoffel
authors.forename: Heinz
authors.initials: H
authors.lastname: Haverkamp
authors.forename: Arno
authors.initials: A
authors.lastname: Kromminga
authors.forename: Karl W
authors.initials: KW
authors.lastname: Lauterbach
authors.forename: Conrad A
authors.initials: CA
authors.lastname: Baldamus
mesh_terms: D000368:Aged; D000740:Anemia / Q000188:drug therapy* / Q000209:etiology / Q000276:immunology*; D000906:Antibodies / Q000097:blood*; D015331:Cohort Studies; D004351:Drug Resistance; D004797:Enzyme-Linked Immunosorbent Assay; D004921:Erythropoietin / Q000276:immunology* / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015531:Radioimmunoprecipitation Assay; D011994:Recombinant Proteins; D012010:Red-Cell Aplasia, Pure / Q000503:physiopathology; D006435:Renal Dialysis; D051437:Renal Insufficiency / Q000150:complications* / Q000628:therapy
chemical_list: D000906:Antibodies; D011994:Recombinant Proteins; D004921:Erythropoietin