title: Intermethod discordance for alpha-fetoprotein measurements in Fanconi anemia.
abstract: BACKGROUND
  The significantly higher serum alpha-fetoprotein (AFP) in patients with Fanconi anemia (FA) than in non-FA aplastic patients has potential diagnostic utility, but the increase is method-dependent. The aim of this study was to compare five AFP assays on FA and non-FA samples and to investigate possible explanations for FA-specific discrepancies.
  
  
  METHODS
  Two methods available in our laboratory (Kryptor and IMx) were compared on 59 FA and 27 non-FA patient samples. Kryptor, Immulite, Elecsys, Immuno-I, and Elsa-2 methods were then compared on 14 FA and 14 non-FA patient samples. The AFP glycosylation profile was analyzed by electrophoretic separation in a lectin-containing gel.
  
  
  RESULTS
  With all six methods, AFP values were significantly higher in FA than in non-FA patients, but the diagnostic precision and optimal cutoff values varied. Indeed, two methods reached 100% sensitivity and specificity, but in other methods, one or both of these parameters were significantly <100%. Neither heterophilic antibodies nor a specific glycosylation profile was detected in FA samples.
  
  
  CONCLUSIONS
  AFP results are method-dependent in FA. New methods must be evaluated before use in differential diagnosis of aplastic patients.
authors.affiliation: Nuclear Medicine Department, Assistance Publique-Hôpitaux de Paris, Saint-Louis Hospital, 75010 Paris, France. cassinat@chu-stlouis.fr
authors.forename: B
authors.initials: B
authors.lastname: Cassinat
authors.forename: D
authors.initials: D
authors.lastname: Darsin
authors.forename: P
authors.initials: P
authors.lastname: Guardiola
authors.forename: M E
authors.initials: ME
authors.lastname: Toubert
authors.forename: J D
authors.initials: JD
authors.lastname: Rain
authors.forename: E
authors.initials: E
authors.lastname: Gluckman
authors.forename: M H
authors.initials: MH
authors.lastname: Schlageter
mesh_terms: D000293:Adolescent; D000328:Adult; D000741:Anemia, Aplastic / Q000097:blood / Q000175:diagnosis; D000910:Antibodies, Heterophile / Q000097:blood; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D004587:Electrophoresis, Agar Gel; D005199:Fanconi Anemia / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000379:methods; D007223:Infant; D037102:Lectins; D008297:Male; D008875:Middle Aged; D020033:Protein Isoforms / Q000097:blood; D011786:Quality Control; D000509:alpha-Fetoproteins / Q000032:analysis*
chemical_list: D000910:Antibodies, Heterophile; D037102:Lectins; D020033:Protein Isoforms; D000509:alpha-Fetoproteins