title: Reference intervals for carcinoembryonic antigen (CEA), CA125, MUC1, Alfa-foeto-protein (AFP), neuron-specific enolase (NSE) and CA19.9 from the NORIP study.
abstract: OBJECTIVE
  Adhering to current IFCC recommendations, we calculated upper 97.5 % reference limits for serum tumor markers.
  
  
  METHODS
  Serum samples from 498 healthy individuals from the Nordic reference interval project (NORIP) were investigated for carcinoembryonic antigen (CEA), CA125 and MUC1 (episialin, CA15.3) using in-house immunofluorometric assays and, for alpha-foetoprotein (AFP), a PerkinElmer Life Sciences assay, neuron-specific enolase (NSE) using an in-house immunoradiometric assay and CA19.9 using a Beckman Access assay. All assays participate in external quality assessment programs.
  
  
  RESULTS
  CEA concentrations increased with age and smoking. Upper reference limits for non-smokers were 3.59 microg/L at 50 years and 4.12 microg/L at 70 years. CA125 concentrations were age-independent and the upper reference limit was 35.8 kU/L. MUC1 increased with age and body mass index (BMI). Upper reference limits were 31.7 kU/L at 40 years and BMI 24, 37.5 kU/L at 70 years and BMI 24, and 33.7 kU/L at 40 years and BMI 30. AFP increases with age, and the upper reference limits were 3.82 kU/L at 20 years and 8.70 kU/L at 60 years. An upper reference limit for NSE was 8.91 microg/L in non-smokers; smokers exhibited significantly lower levels. The upper reference limit for individuals expressing CA19.9 was 28.3 kU/L.
  
  
  CONCLUSIONS
  For AFP, CA125 and CA19.9, the reference levels obtained were close to previously reported reference ranges. Smoking and age were confirmed as covariates for CEA. The associations between MUC1 with age and BMI and between NSE and smoking have not been reported previously.
authors.affiliation: Central Laboratory, Norwegian Radium Hospital, Montebello, Oslo, Norway. johan.bjerner@medisin.uio.no
authors.forename: Johan
authors.initials: J
authors.lastname: Bjerner
authors.forename: Anita
authors.initials: A
authors.lastname: Høgetveit
authors.forename: Katrine
authors.initials: K
authors.lastname: Wold Akselberg
authors.forename: Kirsti
authors.initials: K
authors.lastname: Vangsnes
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Paus
authors.forename: Trine
authors.initials: T
authors.lastname: Bjøro
authors.forename: Ole Petter
authors.initials: OP
authors.lastname: Børmer
authors.forename: Kjell
authors.initials: K
authors.lastname: Nustad
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D018394:CA-125 Antigen / Q000097:blood*; D018395:CA-19-9 Antigen / Q000097:blood*; D002272:Carcinoembryonic Antigen / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018396:Mucin-1 / Q000097:blood*; D010751:Phosphopyruvate Hydratase / Q000097:blood*; D012016:Reference Values; D012044:Regression Analysis; D012537:Scandinavian and Nordic Countries; D000509:alpha-Fetoproteins / Q000032:analysis*
chemical_list: D018394:CA-125 Antigen; D018395:CA-19-9 Antigen; D002272:Carcinoembryonic Antigen; D018396:Mucin-1; D000509:alpha-Fetoproteins; D010751:Phosphopyruvate Hydratase