title: Evaluation of multiplexed cytokine and inflammation marker measurements: a methodologic study.
abstract: BACKGROUND
  Chronic inflammation is etiologically related to several cancers. We evaluated the performance [ability to detect concentrations above the assay's lower limit of detection, coefficients of variation (CV), and intraclass correlation coefficients (ICC)] of 116 inflammation, immune, and metabolic markers across two Luminex bead-based commercial kits and three specimen types.
  
  
  METHODS
  From 100 cancer-free participants in the Prostate, Lung, Colorectal, and Ovarian Cancer Trial, serum, heparin plasma, and EDTA plasma samples were utilized. We measured levels of 67 and 97 markers using Bio-Rad and Millipore kits, respectively. Reproducibility was assessed using 40 blinded duplicates (20 within-batches and 20 across-batches) for each specimen type.
  
  
  RESULTS
  A majority of markers were detectable in more than 25% of individuals on all specimen types/kits. Of the 67 Bio-Rad markers, 51, 52, and 47 markers in serum, heparin plasma, and EDTA plasma, respectively, had across-batch CVs of less than 20%. Likewise, of 97 Millipore markers, 75, 69, and 78 markers in serum, heparin plasma, and EDTA plasma, respectively, had across-batch CVs of less than 20%. When results were combined across specimen types, 45 Bio-Rad and 71 Millipore markers had acceptable performance (>25% detectability on all three specimen types and across-batch CVs <20% on at least two of three specimen types). Median concentrations and ICCs differed to a small extent across specimen types and to a large extent between Bio-Rad and Millipore.
  
  
  CONCLUSIONS
  Inflammation and immune markers can be measured reliably in serum and plasma samples using multiplexed Luminex-based methods.
  
  
  CONCLUSIONS
  Multiplexed assays can be utilized for epidemiologic investigations into the role of inflammation in cancer etiology.
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, 6120 Executive Boulevard, EPS 7072, Rockville, MD 20852, USA. chaturva@mail.nih.gov
authors.forename: Anil K
authors.initials: AK
authors.lastname: Chaturvedi
authors.forename: Troy J
authors.initials: TJ
authors.lastname: Kemp
authors.forename: Ruth M
authors.initials: RM
authors.lastname: Pfeiffer
authors.forename: Angelique
authors.initials: A
authors.lastname: Biancotto
authors.forename: Marcus
authors.initials: M
authors.lastname: Williams
authors.forename: Stella
authors.initials: S
authors.lastname: Munuo
authors.forename: Mark P
authors.initials: MP
authors.lastname: Purdue
authors.forename: Ann W
authors.initials: AW
authors.lastname: Hsing
authors.forename: Ligia
authors.initials: L
authors.lastname: Pinto
authors.forename: J Philip
authors.initials: JP
authors.lastname: McCoy
authors.forename: Allan
authors.initials: A
authors.lastname: Hildesheim
mesh_terms: D015415:Biomarkers / Q000097:blood*; D016207:Cytokines / Q000097:blood*; D005260:Female; D006493:Heparin / Q000097:blood*; D006801:Humans; D007249:Inflammation / Q000097:blood; D008297:Male; D015203:Reproducibility of Results
chemical_list: D015415:Biomarkers; D016207:Cytokines; D006493:Heparin