title: Human aflatoxin albumin adducts quantitatively compared by ELISA, HPLC with fluorescence detection, and HPLC with isotope dilution mass spectrometry.
abstract: Essential to the conduct of epidemiologic studies examining aflatoxin exposure and the risk of heptocellular carcinoma, impaired growth, and acute toxicity has been the development of quantitative biomarkers of exposure to aflatoxins, particularly aflatoxin B(1). In this study, identical serum sample sets were analyzed for aflatoxin-albumin adducts by ELISA, high-performance liquid chromatography (HPLC) with fluorescence detection (HPLC-f), and HPLC with isotope dilution mass spectrometry (IDMS). The human samples analyzed were from an acute aflatoxicosis outbreak in Kenya in 2004 (n = 102) and the measured values ranged from 0.018 to 67.0, nondetectable to 13.6, and 0.002 to 17.7 ng/mg albumin for the respective methods. The Deming regression slopes for the HPLC-f and ELISA concentrations as a function of the IDMS concentrations were 0.71 (r(2) = 0.95) and 3.3 (r(2) = 0.96), respectively. When the samples were classified as cases or controls, based on clinical diagnosis, all methods were predictive of outcome (P < 0.01). Further, to evaluate assay precision, duplicate samples were prepared at three levels by dilution of an exposed human sample and were analyzed on three separate days. Excluding one assay value by ELISA and one assay by HPLC-f, the overall relative SD were 8.7%, 10.5%, and 9.4% for IDMS, HPLC-f, and ELISA, respectively. IDMS was the most sensitive technique and HPLC-f was the least sensitive method. Overall, this study shows an excellent correlation between three independent methodologies conducted in different laboratories and supports the validation of these technologies for assessment of human exposure to this environmental toxin and carcinogen.
authors.affiliation: National Center for Environmental Health, US Centers for Disease Control and Prevention, Atlanta, GA 30341, USA.
authors.forename: Leslie F
authors.initials: LF
authors.lastname: McCoy
authors.forename: Peter F
authors.initials: PF
authors.lastname: Scholl
authors.forename: Anne E
authors.initials: AE
authors.lastname: Sutcliffe
authors.forename: Stephanie M
authors.initials: SM
authors.lastname: Kieszak
authors.forename: Carissa D
authors.initials: CD
authors.lastname: Powers
authors.forename: Helen S
authors.initials: HS
authors.lastname: Rogers
authors.forename: Yun Yun
authors.initials: YY
authors.lastname: Gong
authors.forename: John D
authors.initials: JD
authors.lastname: Groopman
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Wild
authors.forename: Rosemary L
authors.initials: RL
authors.lastname: Schleicher
mesh_terms: D016604:Aflatoxin B1 / Q000009:adverse effects / Q000032:analysis*; D014408:Biomarkers, Tumor / Q000032:analysis*; D006528:Carcinoma, Hepatocellular / Q000737:chemistry / Q000453:epidemiology / Q000209:etiology; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004781:Environmental Exposure / Q000009:adverse effects / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006801:Humans; D015994:Incidence; D007630:Kenya / Q000453:epidemiology; D008113:Liver Neoplasms / Q000737:chemistry / Q000453:epidemiology / Q000209:etiology; D008239:Lysine / Q000009:adverse effects / Q000032:analysis*; D013058:Mass Spectrometry / Q000379:methods*; D015203:Reproducibility of Results
chemical_list: D014408:Biomarkers, Tumor; C066451:aflatoxin B1-lysine adduct; D016604:Aflatoxin B1; D008239:Lysine