Quantitative comparison of aflatoxin B1 serum albumin adducts in humans by isotope dilution mass spectrometry and ELISA

Peter F. Scholl, Paul C. Turner, Anne E. Sutcliffe, Abdoulaye Sylla, Momadou S. Diallo, Marlin D. Friesen, John D. Groopman, Christopher P. Wild

Research output: Contribution to journalArticle

Abstract

Metabolic activation of the hepatocarcinogenic mycotoxin aflatoxin B1 (AFB1) results in the covalent attachment of AFB1 to serum albumin. Digestion of adducted albumin releases AFB1-lysine, a biomarker of exposure status. AF-albumin adducts have been most frequently measured in precipitated serum albumin using an immunoassay (ELISA); however, a sensitive and specific isotope dilution mass spectrometric (IDMS) assay for measurement of AFB1-lysine in serum has recently been developed. The ELISA and IDMS methods were compared using 20 human sera collected in Guinea, West Africa, where AF exposure is endemic. Measurement of AFB1-lysine adduct concentrations by IDMS in serum and albumin precipitated from the same sample revealed that precipitation has no effect on the measured adduct levels. The concentration of AF-albumin adducts measured by ELISA and AFB1-lysine measured by IDMS in 2 mg of albumin were well correlated (R = 0.88, P < 0.0001); however, AF-albumin adduct concentrations measured by ELISA were on average 2.6-fold greater than those of the AFB1-lysine adduct. Although these data suggest that the ELISA is measuring other AF adducts in addition to AFB1-lysine, these biomarkers are comparable in their ability to assess AF exposure at AF-albumin concentrations ≥3 pg AFB1-lysine equivalents/mg albumin. Identification of other adducts may clarify the mechanistic basis for using AF-protein biomarkers to assess exposure status in future epidemiologic studies of liver cancer.

Original languageEnglish (US)
Pages (from-to)823-826
Number of pages4
JournalCancer Epidemiology Biomarkers and Prevention
Volume15
Issue number4
DOIs
StatePublished - Apr 1 2006

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ASJC Scopus subject areas

  • Epidemiology
  • Oncology

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