Human ochratoxin A biomarkers—From exposure to effect

Abstract

Ochratoxin A (OTA) is a nephrotoxic mycotoxin that has received particular attention because of the toxic effects, widespread occurrence in contaminated food and feed chain, suspected causal effect on nephropathies, and, more recently, possibility of exposure by inhalation in domicile and occupational settings. Biomarkers have been used not only to ascertain the role of OTA in inducing chronic renal failure diseases, but also as a means to portray general populations’ risk to the mycotoxin. Biomonitoring can thus be used to assess internal OTA exposure, with no need to recognize the main source of exposure. And so it presents undeniable advantages over the monitoring of external dose. With a just right understanding of biomarkers, it is possible to follow the trail from exposure right to effect, and so contribute both to surveillance plans and etiological studies. In recognition of the long serum half-life and the renal elimination of OTA, most of the studies present serum/plasma and/or urine analyses as markers of exposure. In this review and for each of these main matrices, a comparison over the advantages and disadvantages is offered. Although currently limited, an overview of the current knowledge on OTA biomarkers and the influential role of the individual characteristics, namely gender and age, along with season and geographical location is given. Attention is also given to the ongoing debate over the existence of OTA-DNA adducts, a biomarker of effective dose regarded as an alternative to biomarkers of internal dose. Although unspecific, OTA effect biomarkers are also reviewed.

Keywords::

• Assessment
• biomarker
• biomonitoring
• exposure
• blood
• DNA adducts
• effect
• β2-microglobulin
• milk
• ochratoxin A
• urine

Acknowledgements

The authors are thankful to J. Bento for proofreading the manuscript.

Declaration of interest

The authors’ affiliation is as shown on the first page. The paper was prepared with grant FCT—Fundação para a Ciência e Tecnologia through support from the project PTDC/AGR-ALI/65528/2006 and a PhD fellowship (SFRH/BD/37409/2007) granted to Sofia C. Duarte. The submission to this journal is approved by all authors who alone are responsible for the content and writing of the paper.