{"title":"Knowing the minimal detectable dose can facilitate the interpretation of a hair test result: Case example with chlortalidone","authors":"","doi":"10.1016/j.cca.2024.119890","DOIUrl":null,"url":null,"abstract":"<div><p>In case of an adverse analytical finding, a low (estimate) urine concentration can be the consequence of 2 very different situations: it can be the tail end of a drug voluntarily consumed to enhance athletic performance, even by microdosing (which is not effective for all drugs), or it can be the result of a contamination, irrespective of its source. For numerous doping agents, a hair test can allow discriminating doping from contamination based on the measured concentration or even the absence of the target drug. Given hair produces incremental concentrations, its analysis offers the possibility of establishing a pattern of drug use and thus, verifying self-reported histories of exposure. In order to provide a retrospective calendar of drug use, segmental analysis of the hair strand can be performed. In doping, the usual practice is to test the substance in short segments, such as 1 cm to avoid drug dilution when using larger segments. During the last months, seven athletes have returned an adverse analytical finding for the diuretic chlortalidone, with reported urine concentrations in the range 20 to 50 ng/mL. All these athletes submitted, via their legal team, their hair for establishing a pattern of exposure. Results were always consistent with incidental contamination (hair concentration lower than 5 pg/mg), although the source of contamination was never identified. The interpretation of the findings was established in the light of the limited literature, including hair tests after microdosing and therapeutic use.</p></div>","PeriodicalId":10205,"journal":{"name":"Clinica Chimica Acta","volume":null,"pages":null},"PeriodicalIF":3.2000,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Clinica Chimica Acta","FirstCategoryId":"3","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0009898124021430","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MEDICAL LABORATORY TECHNOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
In case of an adverse analytical finding, a low (estimate) urine concentration can be the consequence of 2 very different situations: it can be the tail end of a drug voluntarily consumed to enhance athletic performance, even by microdosing (which is not effective for all drugs), or it can be the result of a contamination, irrespective of its source. For numerous doping agents, a hair test can allow discriminating doping from contamination based on the measured concentration or even the absence of the target drug. Given hair produces incremental concentrations, its analysis offers the possibility of establishing a pattern of drug use and thus, verifying self-reported histories of exposure. In order to provide a retrospective calendar of drug use, segmental analysis of the hair strand can be performed. In doping, the usual practice is to test the substance in short segments, such as 1 cm to avoid drug dilution when using larger segments. During the last months, seven athletes have returned an adverse analytical finding for the diuretic chlortalidone, with reported urine concentrations in the range 20 to 50 ng/mL. All these athletes submitted, via their legal team, their hair for establishing a pattern of exposure. Results were always consistent with incidental contamination (hair concentration lower than 5 pg/mg), although the source of contamination was never identified. The interpretation of the findings was established in the light of the limited literature, including hair tests after microdosing and therapeutic use.
期刊介绍:
The Official Journal of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC)
Clinica Chimica Acta is a high-quality journal which publishes original Research Communications in the field of clinical chemistry and laboratory medicine, defined as the diagnostic application of chemistry, biochemistry, immunochemistry, biochemical aspects of hematology, toxicology, and molecular biology to the study of human disease in body fluids and cells.
The objective of the journal is to publish novel information leading to a better understanding of biological mechanisms of human diseases, their prevention, diagnosis, and patient management. Reports of an applied clinical character are also welcome. Papers concerned with normal metabolic processes or with constituents of normal cells or body fluids, such as reports of experimental or clinical studies in animals, are only considered when they are clearly and directly relevant to human disease. Evaluation of commercial products have a low priority for publication, unless they are novel or represent a technological breakthrough. Studies dealing with effects of drugs and natural products and studies dealing with the redox status in various diseases are not within the journal''s scope. Development and evaluation of novel analytical methodologies where applicable to diagnostic clinical chemistry and laboratory medicine, including point-of-care testing, and topics on laboratory management and informatics will also be considered. Studies focused on emerging diagnostic technologies and (big) data analysis procedures including digitalization, mobile Health, and artificial Intelligence applied to Laboratory Medicine are also of interest.