RESUMO Os resultados da medicina laboratorial influenciam uma alta porcentagem das decisões tomadas pelos médicos. A globalização requer que os resultados obtidos por métodos diferentes sejam concordantes, garantindo a segurança do paciente. É necessário haver colaboração internacional para difundir essa exigência. Essa colaboração deve basear-se na rastreabilidade da medicina laboratorial, bem como na adoção de procedimentos de medição e materiais de referência de alta hierarquia metrológica e que sejam comutáveis internacionalmente. A aplicação da cadeia de rastreabilidade metrológica facilita essa abordagem universal. A quantificação de colesterol no soro e Hemoglobina sanguínea A1c (HbA1c) no sangue serve como exemplo do processo de padronização de métodos com impacto demonstrado nos resultados clínicos. Por outro lado, a quantificação de paratormônio (PTH) e hemoglobina A2 (HbA2) no sangue revela a variabilidade entre os métodos atualmente em uso, que compromete o tratamento do paciente e demanda, portanto, a harmonização e/ou padronização dos métodos. Os desafios à difusão da rastreabilidade em medicina laboratorial incluem fatores como disponibilidade de materiais e métodos de referência, diferenças geográficas, uso de unidades de medida variadas, ensaios de analitos complexos e coordenação mundial limitada. Uma colaboração abrangente requer o envolvimento das partes interessadas no âmbito mundial, desde especialistas gerais a aqueles com particular experiência em medicina laboratorial, com vivência em laboratórios clínicos de rotina. Um plano de coordenação é apresentado neste artigo com ações atribuídas a cada um dos envolvidos.

ABSTRACT Laboratory medicine results influence a high percentage of all clinical decisions. Globalization requires that laboratory medicine results should be transferable between methods in the interests of patient safety. International collaboration is necessary to deliver this requirement. That collaboration should be based on traceability in laboratory medicine and the adoption of higher order international commutable reference materials and measurement procedures. Application of the metrological traceability chain facilitates a universal approach. The measurement of serum cholesterol and blood HbA1c serve as examples of the process of method standardization where an impact on clinical outcomes is demonstrable. The measurement of plasma parathyroid hormone and blood HbA2 serve as examples where the current between method variability is compromising patient management and method standardization and/or harmonization is required. Challenges to the widespread adoption of traceability in laboratory medicine include the availability of reference materials and methods; geographical differences; the use of variable units; complex analytes and limited global coordination. The global collaboration requires the involvement of several different stakeholder groups ranging from international experts to laboratory medicine specialists in routine clinical laboratories. A coordinated action plan is presented with actions attributable to each of these stakeholder groups.

Methasterone is a designer anabolic steroid that is prohibited for athletes and is monitored by anti-doping laboratories. In this work, our objective is to discover new human phase I metabolites, define their excretion kinetics for 30 days and analyze their phase II metabolism (sulfate, cysteine and N-acetylcysteine conjugates). Urine samples from four volunteers were analyzed by chromatographic techniques. Through gas chromatography coupled to mass spectrometry analysis it was possible to detect methasterone and its nine phase I metabolites in the urine samples after glucuronide enzymatic hydrolysis, from which one were previously unreported. These nine compounds were not excreted in free form. The new proposed metabolite is 17β-hydroxy-2α,17α-dimethyl-5β-androstan-3-one, obtained from the epimerization at C5. The 3α-hydroxy metabolite, currently monitored by anti-doping laboratories, was the most abundant and was detected for the longest time. Furthermore, four other long-term metabolites were identified. By ultra-performance liquid chromatography coupled to tandem mass spectrometry, only the drug and a known metabolite were detected after glucuronide hydrolysis, and phase II metabolites were not found. Thus, our results contribute to elucidating methasterone metabolism, including long-term metabolites besides of the 3α-hydroxy in routine doping analysis, which is very important due to variation in human metabolism.