Endocrine Abstracts

Endocrinology came to its third revolution in the field of hormone determination. As radioimmunoassays in the 60s paved the way to the knowledge of modern endocrinology, and as automated immunoassays in the 70s linked analytical measurement to the clinical practice, nowadays liquid chromatography – tandem mass spectrometry (LC–MS/MS) represents the evolution of the high-throughput approach, typical of automated platforms, toward the high reliability and specificity of the measurement, typical of gas chromatography (GC)–MS, and toward the power of simultaneous profiling of wide panels of hormones working on a small sample volume and with minimal pretreatment of the sample. First introduced for therapeutic drug monitoring and for neonatal screening of inborn errors, LC–MS/MS is breaking into clinical and research laboratories for steroids determination, as proved by a growing literature. Comparison studies between immunoassays and LC- or GC–MS methods, attested with analytical proof what clinicians had already perceived about the lack of specificity and the derived inconsistent results affecting immunoassays. The earlier and more targeted steroid, for the urgency of the problem in the clinical practice, was testosterone, followed by androgens, 17OHprogesterone, cortisol and 25hidroxyvitamin D3. Estrogens and aldosterone are also attracting steroids, but they require last generation devices or additional steps in the sample preparation. Furthermore, LC-MS/MS allows determination of other steroids, like dihydrotestosterone, 21- and 11deoxycortisol, corticosterone, deoxycorticosterone, essential for paediatric deficit diagnosis. The introduction of LC–MS/MS in routine requires specifics site requirements and highly experienced personnel. Furthermore, it needs medium-high initial costs for the instrument installation and maintenance, but they can be rapidly amortized thanks to the low cost-per-sample. An international effort should now be made in order to standardize new LC–MS/MS methods and to produce new shared reference intervals, toward the complete replacement of immunoassays.