The interpretation of immunometric, chromatographic and mass spectrometric data for steroids in diagnosis of endocrine disorders.

ABSTRACT

The analysis of steroids for endocrine disorders is in transition from immunoassay of individual steroids to more specific chromatographic and mass spectrometric methods with simultaneous determination of several steroids. Gas chromatography (GC) and liquid chromatography (LC) coupled with mass spectrometry (MS) offer unrivalled analytical capability for steroid analysis. These specialist techniques were often judged to be valuable only in a research laboratory but this is no longer the case. In a urinary steroid profile up to 30 steroids are identified with concentrations and excretion rates reported in a number of ways. The assays must accommodate the wide range in steroid concentrations in biological fluids from micromolar for dehydroepiandrosterone sulphate (DHEAS) to picomolar for oestradiol and aldosterone. For plasma concentrations, panels of 5-20 steroids are reported. The profile results are complex and interpretation is a real challenge in order to inform clinicians of likely implications. Although artificial intelligence and machine learning will in time generate reports from the analysis this is a way off being adopted into clinical practice. This review offers guidance on current interpretation of the data from steroid determinations in clinical practice. Using this approach more laboratories can use the techniques to answer clinical questions and offer broader interpretation of the results so that the clinician can understand the conclusion for the steroid defect, and can be advised to program further tests if necessary and instigate treatment. The biochemistry is part of the patient workup and a clinician led multidisciplinary team discussion of the results will be required for challenging patients. The laboratory will have to consider cost implications, bearing in mind that staff costs are the highest component. GC-MS and LC-MS/MS analysis of steroids are the choices. Steroid profiling has enormous potential to improve diagnosis of adrenal disorders and should be adopted in more laboratories in favour of the cheap, non-specific immunological methods.