Clinical measurement of steroid metabolism

Analysis of steroids in biological samples is used routinely in the diagnosis of endocrine disorders. Binding assays (radioimmunoassays, immunosorbant immunoassays and non-radioactive immunoassays) are reported often for the analysis of single steroids in plasma and urine. Chromatographic methods (high-performance liquid chromatography and gas chromatography) are used for steroid profiling where complex mixtures of steroids are analysed and the activity of biosynthetic and metabolic pathways deduced. Mass spectrometry is the ideal reference technique for detection of steroids, allowing high specificity and sensitivity. This review describes the practical issues concerning the quality of the assays performed and the potential pitfalls facing the analyst in the design of such methods. Novel approaches for the quantification of steroids, including microarrays and stable-isotope tracers are described, with these being applied in the research environment as opposed to routine biochemical laboratories.