Clinical Applications of LC-MS Sex Steroid Assays
Measurement of sex steroids, particularly testosterone and estradiol, is important for diagnosis or management of a host of conditions, such as puberty disorders, hypogonadism, polycystic ovary syndrome, amenorrhea, and tumors of ovary, testes, breast and prostate.
In a recent study in Current Opinion in Endocrinology, Diabetes, and Obesity, Mayo Clinic researchers Hemamalini Ketha, Ph.D., Stefan Grebe, M.D., Ph.D., and Ravinder Singh, Ph.D., review methodologies for the measurement of sex steroids. The review summarizes why and how liquid chromatography tandem mass spectrometry (LC-MS/MS) is increasingly replacing other methodologies for measurement of testosterone and estradiol.
Historically, metabolites of testosterone and estradiol were measured as ketosteroids in urine using colorimetric assays that lacked sensitivity and specificity due to endogenous and exogenous interferences. While manual radio-immunoassays offered increased sensitivity, they were still imperfect. As testing demand increased, they were displaced by automated immunoassays. These offered better throughput and precision, but suffered worse specificity problems. Further, various immunoassays are all compromised by a limited dynamic measurement range.
To overcome these problems, LC-MS/MS methods have been developed and validated for quantitation of sex steroids. These methods reduce interferences, provide better specificity, improve dynamic range, and reduce between-method bias. According to the article, Endocrine Society and Urology Society guidelines have highlighted the limitations of the immunoassays for sex steroids and have provided convincing evidence that mass spectrometric methods are preferable for measurement of sex steroid hormones.
To learn more about LC-MS/MS testing methods, view Mayo Medical Laboratories' LC-MS/MS tests. The TTST test evaluates men with symptoms or signs of possible hypogonadism, such as loss of libido, erectile dysfunction, gynecomastia, osteoporosis, or infertility. The EEST test is useful for all applications that require moderately sensitive measurement of estradiol.