[Comparative analysis of the determination of serum testosterobe levels by different methods]

The serum concentration of total testosterone were measured in 100 male patients aged 19-65 years who had visited the clinic and polyclinic of the Endocrinology Research Center, Russian Academy of Medical Sciences for complaints about different dysfunctions of the endocrine glands. Testosterone was measured by the well-known currently available technologies: automatic Vitros ECi, Architect, and Access multianalyzers, manual Delfia and DRS enzyme immunoassay kits, and radioimmunoassay (RIA) that had been developed within the framework of the WHO Human Reproduction Programme and adjusted by the reference assay (gas chromatography/mass spectroscopy). The closest results were obtained when determining the level of testosterone by RIA and by means of the Vitros ECi multianalyzer (13.1 vs 13.0 nmol/l, medians). All other technologies demonstrated a low correlation with RIS and had positive biases, especially with the use of the Delfia kits (as high as 60 and, at low concentrations, 100%). The positive bias tends to decrease in patients with higher testosterone levels ( > 10 nmol/l) for all studied methods.