Diagnosis of PCOS by Revised T Assay

Hyperandrogenemia has become an important factor in the diagnosis of polycystic ovary syndrome (PCOS), in Japan as well as Western countries, since the Japanese PCOS diagnostic criteria were revised in 2007. The revised electrochemiluminescence immunoassay (ECLIA) reagent for total testosterone (T) (ECLusys TESTO II ; New T assay), which has lower cross-reactivity with DHEA-S than the previous reagent (ECLusys TESTO I ; Old T assay), has recently been developed. We studied the improvement between New and Old T assays in regards to the diagnostic performance of serum T for patients with PCOS. Serum T levels were measured in both normal women (Control, n=92) and PCOS patients (n=86). The rate of elevated T using each kit was significantly higher in the PCOS group than in the Control group, and significantly higher using New T assay (38/86, 44.2%) compared with Old T assay (26/86, 30.2%). A significant correlation was found between T level and body mass index, but not LH level. Furthermore, higher detection rates of hormonal abnormalities were seen in PCOS patients using combined measurement of both T and LH (63/80) compared with single measurement of either T (37/80) or LH (36/80). Therefore, the serum T assay is essential for the diagnosis of PCOS, and New T assay combined with the LH assay may improve the diagnostic process for PCOS