Influence of state-of-the-art laboratory techniques on the phenotyping of women with polycystic ovary syndrome in the clinical setting

PURPOSE: Evidence-based guidelines for the management of polycystic ovary syndrome (PCOS) recommend clinical laboratories use liquid chromatography-tandem mass spectrometry (LC-MS/MS) for diagnosing biochemical hyperandrogenism. However, automated immunoassays are still mostly used in routine laboratories worldwide. Another hurdle for PCOS phenotyping in the clinical setting is ultrasound assessment of polycystic ovarian morphology. We address the impact of using state-of-the-art (LC-MS/MS) and of an anti-müllerian hormone (AMH) assay on the diagnosis of PCOS in routine practice. METHODS: In a cross-sectional study, we included 359 premenopausal women consecutively evaluated because of symptoms of functional androgen excess or hyperandrogenemia, and finally diagnosed with PCOS. Patients were submitted to routine phenotyping based on serum androgen measurements by immunoassays and an ovarian ultrasound when necessary. Samples of all patients were also assayed by LC-MS/MS for hyperandrogenemia and for circulating AMH. RESULTS: The observed agreement between immunoassays and LC-MS/MS in identifying hyperandrogenemia was poor [78.0%; k(95%CI): 0.366 (0.283;0.449)]. The observed agreement between ultrasound and increased AMH was 27.3% [(95%CI): 0.060 (0.005; 0.115)]. Using LC-MS/MS changed PCOS phenotypes in 60(15.8%) patients. Fifty-two (18.3%) individuals with hyperandrogenemia by routine immunoassays no longer presented with androgen excess by LC-MS/MS. Overall diagnostic agreement between routine assessment using immunoassays and ultrasound and that derived from LC-MS/MS and the addition of AMH to US was moderate [weighted κ (linear weights): 0.512 (0.416;0.608)]. CONCLUSIONS: Immunoassays used in routine practice are unacceptably inaccurate for phenotyping women with PCOS. Our data cast some doubts upon the interchangeability of serum AMH and ultrasound examination for the diagnosis of PCOS.