BASIC SCIENCE: GYNECOLOGY Measurement of hs-CRP is irrelevant to diagnose and stage endometriosis: prospective study of 834 patients Thibault Thubert, MD, MS; Pietro Santulli, MD, MS, PhD; Louis Marcellin, MD, MS; Sophie Menard, MD; Magatte M’Baye, MD; Isabelle Streuli, MD, MS; Bruno Borghese, MD, PhD; Dominique de Ziegler, MD, PhD; Charles Chapron, MD, PhD OBJECTIVE: The pathogenesis of endometriosis is associated with an inflammatory process. Here, we assessed if the levels of high-sensitivity C-reactive protein (hs-CRP) in serum could constitute an effective method for detecting systemic inflammation during endometriosis. STUDY DESIGN: This was a prospective, laboratory-based study, which was carried out in a tertiary care university hospital. Patients with histologically proven endometriosis (n ¼ 370) and unaffected women (n ¼ 464) were enrolled from January 2005 through December 2009. We performed complete surgical excision of endometriotic lesions with pathological analysis. In addition, hs-CRP levels were determined through a particle-enhanced immunoturbidimetric method. The hs- CRP levels were measured in both controls and women with endo- metriosis according to the established surgical classifications of endometriosis: superficial peritoneal endometriosis, endometrioma, and deep infiltration endometriosis. Also, hs-CRP levels were evaluated according to hormonal treatment and menstrual cycle. RESULTS: The hs-CRP serum levels did not statistically differ between women with endometriosis and controls (median in ng/mL [range]: 0.82 [0.04e42.89] vs 0.9 [0.03e43.73], respectively; P ¼ .599). Moreover, subgroup analysis revealed no difference among superficial peritoneal endometriosis, endometrioma, deep infiltration endome- triosis, and controls: 0.8 (0.15e13.35), 0.81 (0.04e38.82), 0.83 (0.09e42.89), and 0.9 (0.03e43.73), respectively; P ¼ .872. Furthermore, no effect was observed regarding hormonal treatment or menstrual cycle. CONCLUSION: Although endometriosis is an inflammatory disease, we failed to identify any systemic changes in hs-CRP serum levels. Therefore, hs-CRP analysis appears to be irrelevant to the diagnosis and staging of endometriosis. Key words: C-reactive protein, endometrioma, endometriosis, high- sensitivity C-reactive protein, inflammation, pathogenesis Cite this article as: Thubert T, Santulli P, Marcellin L, et al. Measurement of hs-CRP is irrelevant to diagnose and stage endometriosis: prospective study of 834 patients. Am J Obstet Gynecol 2014;210:x.ex-x.ex. E ndometriosis is a benign, estrogen- dependent, chronic disease af- fecting 10% of women of reproductive age. It is characterized by the presence of endometrial-like tissue outside the uterus. 1 The most common clinical features of this condition are pelvic pain and/or infertility. The gold stan- dard for conclusive diagnosis of endo- metriosis is laparoscopy with histologic confirmation. However, these procedures can delay diagnosis (6-9 years), and require 5 physician visits before final determination and/or referral. 2 Notably, the severity of endometriosis is graded in relation to the anatomical extension of the lesions following the revised Amer- ican Society for Reproductive Medicine (ASRM) classification 3 or according to a recently published surgical classifica- tion (superficial peritoneal endome- triosis [SUP], endometrioma [OMA], and deep infiltration endometriosis [DIE]). 4,5 Evaluation of the exact nature and extension of endometriotic lesions is essential for effective disease manage- ment. In the case of surgical management, a precise preoperative evaluation of the disease is necessary for planning adequate surgical intervention and for patient referral to appropriate tertiary care cen- ters specialized in endometriosis. 6-8 Over From the Faculty of Medicine Université Paris Descartes, Sorbonne Paris Cité (all authors), and Department of Gynecology, Obstetrics, and Reproductive Medicine, Centre Hospitalier Universitaire Cochin of the Groupe Hospitalier Universitaire Ouest, Assistance Publique-Hôpitaux de Paris (all authors), and the Immunology Laboratory EA 1833, Paris, France (Dr Santulli), and Institut Cochin, Université Paris Descartes, Centre National de Recherche Scientifique (Drs Santulli, Marcellin, Borghese, and Chapron), and Institut National de la Santé et de la Recherche Médicale, Unité de recherche U1016 (Drs Santulli, Marcellin, Borghese, and Chapron), Paris, France. Received Sept. 19, 2013; revised Jan. 13, 2014; accepted Jan. 13, 2014. The authors report no conflict of interest. Presented in poster format at the 42nd Global Congress on Minimally Invasive Gynecology of the American Association of Gynecologic Laparoscopists, National Harbor, MD, Nov. 10-14, 2013, and at the IIIèmes Journées de Chirurgie Gynécologique, Paris, France, Sept. 18-20, 2013. Reprints: Thibault Thubert, MD, MS, Service de Gynécologie-Obstétrique II et Médecine de la Reproduction, Port RoyaleHôpitaux Universitaires Paris Centre, 53, avenue de l’Observatoire, 75679 Paris 14 France. thibault.thubert@gmail.com. 0002-9378/$36.00  ª 2014 Mosby, Inc. All rights reserved.  http://dx.doi.org/10.1016/j.ajog.2014.01.022 MONTH 2014 American Journal of Obstetrics & Gynecology 1.e1 Research www. AJOG.org