title: Proteomics analysis of plasma for early diagnosis of endometriosis.
abstract: OBJECTIVE
  To test the hypothesis that differential surface-enhanced laser desorption/ionization time-of-flight mass spectrometry protein or peptide expression in plasma can be used in infertile women with or without pelvic pain to predict the presence of laparoscopically and histologically confirmed endometriosis, especially in the subpopulation with a normal preoperative gynecologic ultrasound examination.
  
  
  METHODS
  Surface-enhanced laser desorption/ionization time-of-flight mass spectrometry analysis was performed on 254 plasma samples obtained from 89 women without endometriosis and 165 women with endometriosis (histologically confirmed) undergoing laparoscopies for infertility with or without pelvic pain. Data were analyzed using least squares support vector machines and were divided randomly (100 times) into a training data set (70%) and a test data set (30%).
  
  
  RESULTS
  Minimal-to-mild endometriosis was best predicted (sensitivity 75%, 95% confidence interval [CI] 63-89; specificity 86%, 95% CI 71-94; positive predictive value 83.6%, negative predictive value 78.3%) using a model based on five peptide and protein peaks (range 4.898-14.698 m/z) in menstrual phase samples. Moderate-to-severe endometriosis was best predicted (sensitivity 98%, 95% CI 84-100; specificity 81%, 95% CI 67-92; positive predictive value 74.4%, negative predictive value 98.6%) using a model based on five other peptide and protein peaks (range 2.189-7.457 m/z) in luteal phase samples. The peak with the highest intensity (2.189 m/z) was identified as a fibrinogen β-chain peptide. Ultrasonography-negative endometriosis was best predicted (sensitivity 88%, 95% CI 73-100; specificity 84%, 95% CI 71-96) using a model based on five peptide peaks (range 2.058-42.065 m/z) in menstrual phase samples.
  
  
  CONCLUSIONS
  A noninvasive test using proteomic analysis of plasma samples obtained during the menstrual phase enabled the diagnosis of endometriosis undetectable by ultrasonography with high sensitivity and specificity.
  
  
  METHODS
  II.
authors.affiliation: Department of Obstetrics and Gynaecology, Leuven University Fertility Centre, University Hospital Gasthuisberg, Belgium.
authors.forename: Amelie
authors.initials: A
authors.lastname: Fassbender
authors.forename: Etienne
authors.initials: E
authors.lastname: Waelkens
authors.forename: Nico
authors.initials: N
authors.lastname: Verbeeck
authors.forename: Cleophas M
authors.initials: CM
authors.lastname: Kyama
authors.forename: Attila
authors.initials: A
authors.lastname: Bokor
authors.forename: Alexandra
authors.initials: A
authors.lastname: Vodolazkaia
authors.forename: Raf
authors.initials: R
authors.lastname: Van de Plas
authors.forename: Christel
authors.initials: C
authors.lastname: Meuleman
authors.forename: Karen
authors.initials: K
authors.lastname: Peeraer
authors.forename: Carla
authors.initials: C
authors.lastname: Tomassetti
authors.forename: Olivier
authors.initials: O
authors.lastname: Gevaert
authors.forename: Fabian
authors.initials: F
authors.lastname: Ojeda
authors.forename: Bart
authors.initials: B
authors.lastname: De Moor
authors.forename: Thomas
authors.initials: T
authors.lastname: D'Hooghe
mesh_terms: D000328:Adult; D001798:Blood Proteins / Q000032:analysis*; D004715:Endometriosis / Q000097:blood* / Q000175:diagnosis* / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008598:Menstruation / Q000097:blood; D011237:Predictive Value of Tests; D040901:Proteomics; D012720:Severity of Illness Index; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014463:Ultrasonography; D055815:Young Adult
chemical_list: D001798:Blood Proteins