title: Circulating IL-8 and anti-IL-8 autoantibody in patients with ovarian cancer.
abstract: OBJECTIVE
  In an ongoing effort to identify diagnostic ovarian cancer biomarkers, SEREX (serological analysis of recombinant cDNA expression libraries) technique was employed resulting in detection of 20 known genes, nine ESTs and one novel sequence. Interleukin-8 (IL-8) was one of ovarian cancer-associated antigens identified by SEREX screening. The objective of this study was, therefore, to evaluate the potential importance of circulating anti-IL-8 antibody as ovarian cancer biomarker.
  
  
  METHODS
  We developed and optimized a new immunofluorescent bead-based assay for detection of anti-IL-8 antibody in blood serum. Circulating IL-8 and anti-IL-8 IgG concentrations were measured in blood sera from 44 patients with early stage (I-II) ovarian cancer, 50 patients with late stage (III-IV) ovarian cancer, 37 patients with benign pelvic masses, and 80 healthy women using the bead-based assay.
  
  
  RESULTS
  Our data indicate that serum contains IL-8 cytokine, anti-IL-8 antibody, and IL-8:anti-IL-8 complexes. We found that concentrations of IL-8 and anti-IL-8 antibody were elevated in sera of patients with ovarian cancer as compared with healthy controls. Logistic regression analysis of circulating concentrations of anti-IL-8 IgG in patients with stages I-II ovarian cancer versus healthy controls allowed for prediction of early ovarian cancer with 98% specificity, 65.5% sensitivity, 80.3% of patients correctly classified. Combining IL-8 and anti-IL-8 IgG with CA 125 resulted in increased classification power as compared to individual markers analyzed separately.
  
  
  CONCLUSIONS
  Thus, IL-8 and anti-IL-8 autoantibody might potentially serve as additional biomarkers for ovarian cancer.
authors.affiliation: University of Pittsburgh Cancer Institute, Hillman Cancer Center, University of Pittsburgh, 5117 Centre Avenue, Pittsburgh, PA 15213, USA. lokshina@pitt.edu
authors.forename: Anna E
authors.initials: AE
authors.lastname: Lokshin
authors.forename: Mathew
authors.initials: M
authors.lastname: Winans
authors.forename: Douglas
authors.initials: D
authors.lastname: Landsittel
authors.forename: Adele M
authors.initials: AM
authors.lastname: Marrangoni
authors.forename: Lyudmila
authors.initials: L
authors.lastname: Velikokhatnaya
authors.forename: Francesmary
authors.initials: F
authors.lastname: Modugno
authors.forename: Brian M
authors.initials: BM
authors.lastname: Nolen
authors.forename: Elieser
authors.initials: E
authors.lastname: Gorelik
mesh_terms: D001323:Autoantibodies / Q000097:blood*; D014408:Biomarkers, Tumor / Q000097:blood / Q000276:immunology*; D018394:CA-125 Antigen / Q000097:blood; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007075:Immunoglobulin M / Q000097:blood / Q000276:immunology; D020382:Interleukin-18 / Q000276:immunology*; D016209:Interleukin-8 / Q000276:immunology*; D010051:Ovarian Neoplasms / Q000097:blood / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D014408:Biomarkers, Tumor; D018394:CA-125 Antigen; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D020382:Interleukin-18; D016209:Interleukin-8