title: Pleural cancer antigen-125 levels in benign and malignant pleural effusions.
abstract: OBJECTIVE
  To examine the properties of mesothelial cells by measuring pleural cancer antigen 125 (CA-125) levels in different types of benign and malignant pleural effusions.
  
  
  METHODS
  In this retrospective study, pleural fluid was collected from 326 patients; pleural CA-125 levels were measured using radioimmunoassay. Patients were classified into five groups according to the aetiology of pleural effusions: I) tuberculosis, II) malignant, III) pyogenic, IV) congestive heart failure, and V) hepatic hydrothorax.
  
  
  RESULTS
  CA-125 levels were significantly higher in the malignant group than in all benign groups. There was no difference in pleural CA-125 levels between transudate and exudate benign aetiologies. Although pleural CA-125 levels were significantly higher in malignant than benign effusions, about one third of malignant pleural effusions had levels of <600 U/ml. Among malignancies, there were no significant differences in pleural CA-125 levels between histological types.
  
  
  CONCLUSIONS
  CA-125 levels in benign pleural effusions may not be influenced by pleural inflammation or hydrostatic or oncotic pressure changes. Pleural CA-125 levels may not be influenced by the histological type of tumour in malignant pleural effusions, suggesting that mesothelial cell properties may not be altered by these factors in the pleural space.
authors.affiliation: Department of Internal Medicine, Keimyung University, Dongsan Hospital, Daegu, Republic of Korea. wichoi@dsmc.or.kr
authors.forename: W-I
authors.initials: WI
authors.lastname: Choi
authors.forename: D
authors.initials: D
authors.lastname: Qama
authors.forename: M Y
authors.initials: MY
authors.lastname: Lee
authors.forename: K Y
authors.initials: KY
authors.lastname: Kwon
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D018394:CA-125 Antigen / Q000032:analysis*; D016009:Chi-Square Distribution; D004848:Epithelium / Q000276:immunology*; D005260:Female; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000032:analysis*; D008875:Middle Aged; D019152:Paracentesis; D010996:Pleural Effusion / Q000209:etiology / Q000276:immunology*; D016066:Pleural Effusion, Malignant / Q000209:etiology / Q000276:immunology*; D011237:Predictive Value of Tests; D011379:Prognosis; D012372:ROC Curve; D011863:Radioimmunoassay; D012189:Retrospective Studies; D012307:Risk Factors; D015854:Up-Regulation
chemical_list: D014408:Biomarkers, Tumor; D018394:CA-125 Antigen; C451759:MUC16 protein, human; D008565:Membrane Proteins