title: Homocysteine: new tumor marker in pleural fluid.
abstract: There are no published studies examining the utility of total homocysteine (HCY) in pleural fluid. The aim was to measure the accuracy of pleural fluid HCY concentration for diagnosis of malignant pleural effusion (MPE). We studied pleural fluids obtained by thoracocentesis in patients with pleural effusion. Pleural fluid HCY concentration was measured by immunonephelometry using N Latex HCY reagent with monoclonal antibody in automated analyzers BNII (Siemens Diagnostics®). Patients were classified into two groups according to the etiology of pleural effusion: benign pleural effusions (BPE) and MPE. Pleural effusion was categorized as MPE if malignant cells were demonstrated in pleural fluid or pleural biopsy. The accuracy of pleural fluid HCY concentration for diagnosis of MPE was determined using receiver operating characteristic (ROC) techniques by analyzing the area under the ROC curve (AUC). We studied 89 patients with ages between 1 and 96 years old (median = 66). Forty-eight patients were BPE and 41 were MPE. Pleural fluid HCY concentration was significantly higher in patients with MPE (median = 13.70 μmol/L) than in those with BPE (median = 8.05 μmol/L). The AUC value was 0.833 (95 % confidence interval (CI) 0.739-0.903). The optimal cutoff value was 13.1 μmol/L exhibiting 56.1 % (95 % CI 39.8-71.5) sensitivity and 85.4 % (95 % CI 72.2-93.9) specificity. Pleural fluid HCY concentration showed high diagnostic accuracy to predict whether a pleural effusion is benign or malignant. Pleural fluid HCY concentration may be measured easily and quickly in automated analyzers and could be a tumor marker commonly used for diagnosis of MPE.
authors.affiliation: Department of Clinical Laboratory, Puerto Real University Hospital, Carretera Nacional IV-Km. 665, 11510, Puerto Real, Cadiz, Spain. jdsantotoribioc@gmail.com.|Department of Biomedicine, Biotechnology and Public Health, University of Cadiz, Cadiz, Spain. jdsantotoribioc@gmail.com.
authors.forename: Jose D
authors.initials: JD
authors.lastname: Santotoribio
authors.affiliation: Department of Clinical Laboratory, Puerto Real University Hospital, Carretera Nacional IV-Km. 665, 11510, Puerto Real, Cadiz, Spain.|Department of Biomedicine, Biotechnology and Public Health, University of Cadiz, Cadiz, Spain.
authors.forename: Consuelo
authors.initials: C
authors.lastname: Cañavate-Solano
authors.affiliation: Department of Clinical Laboratory, Puerto Real University Hospital, Carretera Nacional IV-Km. 665, 11510, Puerto Real, Cadiz, Spain.|Department of Biomedicine, Biotechnology and Public Health, University of Cadiz, Cadiz, Spain.
authors.forename: Angela
authors.initials: A
authors.lastname: Garcia-de la Torre
authors.affiliation: Health Center Las Beatas, Alcalá de Guadaira, Sevilla, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Del Valle-Vazquez
authors.affiliation: Department of Clinical Laboratory, Puerto Real University Hospital, Carretera Nacional IV-Km. 665, 11510, Puerto Real, Cadiz, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Arce-Matute
authors.affiliation: Department of Clinical Laboratory, Puerto Real University Hospital, Carretera Nacional IV-Km. 665, 11510, Puerto Real, Cadiz, Spain.
authors.forename: Juan F
authors.initials: JF
authors.lastname: Cuadros-Muñoz
authors.affiliation: Department of Biomedicine, Biotechnology and Public Health, University of Cadiz, Cadiz, Spain.
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Sanchez del Pino
authors.affiliation: Department of Biomedicine, Biotechnology and Public Health, University of Cadiz, Cadiz, Spain.
authors.forename: Manuel J
authors.initials: MJ
authors.lastname: Bandez-Ruiz
authors.affiliation: Department of Biomedicine, Biotechnology and Public Health, University of Cadiz, Cadiz, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Piñuela-Rojas
authors.affiliation: Department of Clinical Laboratory, Puerto Real University Hospital, Carretera Nacional IV-Km. 665, 11510, Puerto Real, Cadiz, Spain.|Department of Biomedicine, Biotechnology and Public Health, University of Cadiz, Cadiz, Spain.
authors.forename: Santiago
authors.initials: S
authors.lastname: Perez-Ramos
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D014408:Biomarkers, Tumor / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006710:Homocysteine / Q000032:analysis*; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D009391:Nephelometry and Turbidimetry / Q000379:methods*; D016066:Pleural Effusion, Malignant / Q000175:diagnosis* / Q000378:metabolism; D011379:Prognosis; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D006710:Homocysteine
keywords: Cancer; Homocysteine; Malignant pleural effusion; Pleural fluid; Tumor marker