title: Longitudinal Measurement of Pleural Fluid Biochemistry and Cytokines in Malignant Pleural Effusions.
abstract: Malignant pleural effusion (MPE) is common. Existing literature on pleural fluid compositions is restricted to cross-sectional sampling with little information on longitudinal changes of fluid biochemistry and cytokines with disease progression. Indwelling pleural catheters provide the unique opportunity for repeated sampling and longitudinal evaluation of MPE, which may provide insight into tumor pathobiology.
  
  
  
  We collected 638 MPE samples from 103 patients managed with indwelling pleural catheters over 95 days (median, range 0-735 days) and analyzed them for protein, pH, lactate dehydrogenase, and glucose levels. Peripheral blood was quantified for hematocrit, platelets, leukocytes, protein, and albumin. Cytokine levels (monocyte chemotactic protein [MCP]-1; vascular endothelial growth factor; interleukin-6, -8, and -10; tumor necrosis factor-α; and interferon-gamma) were determined in 298 samples from 35 patients with mesothelioma. Longitudinal changes of all parameters were analyzed using a linear mixed model.
  
  
  
  Significant decreases were observed over time in pleural fluid protein by 8 g/L per 100 days (SE, 1.32; P < .0001) and pH (0.04/100 days; SE, 0.02; P = .0203), accompanied by a nonsignificant rise in lactate dehydrogenase. The ratio of pleural fluid to serum protein decreased by 0.06/100 days (SE, 0.02; P = .04). MPEs from mesothelioma (n = 63) had lower pleural fluid glucose (P = .0104) at baseline and a faster rate of decline in glucose (P = .0423) when compared with non-mesothelioma effusions (n = 38). A progressive rise in mesothelioma pleural fluid concentration of [log] MCP-1 ([log] 0.37 pg/mL per 100 days; SE, 0.13; P = .0046), but not of other cytokines, was observed.
  
  
  
  MPE fluids become less exudative and more acidic over the disease course. The rise in MCP-1 levels suggests a pathobiological role in MPE.
authors.affiliation: Department of Respiratory Medicine, Sir Charles Gairdner Hospital, University of Western Australia, Perth, Australia; School of Medicine and Pharmacology, University of Western Australia, Perth, Australia; Pleural Medicine Unit, Institute of Respiratory Health, University of Western Australia, Perth, Australia.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Thomas
authors.affiliation: School of Medicine and Pharmacology, University of Western Australia, Perth, Australia; Pleural Medicine Unit, Institute of Respiratory Health, University of Western Australia, Perth, Australia.
authors.forename: Hui Min
authors.initials: HM
authors.lastname: Cheah
authors.affiliation: School of Medicine and Pharmacology, University of Western Australia, Perth, Australia; National Centre for Asbestos Related Diseases, University of Western Australia, Perth, Australia.
authors.forename: Jenette
authors.initials: J
authors.lastname: Creaney
authors.affiliation: Centre for Applied Statistics and School of Mathematics and Statistics, University of Western Australia, Perth, Australia.
authors.forename: Berwin A
authors.initials: BA
authors.lastname: Turlach
authors.affiliation: Department of Respiratory Medicine, Sir Charles Gairdner Hospital, University of Western Australia, Perth, Australia; School of Medicine and Pharmacology, University of Western Australia, Perth, Australia; Pleural Medicine Unit, Institute of Respiratory Health, University of Western Australia, Perth, Australia. Electronic address: gary.lee@uwa.edu.au.
authors.forename: Y C Gary
authors.initials: YC
authors.lastname: Lee
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001315:Australia; D001772:Blood Cell Count / Q000379:methods; D018932:Chemokine CCL2 / Q000032:analysis; D016207:Cytokines / Q000032:analysis*; D005122:Exudates and Transudates / Q000276:immunology / Q000378:metabolism; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008175:Lung Neoplasms / Q000150:complications / Q000473:pathology; D008297:Male; D008654:Mesothelioma / Q000150:complications / Q000473:pathology; D000086002:Mesothelioma, Malignant; D008875:Middle Aged; D016066:Pleural Effusion, Malignant / Q000175:diagnosis / Q000209:etiology / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis; D042461:Vascular Endothelial Growth Factor A / Q000032:analysis
chemical_list: D018932:Chemokine CCL2; D016207:Cytokines; D014409:Tumor Necrosis Factor-alpha; D042461:Vascular Endothelial Growth Factor A
keywords: cytokines; glucose; lactate dehydrogenase; malignant pleural effusion; mesothelioma; monocyte chemotactic protein-1; pH; pleural fluid; protein