title: Multi-analyte profiling of inflammatory mediators in COPD sputum--the effects of processing.
abstract: Prior to using a new multi-analyte platform for the detection of markers in sputum it is advisable to assess whether sputum processing, especially mucus homogenization by dithiothreitol (DTT), affects the analysis. In this study we tested a novel Human Inflammation Multi Analyte Profiling® Kit (v1.0 Luminex platform; xMAP®). Induced sputum samples of 20 patients with stable COPD (mean FEV1, 59.2% pred.) were processed in parallel using standard processing (with DTT) and a more time consuming sputum dispersion method with phosphate buffered saline (PBS) only. A panel of 47 markers was analyzed in these sputum supernatants by the xMAP®. Twenty-five of 47 analytes have been detected in COPD sputum. Interestingly, 7 markers have been detected in sputum processed with DTT only, or significantly higher levels were observed following DTT treatment (VDBP, α-2-Macroglobulin, haptoglobin, α-1-antitrypsin, VCAM-1, and fibrinogen). However, standard DTT-processing resulted in lower detectable concentrations of ferritin, TIMP-1, MCP-1, MIP-1β, ICAM-1, and complement C3. The correlation between processing methods for the different markers indicates that DTT processing does not introduce a bias by affecting individual sputum samples differently. In conclusion, our data demonstrates that the Luminex-based xMAP® panel can be used for multi-analyte profiling of COPD sputum using the routinely applied method of sputum processing with DTT. However, researchers need to be aware that the absolute concentration of selected inflammatory markers can be affected by DTT.
authors.affiliation: Pulmonary Research Institute at LungClinic Grosshansdorf, Airway Research Center North, Member of the German Center for Lung Research, Grosshansdorf, Germany; LungClinic Grosshansdorf, Airway Research Center North, Member of the German Center for Lung Research, Grosshansdorf, Germany. Electronic address: f.pedersen@pulmoresearch.de.
authors.forename: Frauke
authors.initials: F
authors.lastname: Pedersen
authors.affiliation: Fraunhofer ITEM, Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research, Hannover, Germany.
authors.forename: Olaf
authors.initials: O
authors.lastname: Holz
authors.affiliation: Takeda Pharmaceuticals International GmbH, Glattpark, Opfikon, Zurich, Switzerland.
authors.forename: Gereon
authors.initials: G
authors.lastname: Lauer
authors.affiliation: Takeda Pharmaceuticals International GmbH, Glattpark, Opfikon, Zurich, Switzerland.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Quintini
authors.affiliation: Ruhr-University Bochum, Faculty of Medicine, Bochum, Germany.
authors.forename: Heidrun
authors.initials: H
authors.lastname: Kiwull-Schöne
authors.affiliation: Pulmonary Research Institute at LungClinic Grosshansdorf, Airway Research Center North, Member of the German Center for Lung Research, Grosshansdorf, Germany.
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Kirsten
authors.affiliation: Pulmonary Research Institute at LungClinic Grosshansdorf, Airway Research Center North, Member of the German Center for Lung Research, Grosshansdorf, Germany.
authors.forename: Helgo
authors.initials: H
authors.lastname: Magnussen
authors.affiliation: LungClinic Grosshansdorf, Airway Research Center North, Member of the German Center for Lung Research, Grosshansdorf, Germany.
authors.forename: Klaus F
authors.initials: KF
authors.lastname: Rabe
authors.affiliation: Clinical and Experimental Pathology, Research Center Borstel, Airway Research Center North, Member of the German Center for Lung Research, Borstel, Germany.
authors.forename: Torsten
authors.initials: T
authors.lastname: Goldmann
authors.affiliation: Pulmonary Research Institute at LungClinic Grosshansdorf, Airway Research Center North, Member of the German Center for Lung Research, Grosshansdorf, Germany.
authors.forename: Henrik
authors.initials: H
authors.lastname: Watz
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000378:metabolism*; D015331:Cohort Studies; D004229:Dithiothreitol / Q000737:chemistry*; D005260:Female; D005541:Forced Expiratory Volume; D020869:Gene Expression Profiling; D006801:Humans; D007249:Inflammation / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010710:Phosphates / Q000737:chemistry; D029424:Pulmonary Disease, Chronic Obstructive / Q000378:metabolism* / Q000503:physiopathology*; D012965:Sodium Chloride / Q000737:chemistry; D013183:Sputum / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D010710:Phosphates; D012965:Sodium Chloride; D004229:Dithiothreitol
keywords: Biomarker; COPD; Dithiothreitol; Induced sputum; Luminex platform