Discovery Of Biomarkers From Pulmonary Fibrosis By Use Of Surface Enhanced Laser Desorption/Ionization Time Of Flight Mass Spectrum

Objective: To screen differentially expressed proteins in bronchoalveolarlavage fluid (BALF) and serum in patients with idiopathic pulmonary fibrosis(IPF) and Rheumatoid Arthritis associated Interstitial Lung Disease (RA-ILD)by Surface enhanced laser desorption/ionization mass spectrometry(SELDI-TOF-MS) with Protein Chip, and to initially establish a ClassificationDiagnostic Models.Methods: In department of Respiratory Medicine of our hospital, selectinginpatients and outpatients with IPF and RA-ILD as the experimental group;selecting patients with cough or chest tightness of normal chest imaging ascontrol group, and the patients of this group underwent bronchoscope toconfirm the diagnosis and showed no abnormal in microscopic examinationand showed that eosinophils were not rise in conventional cytology of BALF.Under patients and family members' informed consent, specimens of serumand bronchoalveolar lavage fluid were collected and saved. During January2010to February2012,34patients with IPF,15patients with RA-ILD, and25patients with control group were collected. After combining CM10chip withserum samples or BALF samples, and then SELDI-TOF-MS with ProteinChip was performed to detect samples of BALF and serum to obtain theprotein fingerprint,the data was analyzed by Biomarker Wizard, BiomarkerPattern and Spss13.0software, Classification Diagnostic Models wasestablished and verified by some selected cases.Results:1.247protein peaks of the mass/charge ratio (M/Z) value inBALF were detected by CM10chip and SELDI-TOF-MS, there were13proteins differentially expressed with statistical significance between patientwith IPF and healthy controls (Student's t-test; P <0.05). Among them,the proteins with M/Z2240.57,3459.32,3501.78,4146.50,4516.51,4615.88and5651.26were increased expression,the proteins with M/Z of4989.10,5043.68,6968.76,14733.3,11687.7and11782.1were decreased expression.The proteins with M/Z3459.32,4516.51,4989.91and14733.3were selected toestablish the diagnostic model, its sensitivity of this model for diagnosingidiopathic pulmonary fibrosis was91.176%(31/34), the specificity was of92.0%(23/25) and area under the curve of ROC was0.949. To verify themodel by randomly selecting15data of BALF from IPF and control group,we found that its sensitivity was93.333%(14/15)and the specificity was86.667%(13/15)；143protein peaks of the M/Z value of serum samples byCM10chip and SELDI-TOF-MS were detected, there were7proteinsdifferentially expressed with statistical significance between patient with IPFand healthy controls (Student's t-test; P <0.05). Among them, the proteinswith M/Z3382.59,4806.03,3453.39were increased expression,the proteinswith M/Z of5825.48,11525.3,11886.0,11689.4were decreased expression.The proteins with M/Z of3459.32,4516.51,4989.91and14733.3wereselected to establish the diagnostic model. The sensitivity of this model fordiagnosing IPF was94.737%(18/19), the specificity was of84.615%(11/13)and area under the curve of ROC was0.913. To verify the model by randomlyselecting10datas of serum samples from IPF and control group, we foundthat its sensitivity was100%(10/10)and the specificity was86.667%(9/10).Comparison of the specificity, sensitivity, corrects rate and ROC betweenserum and BALF in Classification Diagnostic Models of IPF patients by χ~2test, we found that P value exceed0.05and it was no statistically Significance.2.143protein peaks of the M/Z value in serum of RA-ILD and healthcontrols were detected by CM10chip and SELDI-TOF-MS,4proteins hadstatistically significant difference (Student's t-test; P <0.05), The M/Z withincreased expression of which were2876.75,3382.59,11525.3and11886.0.By the protein with M/Z of11525.3and11886.0establishing the diagnosticmodel, we found that the sensitivity was93.333%(14/15), the specificity was92.308%(12/13)and area under the curve of ROC was0.949. To verify the model by randomly selecting10data of serum samples from RA-ILD andcontrol group, we found that its sensitivity was90%(9/10)and the specificitywas90%(9/10).Conclusions:1. SELDI-TOF-MS could screen out the significantlydifferent proteins in the BALF and serum of patients with IPF. The proteinwith M/Z3459.32,4516.51,4989.91and14733.3of the BALF and3459.32,4516.51,4989.91and14733.3of the serum were selected to establishdiagnostic mode, we found that its value were very high and these potentialvalue should further research. In addition, whether differentially expressedproteins between M/Z11689.4,3453.39in serum samples and M/Z11687.7,3459.32in BALF is the homologous, we should further research.2.SELDI-TOF-MS could screen out the significantly different proteins in serumof patients with RA-ILD, the protein with a M/Z11525.3and11886.0ofBALF were selected to establish the diagnostic mode and we found that itsvalue were very high and these potential value should further research.