Longitudinal Blood Transcriptomic Changes Predict Lung Function Decline in patients with Idiopathic Pulmonary Fibrosis
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ABSTRACT: Rationale: Molecular markers of disease progression in idiopathic pulmonary fibrosis are needed. Objective: Derive and validate a blood transcriptomic predictor of forced vital capacity (FVC) decline. Methods: A training cohort (n=74) of IPF patients was stratified according to the presence of progressive disease, defined as ≥10% relative decline in FVC over 12 months. Baseline to 4-month within-patient changes in gene expression were correlated with categorical FVC decline. Genes predictive of FVC decline were identified by two-group comparison with false discovery rate <5% followed by logistic LASSO regression and 10-Fold Cross-Validation for gene list prioritization. Independent validation cohorts with differing transcriptome assay platforms and blood transcriptome sampling times from UChicago (n=27), UPMC (n=35), and Imperial (n=24) underwent receiver operating characteristic with area under the curve (AUC) analyses for validation. Results: A longitudinally-derived FVC-gene predictor accurately discriminated most patients with stable and progressive IPF across four independent IPF cohorts with variable transcriptomic assay platforms and sampling times. The FVC-gene predictorand demonstrated sensitivity and specificity of 74.3% and 82.4% in the combined replication cohort. The likelihood ratio, LR+ and LR- were 4.11 and 0.32, respectively. TGF-beta was the highest-ranking canonical pathway by Gene Set Enrichment Analysis. An approach using longitudinal gene expression changes approach dramatically reduced within-group variation compared to cross-sectional expression for improved prediction modeling. Conclusions: This novel FVC-gene predictor developed from short-term longitudinal gene expression changes successfully discriminates most patients with high likelihood of one-year 10% FVC decline. This tool may better reflect disease activity and prove useful for predictive enrichment of clinical trial populations.
Project description:The Rationale: Molecular markers of disease activity that are predictive of forced vital capacity (FVC) progression in idiopathic pulmonary fibrosis are needed. Objectives: Develop a predictor using longitudinal within-patient gene expression differences (ΔGE) in peripheral blood mononuclear cells (PBMC) to predict of FVC progression. Methods: Patients in the training cohort (n=74) experiencing ≥10% relative reduction in FVC% of predicted over 12 months were categorized as progressors in contrast to the remaining stable patients. Baseline to 4-month within-patient ΔGE were correlated with FVC status. FVC-predictor genes were prioritized by two-group comparison with FDR<5%, logistic LASSO regression with p<0.05, and 10-Fold Cross-Validation with ≥50% support. Receiver operating characteristic with area under the curve (AUC) analyses were conducted in training subsets and independent validation cohorts from UChicago (n=27), UPMC (n=35), and Imperial (n=24) where different transcriptome assay platforms and varying transcriptome sampling times were used to derive ΔGE. Results: Intra-subject Compared to cross-sectional analysis of baseline GE, our longitudinal ΔGE variation approach demonstratedlargely reduced within-group sample variation and increased statistic power fin progressor and stable groups for prediction model development. A 25-gene FVC-predictor separated “progressors” from “stable” by Principal Component Analysis in the training and subsets of the training cohort. The resulting FVC-predictor consistently demonstrated high discriminatory performance independent of transcriptome assay platforms and varying sampling times in validation cohorts (AUC= 0.77-0.80). TGF beta was the highest-ranking canonical pathway by Gene Set Enrichment Analysis. Conclusions: Our novel short-term longitudinal within-patient ΔGE approach identified a FVC-predictor which may reflect disease activity and prove to be a reliable biomarker predictive of future FVC decline.
Project description:Peripheral blood biomarkers are needed to identify and determine the extent of idiopathic pulmonary fibrosis (IPF). Current physiologic and radiographic prognostic indicators diagnose IPF too late in the course of disease. These results demonstrate that the peripheral blood transcriptome can distinguish normal individuals from patients with IPF, as well as extent of disease when samples were classified by percent predicted DLCO, but not FVC. Gene expression profiles of peripheral blood RNA from 93 IPF patients were collected on Agilent microarrays. Blood was collected in PAXRNA tubes. 30 healthy controls are compared to IPF patients classified by disease severity when categorized by DLCO or FVC.
Project description:Idiopathic pulmonary fibrosis (IPF) is a specific form of chronic, progressive fibrosing interstitial disease of unknown cause. It remains impractical to conduct early diagnosis and predict IPF progression just based on gene expression information. Moreover, the relationship between gene expression and quantitative phenotypic value in IPF keeps controversial. To identify biomarkers to predict survival in IPF, we profiled protein-coding gene expression in peripheral blood mononuclear cells (PBMCs). We linked the gene expression level with the quantitative phenotypic variation in IPF, including diffusing capacity of the lung for carbon monoxide (DLCO) and forced vital capacity (FVC) percent predicted. In silico analyses on the expression profiles and quantitative phenotypic data allowed for the generation of a set of IPF molecular signature that predicted survival of IPF effectively.
Project description:Idiopathic pulmonary fibrosis (IPF) is a specific form of chronic, progressive fibrosing interstitial disease of unknown cause. It remains impractical to conduct early diagnosis and predict IPF progression just based on gene expression information. Moreover, the relationship between gene expression and quantitative phenotypic value in IPF keeps controversial. To identify biomarkers to predict survival in IPF, we profiled protein-coding gene expression in peripheral blood mononuclear cells (PBMCs). We linked the gene expression level with the quantitative phenotypic variation in IPF, including diffusing capacity of the lung for carbon monoxide (DLCO) and forced vital capacity (FVC) percent predicted. In silico analyses on the expression profiles and quantitative phenotypic data allowed for the generation of a set of IPF molecular signature that predicted survival of IPF effectively. Total RNA was isolated from PBMCs using standard molecular biology protocols without DNA contamination or RNA degradation. Sample processing (e.g., cDNA generation, fragmentation, end labeling, hybridization to Affymetrix GeneChip Human Exon 1.0 ST arrays) was performed per manufacturer’s instructions. A total of 45 healthy controls and 70 IPF patients were included in the microarray analysis.
Project description:Peripheral blood biomarkers are needed to identify and determine the extent of idiopathic pulmonary fibrosis (IPF). Current physiologic and radiographic prognostic indicators diagnose IPF too late in the course of disease. These results demonstrate that the peripheral blood transcriptome can distinguish normal individuals from patients with IPF, as well as extent of disease when samples were classified by percent predicted DLCO, but not FVC.
Project description:We performed longitudinal plasma proteomics analysis and determined absolute protein levels in a Canadian cohort (n=74) at admission day to hospital for acute COVID-19 and at 3 and 6 months after diagnosis of acute COVID-19. We measured plasma protein on a triple quadrupole mass spectrometer operated in multiple reaction monitoring mode and used internal standards to deduce protein absolute concentrations. We used a validated panel of 269 surrogate heavy labeled peptides. We also measured % predicted forced vital capacity (FVC, %) and diffusing capacity of the lungs for carbon monoxide (DLCO, %) by routine pulmonary function testing. We did functional enrichment and pathway analyses and determined proteins that were increased or decreased from hospital admission to 3-months and 6-months, compared females to males and determined associations of proteins with FVC% and DLCO%.
Project description:Chronic obstructive pulmonary disease (COPD) is an inflammatory lung disease with complex pathological features and largely unknown etiologies. Identification and validation of biomarkers for this disease could facilitate earlier diagnosis, appreciation of disease subtypes and/or determination of response to therapeutic intervention. To identify gene expression markers for COPD, we performed genome-wide expression profiling of lung tissue from 56 subjects using the Affymetrix U133 Plus 2.0 array. Lung function measurements from these subjects ranged from normal, un-obstructed to severely obstructed. Analysis of differential expression between cases (FEV1<70%, FEV1/FVC<0.7) and controls (FEV1>80%, FEV1/FVC>0.7) identified a set of 65 probe sets representing discrete markers associated with COPD. Correlation of gene expression with quantitative measures of airflow obstruction (FEV1 or FEV1/FVC) identified a set of 220 probe sets. A total of 31 probe sets were identified that showed evidence of significant correlation with quantitative traits and differential expression between cases and controls. Keywords: Disease state marker
Project description:Chronic obstructive pulmonary disease (COPD) is an inflammatory lung disease with complex pathological features and largely unknown etiologies. Identification and validation of biomarkers for this disease could facilitate earlier diagnosis, appreciation of disease subtypes and/or determination of response to therapeutic intervention. To identify gene expression markers for COPD, we performed genome-wide expression profiling of lung tissue from 56 subjects using the Affymetrix U133 Plus 2.0 array. Lung function measurements from these subjects ranged from normal, un-obstructed to severely obstructed. Analysis of differential expression between cases (FEV1<70%, FEV1/FVC<0.7) and controls (FEV1>80%, FEV1/FVC>0.7) identified a set of 65 probe sets representing discrete markers associated with COPD. Correlation of gene expression with quantitative measures of airflow obstruction (FEV1 or FEV1/FVC) identified a set of 220 probe sets. A total of 31 probe sets were identified that showed evidence of significant correlation with quantitative traits and differential expression between cases and controls. Experiment Overall Design: We assessed genome-wide expression patterns in lung tissue specimens derived from 56 subjects. These subjects were undergoing lobectomy for removal of a suspected tumor, and tissue for our studies was derived from histologically normal tissue distant from the tumor margin. Subjects underwent routine spirometry prior to surgery. Low values for both FEV1 and FEV1/FVC are characteristic features of COPD and associated with the severity of disease. For our studies, Cases (n=15) were defined as subjects with FEV1<70% and FEV1/FVC<0.7 and Controls (n=18) as subjects with FEV1>80% and FEV1/FVC>0.7. A majority of the subjects were diagnosed with adenocarcinoma (n=26) or squamous cell carcinoma (n=19), while other tumor types or benign lesions were found in the remaining subjects (n=11).
Project description:We sought to find a gene-expression multigene predictor of response to infliximab therapy in Rheumatoid Arthritis patients. Using internal and external cross-validation systems we have built and validated an 8-gene predictor for response to infliximab.
Project description:Idiopathic pulmonary fibrosis (IPF) is a chronic fibrosing lung disease that is difficult to diagnose and follows an unpredictable clinical course. The object of this study was to develop a predictive gene signature model of IPF from whole lung tissue. We collected whole lung samples from 11 IPF patients undergoing diagnostic surgical biopsy or transplantation. Whenever possible, samples were obtained from different lobes. Normals consisted of healthy organs donated for transplantation. We measured gene expression on microarrays. Data were analyzed by hierarchical clustering and Principal Component Analysis. By this approach, we found that gene expression was similar in the upper and lower lobes of individuals with IPF. We also found that biopsied and explanted specimens contained different patterns of gene expression; therefore, we analyzed biopsies and explants separately. Signatures were derived by fitting top genes to a Bayesian probit regression model. We developed a 153-gene signature that discriminates IPF biopsies from normal. We also developed a 70-gene signature that discriminates IPF explants from normal. Both signatures were validated on an independent cohort. The IPF Biopsy signature correctly diagnosed 76% of the validation cases (p < 0.01), while IPF Explant correctly diagnosed 78% (p < 0.001). Examination of differentially expressed genes revealed partial overlap between IPF Biopsy and IPF Explant and almost no overlap with previously reported IPF gene lists. However, several overlapping genes may provide a basis for developing therapeutic targets. 17 samples from 11 patients with IPF (6 patients provided a pair of samples from upper and lower lobes; 5 patients contributed singleton samples); 6 control specimens were obtained from routine lung volume reduction of healthy donor lungs at the time of lung transplantation.