Comparative Profiling of Serum Protein Biomarkers in Rheumatoid Arthritis-Associated Interstitial Lung Disease and Idiopathic Pulmonary Fibrosis.

Interstitial lung disease (ILD) is a frequent complication of rheumatoid arthritis (RA), occurring in up to 40% of patients during the course of their disease. Early diagnosis is critical, particularly given the shared clinicoepidemiologic features between advanced rheumatoid arthritis-associated ILD (RA-ILD) and idiopathic pulmonary fibrosis (IPF). This study was undertaken to define the molecular basis of this overlap through comparative profiling of serum proteins in RA-ILD and IPF. Multiplex enzyme-linked immunosorbent assays (ELISAs) were used to profile 45 protein biomarkers encompassing cytokines/chemokines, growth factors, and matrix metalloproteinases (MMPs) in sera obtained from RA patients with ILD and those without, individuals with IPF, and healthy controls. Levels of selected serum proteins were compared between patient subgroups using adjusted linear regression, principal component analysis (PCA), and least absolute shrinkage and selection operator (LASSO) modeling. Multiplex ELISA-based assessment of sera from 2 independent cohorts (Veterans Affairs [VA] and Non-VA) revealed a number of non-overlapping biomarkers distinguishing RA-ILD from RA without ILD (RA-no ILD) in adjusted regression models. Parallel analysis of sera from IPF patients also yielded a discriminatory panel of protein markers in models adjusted for age/sex/smoking, which showed differential overlap with profiles linked to RA-ILD in the VA cohort versus the Non-VA cohort. PCA revealed several distinct functional groups of RA-ILD-associated markers that, in the VA cohort, encompassed proinflammatory cytokines/chemokines as well as 2 different subsets of MMPs. Finally, LASSO regression modeling in the Non-VA and VA cohorts revealed distinct biomarker combinations capable of discriminating RA-ILD from RA-no ILD. Comparative serum protein biomarker profiling represents a viable method for distinguishing RA-ILD from RA-no ILD and identifying population-specific mediators shared with IPF.

Kass DJ ，Nouraie M ，Glassberg MK ，Ramreddy N ，Fernandez K ，Harlow L ，Zhang Y ，Chen J ，Kerr GS ，Reimold AM ，England BR ，Mikuls TR ，Gibson KF ，Dellaripa PF ，Rosas IO ，Oddis CV ，Ascherman DP ... -  《-》

Biomarkers of rheumatoid arthritis-associated interstitial lung disease.

Interstitial lung disease (ILD) is a relatively common extraarticular manifestation of rheumatoid arthritis (RA) that contributes significantly to disease burden and excess mortality. The purpose of this study was to identify peripheral blood markers of RA-associated ILD that can facilitate earlier diagnosis and provide insight regarding the pathogenesis of this potentially devastating disease complication. Patients with RA who were enrolled in a well-characterized Chinese identification cohort or a US replication cohort were subclassified as having RA-no ILD, RA-mild ILD, or RA-advanced ILD, based on high-resolution computed tomography scans of the chest. Multiplex enzyme-linked immunosorbent assays (ELISAs) and Luminex xMAP technology were used to assess 36 cytokines/chemokines, matrix metalloproteinases (MMPs), and acute-phase proteins in the identification cohort. Unadjusted and adjusted logistic regression models were used to quantify the strength of association between RA-ILD and biomarkers of interest. MMP-7 and interferon-γ-inducible protein 10 (IP-10)/CXCL10 were identified by multiplex ELISA as potential biomarkers for RA-ILD in 133 RA patients comprising the Chinese identification cohort (50 RA-no ILD, 41 RA-ILD, 42 RA-indeterminate ILD). The findings were confirmed by standard solid-phase sandwich ELISA in the Chinese identification cohort as well as an independent cohort of US patients with RA and different stages of ILD (22 RA-no ILD, 49 RA-ILD, 15 RA-indeterminate ILD), with statistically significant associations in both unadjusted and adjusted logistic regression analyses. Levels of MMP-7 and IP-10/CXCL10 are elevated in the serum of RA patients with ILD, whether mild or advanced, supporting their value as pathogenically relevant biomarkers that can contribute to noninvasive detection of this extraarticular disease complication.

Chen J ，Doyle TJ ，Liu Y ，Aggarwal R ，Wang X ，Shi Y ，Ge SX ，Huang H ，Lin Q ，Liu W ，Cai Y ，Koontz D ，Fuhrman CR ，Golzarri MF ，Liu Y ，Hatabu H ，Nishino M ，Araki T ，Dellaripa PF ，Oddis CV ，Rosas IO ，Ascherman DP ... -  《-》

Detection of Rheumatoid Arthritis-Interstitial Lung Disease Is Enhanced by Serum Biomarkers.

Doyle TJ ，Patel AS ，Hatabu H ，Nishino M ，Wu G ，Osorio JC ，Golzarri MF ，Traslosheros A ，Chu SG ，Frits ML ，Iannaccone CK ，Koontz D ，Fuhrman C ，Weinblatt ME ，El-Chemaly SY ，Washko GR ，Hunninghake GM ，Choi AM ，Dellaripa PF ，Oddis CV ，Shadick NA ，Ascherman DP ，Rosas IO ... -  《-》

Identification of citrullinated hsp90 isoforms as novel autoantigens in rheumatoid arthritis-associated interstitial lung disease.

Subsets of patients with rheumatoid arthritis (RA) develop extraarticular complications that include interstitial lung disease (ILD). Because standardized algorithms for identification of RA patients at risk of developing clinically significant ILD are lacking, the purpose of this study was to elucidate unique serologic markers of RA-associated ILD (RA-ILD). Sera from RA patients with ILD and from RA patients without ILD were used to immunoprecipitate citrullinated and uncitrullinated proteins derived from K562 cell extracts. Mass spectrometry was performed to facilitate identification of citrullinated proteins differentially immunoprecipitated by RA-ILD patient sera. These candidate proteins were then used as substrate antigens in custom enzyme-linked immunosorbent assays (ELISAs) for high-throughput screening of sera obtained from cohorts of patients with RA, RA-ILD mixed connective tissue disease (MCTD), or idiopathic pulmonary fibrosis (IPF). Differential immunoprecipitation and subsequent mass spectrometric sequencing identified citrullinated Hsp90α and citrullinated Hsp90β as candidate autoantigens in patients with RA-ILD. ELISAs incorporating uncitrullinated and citrullinated isoforms of Hsp90 as substrate antigens demonstrated that sera from patients with RA-ILD preferentially recognized citrullinated versions of Hsp90 with moderate sensitivity (range 20-30%) and great specificity (>95%) relative to sera derived from patients with RA alone (without ILD), patients with MCTD, or patients with IPF. These studies demonstrate the utility of a novel autoantigen discovery method based on differential immunoprecipitation of citrullinated protein extracts. Application of these techniques identified citrullinated versions of Hsp90α and Hsp90β as autoantibody targets distinguishing RA-ILD from RA without ILD, MCTD, and IPF, suggesting that anti-citrullinated Hsp90α/β autoantibodies may serve as effective biomarkers for the potentially devastating pulmonary manifestations of RA-ILD.

Harlow L ，Rosas IO ，Gochuico BR ，Mikuls TR ，Dellaripa PF ，Oddis CV ，Ascherman DP ... -  《-》

Increased circulating Wnt5a protein in patients with rheumatoid arthritis-associated interstitial pneumonia (RA-ILD).

An early diagnosis of interstitial lung disease (ILD) is important for guiding treatments of rheumatoid arthritis (RA)-associated ILD (RA-ILD) in clinical settings. The non-canonical Wnt signaling representative ligand Wnt5a was recently found to involve in idiopathic pulmonary fibrosis (IPF) and pathogenesis of RA. The goal of this study was to examine the clinical relevance of Wnt5a in RA-ILD. In this report, the clinical relevance of plasma Wnt5a protein was evaluated in 40 RA-ILD patients and 41 non-ILD RA cohorts. The results showed an elevated Wnt5a protein in plasmas of RA-ILD patients compared with non-ILD RA patients (p < 0.01), which was positively correlated with the plasma level of rheumatoid factor (RF). Of note, more abundant Wnt5a was also found in patients with usual interstitial pneumonia (UIP) than those with nonspecific interstitial pneumonia (NSIP) and other ILD patterns. More importantly, the disease severity was correlated with the circulating Wnt5a as ascertained by high-resolution computed tomography (HRCT)-UIP scores. The multiple-factor non-conditional logistic regression analysis further revealed that the age, RA duration, smoking and plasma Wnt5a were risk factors with clinical significance for RA-ILD. Interestingly, more Wnt5a-positive patients were identified in RA-ILD smokers relative to RA-ILD never-smokers, and longer smoking duration was strongly correlated with Wnt5a in RA-ILD patients. In consistence, ROC curve also suggested that the Wnt5a was a potential candidate biomarker for identifying patients with RA-UIP. These results demonstrate that the circulating Wnt5a may be a risk factor and potential biomarker for identifying UIP and accessing the severity and progression of ILD in RA patients.

Yu M ，Guo Y ，Zhang P ，Xue J ，Yang J ，Cai Q ，You X ，Ma J ，Yang D ，Jia Y ，Wang Y ，Li F ，Chi S ，Cao M ，Chen J ，Liu X ... -  《-》