Plasma Matrix Metalloproteinase Concentrations and Risk of Interstitial Lung Disease in a Prospective Rheumatoid Arthritis Cohort.

OBJECTIVE: To evaluate the associations of plasma matrix metalloproteinases (MMPs) with prevalent and incident interstitial lung disease (ILD) in people with rheumatoid arthritis (RA). METHODS: Within a multicenter, prospective cohort of US veterans with RA, we performed a cross-sectional study of prevalent ILD and cohort study of incident ILD. ILD diagnoses were validated by medical record review of provider diagnoses and chest imaging and/or pathology reports. MMP-1, 3, 7, and 9 concentrations were measured in plasma samples, then standardized and categorized into quartiles. The associations of MMPs with prevalent and incident ILD were assessed with logistic (prevalent) and Cox (incident) regression models adjusted for RA-ILD risk factors. RESULTS: Among 2,312 participants (88.9% male; mean age 63.8 years), 96 had prevalent ILD. Incident ILD developed in 130 participants over 17,378 person-years of follow-up (crude incidence rate 7.5/1,000 person-years). Participants with the highest quartile of MMP-7 concentrations had a nearly four-fold increased odds of prevalent ILD (adjusted odds ratio 3.78 [95% confidence interval (95% CI) 1.86-7.65]) and over two-fold increased risk of incident ILD (adjusted hazard ratio 2.33 [95% CI 1.35-4.02]). Higher MMP-9 concentrations were also associated with prevalent and incident ILD, as well as negatively correlated with forced vital capacity among those with prevalent ILD (r = -0.30, P = 0.005). CONCLUSION: MMP-7 and MMP-9 were strongly associated with both prevalent and incident ILD in this large, multicenter RA cohort after adjustment for other RA-ILD risk factors. These population-level findings further support a potential pathogenic role for MMPs in RA-ILD and suggest that their measurement could facilitate RA-ILD risk stratification.

Enhancing the identification of rheumatoid arthritis-associated interstitial lung disease through text mining of chest computerized tomography reports.

OBJECTIVES: Algorithms have been developed to identify rheumatoid arthritis-interstitial lung disease (RA-ILD) in administrative data with positive predictive values (PPVs) between 70 and 80%. We hypothesized that including ILD-related terms identified within chest computed tomography (CT) reports through text mining would improve the PPV of these algorithms in this cross-sectional study. METHODS: We identified a derivation cohort of possible RA-ILD cases (n = 114) using electronic health record data from a large academic medical center and performed medical record review to validate diagnoses (reference standard). ILD-related terms (e.g., ground glass, honeycomb) were identified in chest CT reports by natural language processing. Administrative algorithms including diagnostic and procedural codes as well as specialty were applied to the cohort both with and without the requirement for ILD-related terms from CT reports. We subsequently analyzed similar algorithms in an external validation cohort of 536 participants with RA. RESULTS: The addition of ILD-related terms to RA-ILD administrative algorithms increased the PPV in both the derivation (improvement ranging from 3.6 to 11.7%) and validation cohorts (improvement 6.0 to 21.1%). This increase was greatest for less stringent algorithms. Administrative algorithms including ILD-related terms from CT reports exceeded a PPV of 90% (maximum 94.6% derivation cohort). Increases in PPV were accompanied by a decline in sensitivity (validation cohort -3.9 to -19.5%). CONCLUSIONS: The addition of ILD-related terms identified by text mining from chest CT reports led to improvements in the PPV of RA-ILD algorithms. With high PPVs, use of these algorithms in large data sets could facilitate epidemiologic and comparative effectiveness research in RA-ILD.

Inhalant and Additional Mucosal-Related Environmental Risks for Rheumatoid Arthritis.

Rheumatoid arthritis (RA) occurs as the result of a complex interplay of environmental factors in a genetically susceptible individual. There is considerable evidence that the lungs may serve as an initial site of tolerance loss in the generation of RA-related autoimmunity, and several environmental inhalant exposures and lung diseases have been associated with RA risk. There is additional evidence that immune and microbial dysregulation of other mucosal sites, including the oral and gastrointestinal mucosa, may contribute to the development of RA. Epidemiologic evidence linking mucosal exposures to various environmental insults as risk determinants in RA will be reviewed.

Predictive ability, validity, and responsiveness of the multi-biomarker disease activity score in patients with rheumatoid arthritis initiating methotrexate.

BACKGROUND/OBJECTIVE: We assessed the predictive value, validity, and responsiveness of the multi-biomarker disease activity (MBDA) score in rheumatoid arthritis (RA) patients initiating methotrexate. METHODS: We examined data from a 16-week, open-label study of methotrexate in RA. Disease activity was assessed and the MBDA score was calculated using serum that was collected and banked from baseline and week 16. Multivariable logistic regression models assessed whether MBDA scores predicted treatment response. Pearson correlations assessed the convergent validity and external responsiveness of the MBDA score with other measures of RA disease activity. Internal responsiveness was assessed by calculating standardized response means (SRMs). RESULTS: A total of 130 patients initiated the study, with follow-up MBDA scores available on 95 patients. Baseline MBDA scores did not predict ACR response or achieving low disease activity. Higher baseline DAS28-ESR scores were significantly associated with an ACR20 response (odds ratio 1.89 per unit, 95% CI 1.20-2.96) but not ACR50, ACR70, or low disease activity. The MBDA score moderate-to-weakly correlated with the DAS28-ESR and ESR at baseline and week 16, with weak-to-very weak correlations with patient global and function. Change in MBDA scores moderately correlated with changes in DAS28-ESR and ESR, while weakly correlating with changes in patient global and function. The DAS28-ESR (SRM 1.31) demonstrated greater responsiveness following methotrexate treatment than the MBDA score (SRM 0.71). CONCLUSIONS: MBDA scores did not predict treatment response to methotrexate. The MBDA score weak-to-moderately correlated with baseline and post-treatment disease activity measures and was less responsive to methotrexate-related improvement than the DAS28-ESR.