Serum level of interleukin-33 in rheumatoid arthritis patients and its association with bone erosion and interstitial lung disease

Serum alarmins and the risk of incident interstitial lung disease in rheumatoid arthritis

OBJECTIVES

To quantify associations of serum alarmins with risk of rheumatoid arthritis-associated interstitial lung disease (RA-ILD).

METHODS

Using serum collected at enrolment, three alarmins (IL-33, thymic stromal lymphopoietin [TSLP] and IL-25) were measured in a multicentre prospective RA cohort. ILD was classified using systematic medical record review. Cross-sectional associations of log-transformed (IL-33, TSLP) or quartile (IL-25) values with RA-ILD at enrolment (prevalent RA-ILD) were examined using logistic regression, while associations with incident RA-ILD developing after enrolment were examined using Cox proportional hazards. Covariates in multivariate models included age, sex, race, smoking status, RA disease activity score and anti-cyclic citrullinated antibody positivity.

RESULTS

Of 2835 study participants, 115 participants (4.1%) had prevalent RA-ILD at baseline and an additional 146 (5.1%) developed incident ILD. There were no associations between serum alarmin concentrations and prevalent ILD in unadjusted or adjusted logistic regression models. In contrast, there was a significant inverse association between IL-33 concentration and the risk of developing incident RA-ILD in unadjusted (hazard ratio [HR] 0.73 per log-fold increase; 95% CI: 0.57, 0.95; P = 0.018) and adjusted (HR 0.77; 95% CI: 0.59, 1.00; P = 0.047) models. No significant associations of TSLP or IL-25 with incident ILD were observed.

CONCLUSION

In this study, we observed a significant inverse association between serum IL-33 concentration and the risk of developing incident RA-ILD, but no associations with prevalent ILD. Additional investigation is required to better understand the mechanisms driving this relationship and how serum alarmin IL-33 assessment might contribute to clinical risk stratification in patients with RA.

Peripheral Blood Biomarkers for Rheumatoid Arthritis-Associated Interstitial Lung Disease: A Systematic Review

BACKGROUND

Biomarkers have been proposed as tools to aid in the identification and prognostication of interstitial lung disease (ILD) in rheumatoid arthritis (RA). We performed a systematic review of studies evaluating peripheral blood biomarkers and their association with RA-ILD and its prognosis.

METHODS

Medline, Embase, the Cochrane Library, and Scopus were queried for relevant studies, with the final search update on July 12, 2021. We included studies evaluating peripheral blood biomarkers for the identification and/or prognostication of RA-ILD, extracting the performance of individual biomarkers for identifying RA-ILD, and predicting prognosis. Modified versions of the Quality Assessment of Diagnostic Accuracy Studies 2 and the Quality in Prognosis Studies tools were used for quality assessment.

RESULTS

Seventy studies met eligibility criteria. Study and patient characteristics, analytical methods, strength and consistency of associations, and study quality were heterogeneous. A total of 92 biomarkers were positively associated and 12 were negatively associated with RA-ILD among patients with RA in one or more report. Only a small number of biomarkers were evaluated in multiple cohorts using adjusted analyses. Biomarkers most strongly associated with RA-ILD overlapped with those identified for idiopathic pulmonary fibrosis. Few prognostic biomarkers of RA-ILD were identified.

CONCLUSION

Several peripheral blood biomarkers are associated with the presence of RA-ILD, but few have been assessed in multivariable models, have been externally validated, have discriminated RA-ILD from other lung disease, or have prognosticated the disease course. High-quality studies investigating and validating peripheral biomarkers in RA-ILD are needed before they can be employed in clinical care.

Screening of interstitial lung disease in patients with rheumatoid arthritis: A systematic review

AIMS

Interstitial lung disease (ILD) is frequent in patients with rheumatoid arthritis (RA) and is associated with significant morbidity and mortality. The aim of this review was to identify the different screening methods for ILD in patients with RA.

METHODS

We ran a systematic search in Pubmed, Embase and Cochrane Library up to April 2020 and did a hand search of the references of the retrieved articles. The search was limited to humans and articles published in English, Spanish or French. We selected studies with any design where: (a) the population included adult patients with RA; (b) the intervention was any screening method for ILD; and (c) validity or reliability of the screening method were evaluated, or a screening method was described. Two reviewers independently screened the articles by title and abstract and subsequently extracted the information using a specific data extraction form.

RESULTS

25 studies were included with a total of 2593 patients. The most frequently used tool for ILD screening was high resolution computed tomography (HRCT) of the lung. Electronic auscultation, biochemical markers, bronchoalveolar lavage (BAL), pulmonary function tests (PFTs) and lung ultrasonography were also evaluated. Across the different studies, electronic auscultation and lung ultrasonography achieved higher accuracy than PFTs, BAL and biochemical markers.

CONCLUSIONS

HRCT resulted as the most sensitive tool for ILD screening in patients with RA. Given its harmlessness and high sensitivity, lung ultrasonography may become the first-choice tool in the future.

Epithelial Alarmins in Serum and Exhaled Breath in Patients with Idiopathic Pulmonary Fibrosis: A Prospective One-Year Follow-Up Cohort Study

Background: Recently, epithelial alarmins have been shown to play important roles in non-allergen driven respiratory diseases like idiopathic pulmonary fibrosis (IPF). Little is known about the expression of the epithelial alarmins in IPF. Methods: This study aimed to prospectively examine interleukin (IL)-25, IL-33, and thymic stromal lymphopoietin (TSLP) levels in the serum and exhaled breath condensate (EBC) in patients with IPF before and after one-year of antifibrotic treatment. A total of 82 volunteers, including 52 patients diagnosed with IPF that qualified for antifibrotic therapy as well as 30 controls, were examined. All study participants underwent baseline peripheral blood and EBC sampling. In 35 out of 52 IPF subjects, a follow-up sampling was performed after 12 months of antifibrotic treatment. Concentrations of alarmins in the serum and EBC were evaluated by means of ELISA. Results: Baseline TSLP concentrations were significantly elevated in patients with IPF compared to controls both in the serum (p < 0.05) and EBC (p < 0.0001). Baseline IL-25 and IL-33 serum and EBC levels did not differ significantly between IPF subjects and controls. Prospective analysis of changes in the epithelial alarmin levels showed significantly decreased IL-25 and TSLP EBC concentrations after 12 months of antifibrotic treatment (p < 0.05), which was observed in the subgroup of IPF patients treated with pirfenidone, but not in those treated with nintedanib. In stable patients with IPF over a study period (absolute forced vital capacity (FVC) % of predicted decline/year ≤ 5%, n = 25), a significant decrease in the EBC levels of both IL-25 and TSLP after 12 months of antifibrotic treatment was noted (p < 0.05), whereas, in progressor IPF patients (absolute FVC % of predicted decline/year > 5%, n = 10), a significant decrease was noted in the IL-25 EBC levels only (p < 0.05). Conclusions: Elevated TSLP levels in patients with IPF and their significant decrease in the lung compartment during antifibrotic therapy in stable patients with IPF, but not in progressors, support its significant contribution to pro-fibrotic type 2 immune responses in IPF. Noted changes in the epithelial alarmins concentration in the lung compartment during pirfenidone therapy may suggest its possible interaction with epithelial alarmins pathways in IPF.

Inter-observer agreement of standard joint count examination and disease global assessment in a cohort of Egyptian Rheumatoid Arthritis patients

OBJECTIVES

To assess the inter-observer agreement of standard joint count between experienced Rheumatology professor (Prof) and young Rheumatology fellow (candidate), and to compare disease global assessment between professor, young candidate and patients.

METHODS

This study included one hundred rheumatoid arthritis patients. For all patients independent clinical evaluation was done by two rheumatologists (professor and candidate) for detection of tenderness in 28 joints and swelling in 26 joints. The study also involved global assessment of disease activity by the provider (Prof and candidate) (EGA) as well as by the patient (PGA). The EGA was determined without previous knowledge of the patient's laboratory test results.

RESULTS

A highly significant accordance (correlation) between professor and candidate was found in both the number of tender joints (p<0.001) (r=0.946), and the number of swollen joints (p<0.001) (r=0.797). Regarding swollen joints, the highest agreement was in right knee (0.929), while poor agreement was found in the right 5th MCP (0.049). Regarding tender joints, the highest analogy was in the right elbow (0.899), in contrast to the left 3rd PIP (0.462) which showed the least congruence. Agreement study using kappa measurement for disease global assessment showed: moderate agreement (between professor and candidate) (0.405), fair agreement between (professor and patient) (0.213), fair agreement between (candidate and patient) (0.367).

CONCLUSION

Inter-observer reliability was better for TJCs than SJCs. Regarding SJCs agreement was better in large joints such as the knees compared to the small joints such as the MCPs. Disease global assessment may show discrepancy between patients and physicians.