Factors associated with interstitial lung disease and the progressive fibrosing phenotype in rheumatoid arthritis–related interstitial lung disease

The prevalence and risk factors of rheumatoid arthritis-associated interstitial lung disease: a systematic review and meta-analysis

BACKGROUND

Interstitial lung disease (ILD) is the most widespread and fatal pulmonary complication of rheumatoid arthritis (RA). Existing knowledge on the prevalence and risk factors of rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is inconclusive. Therefore, we designed this review to address this gap.

MATERIALS AND METHODS

To find relevant observational studies discussing the prevalence and/or risk factors of RA-ILD, EMBASE, Web of Science, PubMed, and the Cochrane Library were explored. The pooled odds ratios (ORs) / hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated with a fixed/ random effects model. While subgroup analysis, meta-regression analysis and sensitivity analysis were carried out to determine the sources of heterogeneity, the I2 statistic was utilized to assess between-studies heterogeneity. Funnel plots and Egger's test were employed to assess publication bias. Following the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines, our review was conducted.

RESULTS

A total of 56 studies with 11,851 RA-ILD patients were included in this meta-analysis. The pooled prevalence of RA-ILD was 18.7% (95% CI 15.8-21.6) with significant heterogeneity (I2 = 96.4%). The prevalence of RA-ILD was found to be more likely as a result of several identified factors, including male sex (ORs = 1.92 95% CI 1.70-2.16), older age (WMDs = 6.89, 95% CI 3.10-10.67), having a smoking history (ORs =1.91, 95% CI 1.48-2.47), pulmonary comorbidities predicted (HRs = 2.08, 95% CI 1.89-2.30), longer RA duration (ORs = 1.03, 95% CI 1.01-1.05), older age of RA onset (WMDs =4.46, 95% CI 0.63-8.29), positive RF (HRs = 1.15, 95%CI 0.75-1.77; ORs = 2.11, 95%CI 1.65-2.68), positive ACPA (ORs = 2.11, 95%CI 1.65-2.68), higher ESR (ORs = 1.008, 95%CI 1.002-1.014), moderate and high DAS28 (≥3.2) (ORs = 1.87, 95%CI 1.36-2.58), rheumatoid nodules (ORs = 1.87, 95% CI 1.18-2.98), LEF use (ORs = 1.42, 95%CI 1.08-1.87) and steroid use (HRs= 1.70, 1.13-2.55). The use of biological agents was a protective factor (HRs = 0.77, 95% CI 0.69-0.87).

CONCLUSION(S)

The pooled prevalence of RA-ILD in our study was approximately 18.7%. Furthermore, we identified 13 risk factors for RA-ILD, including male sex, older age, having a smoking history, pulmonary comorbidities, older age of RA onset, longer RA duration, positive RF, positive ACPA, higher ESR, moderate and high DAS28 (≥3.2), rheumatoid nodules, LEF use and steroid use. Additionally, biological agents use was a protective factor.

Silica-associated lung disease in developing countries

PURPOSE OF REVIEW

There is a considerable burden of silica-associated lung diseases in the developing world. This review summarizes the epidemiology of these diseases, especially silicosis and silico-tuberculosis, mitigative efforts and treatment, especially in the context of developing countries.

RECENT FINDINGS

In 2017, the highest incidence of silicosis was in China, India and Brazil among the developing countries. The prevalence of silicosis amongst exposed workers may vary from 4 to 55%; there is a risk of underestimation because of the 'healthy worker effect'. The permissible exposure limit for respirable silica adopted by governments in developing countries remains higher than the proposed 0.025 mg/m3. Silica exposure in informal or unorganized industries is challenging, as it falls outside statutory controls. Recent efforts on regulation and compensation by various governments in developing countries are encouraging but need proper implementation on the ground. Biomarkers such as club cell protein 16 and imaging methods such as computed tomography may offer earlier and easier detection of silicosis. Advanced silicosis remains incurable; novel treatments such as antifibrotics agents may be potentially effective.

SUMMARY

Silica-associated lung diseases are prevalent in developing countries. Efforts directed at preventing or minimizing exposure to respirable crystalline silica are required for mitigation.