Background: There is increasing evidence that environmental air pollution is associated with the development of chronic inflammatory arthritides (CIA). The role of air pollutants on the biological treatment (biological disease-modifying antirheumatic drugs [bDMARDs]) response of CIA is still unclear.
Methods: We retrieved longitudinal data on patients affected by CIA on biological therapies and on the daily concentration of air pollutants in the Verona area. We designed a case-crossover study to compare the exposure to pollutants in the 60-day period preceding a drug switch or swap due to disease progression referent to the 60-day period preceding a visit with stable treatment for at least 6 months.
Results: A total of 1257 patients with CIA (863 with rheumatoid arthritis, 256 with psoriatic arthritis, and 138 with ankylosing spondylitis) with 5454 follow-up visits were included in the study (median follow-up 2.09 years [interquartile range: 0.82-2.58 years]). A total of 282 patients were included in the case-crossover study. We retrieved 13 636 daily air pollution records. We found that air pollutants' concentrations were higher in the 60-day period before a failure of bDMARD response and prior to a switch or swap compared with the period preceding a visit with stable bDMARD therapy for at least 6 months.
Conclusion: We found that environmental air pollution was a determinant of poor response to bDMARDs in a cohort of patients with CIA followed over a 5-year period. An intervention aimed at decreasing fossil combustion emissions might have beneficial effects on biologic persistence rates of patients with CIA and economic expenditures related to switches and swaps.
© 2021 The Authors. ACR Open Rheumatology published by Wiley Periodicals LLC on behalf of American College of Rheumatology.