Rheumatoid arthritis-associated lung disease significantly increase risk of serious infection: Study

A new study published in the journal of Arthritis & Rheumatology revealed that a considerable elevated risk of severe infection across anatomic locations and a variety of pathogen types is linked to rheumatoid arthritis-associated lung disease (RA-LD), especially RA-associated interstitial lung disease (RA-ILD).

An estimated 1% of people in the US and northern European nations suffer with rheumatoid arthritis (RA), a systemic inflammatory disease. Clinically, RA may virtually impact any lung compartment, including the pleura, which can cause pleural inflammation and/or effusions; small and large airways; the pulmonary vasculature; and the parenchyma, which can show up as rheumatoid nodules or ILD. Thus, this study examined the relationship between the risk of significant infection and RA-LD.

Using the MGB Biobank (Boston, Massachusetts), researchers performed a retrospective cohort study that matched RA-LD patients by age, sex, and length of RA to RA patients without lung disease (RA-no LD). Medical record review and chest imaging for clinically evident RA-associated bronchiectasis (RA-BR) and/or RA-ILD were used to confirm RA-LD patients.

Serious infection was the main outcome taken for this study. To account for competing risk of mortality, incidence rates and propensity score-adjusted sub distribution hazard ratios (sdHR) were computed using the Fine and Gray models.

In comparison to 980 RA-no LD comparators, 221 RA-LD patients (151 RA-ILD and 70 RA-BR) had a substantially increased risk of severe infection (55.8 vs. 25.8 per 1,000 person-years, sdHR 1.60, 95%CI 1.20-2.12). For RA-ILD patients (sdHR 1.79, 95%CI 1.33-2.41), the elevated risk persisted, but not for RA-BR cases (sdHR 1.19, 95%CI 0.72-1.97).

RA-LD was linked to a number of pathogen species, including bacteria, fungi, viruses, and mycobacteria. The most frequent anatomic locations of infection in RA-LD were the lungs, skin and soft tissues, and the ears, nose, and throat. Certain infections, such as influenza virus, Staphylococcus, pseudomonas, respiratory syncytial virus, and nontuberculous mycobacteria, were more common in RA-LD patients, especially among RA-BR.

Overall, serious infections involving several body parts and a broad spectrum of microorganisms are significantly more likely to occur in patients with rheumatoid arthritis-related lung disease, particularly interstitial lung disease. In particular, an increased risk of lung infections is related with bronchiectasis associated with RA (RA-BR).

Reference:

Zhang, Q., Qi, Y., Wang, X., McDermott, G. C., Chang, S. H., Chaballa, M., Khaychuk, V., Paudel, M. L., & Sparks, J. A. (2025). Risk of serious infection in patients with rheumatoid arthritis-associated interstitial lung disease or bronchiectasis: A comparative cohort study. Arthritis & Rheumatology. https://doi.org/10.1002/art.43338