The combination of male sex, seropositivity, and smoking history increased the risk of rheumatoid arthritis-associated interstitial lung disease (RA-ILD)  nearly 13 times, according to Gregory McDermott, MD, during his presentation at the ACR Convergence on November 13.

Dr McDermott is a practicing rheumatologist and internal medicine specialist at the Brigham and Women's Hospital in Boston, Massachusetts.

The most common RA-ILD subtypes are interstitial pneumonia (RA-UIP), characterized by fibrosis, and nonspecific interstitial pneumonia (RA-NSIP), characterized by inflammation of the lungs. “Despite these differences, most prior research studied RA-ILD as a single entity rather than examining individual subtypes,” Dr McDermott explained. “Therefore, we investigated differences in demographic, serologic, and lifestyle risk factors for RA-ILD and major RA-ILD subtypes.”

The investigators compared RA-ILD cases (n=201, mean age 51 years, 66.2% female) and controls with RA but without ILD (n=547, mean age 49 years, 78.1% female) and identified RA-ILD subtypes. They further stratified their findings based on gender, RA-related autoantibody testing, and smoking history.

Among the RA-ILD cohort 69 patients (34.3%) had RA-UIP, 34 patients (16.9%) had RA-NSIP, and 98 patients (48.8%) had other subtypes or were indeterminate. In the same cohort, RA-ILD was associated with male sex (OR 1.63, 95% CI), seropositivity (OR 2.23, 95%CI), and smoking (OR 1.71, 95%CI)

“Patients with all 3 risk factors mentioned—male, seropositive, smoking—displayed an even stronger association with RA-ILD (OR 6.09, 95%CI),” Dr McDermott said. The association was particularly stronger with RA-UIP (OR 12.8, 95%CI) compared to RA-NSIP (OR 2.96 95%CI)

“RA-UIP is considered to be the most severe RA-ILD subtype,” Dr McDermott explained. “And the male sex and elevated anti-CCP were strongly associated with RA-UIP.”

Reference:
McDermott G. 1269-The impact of sex, serostatus, and smoking on risk for rheumatoid arthritis-associated interstitial lung disease subtypes. Presented at: American College of Rheumatology Convergence. November 13, 2023. San Diego.