Identification and Prognosis of Patients With Interstitial Pneumonia With Autoimmune Features

Area of Science:

• Pulmonology
• Rheumatology
• Immunology

Background:

• Interstitial pneumonia with autoimmune features (IPAF) describes patients with interstitial lung disease (ILD) and autoimmune characteristics who don't meet criteria for connective tissue diseases (CTDs).
• Accurate classification and prognostic evaluation of IPAF are crucial for patient management.

Purpose of the Study:

• To identify and reclassify patients as IPAF, CTD-ILD, or idiopathic pulmonary fibrosis (IPF) within a pulmonary cohort.
• To evaluate the prognosis of patients diagnosed with IPAF.

Main Methods:

• Retrospective review of 456 patients from a single-center ILD cohort.
• Reclassification of diagnoses by a multidisciplinary panel, including rheumatologists.
• Comparison of transplant-free survival using Kaplan-Meier analysis and prognostic factor identification via Cox models.

Main Results:

• Identified 60 IPAF, 113 CTD-ILD, and 126 IPF patients.
• IPAF patients showed no statistically significant difference in transplant-free survival compared to CTD-ILD or IPF groups.
• Male sex was an independent predictor of worse transplant-free survival in IPAF patients (HR, 4.58).
• Only 10% of IPAF patients progressed to CTD-ILD, most commonly antisynthetase syndrome.

Conclusions:

• Most IPAF patients do not progress to CTD-ILD, but those who do often develop antisynthetase syndrome, emphasizing the importance of autoantibody testing.
• Male sex may indicate a poorer prognosis in IPAF, similar to other ILD types.
• Integrating rheumatologists into ILD multidisciplinary evaluations improves classification accuracy and prognostic understanding.