Connective tissue disease-associated interstitial lung diseases and interstitial pneumonia with autoimmune features: different entities?

Aims and Objectives: To explore the differences between patients with connective tissue disease-associated interstitial lung diseases (CTD-ILD) and interstitial pneumonia with autoimmune features (IPAF). Methods: 77 patients were included prospectively and consecutively in the study. 42 had CTD-ILD, and 35 had IPAF. All subjects were from the ILD-Diagnostic Program of the Hospital Clinic, Barcelona. Bi-variate analysis from demographic features, clinical, patterns on chest high-resolution computed tomography (HRCT), pulmonary function tests, exacerbation history, and treatments were performed. Results: General characteristics of the patients are included in Table 1. The most common pattern in HRCT was nonspecific interstitial pneumonia (NISP) in both groups. Patients from CTD-ILD group have a higher frequency of exacerbations and fine crackles at auscultation. Patients with CTD-ILD have a higher frequency of therapy with Oral corticosteroid plus immunosuppressor than IPAF group, who a high percentage of patients did not initially receive any therapy. Conclusion: CTD-ILD and IPAF have some similarities and also differences in demographic, clinical, pulmonary function, and treatment characteristics. The “real” niche of IPAF in the ILDs grouping still remains something to clarify.