Hypersensitivity Pneumonitis With and Without Autoimmune Features: A Clinical Comparative Analysis

Area of Science:

• Pulmonology
• Immunology
• Rheumatology

Background:

• Hypersensitivity pneumonitis (HP) is an interstitial lung disease (ILD) triggered by inhaled antigens, with poorly understood immunopathology.
• The overlap between HP and autoimmune diseases is recognized, but its impact on HP prognosis remains unclear.

Purpose of the Study:

• To investigate the clinical characteristics and outcomes of HP patients with concomitant autoimmune features (HPAF) compared to those without.
• To determine if coexisting autoimmunity influences the prognosis of hypersensitivity pneumonitis.

Main Methods:

• Retrospective analysis of 73 HP patients from an ILD registry, categorizing them into HPAF and non-HPAF groups.
• Comparison of demographics, clinical data, treatment, and outcomes, including transplant-free survival, using Cox proportional hazards models.

Main Results:

• HPAF patients exhibited a higher prevalence of echocardiographic pulmonary hypertension (48.8% vs 23.3%) and arthritis (20.9% vs 3.3%).
• No significant differences were observed in pulmonary function, oxygen needs, mortality, or lung transplant rates between the groups.
• Transplant-free survival did not differ significantly between HPAF and non-HPAF HP patients (p=0.836).

Conclusions:

• Concomitant autoimmunity in HP patients is associated with increased likelihood of pulmonary hypertension and arthritis.
• Autoimmune features in HP patients do not appear to worsen overall clinical outcomes or long-term survival.