Abstract Introduction Identifying the etiology of an obstructive lung disease is crucial for treatment. We present a case where determining the cause of a severe fixed obstruction on pulmonary function testing was challenging, especially as the patient experienced worsening chronic hypercapnia and recurrent, persistent pulmonary infections. Case Description A 42-year-old woman with a history of Hashimoto’s thyroiditis, chronic kidney disease, and uncontrolled asthma was referred to pulmonary in January 2024. Her social history included a 10-pack-year smoking history and marijuana vaping. Pulmonary testing demonstrated severe fixed obstruction (FEV1/FVC 27%) with air trapping and preserved DLCO. Alpha-1 antitrypsin testing indicated a normal variant. A CT scan of the chest revealed significant mosaic attenuation with air trapping and without significant fibrotic changes (Figure 1). Starting late 2024, she experienced recurrent hospitalizations for pneumonia. Follow-up CT scans showed ground-glass opacities and new upper lobe cavitary lesions (Figure 1). Bronchoscopy with biopsies revealed necrotizing granulomatous inflammation, and bronchoalveolar lavage grew Mycobacterium avium intracellulare (MAI). Fungal tests were negative. Later, sputum cultures grew methicillin-resistant Staphylococcus aureus and multidrug-resistant Pseudomonas. Autoimmune testing revealed positive ANA and RF, but negative Anti-Ro/Anti-La, and ANCA. Rheumatology evaluated for background autoimmune conditions and found no typical features of rheumatoid arthritis or systemic lupus erythematosus, but they noted sicca symptoms and keratitis. A lip biopsy confirmed seronegative Sjogren’s syndrome (SS), and SS-related bronchiolitis obliterans was diagnosed as the cause of her fixed obstructive pulmonary disease. She also had two indeterminate sweat chloride tests suggesting an underlying cystic fibrosis (CF) phenotype. CF panel revealed a heterozygous ΔF508 CFTR mutation, which can impair mucociliary clearance and predispose to infections. She was started on corticosteroids and rituximab judiciously given background active infection, and her symptoms improved for several months post-hospitalization. She also received treatment for MAI concurrently under infectious disease consultation. Due to worsening chronic respiratory failure with hypercapnia, she eventually underwent successful lung transplantation. Conclusions Bronchiolitis obliterans is an atypical manifestation of SS, and the unfortunate coexistence of a CFTR mutation, autoimmune pulmonary disease, and MAI coinfection with other opportunistic pathogens made diagnosis challenging. Managing these cases is difficult, as it involves balancing the need for immunosuppression with the presence of severe infection. This case underscores the importance of recognizing airway manifestations of autoimmune disease and thoroughly investigating all causes of impaired mucociliary clearance in severe bronchiectasis and cavitary lung disease. Early transplant evaluation is crucial in these atypical cases. This abstract is funded by: None
Alam et al. (Fri,) studied this question.