Diagnostic and Therapeutic Dilemmas in Recurrent Pulmonary Alveolar Proteinosis After Bilateral Lung Transplantation

Pulmonary alveolar proteinosis (PAP) is a rare granulocyte-macrophage colony-stimulating factor (GM-CSF) dependent lung disease treated primarily with whole-lung lavage (WLL); recurrence after lung transplantation is uncommon and poorly characterised. We present a 73-year-old Hispanic man with PAP who developed recurrent disease more than 3 years after bilateral lung transplantation. High-resolution CT showed evolving ground-glass opacities and crazy-paving, and anti-GM-CSF antibodies were positive, yet repeated bronchoalveolar lavage and transbronchial biopsies were initially PAS-negative. Concomitant Mycobacterium avium complex, Aspergillus and Nocardia infections mimicked recurrent PAP and coincided with an atypical shift in spirometry from supranormal airflow (FEV₁ 110% predicted; FEV₁/FVC 91%) to obstruction (FEV₁ 99% predicted; FEV₁/FVC 68%). Ultimately, repeat lavage revealed PAS-positive lipoproteinaceous material, and treatment with inhaled sargramostim plus two sequential WLLs produced marked radiographic clearance, symptomatic relief and partial spirometric recovery. Our case highlights how multimodal, longitudinal clinical surveillance remains essential in lung transplant recipients.