Marked improvement in autoimmune pulmonary alveolar proteinosis with severe hypoxemia in a patient treated with ambroxol: a case report

INTRODUCTION: Pulmonary alveolar proteinosis is characterized by accumulation of surfactant and phospholipids in the pulmonary alveoli. Whole lung lavage is considered the first-line therapy, which requires special techniques. To the best of our knowledge, there have only been limited reports that have demonstrated the effectiveness of ambroxol on a mild case of pulmonary alveolar proteinosis. CASE PRESENTATION: A 72-year-old Japanese woman presented to our hospital with a one-year history of productive cough and progressive dyspnea. Her chest computed tomography scan showed a bilateral crazy-paving pattern in both of her lungs. She was diagnosed with autoimmune pulmonary alveolar proteinosis based on bronchoalveolar lavage findings and the presence of serum anti-granulocyte macrophage colony-stimulating factor antibodies. She was severely hypoxemic, so we recommended whole lung lavage or inhaled granulocyte macrophage colony-stimulating factor treatment, which she refused. We initiated treatment with ambroxol and her symptoms markedly improved. CONCLUSIONS: Although whole lung lavage is the first-line therapy for pulmonary alveolar proteinosis, oral ambroxol could be an alternative treatment option, even in patients with severe respiratory compromise.