Autoimmune Pulmonary Alveolar Proteinosis: A Case Report

Autoimmune pulmonary alveolar proteinosis (APAP) is a rare interstitial lung disease characterised by abnormalities in surfactant metabolism. It is typically diagnosed in the 3rd or 4th decade of life with cough and dyspnoea being the most common manifestations. The condition is generally mild. The most advanced cases, in which the dyspnoea leads to limitation in daily activity, require treatment, and whole-lung lavage is the treatment of choice. We report a case of a 37-year-old female with incidental diffuse changes on a plain chest X-ray. The initial high-resolution computed tomography (HRCT) scan suggested allergic alveolitis, but due to the oligosymptomatic course of the disease and only mildly abnormal pulmonary function no further diagnostic tests were performed and the patient was left under observation. Due to the persistence of the radiographic abnormalities a decision was made to perform an open lung biopsy. Based on the histopathology results and the presence of antibodies to granulocyte-macrophage colony-stimulating factor (GM-CSF) the final diagnosis of APAP was made.