A 44-year-old man with an active smoking history of 50 pack-years was referred to the local Department of Respiratory Medicine due to at least 1 year of declining general condition with recurrent episodes of acute respiratory worsening interpreted as pneumonias, weight loss of 10 kg, fatigue, dry cough, and progressive dyspnea. The patient had a noteworthy alcohol intake of approximate 49 units per week. He was working in an office environment and had, besides smoking, no other exposures. At physical examination finger clubbing was observed, and lung auscultation revealed bibasilar crackles.
Spirometry showed a forced expiratory ventilation in 1 sec (FEV1) of 2.79 l (69% of predicted) and a forced vital capacity (FVC) of 4.04 l (81% of predicted) with an index of 69%. The diffusion capacity (diffusion capacity of the lung for carbon monoxide, DLCO) and coefficient (KCO) was 22%/32%, respectively. At rest, oxygen saturation was between 84 and 90% on room air, and a 6 min walking test with a walking distance of 490 m caused a significant desaturation of nine percent points from 89 to 78%. Biochemistry showed elevation of lactate dehydrogenase (339 U/l; reference 105-205 U/l). Repetitive chest x-rays (CXR) showed a reticular pattern and bilateral infiltrates (Figure 1). High-resolution computed tomography (HRCT) of the thorax showed interlobular septal thickening with diffuse as well as interlobular ground glass opacities (GGOs) with fluctuating consolidation presenting in a 'crazy paving' pattern (Figure 2). A following bronchoalveolar lavage (BAL) revealed a milky white BAL fluid. Microbiological analyses of BAL were either normal or negative. Supplemental transbronchial biopsies (TBB) performed during bronchoscopy revealed intraalveolar accumulation of a proteinaceous material, which was consistent with the diagnosis PAP (Figure 3). A subsequent blood sample confirmed the diagnosis of autoimmune PAP due to positive anti-GM-CSF (granulocyte-macrophage colony-stimulating factor) antibodies.