Clinical characteristics of pulmonary alveolar proteinosis.

Objectives: Pulmonary alveolar proteinosis (PAP) is a rare disease with non-specific and various clinical manifestations, often leading to misdiagnosis. This study aims to raise the awareness of this disease via summarizing the clinical characteristics, diagnosis, and therapy of PAP.

Methods: We retrospectively analyzed clinical data of 25 hospitalized cases of PAP during 2008 and 2019 in the Department of Respiratory and Critical Care Medicine of the Second Xiangya Hospital of Central South University.

Results: Cough with unkown reason and dyspnea were common clinical manifastations of PAP. Five patients had a history of occupational inhalational exposure. Sixteen patients had typical image features including ground-glass opacification of alveolar spaces and thickening of the interlobular and intralobular septa, in typical shapes called crazy-paving and geographic pattern. Fourteen patients underwent pulmonary function tests, revealing a reduction in the diffusing capacity for carbon monoxide. The positive rate of transbronchial biopsy was 95%. Five patients received the whole lung lavage and the symptoms and imaging fcauters significantly relieved after five-years follow-up.

Conclusions: PAP is characterized by radiographic pattern and pathology. Transbronchial lung biopsy is effective to make diagnosis of PAP. The whole lung lavage remains a efficient therapy.