Characterization and outcomes of pulmonary alveolar proteinosis in Brazil: a case series

OBJECTIVE: Pulmonary alveolar proteinosis (PAP) is a rare disease, characterized by the alveolar accumulation of surfactant, which is composed of proteins and lipids. PAP is caused by a deficit of macrophage activity, for which the main treatment is whole-lung lavage (WLL). We report the experience at a referral center for PAP in Brazil. METHODS: This was a retrospective study involving patients with PAP followed between 2002 and 2016. We analyzed information regarding clinical history, diagnostic methods, treatments, and outcomes, as well as data on lung function, survival, and complications. RESULTS: We evaluated 12 patients (8 of whom were women). The mean age was 41 ± 15 years. Most of the patients were diagnosed by means of BAL and transbronchial biopsy. The mean number of WLLs performed per patient was 2.8 ± 2.5. One third of the patients never underwent WLL. Four patients (33.3%) had associated infections (cryptococcosis, in 2; nocardiosis, in 1; and tuberculosis, in 1), and 2 (16.6%) died: 1 due to lepidic adenocarcinoma and 1 due to complications during anesthesia prior to WLL. When we compared baseline data with those obtained at the end of the follow-up period, there were no significant differences in the functional data, although there was a trend toward an increase in SpO(2). The median follow-up period was 45 months (range, 1-184 months). The 5-year survival rate was 82%. CONCLUSIONS: To our knowledge, this is the largest case series of patients with PAP ever conducted in Brazil. The survival rate was similar to that found at other centers. For symptomatic, hypoxemic patients, the treatment of choice is still WLL. Precautions should be taken in order to avoid complications, especially opportunistic infections.