An eleven-year retrospective cross-sectional study on pulmonary alveolar proteinosis

Pulmonary alveolar proteinosis (PAP) is a rare disease in the field of pulmonary medicine. The efficacy of whole-lung lavage (WLL) as the treatment of PAP had never been evaluated in the Iranian population. Therefore, there is a real need to investigate the characteristics of PAP and also to evaluate the efficacy of WLL in this rare disease. The study aimed to investigate demographic features, clinical presentation and treatment outcomes of the disease in Iranian PAP patients.

Data of 45 patients with definite diagnosis of PAP, who had regular follow-ups from March 2004 to March 2015 at an Iranian referral respiratory hospital, were collected. Whole-lung lavages (WLL) efficacy was assessed by comparing spirometric, arterial blood gas parameters and six-minute walk test (6MWT) results before and after all lavages.

Mean age at diagnosis of disease was 30.33 ± 14.56 years. Four patients (8.8%) reported non-massive hemoptysis and three subjects (6.6%) had concomitant pulmonary tuberculosis. In 71.1% of cases, transbronchial lung biopsy and bronchoalveolar lavage were sufficient for diagnosis. Spirometric results and arterial blood gas parameters and 6MWD improved significantly after all the lavages. Four patients (8.8%) died because of respiratory failure. The only variable capable of predicting treatment failure was the history of hemoptysis.

The study revealed sufficiency of WLL as the PAP patients' treatment. Also hemoptysis was found to be the independent factor that can predict treatment failure.