Long term follow-up in patients with pulmonary alveolar proteinosis

Pulmonary alveolar proteinosis (PAP) is a rare lung disease characterized by respiratory failure due to surfactant accumulation within the lung. PAP is currently treated by whole lung lavage (WLL). Since 1977, our cohort is 52 (35 male, 17 female) idiopathic PAP patients. Median age - 37±9 y.o. Most patients are current or former smokers (64%) and have occupational history (55%). Most patients have moderate impairments in functional parameters (mean DLCO - 65±15% pred., mean pulmonary artery systolic pressure - 30±6 mm Hg). The majority of patients (88.4%) received WLL therapy. 3 patients (5.8%) had segmental lavage, 3 patients (5.8%) - N-acetylcysteine (NAC) as monotherapy. The average number of WLL procedures was 2 (1-7). 34.6% received only one WLL and demonstrated long-term improvement after the procedure. 5-years survival rate is 100%. Spontaneous resolution was observed in 2 patients (3.8%) on NAC treatment. In most cases the course of PAP was slowly progressive. 8 patients (15.4%) had rapid progressive deterioration with respiratory failure despite repeated WLL. Predictors of fast progression were estimated. No associations with gender, age, smoking status were found. Long antibiotics and corticosteroids (CS) intake due to incorrect diagnoses before PAP diagnostic (p<0.05) and more than 3 years since first symptoms occurred till PAP diagnostic (p<0.05) correlated with progressive deterioration despite repeated WLL treatments. Besides, long CS intake increased the risk of secondary infections: pneumonia in 3 patients (5.8%), tuberculosis in 3 patients (5.8%), aspergillosis – 1 patient (1.9%). Avoiding of delayed diagnosis/incorrect treatment increases the probability of long symptom-free period after WLL.