35 years of the Italian cohort of Pulmonary Alveolar Proteinosis (PAP)

<bold>Rationale.</bold> PAP is characterized by surfactant homeostasis accumulation within airspaces impairing gas transfer. Whole lung lavage (WLL) currently is the therapeutic standard. <bold>Methods.</bold> In this registry, we provide data from a cohort of PAP patients (pts) followed for 35 years at the San Matteo Hospital, Pavia, Italy. <bold>Results.</bold> We enrolled 157 PAP pts from 1989 to 2024; 90% of the registry subjects were affected by autoimmune PAP. The disease affects males and females with a ratio of 2:1 and 37.6% of pts are nonsmokers. The intra-patient mean interval between first symptoms and diagnosis was 13+22.8 months. At the diagnosis, 57.6% of pts had hypercolesterolemia (mean 239 +28 mg/dl). With reference to the PAP clinical course, 70 pts did not necessitate WLL, while 87 PAP pts underwent therapeutic WLL: in 47 subjects a single WLL was sufficient to provide long term, durable benefit, whereas 37 patients required multiple WLLs. On 2009, in our center we firstly introduce inhaled GM-CSF therapy; since then, 30 patients have been treated and despite an increase in the number of pts followed, the mean number of WLLs/pts in follow reduced (15,6% vs 9%) (fig.1). <bold>Conclusion.</bold> The establishment of a registry for an ultra-rare disease, such as PAP, followed at a single reference center with long experience, has provided useful information on the natural history and clinical course of the disease. <fig><object-id>erj;64/suppl_68/PA4281/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>