Abstract
Rationale: PAP is caused by a dysfunction in surfactant catabolism due to the disruption of GM-CSF signalling. A typical feature of PAP is the accumulation of proteinaceous material within the air spaces. Focal, mild fibrosis may be present, but extensive interstitial fibrotic disease is a rare occurrence in PAP.
Aims: We aim to characterize PAP patients (pts) who develop lung fibrosis.
Method: We retrospectively analyse a cohort of 64 PAP pts. Functional data (VC%, FVC%, TLC%, DLCO%) and alveolar-arterial gradient values (A-aO2) were collected at diagnosis (t0) and at 8 year of follow up (t1).
Results: In our cohort, 12 pts developed lung fibrosis (study group) within 8 years from PAP diagnosis; 58,3% were female with previous (41,7%) or no smoking (41,7%) habits. The mean age at PAP diagnosis was 46 years. The remaining 52 pts did not show lung fibrosis at HRTC (control group); 73% were male, former (34,6%) or never smokers (38,4%), with a mean age at PAP diagnosis of 41 years. In the study group 75% of pts (vs 73% of controls) underwent at least one WLL and 44.4% (vs 40,3% of controls) underwent more than one WLL; in 50% of the cases (vs 23% of controls), WLL was followed by inhaled rGM-CSF therapy. Multivariate analysis show a significantly better improvement in DLCO% (p=0,002) and PaO2 (p=0,011), from t0 to t1, in the control group compared with study group.
Conclusion: We demonstrated finding of lung fibrosis in 9.2% of our PAP pts. This result supports the hypothesis of a possible fibrosing evolution of PAP, rather than a distinct disease. Moreover DLCO% and PaO2 seems act as predictors of lung fibrosis in PAP.
Footnotes
Cite this article as: European Respiratory Journal 2021; 58: Suppl. 65, PA2369.
This abstract was presented at the 2021 ERS International Congress, in session “Prediction of exacerbations in patients with COPD”.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
- Copyright ©the authors 2021