Abstract
Introduction: Lymphangioleiomyomatosis (LAM) is a rare lung disease that presents with multiple cysts on chest imaging and progressive pulmonary function impairment. LAM patients are reported to to have 3-4 fold decrease in small airways compared to healthy subjects. While spirometry used to monitor of LAM, it is known to be poorly sensitive to small airways. Oscillometry (Osc), a new PFT modality, is highly sensitive to changes in the small airways. Quantitative analysis of high-resolution chest tomography (CT) is increasingly used in different disease as markers of severity.
Objective: To characterize Osc and CT measurements in LAM patients.
Methods: All LAM patients followed at our center were enrolled for Osc prior to routine PFTs from Aug 2020 onward. CTs done within 6 months of the PFT/Osc were used for lung density and volume analysis.
Results: Of 35 LAM patients (age=48.8±12.5 yrs; 34F,1M), 12 had Sporadic (S-LAM), 11 had Tuberous Sclerosis Complex (TSC-LAM) and 12 had unknown LAM type (NYD-LAM). Spirometry and plethysmograph-derived total lung capacity (TLC) were normal and similar amongst 3 groups (mean ± SD: %FEV1=76.6±21.8, %FVC=90.1±16, %TLC=99.3±11.2). However, Osc indicated ventilatory inhomogeneity with mildly elevated AX (area of reactance, >8.0 cmH2O/L) in all groups. Higher AX reflects smaller lung volumes in communication with ventilation. CT low attenuation area (%LAA-950), a metric of cystic disease burden, was highest in NYD-LAM.
Conclusion: These data suggests that Osc and quantitative CT may provide additional information about subtle physiologic abnormalities in LAM patients that are not apparent with PFTs alone
Footnotes
Cite this article as Eur Respir J 2022; 60: Suppl. 66, 2585.
This article was presented at the 2022 ERS International Congress, in session “-”.
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).
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