Clinical Characteristics and Outcomes of Patients with Lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) is a rare, progressive cystic lung disease that affects women of reproductive age. Although registries from Western countries have provided key insights, comprehensive nationwide data from Asian countries are scarce. This study aimed to characterise the clinical, functional and outcome features of Korean patients with LAM from a nationwide multicentre registry.

We analyzed data from patients with LAM enrolled in the Korean Nationwide Rare Interstitial Lung Disease Registry in 2024. Data on clinical and functional characteristics were collected from 20 centers. Longitudinal changes in pulmonary function were assessed using linear mixed-effects models. Individual annual forced expiratory volume in 1 s (FEV₁) change rates were estimated using linear regression and analyzed to identify associated factors.

Eighty-six women (mean age, 47.3 years) were included; 50% were asymptomatic at diagnosis and 61.6% had complications, including pneumothorax (29.1%) and renal angiomyolipoma (25.6%). Baseline mean forced vital capacity (FVC) and FEV₁ were relatively preserved (89.6% and 78.7% predicted, respectively), whereas diffusing capacity for carbon monoxide was mildly reduced (64.3% predicted). Longitudinal analysis revealed no significant overall decline in lung function. However, cough at presentation and higher baseline FEV₁ or FVC were independently associated with disease progression. A total of 54.7% of patients received mechanistic target of rapamycin (mTOR) inhibitors, but no statistically significant differences in the rate of functional decline were observed between users and non-users.

This study provides a nationwide characterization of LAM in Korea, showing preserved lung function at diagnosis and frequent mTOR inhibitor use.