Long-term clinical course and outcomes in patients with lymphangioleiomyomatosis

Abstract

Background: Lymphangioleiomyomatosis (LAM) is a rare multisystemic disorder with various clinical manifestations. Despite the recognition of several prognostic factors, the long-term clinical course and prognosis of patients with LAM in the era of sirolimus therapy are not established. Methods: The clinical data of 104 patients with LAM were retrospectively analyzed. Death or lung transplantation was defined as the primary outcome. Disease progression (DP) was defined as a 10% absolute decline in forced expiratory volume in one second (FEV1). Results: The mean age of all patients was 40.3 years. Over a median follow-up period of 7.1 years, of all patients, 6.7% died and 1.9% underwent lung transplantation, while of 92 patients with serial lung function data, 35.9% experienced DP. The 5-year and 10-year overall survival rates were 93.0% and 90.9%, respectively. The multivariable Cox analysis revealed that older age (hazard ratio [HR]: 1.136, P = 0.025), lower FEV1 (HR: 0.956, P = 0.026) or diffusing capacity for carbon monoxide (HR: 0.914, P = 0.003), and shorter distance during the 6-min walk test (HR: 0.993, P = 0.020) were independent prognostic factors for mortality. A propensity score-matched comparative analysis performed between patients who received sirolimus therapy and those who did not, found no differences in survival, DP, complications, and lung function decline rate. Conclusions: Over a follow-up period of approximately 7 years, one-tenth of all patients experienced death, while one-third experienced DP. Older age, lower lung function, and reduced exercise capacity were associated with a poor prognosis in patients with LAM.