Introduction: Serum vascular endothelial growth factor-D (VEGF-D) is a lymphangiogenic growth factor that is considered a valuable tool in the diagnosis of lymphangioleiomyomatosis (LAM). Previous studies have reported a wide variability in VEGF-D serum levels in LAM patients and it seems to be associated with pulmonary impairment and lymphatic involvement.
Methods: We conducted a cross-sectional study from 2009 to 2017 that evaluated VEGF-D serum levels in a cohort of LAM patients who were never treated with mTOR inhibitors and compared them to healthy age-matched volunteers. Clinical and functional parameters were assessed and correlated with their respective serum VEGF-D levels.
Results: One hundred and four patients were included in the analysis. Serum VEGF-D levels were higher in LAM patients compared to healthy controls: 796 (404-1588) versus 162 (117-232) pg/mL, respectively (p < 0.001). Patients with tuberous sclerosis complex-LAM, TSC-LAM (20%), had higher levels of VEGF-D when compared to patients with sporadic LAM (80%) [1005 (641-2732) vs. 772 (370-1383), p = 0.05]. Serum VEGF-D levels were weakly correlated with DLCO (r = - 0.26, p = 0.001) and lymphatic involvement was more frequent in those with serum VEGF-D levels equal or above 800 pg/mL (35% vs. 13%, p = 0.02).
Conclusions: In LAM, serum VEGF-D is weakly associated with lung function impairment and strongly associated with lymphatic involvement. VEGF-D is validated for use in Brazilian patients with LAM whose characteristics must be accounted for when evaluating their serum VEGF-D levels.
Keywords: Interstitial lung disease; Lymphangioleiomyomatosis; Pulmonary function tests; Vascular endothelial growth factor.