The Role of Moesin in Diagnosing and Assessing Severity of Lymphangioleiomyomatosis

Background: Lymphangioleiomyomatosis (LAM) is a rare disease which is easily misdiagnosed. Vascular endothelial growth factor D (VEGF-D), as the most common biomarker, however, is not so perfect for the diagnosis and severity assessment of LAM. Materials and methods The isobaric tags for relative and absolute quantitation (iTRAQ)-based method was used to identify a cytoskeleton protein, moesin. 84 patients with LAM, 44 patients with other cystic lung diseases (OCLD), and 37 healthy control subjects were recruited for collecting blood samples and clinical data. The levels of moesin in serum were evaluated by ELISA assay. The relationships of moesin with lymphatic involvement, lung function, and treatment decision were explored in patients with LAM. Results The candidate protein moesin was identified by the proteomics-based bioinformatic analysis. The serum levels of moesin were higher in patients with LAM [219.0 (118.7-260.5) pg/mL] than in patients with OCLD (125.8 ± 59.9 pg/mL, P  < 0.0001) and healthy women [49.6 (35.5–78.9) ng/mL, P  < 0.0001]. Moesin had an area under the receiver operator characteristic curve (AUC) of 0.929 for predicting LAM diagnosis compared to healthy women (sensitivity 81.0%, specificity 94.6%). The combination of moesin and VEGF-D made a better prediction in differentiating LAM from OCLD than moesin or VEGF-D alone. Moreover, elevated levels of moesin were related to lymphatic involvement in patients with LAM. Moesin was found negatively correlated with FEV 1 %pred, FEV 1 /FVC, and DLCO%pred ( P  = 0.0181, r = -0.3398; P  = 0.0067, r = -0.3863; P  = 0.0010, r = -0.4744). A composite score combining moesin and VEGF-D improved prediction for sirolimus treatment, compared with each biomarker alone. Conclusion Higher levels of moesin in serum may indicate impaired lung function and lymphatic involvement in patients with LAM, suggest a more serious condition, and provide clinical guidance for sirolimus treatment.