Proteomic Analysis of Meibomian Gland Secretions in Patients With Blepharokeratoconjunctivitis

PURPOSE: To screen and compare the differential proteins in meibomian gland secretions between patients with blepharokeratoconjunctivitis (BKC) and healthy individuals and to identify target proteins that may participate in the occurrence and development of BKC. METHODS: Thirteen patients diagnosed with BKC in Shenzhen Eye Hospital and five healthy volunteers were included in this study. Meibomian gland secretions and clinical traits were collected before and after 1 month of standard BKC treatment. Label-free mass spectrometry was used for proteomic detection of meibomian gland secretions. Weighted protein coexpression network analysis (WPCNA) and several different protein analyses were performed to identify hub proteins associated with BKC and its clinical characteristics. RESULTS: Patients with BKC had significantly lower cleanliness of the eyelid margin, higher palpebral margin scores, more serious clinical manifestations of secretions, and more damaged meibomian gland morphology compared with the healthy controls. One hundred fifteen differential proteins were associated with the clinical traits, which included diagnosis, sex, age, severity, corneal neovascularization, disease course, eyelid margin cleanliness, palpebral margin score, secretion characteristics, and meibomian gland morphology. Four hub proteins related to inflammation and the immune response (namely, S100A8, S100A9, ANXA3, and LCN2) were increased in BKC and remained increased after 1 month of treatment. The cleanliness, blepharon eyelid score, and secretion characteristics were improved after BKC treatment. CONCLUSIONS: S100A8, S100A9, ANXA3, and LCN2 are BKC-associated proteins probably involved in the chronic inflammation of BKC. TRANSLATIONAL RELEVANCE: Hub proteins probably involved in chronic inflammation of BKC were identified by proteomic methods.