Detection & analysis of inflammatory cytokines in tears of patients with lacrimal duct obstruction

Background & objectives: Tear proteomic changes can be a candidate etiopathogenesis of lacrimal duct obstruction diseases (LDODs). Studies on proteomics have focused primarily on nasolacrimal duct obstruction, and some specific inflammatory cytokines such as interferon (IFN)-alpha 2a, interleukin (IL)-8 and IL-10, have not been investigated. In addition, differences in inflammatory cytokines in tears according to the LDOD subtype have not been reported. This study aimed to quantitatively compare inflammatory cytokines in tears from patients with LDOD and investigate tear-cytokine differences among different LDOD subtypes. Methods: Tear samples were collected from both eyes of 30 patients with unilateral LDOD: five patients with prelacrimal obstruction, five with acute dacryocystitis and 20 with chronic dacryocystitis. The contralateral eyes were used as controls. IFN-alpha 2a, IFN-beta, IFN-gamma, IL-17A, IL-6, IL-8, tumour necrosis factor-alpha (TNF-alpha), vascular endothelial growth factor (VEGF)-A, induced protein-10 (IP-10) and monocyte chemotactic protein-1 (MCP-1) were quantified in all samples. Results: The expression of eight cytokines (except for IP-10 and MCP-1) were significantly increased in the affected eyes compared with those in the control eyes. The levels of nine inflammatory cytokines (except for IP-10) in the affected eyes of patients with chronic dacryocystitis were higher than those in the affected eyes of patients with prelacrimal obstruction. In addition, patients with chronic dacryocystitis presented significantly higher IFN-gamma level than those with prelacrimal obstruction or acute dacryocystitis. Interpretation & conclusions: Specific pro-inflammatory cytokines were increased in tears of patients with LDOD compared with those in the controls. The specific cytokine profiles observed in the tears of individuals with different LDOD subtypes may be associated with the unique aetiopathogenesis of these conditions.