Abstract
Purpose :
To compare the levels of tear cytokines and monocyte chemotactic protein-1 (MCP-1) in superior limbic keratoconjunctivitis (SLK) patients, and to investigate the expression of MCP-1 and its correlation to mast cells between SLK and normal subjects.
Methods :
Fourteen eyes of seven SLK patients were recruited from 2014 to 2016. All the patients received medical treatment, including topical steroids, mast cell stabilizer, and lubricants, for at least one month. The eyes refractory to medical treatment underwent conjunctival resection with Tenon’s capsule excision. Tear samples were collected at the first visit, one month after medical treatment, and three months after surgical treatment. Tear concentrations of interleukin (IL)-1a, IL-1b, IL-4, IL-6, IL-8, IL-10, IL-13, MCP-1, interferon (IFN)-g, and tumor necrosis factor (TNF)-a were measured by Quantibody array. Protein expression of MCP-1 and anti-mast cell tryptase in conjunctival specimens was detected by immunohistochemistry.
Results :
Reducing levels of MCP-1, IL-6, IL-8, and IFN-g were found comparing with their baseline levels (P<0.05) on these SLK patients after one-month medical treatment. Much lower levels of cytokines were measured in the medically responsive group than those in medically unresponsive group (P<0.05). However, significant reduced cytokine levels could be found in patients after surgical treatment (P<0.001). Meanwhile, higher immunostaining intensity of MCP-1 was found in the conjunctival epithelium and subepithelial stroma of SLK patients than that in normal subjects (P<0.05). MCP-1 immunointensity was also correlated with the number of tryptase (+) mast cells in conjunctival subepithelial stroma (P<0.05).
Conclusions :
In this study, significantly reduced levels of MCP-1 and dry eye-associated tear cytokines, IL-6, IL-8, and IFN-g, were found in SLK patients after appropriate treatment. Overexpression of MCP-1 correlated to the number of mast cells was also noted in the conjunctival specimens of SLK patients. This study suggests that surgical resection has better anti-inflammatory effect in SLK patients and MCP-1 may be one of the factors affecting mast cell activities in SLK.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.