Comparative Analysis of Inflammatory Mediators in Children, Adolescents, and Adults with Vernal Keratoconjunctivitis

This study aims to analyze the expression of presumably critical inflammatory mediators including cytokines, chemokines, secretory, binding, and matrix proteins, and IgE in Vernal keratoconjunctivitis (VKC)-relevant age groups: children, adolescents, and adults.

The tears (n = 16) and serum (n = 12) samples from active, chronic VKC cases, without treatment at the time of sampling, were collected from the tertiary eye care centers of L V Prasad Eye Institute, located in Hyderabad and Bhubaneswar, during 2021-2022. The age-matched healthy individuals were taken as controls. The subjects were grouped as: children (1-11 years), adolescents (12-21 years), and adults (> 21 years). The expression of a specific panel of Th1- (IL-36γ and MMP-9) and Th2-inflammatory mediators (IL-6, Vitamin D-binding protein (VDBP), MUC5AC, FcεR1, MCP-1, IgE, GM-CSF) was analyzed through ELISA.

Compared to controls, the expression of IgE was upregulated in tears and serum samples of all VKC patients, whereas IL-6, MMP-9, and MUC5AC were upregulated, and VDBP was downregulated in children's tear samples. The VDBP and MCP-1 recorded the highest and lowest protein expression (pg/ml) among all the inflammatory mediators, respectively. The IL-36γ was upregulated in tears and serum samples of adolescents and adults.

Our results suggest differential expressions of chosen Th1- and Th2-mediators in tears and serum samples of children, adolescents, and adults with active VKC. Compared with controls, our findings specifically suggest: i) upregulation of IgE, IL-6, MMP-9, and MUC5AC, and downregulation of VDBP in tear samples of children, and ii) upregulation of IgE and IL-36γ in adolescents and adults.