Abstract
Purpose::
To investigate the cytokine profile in a rabbit model of staphylococcus epidermidis endophthalmitis.
Methods::
The right eye of 3 New Zealand white rabbits received an intravitreal injection of 3.5 X 105 to 4.0 x 105 staphylococcus epidermidis organisms. The left eye of each animal served as a control and received no intervention. Each eye was examined at 24 hours following injection for signs of endophthalmitis (photophobia, conjunctival injection, and vitritis) using a standardized grading protocol (scaled from 0 to 4 for increasing severity). Animals were then euthanized and each eye was separately enucleated. The vitreous cavity contents of infected (right) and control (left) eyes were analyzed for multiple cytokine levels by Quansys Biosystems on their Q-Plex miniaturized sandwich ELISA mouse and human arrays.
Results::
All infected eyes showed clinical signs of endophthalmitis including photophobia, conjunctival injection, and vitritis. None of the control eyes showed signs of infection. A total of 16 different cytokine levels were assayed in the mouse array and 12 different cytokine levels in the human array for each sample. In the mouse array, IL-1a, IL-1b, MIP-1a, IL-3, and IL-9 were uniformly increased, and IFNγ and RANTES uniformly decreased in infected eyes compared to control eyes. In the human array, IL-1b, IL-5, IL-8, and IL-13 were uniformly increased in infected eyes compared to control eyes.
Conclusions::
Our results show that experimental endophthalmitis with staphylococcus epidermidis induces a specific cytokine response. We are currently expanding this study to develop a more complete profile as a function of time after infection. Understanding this cytokine profile may lead to a better understanding of inflammatory cascade mechanisms and ultimately to better diagnostic and therapeutic alternatives for patients with infectious endophthalmitis.
Keywords: cytokines/chemokines • endophthalmitis • Staphylococcus