Abstract
Abstract: :
Purpose: To measure the levels of selected inflammatory cytokines in vitreous samples obtained in patients with active posterior uveitis. Methods: Vitreous samples were obtained from 21 patients (23 eyes) with active posterior uveitis who underwent diagnostic or therapeutic pars plana vitrectomy. Undiluted vitreous was stored at -80 F until assay. Samples were thawed and IL-1a, IL-1b, IL-2, IL-6, TNF alpha levels were measured by Elisa using commercial kits (Endogen). Undiluted vitreous from 6/23 samples was stained for T and B cell markers (CD3, CD4, CD8, CD45, CD20) and analyzed by flow cytometry (Beckton-Dickinson). Results: There was no measurable IL-1a, IL1-b, IL-2, or TNF alpha in the vitreous samples. IL-6 was the only cytokine elevated in 44% (10/23) of the samples tested. We found no correlation between diagnosis and the presence of IL-6. However, patients with CNS lymphoma had no detectable IL-6 levels present in the vitreous (2/23 samples). Although flow ctometry was not performed on all samples, the limited number of assayed vitreous was consistent with the presence of mostly T cells with mixed CD4 and CD8 phenotype. Conclusion: IL-6 is detectable in vitreous from patients with active intraocular inflammation. These results are consistent with an animal model of induced uveitis in which elevated levels of IL-6 abolish immune privilege. IL-1a, IL-1b, IL-2, or TNF alpha were not detected and hence may not play a significant role in posterior uveitis.
Keywords: 380 cytokines/chemokines • 629 vitreous • 437 inflammation