Abstract
Purpose: :
Lymphoid neogenesis is known to associate various chronic inflammatory diseases and may play roles for chronicization and affects disease severity. Atopic keratoconjunctivitis (AKC) and vernal keratoconjunctivitis (VKC) are severe chronic form of allergic conjunctivitis often accompany with giant papillae formation. To clarify possible involvements of lymphoid neogenesis (tertiary lymphoid organ:TLO) for the pathogenesis of severe chronic allergic conjunctivitis, we investigated the expression of lymphoid markers in the resected giant papillae obtained from AKC / VKC patients.
Methods: :
Anti-LYVE-1, CD3, CD20, CD35, CD138, IgE, PNAd, Ki-67, CCR7, CCL21 and CXCL13 immnunohistochemical staining was performed with the resected conjunctivae obtained from AKC/VKC patients. RT-PCR analysis and subsequent direct seqencing were carried out to examine ε-chain- and activation-induced cytidine deaminase (AID)-mRNA expression in a giant papilla obtained from a VKC patient.
Results: :
TLO, composed from CD20+-B cells and marginal CD3+-T cells, were observed at the vicinity of LYVE-1+-lymphatic vessels in the substantia propria of the giant papillae. CD35+-follicular dendritic cells (FDC) and CD138+-plasma cells were observed within and around the TLO. CCL21 expression was observed in the LYVE-1+-lymphatic vessels, CXCL13 expression was observed in the FDC. Limited number of IgE+ cells were observed among B cells or among plasma cells, and ε-chain-/AID-mRNA expression was detected in the giant papilla.
Conclusions: :
Lymphoid neogenesis plays roles for the chronicization and severity of allergic conjunctivitis by direct immune response against external stimuli and class switch recombination to IgE immunoglobulin at regional TLO.
Keywords: conjunctiva • immunohistochemistry • inflammation