Analysis of Cytokine Production Profiles of Local and Systemic Lymphocytes in Sick Building Syndrome Compared with Ocular Allergy

PURPOSE: We have previously studied clinical and allergological aspects of sick building syndrome (SBS) cases with ocular disorders and found that SBS is suggested to be partially induced by an allergic response. We analyzed the cytokine production profiles of conjunctival and peripheral blood lymphocytes in patients with SBS with ocular manifestations to further evaluate the pathophysiology of SBS from an immunological standpoint. METHODS: We obtained conjunctival samples and peripheral blood mononuclear cells (PBMC) from 15 cases of SBS with ocular findings, 49 cases of allergic conjunctival diseases (ACD) (allergic conjunctivitis (AC), atopic keratoconjunctivitis (AKC), and vernal keratoconjunctivitis (VKC)), and normal controls. Frequencies of cytokine-producing T cells were analyzed by flow cytometry based on an intracellular cytokine staining method. RESULTS: Although no significant difference was observed in the percentage of interferon (IFN)-γ-producing CD4+ T cells in PBMC between patients with SBS and controls, the percentage of interleukin (IL)-4-producing PBMC CD4+ T cells in patients with SBS was significantly higher than that in controls. The percentage of IL-4-producing CD4+ T cells in the conjunctiva in patients with SBS was significantly higher than that in controls, whereas it was significantly lower than that in AKC and VKC. A significant correlation was observed between the percentage of IL-4-producing CD4+ T cells in the conjunctiva and clinical score. CONCLUSION: These results suggest that SBS may be a kind of allergic disorder and that IL-4 plays a role in the development of allergic disorders in SBS ocular lesions.