Different distribution patterns of

Different distribution patterns of lymphocyte subsets were observed in the lacrimal sac walls. Both CD20+ B lymphocytes and CD3+ T lymphocytes accumulated in organized lymphoid follicles, and CD3+ T cells were also distributed in a diffuse manner. Among the two subsets of T cells, CD4+ T cells were more abundant than CD8+ T cells. Both the immunohistochemical staining and real-time PCR results revealed significantly higher expression levels of IFN-γ than those of IL-4. The levels of Th1- and Th2-related cytokines and chemokines measured were significantly higher in the tears of patients than in those of controls.