The Imbalance of Lymphocyte Subsets and Cytokines: Potential Immunologic Insights Into the Pathogenesis of Chronic Dacryocystitis.

Purpose To explore the quantitative distributions of different lymphocyte subsets in the lacrimal sac mucosa and identify changes of Th1- and Th2-associated cytokines in the tears of patients with chronic dacryocystitis. Methods Lacrimal sac mucosal specimens from patients with chronic dacryocystitis were analyzed. Hematoxylin-eosin staining and Masson staining were performed for pathologic analysis, and immunohistochemical staining was performed for the detection of CD3+, CD4+, CD8+, CD20+, Th1, and Th2 lymphocytes. Quantitative real-time PCR was performed to analyze IFN-γ and IL-4 mRNA expression. In addition, tear samples from patients with chronic dacryocystitis and healthy volunteers were collected and analyzed with an antibody array system for Th1- and Th2-associated cytokines and chemokines. Results 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. Conclusions The different distribution patterns of lymphocyte subsets provide insight into a potential immunologic mechanism for dacryocystitis. The cytokines secreted by Th1 or Th2 cells may play a major role in the pathogenesis of dacryocystitis and could be explored as therapeutic targets.