Purpose: This study deduced the pathological and immunophenotypic features of idiopathic dacryoadenitis, and researched into the possible immune mechanism of this lesion.
Methods: Here are 23 lesions of idiopathic lacrimal gland inflammation collected retrospectively, whose histopathologic types were classified based on different characteristics, while the fibrosis degrees were measured. The immunohistochemical staining was performed on tissue sections using monoclonal antibodies against CD20, CD45RO, IL-4 and IFN-γ, the percentages of mononuclear inflammatory cells staining for CD20, CD45RO and the quantities of cells staining positively for IL-4 and IFN-γ were enumerated.
Results: Lymphoid follicular and sclerosing lesions are two most common pathological types with different lymphocyte and fibrosis pattern. The proportions of CD20 cells have significant difference between lymphoid follicular (48.6 ± 14.9%) and sclerosing lesions (21.8 ± 12.2%), and the proportions of CD45RO cells are also different in the two types (27.2 ± 6.5% and 43.5 ± 15.1%, respectively). The quantities of lacrimal inflammatory cells staining positively for IL-4 are significantly different in lymphoid follicular (43 ± 27) and sclerosing lesions (11 ± 9), and for IFN-γ are also different (13 ± 8 and 22 ± 16 respectively).
Conclusion: Different immune processes exist in idiopathic dacryoadenitis: Th2 mediated B-cell humoral immune response presents in lymphoid follicular type and Th1 mediated cellular immune response presents in sclerosing type.