CD3-positive T cells in Reactive and Neoplastic Follicles. Specially the distributional relation ship between CD23-positive follicular dendritic cells and CD3-positive T cells.

Using formalin-fixed paraffin-embedded tissues, we attempted to analyze quantitatively the distributional relationship between CD23-positive (CD23+) follicular dendritic cells (FDCs) and CD3-positive (CD3+) T cells. The distribution of CD3+ T cells and CD23+ FDCs in reactive and neoplastic follicles was studied by an indirect immunoperoxidase method using monoclonal antibodies on formalin-fixed paraffin-embedded tissues. The tissues examined included specimens from Kimura's disease, Warthin's tumor, normal tonsils, atypical lymphoid hyperplasia, and follicular lymphoma. CD23+ FDCs were distributed in a crescent-shaped pattern coinciding with the light zone of the germinal centers (GCs), and CD3+ T cells also tended to be distributed mainly in the light zone. These patterns were detected within the GCs of Warthin's tumor, normal tonsils, and atypical lymphoid hyperplasia. In Kimura's disease, on the other hand, CD23+ FDCs were detected throughout the entire GCs, and CD3+ T cells were very densely distributed in CD23+ areas. In contrast, the density of CD3+ T cell distribution in follicular lymphoma was very low. These results suggest that CD23+ FDCs play an important role in interacting with T cells in follicles, and are essentially involved in GC formation and the maintenance of follicular structure in vivo.