IMMUNOHISTOCHEMICAL ANALYSIS OF T-CELL PROLIFERATION IN NORMAL TONSILAND B-CELL LYMPHOMA

A double immunohistochemical technique, incorporating MIB1 and CD3, wa s used to identify proliferating T cells in paraffin wax sections of n ormal tonsil and B cell lymphomas. The number of double stained T cell s as a percentage of the total T cells was then determined, In normal tonsil and follicular lymphoma the follicle centre and T cell zones we re counted independently. In normal tonsil very few T cells in the fol licle centre expressed MIB1. Proliferating T cells were concentrated i n the T cell zones. The same pattern was observed in follicular lympho ma. In contrast, the percentage of T cells expressing MIB1 was higher in mucosa associated lymphoid tissue type lymphoma and lymphocytic lym phoma, suggesting that T cell activation occurs in these tumours, The highest percentage of MIB1 positive T cells was observed in high grade lymphoma, This suggests that transformation to high grade lymphoma is associated with an increase in T cell activation.