Figure 6.

Histological findings of biopsy samples from the colonic mucosa. HE staining showed marked lymphocyte infiltration and apoptosis of crypt cells (A). With anti-CD20 immunostaining, there were a small number of CD20-positive B lymphocytes in a high-magnification field (B). In contrast, there were many CD3-positive T lymphocytes detected with anti-CD3 immunostaining (C). Anti-CD8 immunostaining showed that the T lymphocytes predominantly included CD8-positive T lymphocytes (D). Some T lymphocytes had directly infiltrated the crypts (arrows) (D). HE: Hematoxylin and Eosin, CD: cluster of differentiation