Immunocytochemistry of spleen. Serial sections were prepared and stained with anti-CD3 (A-B) and anti-CD20cy (C-D) and antistomatin (E-F) antibodies. Patient (A-II-1) sections are shown in the left column (A,C,E,G) against a normal spleen in the right-hand column (B,D,F,H). T-cell and B-cell areas of the white pulp surrounding a central artery are identified by staining with specific antibodies. In neither normal nor OHSt spleen was stomatin immunoreactivity selectively associated with predominantly T- or B-cell areas of the spleen. In normal spleen (F), the red pulp that is distant from the central artery is strongly stomatin immunoreactive, consistent with the concentrated red cell population, whereas in the patient (E), the equivalent area is less strongly positive. Note the specific stomatin-positive staining of the arterial endothelium in panels E-F (arrows). (G-H) Negative controls for antistomatin antibody (G) and murine monoclonal antibodies (H). Bar represents 10 μm.