The Splenic White Pulp in Chronic Lymphocytic Leukaemia: A Microenvironment Associated with CR2 (CD21) Expression, Cell Transformation and Proliferation

Abstract

Splenectomy specimens from 8 cases of chronic lymphocytic leukaemia (CLL) were examined. The infiltrate in the red pulp consisted predominantly of small lymphocytes. In contrast the predominant cells in the white pulp were pro-lymphocytes and para-immunoblasts. The Ki67 marker, which identifies cells in growth phase, was also concentrated among the transformed cells in the white pulp. Staining with monoclonal antibodies for CD21, which identifies the CR2 receptor, showed that the cells in the white pulp were strongly positive in contrast to those in the red pulp which were weak or negative. These findings suggest that factors present in the white pulp promote transformation and proliferation of CLL cells.

Key Words:

• Spleen
• white pulp
• CLL
• leukemia
• lymphocytes
• microenvironment
• CR2
• CD-21