CD5 and B-cell chronic lymphocytic leukemia: The mechanisms of development of vasculitis in CLL include 1) immune complexes, 2) activation of B-lymphocytes, 3) antibodies directed toward endothelial antigens, 4) the direct effect of a malignancy on the vascular wall, 5) adverse reactions to anticancer drugs, and 6) CD5-positive B cells present in CLL may produce auto antibodies and monoclonal immunoglobulins with various autoantibody activities [4].