Histopathologic spectrum of hypersensitivity reactions associated with anti-CD52 therapy (alemtuzumab).

Background: Alemtuzumab is a humanized monoclonal antibody directed against CD52, a cell surface antigen on B and T lymphocytes, and used to treat B-cell chronic lymphocytic leukemia and cutaneous T-cell lymphoma. Skin rash is a common adverse reaction following treatment with alemtuzumab. However, the clinicopathologic features and immunologic basis for the reaction have not been previously reported.