Monoclonal IgG–Lysozyme (Muramidase) Complex in Acute Myelomonocytic Leukemia: An Unusual Finding

Abstract

A non-myelomatous, monoclonal IgG immunoglobulin complexed with lysozyme demonstrating functional activity has been identified in a 72-year-old man with acute myelomonocytic leukemia. The protein and immunoelectrophoretic pattern in this case are characterized by a distinct band manifesting both IgG identity and lysozymal activity. This unusual finding aids in the interpretation of nonmyelomatous peaks in the gamma region. The interrelationships between IgG and lysozyme in this case are discussed and the possibility of an antibody–antigen immune complex is suggested.