VALUE OF HAMA-DETERMINATION IN CLINICAL-PRACTICE - AN OVERVIEW

HAMAs (human anti mouse antibodies) in serum of patients may be stimul ated as an immunologic reaction to the application of animal protein. They are differentiated into heterophilic (species-unspecific) and mou se-specific anti-isotypic (often IgG(1)) or-idiotypic antibodies as we ll as according to the human immunoglobulin type (IgG or IgM). Besides infrequent clinically immunologic side effects (anaphylactic reaction ), their influence on tumor marker measurements predominates in the fo llow-up of tumor patients by the possible impairment of newly applied monoclonal antibodies. The detection of HAMAs is performed on suspicio n of a tumor by self-mane or commercial tests, however, there is no co nsensus standardization of tests, standards and controls. Experiences are repelled herein on the occurrence of heterophilic antibodies, reas ons of suspicion, detection and removal comparative determination of H AMAs by two commercially available tests (ImmunoSTRIP HAMA, Enzygnost) and HAMA induction in patients following immunoscintigraphy (OC-125, n=27). Besides the rare appearance of HAMAs in patients without pretre atment or following biologic therapy i.v. application of monoclonal an tibodies for diagnosis (immunoscintigraphy) or therapy represents the most frequent reason for HAMA development that should always be ruled out in case of anamnestic indication and clinically unexplained tumor marker changes.