Long-term persistence of human anti-murine antibody responses following radioimmunodetection and radioimmunotherapy of cutaneous T-cell lymphoma patients using 131I-T101

Five cutaneous T-cell lymphoma (CTCL) patients have been imaged and treated with radiolabeled murine monoclonal antibody 131I-T101 in our laboratory. All patients developed human anti-murine antibody responses (HAMA) 14 days after the primary antibody infusion. HAMA responses could still be detected more than 22 months after T101 treatment. A substantial proportion of HAMA was crossreactive with any IgG2a antibody tested, although there did exist a specific anti-idiotypic component to HAMA. HAMA were of both IgM and IgG isotype. We also analyzed the effects of plasmapheresis on the specific HAMA isotypes in three patients who were retreated at the time of disease progression