High titer of interferon (IFN)-neutralizing antibody in a patient with glioblastoma treated with IFN-α

Abstract
✓ In a patient with glioblastoma treated with interferon (IFN-α) for a long period of time, a high titer of IFN-neutralizing antibody was detected in the serum during and after IFN therapy. Computerized tomography findings and neurological symptoms in this patient were unchanged during IFN therapy. General malaise, fever, anorexia, nausea, and decrease of leukocytes, platelets, erythrocytes, hemoglobin, and hematocrit were recognized transiently as side effects of IFN administration. These side effects were not serious and resolved spontaneously without discontinuation of therapy. The appearance of IFN-neutralizing antibody is clinically important because the antibody probably neutralizes the effect of systemically administered IFN before it reaches the site of action.