Modulation of immune functions by long-term treatment with recombinant interferon-alpha 2 in a patient with...

Serial in vitro immune function studies of peripheral blood mononuclear cells (PBMC) were carried out during the long-term treatment with recombinant interferon-alpha 2 (IFN-alpha 2) in a patient with hairy-cell leukemia (HCL). Parameters of B- and T-cell functions as well as NK-cell activity were determined. Treatment with IFN-alpha 2 is associated with temporary and long-term depression of some immune functions, but can also normalize immune responses: in vitro-induced immunoglobulin synthesis, which was normal at diagnosis, was inhibited during the first weeks of IFN therapy but subsequently rose to normal levels. Lymphocyte proliferative responses to mitogens and antigens that were markedly reduced pretherapeutically were further depressed by IFN treatment but, with the exception of pokeweed mitogen (PWM)-induced responses, normalized completely by the 15th to 17th week of treatment. Cocultivation of PBMC with monocytes from normal individuals enhanced depressed lymphocyte proliferative responses. NK-cell activity, which was low at diagnosis, did not rise to the normal range during IFN treatment, but rapidly normalized when IFN therapy was stopped. A discussion is presented on the implications of the alteration of immune functions by treatment with IFN.