Interferon fever: absence of human leukocytic pyrogen response to recombinant alpha-interferon

A sensitive in vitro assay for generation of human leukocytic pyrogen has been used to study the pathogenesis of fever accompanying administration of human alpha-interferon. Unlike other potent pyrogens, two recombinant interferon preparations tested over a wide concentration range did not stimulate release of leukocytic pyrogen. This result suggests that interferon may cause fever by a novel mechanism not dependent on leukocytic pyrogen.