[Immunization against interferon in man]

We have summarized 14 human cases with antibodies to interferon (anti-IFN) reported in the literature. In 4 cases, the patients developed auto-antibodies without any injection of exogenous interferon (IFN). In most cases, antibodies were directed against alpha IFN (13/14) and especially against recombinant alpha 2 IFN (8/14). When tested, antibodies to IFN were always IgG. In a few subjects, the IFN system has been studied more completely with the following results: the competent cells are able, after induction, to produce IFN; the endogenous IFN is neutralized by the antibodies to IFN; the antibodies to IFN are able to inhibit the interaction of IFN with its specific cellular receptors. Clinically, the raising of an anti-IFN immunization does not seem to impair the antiviral or antitumoral effects of IFN. These data can be related to the relative low neutralizing titres of antibodies to IFN with regard to levels of IFN produced at the site of the viral infection. We discuss the putative benefit of antibodies on the availability of circulating IFN and the possible role of antibodies to IFN in autoimmune diseases.