High-titer interferon-α antibodies in a patient with pemphigus foliaceus

Among 13 patients with pemphigus or bullous pemphigoid, high titers of anti-interferon-α (IFN-α) antibodies were present in all serum samples of one patient suffering from pemphigus foliaceus. This patient was characterized by a relatively benign course of the disease. The IFN antibodies were of oligoclonal or polyclonal origin, predominantly of the IgG subtype, and displayed a broad spectrum of specificity including various natural and recombinant IFN-α subtypes as well as recombinant IFN-ω1. In vitro, these antibodies neutralized both the antiviral and antiproliferative activities of the respective IFN types. Recognition of the patient's endogenous IFN-α demonstrated their autoantibody nature. The IFN antibodies were present at diagnosis and resistant to continued immunosuppressive treatment. Despite clinical remission, the IFN antibodies persisted, suggesting that they were not pathogenically related to the skin manifestations of the pemphigus. There were no signs of immune complex-mediated organ damage. IFN antibodies constitute a new class of autoantibodies that may occur in conjunction with pemphigus and likely interfere with the endogenous IFN system.