Long-term interferon-alpha therapy induces autoantibodies against epidermis

While interferon (IFN) is known for its immunoregulatory properties, it has also been shown to induce autoimmune disorders such as lupus erythematosus, hypothyroidism, antiphospholipid syndrome and, recently, bullous pemphigus-like eruptions.

The purpose of this study was to determine the percentage of antibodies against epidermis induced by IFN-alpha therapy, as detected by indirect immunofluorescence and Western blotting (WB).

We have studied the sera of 47 patients treated with low doses of IFN-alpha 2a for malignant melanoma or cutaneous T cell lymphoma for a period of 12 months. These sera were tested by standard IIF and WB.

32% of patient sera were positive after 6 months of treatment. Antibodies against epidermis were most often of the pemphigus type as confirmed by WB. Two types of labeling were noted for anti-basement membrane antibodies: basal cytoplasmic pattern in 4 sera and along the dermal side of the basal keratinocytes in 2 sera.

This study brings biological arguments to confirm the direct role of IFN-alpha in the development of pemphigus-like eruption, and emphasizes the need for clinical follow-up of patients treated with IFN-alpha over a long period of time.