ANTIBODIES AGAINST DOUBLE-STRANDED DNA AND DEVELOPMENT OF POLYMYOSITIS DURING TREATMENT WITH INTERFERON

Alpha interferons have become effective palliative treatments for pati ents with neuroendocrine tumours such as carcinoids and endocrine panc reatic tumours. However, several reports indicate an increased inciden ce of both autoantibodies and autoimmune diseases in patients treated with interferon-alpha (IFN-alpha). We studied the development of antib odies against double-stranded DNA (dsDNA) and clinical signs of autoim mune disease in 214 patients with malignant carcinoids or endocrine pa ncreatic tumours consecutively admitted for treatment with IFN-alpha. Seventeen patients (8%) developed antibodies against dsDNA, predominan tly females (12 females and 5 males). One patient had clinical and lab oratory signs of polymyositis. Among the other 16 patients, three deve loped hypothyroidism and in six patients the anti-dsDNA autoantibodies normalized despite continuing therapy. Although a significant number of patients developed autoantibodies against dsDNA, overt autoimmune d isease related to these antibodies is a rare event and many patients s pontaneously normalize these titres despite continuing IFN-alpha treat ment.