Interferon alfa clinical features

The spectrum of interferon alfa-induced thyroid disorders ranges from asymptomatic appearance or increase in antithyroid autoantibody titers to moderate or severe clinical features of hypothyroidism, hyperthyroidism, and acute biphasic thyroiditis. Antithyroid hormone antibodies have also been found in one patient, and this could have been the cause of erroneously raised thyroid hormone concentrations (504). 

The clinical, biochemical, and thyroid imaging characteristics of thyrotoxicosis resulting from interferon alfa treatment have been retrospectively analysed from data on 10 of 321 patients with chronic hepatitis (75 with chronic hepatitis B and 246 with chronic hepatitis C) who developed biochemical thyrotoxicosis (505). Seven patients had symptomatic disorders, but none had ocular symptoms or a palpable goiter. Six had features of Graves disease that required interferon alfa withdrawal in four and prolonged treatment with antithyroid drugs in all six. Three presented with transient thyrotoxicosis that... 

The clinical features, management, and prognosis of psychiatric symptoms in patients with chronic hepatitis C have been reviewed using data from 943 patients treated with interferon alfa (85%) or interferon beta (15%) for 24 weeks (333). Interferon-induced psychiatric symptoms were identified in 40 patients (4.2%) of those referred for psychiatric examination. They were classified in three groups according to the clinical profile 13 cases of generalized anxiety disorder (group A), 21 cases of... 

Interferon alfa was also suspected to be involved in one case of biopsy-proven bronchiolitis obliterans-organizing pneumonia (41). Clinical symptoms of pneumonitis appeared 3-12 weeks after the onset of interferon alfa therapy, and after withdrawal of treatment they usually completely resolved, either spontaneously or after a short course of glucocorticoid treatment. Immune-mediated pulmonary toxicity involving the activation of T cells was considered as a likely mechanism. The uncommon features of bronchiolitis obliterans-organizing pneumonia have been reported in three other patients who received interferon alfa together with ribavirin or cytosine arabino-side (42,43). 

In contrast to interferon alfa, the autoimmune consequences of interferon beta treatment have been poorly evaluated. Interferon beta does not appear to be associated with the appearance or increased titres of several auto-antibodies, and no clinical features of autoimmune disease were observed in patients receiving a 6-month course of interferon beta-la or interferon beta-lb (66,67). 

---