Interferontherapie bei Myokarditis – Pro und Kontra

Abstract

Viral myocarditis is a non-ischemic inflammatory disease of the myocardium that may be associated with severe cardiac dysfunction and unfavorable prognosis. It can result from virtually any infectious agent but viral infections that cause common infectious illnesses are considered its most frequent cause. Symptomatic heart failure therapy may improve clinical symptoms and hemodynamic compromise but it does not affect the underlying viral cause of the disease. Therefore, more specific treatment options are needed which directly address the underlying viral or inflammatory causes of the disease. The current challenge of any antiviral therapy in patients with cardiac viral infections is the establishment of new treatment strategies which can prevent further virus spreading and achieve in time virus clearance, before the chronically infected heart tissue has been damaged irreversibly. Interferons serve as a natural defense against many viral infections. Their innate production is associated with clinical recovery from viral infection and subsequent sequelae while exogenous administration is protective. Type I interferons therefore constitute a promising choice for treatment. Data from few uncontrolled pilot trials and one randomized IFN-β phase II study (BICC-trial) provided first evidence that antiviral IFN-β 1a therapy effectively clears certain cardiotropic viruses and improves clinical symptoms in patients with chronic viral heart disease. The treatment was well tolerated and there were no unexpected non-cardiologic or cardiologic side effects in association with the interferon β-1b therapy. On the other hand, the interferon application constitutes a virus-type dependent treatment effect with preferable efficacy against enteroviruses and adenoviruses but a lower efficacy against other viruses. Therefore, more specific treatment conditions have to be evaluated for the other viral pathogens. Furthermore, treatment costs and lacking concession for regular prescription actually hamper a more widespread use of interferons. At present, however, there are no treatment alternatives that might improve prognosis of viral heart disease.