Favorable response to high-dose interferon-alpha in idiopathic hypereosinophilic syndrome with restrictive cardiomyopathy--case report and literature review.

The idiopathic hypereosinophilic syndrome is characterized by a prolonged overproduction of eosinophils of unknown cause in addition to specific organ damage due to eosinophil-derivated protein toxicity. Its prognosis is correlated with heart involvement that results in a restrictive cardiomyopathy. This is frequently biventricular. Isolated left ventricular infiltration has rarely been reported. The authors report a case of idiopathic hypereosinophilic syndrome with cardiac involvement obliterating the left ventricular cavity with a favorable clinical outcome following a combination therapy with interferon-alpha, hydroxyurea and prednisone. Data from other studies dealing with the treatment of idiopathic hypereosinophilic syndrome with interferon-alpha are reviewed and discussed.