Therapeutic possibilities in hypereosinophilia syndrome with Löffler's fibroplastic endomyocarditis. Efficacy of cytarabine and 6-thioguanine

In two of four patients with hypereosinophilia and Löffler's myocarditis (confirmed by biopsy) the activity of the disease was contained with prednisone, in one instance combined with hydroxycarbamide. In two patients, in whom the disease was taking a fulminant course and other treatment had failed, cytarabine and 6-thioguanine proved effective, providing a 16-month symptom-free period in one of them. But the second patient died from septicaemia associated with treatment-induced bone-marrow hypoplasia. Prednisone (1 mg/kg daily) and hydroxycarbamide (0.5-1.5 g daily) are the drugs of choice in the hypereosinophilia syndrome. If they fail, cytarabine (100 mg/m2 on days 1-5, repeated on day 28) and 6-thioguanine (100 mg/m2 daily) should be given.