Immunological features in a case of hypereosinophilic syndrome and myocarditis

The clinical and immunological follow-up of a 38-year-old female patient with hypereosinophilic syndrome and classical cardiac involvement, but without demonstrable degranulation of eosinophils and lacking binding of a specific antibody for activated eosinophils, is presented. Instead, the patient demonstrated all the immunological features of autoreactive myocarditis: cytolytic, complement-fixing antimyolemmal antibodies and increased concentrations of circulating immune complexes were present over 3 years.