Abstract: | A report is presented on a case of hypereosinophilic syndrome (HES) characterized by an increase of leukocytes to 70.0 X 10(9) per litre and a percentage of eosinophils up to 87 per cent in the differential hemogram. As a peculiarity hitherto not described increased values were observed in 4 immunoglobulin fractions, IgA, IgG, IgM and with an extreme content of IgE of more than 40.000 IU/ml. |