Although HES is defined by the combination of unexplained prolonged eosinophilia and evidence of organ involvement, these observations suggest that increased production of eosinophil-stimulating cytokines from the abnormal T-cells with phenotype CD3- CD4+ or CD3+ CD4- CD8- may cause eosinophilia, some of which have been diagnosed as HES..     ///    "Recently, we and other groups have reported several cases of eosinophilia including hypereosinophilic syndrome (HES) accompanied with proliferation of abnormal T-cells with an unusual phenotype CD3- CD4+ or CD3+ CD4- CD8- in the peripheral blood. "