'Brassy' Eosinophilic Granulocytes and their Possible Role in Iron Transport

Abstract

IN blood films stained by one of the Romanowsky modifications, the granules of the eosinophiles are ordinarily scarlet. Occasionally, however, they exhibit a range of colour modification which varies from brownish-red, through grey to almost coal-black. The latter granules are not to be confused with those of the basophilic granulocyte, which have also been found in otherwise unaltered 'eosinophiles' in autochthonous hyperheparinsæmias ; truly basophilic granules are metachromatic when stained with toluidine blue, while the dark granules of the 'brassy' eosinophiles (as such cells have come to be termed in laboratory parlance) are not basophilic nor do they stain with toluidine blue. The appearance of the 'brassy' granule does not seem to be a staining artefact, as they appear preponderantly in the blood films of certain individuals even though these blood films have been subjected to identical and concurrent staining procedure with films exhibiting the scarlet eosinophilic granule.