Agranulocyte

AGRANULOCYTE (from Greek a- negative particle, Latin granulum-grain and Greek kytos-cell), a non-granular white blood cell. In contrast to granulocytes, A. refers to white blood cells that do not contain granular inclusions that stain selectively with acid or basic dyes from mixtures, and do not give a reaction to oxidase. Lymphocytes of normal blood belong to A., as well as the earliest stages of embryonic development of blood cells (lymphoidocytes). Previously, monocytes were also included in this group, but the latter contain a small number of oxyphilic granules and accordingly give a positive reaction to oxidase. In the body of A., predominantly in large blood lymphocytes, azurophilic granules are found in variable but usually small amounts (see Azurophilia). In humans, the number of A. constitutes about 30% of the total number of white blood cells.