Basophilic leucocytes in children in health and disease.

The presence of basophilic leucocytes (basophils)* in human blood was first established by Ehrlich (1891). These cells differ from other polymorphs by their slightly smaller size, by the metachromatic staining reaction of their granules, and by their slower rate of motility (Sabin, 1923). Probably less is known about the basophils than about any of the other formed elements in the blood, mainly because they are very scanty in the peripheral blood and because until 1953 there was no satisfactory method of counting them accurately. Counts based on examination of blood smears are unreliable unless very large numbers of cells are counted and consequently in most studies of the variations of leucocytes in disease the basophils have been ignored or dismissed in a few words as of no significance. In his monograph on mast cells, Michels (1938) gathered most of the information about basophils available at that time and the inaccuracy and contradictions of many of the earlier papers are readily apparent on reading this review, in which the author stigmatized much of the previous literature as 'worthless'. The few standard paediatric textbooks which do more than mention the existence of basophils merely remark on the lack of information available. For example, Nelson's Textbook of Pediatrics (Nelson, 1954) states that 'basophils occur in small numbers in the blood of children. Their function is unknown and they appear to have clinical significance only in that they are consistently elevated in chronic myelogenous leukemia in children'. Recent evidence that basophils contain heparin (Behrens and Taubert, 1952; Martin and Roka, 1953) and histamine (Graham, Lowry, Wheelwright, Lenz and Parish, 1955; Code and Mitchell, 1957) throws fresh light on the function of these cells, while the introduction of a chamber-counting method by Moore and James (1953) has made it possible to