Proceedings: Studies of leucocyte electrolytes in renal failure and hypertension.

and Fabry's diseases, as well as metachromatic leucodystrophy). Leucocyte studies of families have done much to increase our knowledge of the genetics of the inherited metabolic disorders and in many cases the heterozygous state can be clearly delineated using these readily available cells. Direct enzyme assay on the isolated cells is usually satisfactory, although in some cases the white cell of choice may be the stimulated lymphocyte. Accumulation of material within leucocytes (Pomp-'s disease, cystic fibrosis) may aid diagnosis, as do functional tests on leucocytes, such as the loss of ability of these cells to phagocytose and kill bacteria or to take up nitrotetrazolium blue as is seen in chronic granulomatous disease. Leucocyte assay (not necessarily enzyme orientated) may also have potential use in early recognition of graft rejection, and radioactive leucocytes may prove useful probes in seeking out septic foci in the body. Preliminary reports suggest that pyruvate kinase levels in the leucocyte of the mother may be a useful diagnostic tool to monitor fetal malnutrition. Histochemical examination of enzyme activity in the leucocyte has been suggested to be of value in the differential diagnosis of certain leukaemias.