Studies of Granulopoiesis and Granulocyte Kinetics in Down's Syndrome

Normal mitotic and maturation granulocyte pools in Down's syndrome are evidenced by the finding of normal marrow cellularity and morphology. Normal marrow granulocyte reserves are indicated by a normal response to endotoxin injection. The normal levels of serum muramidase support the concept of a normal granulocyte turnover rate. Therefore, it is considered unlikely that there is a significant abnormality of granulocyte kinetics in Down's syndrome. It is also unlikely that increases in leukocvte enzymes in this condition are due to a relatively immature granulocyte population. Rather, they may reflect some general effect of genetic imbalance.