[Kinetics of polynuclear cells]

Polymorphonuclear leukocytosis and granulopenia in infectious diseases have been studied for several years, either by intravascular kinetics of the polymorphs labelled previously in vitro, or by isotopic labelling in vivo and autoradiography of the bone marrow, using medullary kinetic study of granulopoiesis. Polymorpho-nuclear leukocytosis is usually due to an increased production and a relative mobilisation of reserves. Leukopenia may be due to various mechanisms, but there does not seem to be any qualitative disorder of circulating polymorphonuclear leukocytes with corpuscular hyperdestruction nor any abnormalities of multiplication of the bone marrow nor of maturation. On the other hand, one frequently finds abnormalities of distribution between the marginal and circulating compartments, increased extracorpuscular destruction, reduction in production due to reduction in absolute number or differentiation of the granulopoietic parent cells.