THE EFFECT OF PLASMA WITH COLONY SIMULATING ACTIVITY (CSA) IN CYCLIC NEUTROPENIA (CN)

Abstract

A 2 year old M and a 10 year old F with 21-day cycles of neutropenia and apthous stomatitis were studied. Bone marrow aspirates at the cycles' nadir showed a maturation arrest at the myelocyte stage. In vitro bone marrow culture in agar documented quantitatively normal colony formation with rare colonies of neutrophils (PMN). Serial liquid suspension cultures (Marbrook chamber) yielded cell counts which were in the normal range or higher than companion control cultures. CN PMN maturation was defective early in culture; some mature PMNs appeared after 7 days and persisted for up to 25 days. Plasma, obtained from normal donors and from those given typhoid vaccine and plasmaphoresed 1 hour later, was assayed for CSA, using normal and CN bone marrow. Only plasma which stimulated normal marrow promoted PMN maturation in CN marrow in vitro. In vivo, administration of plasma containing CSA increased PMN production and ameliorated the clinical symptoms of neutropenia. It is concluded that one type of CN involves a maturation defect of PMNs, which may be altered in vitro and in vivo by plasma containing CSA. Supported by Grant 5-M01-RR00199.