Modifications of granulocyte subpopulations and of their adherence property during filtration leukapheresis in man

Abstract

Polymorphonuclear leucocytes (PMN) isolated from the peripheral blood of 23 blood donors undergoing filtration leukapheresis were examined with regard to their number, expression of membrane receptors for rabbit IgG or human C3b and their ability to adhere to nylon fibres. All the donors showed an early granulocytopenia followed by a gradual return of PMN into the circulation, but differed in the number of PMN appearing in the rebound phase. Evaluation of rosette forming cells (RFC) and cells adhering to nylon fibres in this phase led to the recognition of two main groups of donors. In one of these groups the number of PMN, RFC and adhering cells remained unchanged compared to the pre-apheresis values. The other group showed marked leucocytosis accompanied by a relative increase in the number of non-RFC and non-adhering cells. Possible mechanisms involved in the changes of PMN subpopulations are discussed.