In vitro granulocyte function as affected by filter loading time and tapping during filtration leukapheresis

Abstract

Granulocytes (PMNs) were harvested from 16 normal subjects by filtration leukapheresis (FL) in which the filter loading time (FLT) ranged between 30 min and 4 h, and the rate of filter perfusion was 60 ml whole blood x min-1. The function of PMNs eluted from filters with or without the aid of manual tapping (MT) at each of the various FLTs was assessed in vitro by tests of chemotaxis, phagocytosis and bactericidal capacity. The results indicated that the function of PMNs in vitro was compromised by eluting filters with MT, and this appeared to be independent of the FLT. PMNs collected without MT were nearly normal relative to the control regardless of the FLT.