The function and structure of granulocytes collected using the IBM 2997 separator.

The effect of oral methylprednisolone and the sedimenting agent, hydroxyethyl starch, on granulocyte recovery, morphology, and function was studied in a volunteer donor programme. Using the IBM 2997, 10 litres of whole blood were processed, with an average procedure time of 2.4 hours and a collection volume of 300 ml. Donors not receiving methylprednisolone (n = 80) had a mean total granulocyte count of 3.5 X 10(9)/litre (range 1.6-5.3 X 10(9)/litre) and mean granulocyte yields were 1 X 10(10) (range 0.2-3.0 X 10(10)). Those receiving 48 mg oral methylprednisolone 6-8 hours before the procedure (n = 320) had a mean granulocyte count of 6.3 X 10(9)/litre (range 3.2-11.4 X 10(9)/litre) and significantly superior mean granulocyte yields of 2.0 X 10(10) (0.3-6.5 X 10(10)) (P less than 0.05). For both groups the mean packed cell volume of 0.08 litre/litre (range 0.02-0.17) and platelet contamination 1.9 X 10(11) (range 0.3-5.0 X 10(11)). In all these procedures, hydroxyethyl starch was added to the blood entering the centrifuge channel. In none of the procedures were any untoward symptoms experienced by the donors. Light microscopy and ultrastructural studies showed no difference between control granulocytes and those collected following the addition of hydroxyethyl starch or after oral methylprednisolone. Similarly, granulocyte function measured with a random migration, chemotaxis, phagocytosis, and intracellular killing was not significantly different between control cells and those exposed to the sedimenting agent or the adrenocorticosteroids (P greater than 0.10). It is concluded that donor premedication with methylprednisolone significantly enhances granulocyte yields in the presence of hydroxyethyl starch and neither agent has any demonstrable effect on granulocyte morphology or function.