Granulocyte Transfusion: Update 2020

The prescription of granulocyte transfusions as a therapeutic approach in the clinical routine is - in contrast to other blood components - inconsistent and rare. This restrained application practice is due to the lack of broad evidence, logistical and financial problems, and the availability of other potent therapy options of neutropenic infections, amongst others. Nevertheless, in the last few years newsworthy scientific findings regarding this topic arose. Not only the characterization of cellular defense strategies, but also of the pathophysiological role of granulocytes, like a contribution to thrombotic and malignant events, got developed. Moreover, the therapeutic effect of these cells has been further elaborated. This effect depends on a multitude of parameters, e.g. the sort of infection, the timing and the dose of transfusions. This makes the indication a complex decision for each individual case and the heterogenous data needs to be systematically reviewed. Furthermore, the well-established indications of neutropenic and neutropathic infections got complemented by experimental, potential new application areas like mucositis or treatment of leukemia. Successful application requires a suitable, modern manufacturing process. Common apheresis procedures expose donors to relatively high physical stress, for example due to adverse effects of the mobilization regime or sedimentation agents. New protocols, like the extraction of granulocytes from buffy coats or whole blood, promise a reduction of logistical problems and adverse events in donors. Undesirable effects on recipients of granulocyte transfusions should still be taken into consideration and being weighed up against an expected therapeutic effect.