GM-CSF increases in vitro the respiratory burst of human neutrophils afterliver transplantation

Objective: Superoxide production by polymorphonuclear neutrophils (PMNs) un der cyclosporin A (CsA) therapy following kidney transplantation is impaire d. We investigated if the respiratory burst of PMNs is similarly depressed in patients undergoing CsA treatment following orthotopic liver transplanta tion (OLTx). Additionally, the in vitro influence of granulocyte-macrophage colony-stimulating factor (GM-CSF) on the superoxide anion production was examined during the respiratory burst. Patients: 10 patients after OLTx and 10 healthy blood donors (control group ). Measurements and results: PMNs were stimulated with bacteria (Escherichia c oli) or a combination of tumour necrosis factor alpha (TNF alpha) and N-for myl-methionyl-leucyl-phenylalanine (FMLP). The respiratory burst was measur ed by oxidation of non-fluorescent dihydrorhodamine to the fluorescent rhod amine by means of flow cytometry. No differences in respiratory bursts from OLTx patients compared to those from healthy blood donors could he seen. U nder TNF alpha/FMLP stimulation, the respiratory burst was significantly in creased after in vitro incubation with GM-CSF (500 U ml(-1)) in patients fo llowing OLTx (from 58.2 to 73.5 %) as well as in the control group (from 47 .4 to 61.9 %). Conclusions: Our results demonstrate that superoxide production is not impa ired under CsA treatment following OLTx. The respiratory burst of these pat ients' PMNs can even be augmented by GM-CSF in vitro.