Characterizing the early inflammatory contribution of the donor kidney following reperfusion.
BACKGROUND
Donor kidneys contain a large reservoir of passenger leucocytes that contribute to acute rejection via direct alloantigen presentation and pro-inflammatory cytokine secretion. However, the early contribution of these cells following revascularization has not previously been described. We performed a secondary, high-volume preservation flush following cold storage to characterize the inflammatory contribution of the donor kidney upon reperfusion.


METHODS
Porcine kidneys were retrieved using a protocol analogous to current UK clinical practice. Following 2 h of cold static preservation, kidneys underwent a secondary flush with Ringer's solution. The venous effluent was collected and leucocytes phenotyped via flow cytometry. Inflammatory mediators, including cytokines and cell-free DNA, were then assessed to determine the inflammatory contribution of the donor kidney.


RESULTS
Upon reperfusion, a significant population of donor-derived CD45 +  leucocytes mobilized from the renal vasculature via the renal vein [mean 4.738 × 10 8  (SD 1.348 × 10 8 )]. Within this population, T cells were dominant, representing >60% of the leucocyte repertoire. Granulocytes, monocytes and natural killer cells were also identified, but in comparatively lower numbers. Significant concentrations of cytokines and cell-free DNA were also eluted upon reperfusion.


CONCLUSIONS
The donor kidney contains a significant immune load that rapidly mobilizes following reperfusion. Performing a secondary preservation flush prior to implantation may reduce this inflammatory burden via diversion of donor leucocytes and inflammatory mediators from entry into the recipient circulation. This may modulate direct presentation and reduce the inflammatory contribution of the donor kidney following transplantation.
Manchester Collaborative Centre for Inflammation Research, University of Manchester, Manchester, UK.|Transplant Centre, University Hospital of South Manchester, Manchester, UK.
John P
JP
Stone
Manchester Collaborative Centre for Inflammation Research, University of Manchester, Manchester, UK.|Transplant Centre, University Hospital of South Manchester, Manchester, UK.
Muna
M
Mohamud
Manchester Collaborative Centre for Inflammation Research, University of Manchester, Manchester, UK.|Transplant Centre, University Hospital of South Manchester, Manchester, UK.
Kavit
K
Amin
Manchester Collaborative Centre for Inflammation Research, University of Manchester, Manchester, UK.|Transplant Centre, University Hospital of South Manchester, Manchester, UK.
William R
WR
Critchley
Manchester Collaborative Centre for Inflammation Research, University of Manchester, Manchester, UK.|Transplant Centre, University Hospital of South Manchester, Manchester, UK.
Rebecca J
RJ
Edge
Transplant Unit, Queen Elizabeth University Hospital, Glasgow, UK.
Marc J
MJ
Clancy
Manchester Collaborative Centre for Inflammation Research, University of Manchester, Manchester, UK.|Transplant Centre, University Hospital of South Manchester, Manchester, UK.
Alexandra L
AL
Ball
Manchester Collaborative Centre for Inflammation Research, University of Manchester, Manchester, UK.|Transplant Centre, University Hospital of South Manchester, Manchester, UK.
James E
JE
Fildes
D000818:Animals; D016207:Cytokines / Q000378:metabolism; D007249:Inflammation / Q000503:physiopathology*; D007668:Kidney / Q000098:blood supply / Q000276:immunology* / Q000378:metabolism; D016030:Kidney Transplantation / Q000379:methods*; D009926:Organ Preservation / Q000379:methods*; D015424:Reperfusion; D013552:Swine; D014019:Tissue Donors
D016207:Cytokines
acute rejection; immunogenicity; kidney transplantation; passenger leucocyte; preservation