Unacceptable human leucocyte antigens for organ offers in the era of organ shortage: influence on waiting time before kidney transplantation.
BACKGROUND
The assignment of human leucocyte antigens (HLAs) against which antibodies are detected as unacceptable antigens (UAGs) avoids allocation of HLA- incompatible allografts. There is uncertainty as to what extent UAGs decrease the probability of receiving a kidney offer.


METHODS
Kidney transplantations in 3264 patients on the waiting lists of six German transplant centres were evaluated for a period of at least 2 years. The proportion of excluded offers due to UAGs was calculated as virtual panel-reactive antibodies (vPRAs).


RESULTS
In the common Eurotransplant Kidney Allocation Scheme, the transplant probability was unaffected by vPRAs in exploratory univariate analyses. In the multivariable model, a 1% increase in vPRA values was outweighed by an additional waiting time of 2.5 weeks. The model was confirmed using an external validation cohort of 1521 patients from seven centres. If only patients with standard risk were considered (e.g. no simultaneous transplantation of other organs), only 1.3 weeks additional waiting time was needed. In the Eurotransplant Senior Program, patients with vPRA values >50% had a strongly reduced transplant probability in the unadjusted analyses. In the multivariable model, a 1% increase in vPRA values was outweighed by an additional waiting time of 5 weeks.


CONCLUSIONS
This study demonstrates that the assignment of UAGs decreases the transplant probability in both main Eurotransplant allocation programs because of insufficient compensatory mechanisms. At present, for immunized patients, a prolonged waiting time has to be weighed against the increased immunologic risk due to donor-specific antibodies not assigned as UAGs.
Institute of Transfusion Medicine, University Hospital of Schleswig-Holstein, Ratzeburger Allee 160, 23538?Lübeck, Germany.
Malte
M
Ziemann
Institute of Medical Biometry and Statistics, University Medical Center Schleswig-Holstein, Campus Lübeck, Lübeck, Germany.
Nicole
N
Heßler
Institute of Medical Biometry and Statistics, University Medical Center Schleswig-Holstein, Campus Lübeck, Lübeck, Germany.
Inke R
IR
König
HLA Laboratory, Center for Tumor Medicine, Charité-Universitätsmedizin Berlin, Berlin, Germany.
Nils
N
Lachmann
Department of Transfusion Medicine, Ludwig-Maximilians-University München, Munich, Germany.
Andrea
A
Dick
Institute of Transfusion Medicine, Kliniken der Stadt Köln, Cologne, Germany.
Vanessa
V
Ditt
Medizinische Klinik m. S. Nephrologie, Charité Universitätsmedizin Berlin, Campus Mitte, Berlin, Germany.
Klemens
K
Budde
Clinic for Nephrology, Charité Campus Virchow-Klinikum, Berlin, Germany.
Petra
P
Reinke
Department of Nephrology, University Hospital Essen, Essen, Germany.
Ute
U
Eisenberger
Medizinische Klinik D, University Hospital Münster, Münster, Germany.
Barbara
B
Suwelack
Department of Surgery, Knappschaftskrankenhaus, Ruhr-University Bochum, Bochum, Germany.
Thomas
T
Klein
Medizinische Klinik I, University Hospital Marien Hospital Herne, Herne, Germany.
Timm H
TH
Westhoff
Medizinische Klinik I, Kliniken der Stadt Köln, Cologne, Germany.
Wolfgang
W
Arns
Klinik für Nephrologie, Universitätsklinikum Düsseldorf, Düsseldorf, Germany.
Katrin
K
Ivens
Transplant Center, Ludwig-Maximilians-University München, Munich, Germany.
Antje
A
Habicht
Department of Nephrology, Technical University of Munich, Klinikum rechts der Isar, Munich, Germany.
Lutz
L
Renders
Transplant Center Cologne, University of Cologne, Cologne, Germany.
Dirk
D
Stippel
Medizinische Klinik I, University Hospital Bonn, Bonn, Germany.
Dominik
D
Bös
Transplant Center, Klinikum Augsburg, Augsburg, Germany.
Florian
F
Sommer
Institute of Transfusion Medicine, University Hospital of Schleswig-Holstein, Ratzeburger Allee 160, 23538?Lübeck, Germany.
Siegfried
S
Görg
Transplant Center, University Hospital of Schleswig-Holstein, Lübeck, Germany.
Martin
M
Nitschke
Department of Nephrology, University Hospital of Schleswig-Holstein, Kiel, Germany.
Thorsten
T
Feldkamp
Institute for Transfusion Medicine, University Hospital Essen, Essen, Germany.
Falko M
FM
Heinemann
Institute of Transfusion Medicine and Transplantation Immunology, University Hospital Münster, Münster, Germany.
Reinhard
R
Kelsch
D000328:Adult; D000368:Aged; D005260:Female; D006680:HLA Antigens / Q000276:immunology*; D006650:Histocompatibility Testing; D006801:Humans; D007668:Kidney / Q000276:immunology*; D007676:Kidney Failure, Chronic / Q000601:surgery*; D016030:Kidney Transplantation / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014019:Tissue Donors; D009927:Tissue and Organ Procurement / Q000379:methods*; D014184:Transplantation, Homologous; D014850:Waiting Lists
D006680:HLA Antigens
HLA antibodies; kidney transplantation; unacceptable HLA antigens; virtual PRAs; waiting time