Posttransplant HLA alloreactivity in stable kidney transplant recipients-incidences and impact on long-term allograft outcomes.
Humoral alloreactivity is well established to predict adverse allograft outcomes. However, in some recipients, alloantibodies may also occur in the absence of graft dysfunction. We evaluated if and how often complement- and noncomplement-fixing alloantibodies are detectable in stable recipients and whether, in this context, they affect long-term outcomes. Sera obtained from 164 kidney transplant recipients at 2, 6 and 12 months were evaluated by FlowPRA screening and single-antigen testing for detection of IgG- or C4d-fixing HLA panel reactivity and donor-specific antibodies (DSA). Applying stringent criteria, we selected 34 patients with an uneventful 1-year course (no graft dysfunction or rejection) and excellent graft function at 12 months [estimated glomerular filtration rate (eGFR) >or=60 mL/min and proteinuria <or=0.5 g/24 h]. Nine (27%) and 5 (15%) of these recipients tested positive by [IgG] and [C4d]FlowPRA screening, respectively. In five cases, DSA were identified. Frequencies of positive test results and DSA binding intensities were not significantly lower than those documented for patients who did not fulfill the above criteria. In recipients with an excellent 1-year course, FlowPRA reactivity was not associated with lower eGFR or increased protein excretion during 68-month median follow-up. Our results suggest cautious interpretation of antibody monitoring in patients with normal-functioning grafts.
Division of Nephrology and Dialysis, Department of Medicine III, Medical University of Vienna, Austria.
G
G
Bartel
H
H
Regele
M
M
Wahrmann
N
N
Huttary
M
M
Exner
W H
WH
Hörl
G A
GA
Böhmig
D000328:Adult; D000906:Antibodies / Q000097:blood*; D015935:Complement C4b; D005260:Female; D006084:Graft Rejection / Q000453:epidemiology / Q000276:immunology; D006680:HLA Antigens / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D015994:Incidence; D016030:Kidney Transplantation / Q000276:immunology*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D010446:Peptide Fragments / Q000097:blood; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D014180:Transplantation; D014184:Transplantation, Homologous
D000906:Antibodies; D006680:HLA Antigens; D007074:Immunoglobulin G; D010446:Peptide Fragments; D015935:Complement C4b; C032261:complement C4d