Posttransplant allosensitization in low immunological risk kidney and kidney-pancreas graft recipients.
BACKGROUND
Posttransplantation allosensitization prevalence and effect on kidney grafts outcomes remain unsettled.


METHODS
Between 2007 and 2012, 408 patients received a primary kidney graft (with 68 patients also receiving a pancreas graft) after a negative cytotoxic crossmatch. All patients had a pretransplant negative anti-HLA screening and 0% panel reactive antibodies. We analyzed retrospectively the results of anti-HLA antibodies screening by Luminex assay, performed between 6 and 24 months after transplant, and searched for the risk factors for antibody positivity and its impact on kidney graft outcomes.


RESULTS
Anti-HLA antibodies prevalence at 6 months was 17.4%. Previous steroid-insensitive acute rejection was the only risk factor for both anti-HLA classes detected antibodies. Antithymocyte globulin induction was also a risk factor for anti-HLA-I antibodies. Antibody positivity status was associated with reduced graft function at 12 months and graft survival at 5 years (91.5% versus 96.4%, P = 0.03). In multivariable Cox analysis, delayed graft function (HR = 6.1, P < 0.01), HLA mismatches >3 (HR = 10.2, P = 0.03), and antibody positivity for anti-HLA class II (HR = 5.1, P = 0.04) or class I/II (HR = 13.8, P < 0.01) were independent predictors of graft loss.


CONCLUSIONS
Allosensitization against HLA class II ± I after transplant was associated with adverse kidney graft outcomes. A screening protocol seems advisable within the first year in low immunological risk patients.
Nephrology and Kidney Transplantation Department, Centro Hospitalar do Porto, Hospital de Santo António, Largo Prof. Abel Salazar, 4099-001 Porto, Portugal.
Jorge
J
Malheiro
Centro do Sangue e Transplantação do Porto, Rua de Bolama No. 133, 4200-139 Porto, Portugal.
Sandra
S
Tafulo
Nephrology and Kidney Transplantation Department, Centro Hospitalar do Porto, Hospital de Santo António, Largo Prof. Abel Salazar, 4099-001 Porto, Portugal.
Leonídio
L
Dias
Nephrology and Kidney Transplantation Department, Centro Hospitalar do Porto, Hospital de Santo António, Largo Prof. Abel Salazar, 4099-001 Porto, Portugal.
La Salete
0000-0002-6110-2102
LS
Martins
Nephrology and Kidney Transplantation Department, Centro Hospitalar do Porto, Hospital de Santo António, Largo Prof. Abel Salazar, 4099-001 Porto, Portugal.
Isabel
0000-0001-8984-1751
I
Fonseca
Nephrology and Kidney Transplantation Department, Centro Hospitalar do Porto, Hospital de Santo António, Largo Prof. Abel Salazar, 4099-001 Porto, Portugal.
Manuela
M
Almeida
Nephrology and Kidney Transplantation Department, Centro Hospitalar do Porto, Hospital de Santo António, Largo Prof. Abel Salazar, 4099-001 Porto, Portugal.
Sofia
0000-0002-8539-906X
S
Pedroso
Centro do Sangue e Transplantação do Porto, Rua de Bolama No. 133, 4200-139 Porto, Portugal.
Fátima
F
Freitas
Nephrology and Kidney Transplantation Department, Centro Hospitalar do Porto, Hospital de Santo António, Largo Prof. Abel Salazar, 4099-001 Porto, Portugal.
Idalina
I
Beirão
Nephrology and Kidney Transplantation Department, Centro Hospitalar do Porto, Hospital de Santo António, Largo Prof. Abel Salazar, 4099-001 Porto, Portugal.
António
A
Castro Henriques
Nephrology and Kidney Transplantation Department, Centro Hospitalar do Porto, Hospital de Santo António, Largo Prof. Abel Salazar, 4099-001 Porto, Portugal.
António
A
Cabrita
D000328:Adult; D000961:Antilymphocyte Serum / Q000008:administration & dosage / Q000009:adverse effects; D005260:Female; D006084:Graft Rejection / Q000097:blood / Q000276:immunology*; D006085:Graft Survival / Q000276:immunology*; D006680:HLA Antigens / Q000276:immunology*; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage / Q000009:adverse effects; D007518:Isoantibodies / Q000097:blood / Q000276:immunology*; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D016035:Pancreas Transplantation; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors
D000961:Antilymphocyte Serum; D006680:HLA Antigens; D007166:Immunosuppressive Agents; D007518:Isoantibodies