Renal graft survival according to Banff 2013 classification in indication biopsies.
BACKGROUND
The impact of acute rejection in kidney graft survival is well known, but the prognosis of other diagnoses is uncertain. We evaluated the frequency and impact on graft survival of different diagnostic categories according to the Banff 2013 classification in a cohort of renal transplant recipients.


METHODS
Retrospective study of 495 renal biopsies by indication in 322 patients from 1990-2014. Two independent observers reviewed the histological reports, reclassifying according to the Banff 2013 classification.


RESULTS
Of 495 biopsies, 28 (5.7%) were not diagnostic. Of the remaining 467, 10.3% were «normal» (category 1), 19.6% antibody-mediated changes (category 2), 5.9% «borderline» changes (category 3), 8.7% T-cell-mediated rejection (category 4), 23.4% interstitial fibrosis/tubular atrophy (IFTA) (category 5) and 26.5% with other diagnoses (category 6). As time after transplantation increases, diagnoses of categories 1, 3 and 4 decrease, while categories 5 and 2 increase. Worse graft survival with category 2 diagnosis was observed (45% at 7.5 years, HR 4.29 graft loss [95% CI, 2.39-7.73]; P≤.001, compared to category 1). Grafts with «unfavourable histology» (chronic antibody-mediated rejection, moderate-severe IFTA) presented worse survival that grafts with «favourable histology» (normal, acute tubular necrosis, mild IFTA).


CONCLUSIONS
The Banff 2013 classification facilitates a histological diagnosis in 95% of indication biopsies. While diagnostic category 6 is the most common, a change in the predominant histopathology was observed according to time elapsed since transplantation. Antibody-mediated changes are associated with worse graft survival.
Servicio de Nefrología, Hospital del Mar, Barcelona, España.
Carlos
C
Arias-Cabrales
Servicio de Nefrología, Hospital del Mar, Barcelona, España.
Dolores
D
Redondo-Pachón
Servicio de Nefrología, Hospital del Mar, Barcelona, España.
María José
MJ
Pérez-Sáez
Anatomía Patológica, Hospital del Mar, Barcelona, España.
Javier
J
Gimeno
Anatomía Patológica, Hospital del Mar, Barcelona, España.
Ignacio
I
Sánchez-Güerri
Servicio de Nefrología, Hospital del Mar, Barcelona, España.
Sheila
S
Bermejo
Servicio de Nefrología, Hospital del Mar, Barcelona, España.
Adriana
A
Sierra
Servicio de Nefrología, Hospital del Mar, Barcelona, España.
Carla
C
Burballa
Servicio de Nefrología, Hospital del Mar, Barcelona, España.
Marisa
M
Mir
Servicio de Nefrología, Hospital del Mar, Barcelona, España.
Marta
M
Crespo
Servicio de Nefrología, Hospital del Mar, Barcelona, España. Electronic address: julpascual@gmail.com.
Julio
J
Pascual
D000328:Adult; D001706:Biopsy; D005260:Female; D006084:Graft Rejection; D006085:Graft Survival; D006801:Humans; D007668:Kidney / Q000473:pathology*; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies
Banff 2013 classification; Biopsia renal; Clasificación de Banff 2013; Graft survival; Renal biopsy; Renal transplant; Supervivencia del injerto; Trasplante renal