Chronic kidney disease after nonrenal solid organ transplantation:  a histological assessment and utility of chronic allograft damage index scoring.
BACKGROUND
It is proposed that chronic calcineurin inhibitor (CNI) nephrotoxicity has a central role in chronic kidney disease after nonrenal solid organ transplantation (NRSOT), although there are little data on renal histology in this setting. The aim of this study was to assess the histological features and renal outcomes of a cohort of patients with chronic kidney disease after NRSOT.


METHODS
Renal biopsies of 62 NRSOT recipients were evaluated for histological diagnoses. Biopsies were graded for chronic allograft damage index parameters and for arteriolar hyalinosis. The sum of all chronic allograft damage index parameters and arteriolar hyalinosis scores was called chronic damage index.


RESULTS
The biopsies were performed at a median of 4 (range: 0.3-15.9) years after NRSOT and at serum creatinine of 318±17.7 μmol/L (mean±standard deviation). Twenty-two (35.5%) biopsies showed predominant features of chronic CNI nephrotoxicity, 27 (43.5%) predominant features of hypertensive nephropathy, and 12 (19.3%) an alternative primary renal pathology. Twenty-four (38.7%) patients had progression to end-stage renal disease, at a median of 1.5 (0-10.1) years after biopsy and 6.9 (0.3-19.2) years after NRSOT. The risk of renal progression was associated with in situ damage measured by chronic damage index.


CONCLUSIONS
Although CNI nephrotoxicity is an important cause of renal failure after NRSOT, many patients do not have overt histological evidence of CNI toxicity. Quantitative parameters of chronic damage can stratify renal prognosis.
Department of Nephrology and Renal Transplantation, Renal Institute of Birmingham, University Hospital Birmingham, Birmingham, United Kingdom. sakubal@iupui.edu
Chandrashekhar
C
Kubal
Paul
P
Cockwell
Bridget
B
Gunson
Mark
M
Jesky
Rajesh
R
Hanvesakul
Vamsidhar
V
Dronavalli
Robert S
RS
Bonser
Desley
D
Neil
D000328:Adult; D000368:Aged; D001160:Arterioles / Q000378:metabolism / Q000473:pathology; D001706:Biopsy; D065095:Calcineurin Inhibitors; D002908:Chronic Disease; D015331:Cohort Studies; D003404:Creatinine / Q000097:blood; D018450:Disease Progression; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology; D016027:Heart Transplantation; D006801:Humans; D006818:Hyalin / Q000378:metabolism; D007668:Kidney / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology; D007674:Kidney Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000473:pathology*; D016031:Liver Transplantation; D016040:Lung Transplantation; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D014184:Transplantation, Homologous
D065095:Calcineurin Inhibitors; D003404:Creatinine