Vitamin D and the risk of acute allograft rejection following human liver transplantation.
BACKGROUND
Vitamin D may act as an immune modulator in experimental and human organ transplantation, but these data are yet to be confirmed in human liver transplantation (LT).


OBJECTIVE
This study aimed to assess the relationship between acute liver allograft cellular rejection (ACR) and pretransplant serum vitamin D concentration or post-transplant vitamin D supplementation.


METHODS
We studied 133 LT recipients who underwent two per protocol allograft biopsies in the early post-operative period, plus on-demand biopsies as clinically indicated. ACR estimate was given according to the Banff scheme in biopsies obtained along two follow-up periods: (a) from the transplant operation to the end of the second month (0-2 months); (b) and from the third month to the end of the eighth month (3-8 months) post-LT.


RESULTS
The median pretransplant serum 25-hydroxyvitamin D concentration was 12.5 ng/ml; 40 patients had concentrations < or =12.5 ng/ml, of whom six had < or =5.0 ng/ml. Seventy-nine recipients received oral vitamin D(3) supplementation to treat post-transplant osteoporosis. In the 0-2 months period, moderate-to-severe rejection episodes were independently associated with cytomegalovirus reactivation (P<0.005) and progressively lower pretransplant serum 25-hydroxyvitamin D concentrations (P<0.02). Early vitamin D(3) supplementation was independently associated with a lack of ACR (P<0.05).


CONCLUSIONS
These results suggest that vitamin D may favour immune tolerance towards the liver allograft.
Bitetto
Davide
D
DPMSC Medical Liver Transplantation Unit, Internal Medicine, University of Udine, Udine, Italy.
Fabris
Carlo
C
Falleti
Edmondo
E
Fornasiere
Ezio
E
Fumolo
Elisa
E
Fontanini
Elisabetta
E
Cussigh
Annarosa
A
Occhino
Giuseppa
G
Baccarani
Umberto
U
Pirisi
Mario
M
Toniutto
Pierluigi
P
D000208:Acute Disease; D000328:Adult; D000368:Aged; D002112:Calcifediol / Q000097:blood; D002117:Calcitriol / Q000627:therapeutic use; D002762:Cholecalciferol / Q000627:therapeutic use*; D005260:Female; D006084:Graft Rejection / Q000473:pathology / Q000517:prevention & control*; D006801:Humans; D008099:Liver / Q000473:pathology; D016031:Liver Transplantation; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000188:drug therapy; D014815:Vitamins / Q000627:therapeutic use; D055815:Young Adult
D014815:Vitamins; D002762:Cholecalciferol; D002117:Calcitriol; D002112:Calcifediol