Mucosal vascular alterations in isolated small-bowel allografts: relationship to humoral sensitization.
Acute vascular rejection (AVR) in human small-bowel transplantation is an inadequately characterized entity whose frequency and severity is not well understood. As compared to severe AVR, changes identifying early, mild or evolving AVR are not known. We created a scoring system to evaluate subtle mucosal vascular changes and examined 188 biopsies from 21 patients obtained in the first 3 months post transplant. A majority of patients had a transient rise in vascular injury, often within 30 days of transplant. Small-vessel congestion and erythrocyte extravasation were the most common alterations. The vascular injury score was not related to acute cellular rejection, HLA type or HLA antigen disparities. However, the patients with the vascular changes had significantly higher peak panel reactive antibodies (PRA) and a higher incidence of positive T-cell and B-cell crossmatch. Finally, graft survival was significantly lower in the patients demonstrating the early vascular lesions. These data suggest that the vascular injury is partially associated with humoral presensitization of the recipient and may be a form of acute vascular rejection. Since these vascular changes are frequent, we advocate early post-transplant monitoring to identify and manage potentially high-risk patients.
Ruiz
Phillip
P
Department of Pathology, University of Miami School of Medicine, Miami, Florida 33136, USA. pruiz@med.miami.edu
Garcia
Monica
M
Pappas
Peter
P
Berney
Thierry
T
Esquenazi
Violet
V
Kato
Tomoaki
T
Mittal
Naveen
N
Weppler
Deborah
D
Levi
David
D
Nishida
Seigo
S
Nery
Jose
J
Miller
Joshua
J
Tzakis
Andreas
A
D000906:Antibodies / Q000276:immunology; D006084:Graft Rejection / Q000145:classification* / Q000276:immunology / Q000503:physiopathology; D006085:Graft Survival; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D006801:Humans; D007421:Intestine, Small / Q000276:immunology / Q000473:pathology / Q000637:transplantation*
D000906:Antibodies; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II