Effect of ischemic injury on subsequent rat lung allograft rejection.
BACKGROUND
It has been suggested that the frequency and severity of allograft rejection may be related to the degree of allograft ischemia. The purpose of this study was to determine whether ischemic insult correlates with lung allograft rejection.


METHODS
Forty-eight left lung transplants were performed from Lewis donor rats into F344 recipient rats. Allografts were divided into two groups based on the degree of ischemic insult. Transplantation was performed immediately (group 1, minimum injury) or after 18 hours of cold (1 degree C) preservation (group 2, severe injury). Allografts were evaluated radiographically based on aeration scores (0 = opaque to 6 = normal). Animals were randomly sacrificed on days 7, 14, or 21 for histologic and immunohistochemical evaluation of rejection.


RESULTS
On postoperative day 3, significantly lower aeration score was demonstrated in group 2 (3.69 +/- 1.71) compared to group 1 (5.0 +/- 1.09) (p < 0.05) as a result of the difference in reperfusion injury. However, by day 7 and thereafter, there was no significant difference. Histologic rejection was present by day 7 and peaked at day 14 with no significant difference between groups. There was also no difference in CD4+, CD8+ infiltrating lymphocyte population or expression of class II major histocompatibility complex antigen on bronchial epithelium.


CONCLUSIONS
We conclude that ischemic injury in rat lung allograft does not correlate with the onset or severity of rejection.
Shiraishi
T
T
Department of Surgery, Washington University School of Medicine, Barnes Hospital, St. Louis, Missouri, USA.
Mizuta
T
T
DeMeester
S R
SR
Ritter
J H
JH
Swanson
P E
PE
Wick
M R
MR
Cooper
J D
JD
Patterson
G A
GA
D000818:Animals; D006084:Graft Rejection / Q000473:pathology; D016040:Lung Transplantation / Q000473:pathology; D008297:Male; D015428:Myocardial Reperfusion Injury / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D051381:Rats; D011916:Rats, Inbred F344; D011917:Rats, Inbred Lew; D013997:Time Factors; D014184:Transplantation, Homologous