Background:
Central venulitis (CV), a distinct histologic lesion described in adult liver
transplants, can occur with acute portal tract rejection or in isolation
(isolated central venulitis, ICV). The etiology of ICV is uncertain: is it a
result of immunosuppressive drug toxicity, acute cellular rejection, viral
hepatitis or recurrent disease? Biopsy material and clinical data were collected
on pediatric liver recipients to characterize CV in patients who generally do
not develop viral hepatitis or recurrent disease.
Design: 45
of 59 children who received orthotopic liver transplants had
127 post-transplant liver biopsies available for review. Only four liver
transplants were performed for potentially recurrent diseases (ie, primary
sclerosing cholangitis) and none were performed for viral hepatitis. 44 of the
45 children received tacrolimus-based
immunosuppression.
Results: ICV was identified in 12 of 127
post-transplant biopsies and in 7 of 45 allograft recipients. Acute portal tract
rejection was first detected in allograft biopsies at a mean±SEM of 12.9±2.8
days post-transplantation, while ICV develop at 65.1±26.9 days. The finding of
CV was not correlated with elevation of tacrolimus levels, reason for
transplant, donor/recipient CMV status or blood type, cold ischemic times or the
incidence of outflow obstruction. The responses of CV to therapy were variable
and although the majority of cases resolved, several episodes persisted or
recurred.
Conclusions: ICV occurred in 16% of pediatric
post-transplant liver recipients and 9% of post-transplant liver biopsies. Since
ICV was not associated with elevated tacrolimus levels, viral hepatitis or
recurrent disease, since it developed later than acute portal-based rejection,
and since it was responsive to anti-rejection therapy, ICV may be a variant of
cellular rejection.