Early diagnosis and treatment of pancreas allograft rejection

Abstract

A major problem in vascularized pancreas transplantation is the lack of reliable methods for the early diagnosis and effective treatment of allograft rejection. Over a 2-year period, 54 rejection episodes occurred in 31 patients (13 isolated pancreas, 18 simultaneous pancreas-kidney recipients) with pancreaticoduodenocystostomy. A total of 253 radionuclide pancreas examinations were performed (mean 8.4 per patient) utilizing 99mtechnetium-DTPA. Computer analysis generated a quantitative measure of blood flow to the allograft caused the technetium index (TI). Rejection episodes were characterized as isolated pancreas (22), combined pancreas-kidney (16), or isolated renal (16) allograft rejection in combined engraftments. The majority of rejection episodes occurred early (within 3 months of transplant, N = 47) and were more responsive than late rejection to anti-rejection therapy (89.4% vs 42.9%, P = 0.01). Mean urinary amylase (UA) levels and TI during normal allograft function were 29,398 U/l and 0.55%, while levels heralding rejection were 6,528 U/l and 0.40%, respectively (P less than 0.05). The treatment of rejection based upon renal dysfunction or combined renal and pancreas dysfunction resulted in significantly higher graft salvage with a lower incidence of hyperglycemia when compared to isolated pancreas allograft rejection. Of the 11 patients who developed hyperglycemia, 8 (72.7%) ultimately lost their pancreas grafts (P less than 0.001). Following therapy, a TI above 0.3% was associated with 97.4% graft survival, while levels below 0.3% resulted in a 70% rate of graft loss (P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Use of UW Solution in Pancreas Transplantation

“…UA levels, which we and others (14)(15)(16) use to monitor allograft rejection, also appear to be a sensitive indicator of the quality of preservation. The Tl indicates good early pancreas-allograft perfusion but appears to have as its major advantage the monitoring of transplant rejection (7). SA, with the exception of early severe graft pancreatitis, which we did not observe, may not be a good indicator of preservation as suggested by Abouna et al (10).…”

“…Tl ( 99m Tc-labeled DTPA) is a quantitative measure of blood pooling in the pancreas allograft determined by computer analysis of the percentage of tracer present in the graft after the 2nd min of scanning (7). Overall graft function was evaluated, including the effect of preservation time on allograft function.…”

MRI of the pancreas transplant: Lack of correlation between imaging and clinical status

“…Using these clinical criteria, our group of 13 abnormal pancreas transplants would have been diagnosed as rejection in 8 cases and pancreatitis in 5 cases. Unfortunately, serum hyperamylasemia has been shown to be nonspecific and has been associated with rejection, preservation injury, and infected ascites (2). In the absence of biopsy proof, we thus decided not to emphasize the distinction between pancreatitis and rejection.…”

“…Graft survival is increasing; a two-year graft survival of 84% has recently been reported at our institution ( I ) . Despite the increasing success of pancreas transplantation, results remain inferior to the results for other solid organs, in part due to difficulties in distinguishing between the different etiologies of transplant dysfunction (2). Although the most frequent cause of graft failure remains rejection, the differential diagnosis of pancreatic transplant dysfunction includes pancreatitis and vascular occlusion.…”

Duct-drained versus duct-occluded pancreatic grafts: a personal view

“…One reason for changing the technique was that a marker for graft rejection was required in order for us to be able to proceed with our program for transplanting isolated pancreatic grafts. The monitoring of graft function by measuring urinary output of amylase seemed to be feasible, judging from reports from several centres [30,37].…”