EXPERIENCE WITH PROTOCOL BIOPSIES AFTER SOLITARY PANCREAS TRANSPLANTATION

The early detection of allograft rejection remains elusive after solit ary pancreas transplantation (PTX). We have previously described a mod ified technique of cystoscopic transduodenal PTX biopsy using the Biop ty gun under ultrasound guidance. During the last 2 years, we performe d 24 solitary PTXs with prospective protocol biopsy monitoring as well as biopsies performed whenever clinically indicated. The study group included 17 pancreas transplants alone, 6 sequential pancreas after ki dney transplants, and 1 sequential pancreas after liver transplant. Fi ve patients received pancreas retransplants. A total of 92 cystoscopic ally directed core PTX biopsies were performed, including 50 protocol biopsies (mean 2.1 per patient), Protocol biopsies were performed at 1 month (19), 2 months (3), 3 months (20), 6 months (7), and 12 months (1) after PTX. Adequate PTX tissue for histopathologic examination was obtained in 49 cases (98%). Biopsy findings included no rejection (34 ), mild rejection (13), pancreatitis (1), and cytomegalovirus infectio n (1). Overall, 15 of the 49 evaluable biopsies (31%) had significant histopathologic findings. All but 1 of the cases of mild rejection wer e treated with bolus steroids. Eight of these patients subsequently de veloped recurrent biopsy-proven rejection within 2 months; 5 grafts we re subsequently lost to rejection between 3 and 13 months after PTX. T hree biopsy complications occurred: 1 hematoma, 1 pancreatitis, and 1 ileus. Patient survival is 96% and PTX graft survival (complete insuli n independence) is 75% after a mean follow-up of 15 months. In the rem aining 42 clinically indicated biopsies, 3 were insufficient, 8 showed no rejection, and 31 (79%) had rejection. In half of these cases, the rejection was graded as moderate to severe. In conclusion, prospectiv e monitoring with protocol PTX biopsies may result in the earlier dete ction of allograft rejection and have a direct effect on improving res ults after solitary PTX.