P0773 A SIMPLE BIOLOGICAL MARKER OF ACUTE INTESTINAL GRAFT REJECTION.

Abstract

Introduction: Acute graft rejection (AGR) is one of the most severe complication after small bowel transplants (SBTx). Only few biological markers exist for the diagnosis of AGR. We examined the impact of AGR on protein losses from the intestinal graft after SBTx. Methods: A total of 12 patients were followed up after isolated (n=7) or combined liver-intestine (n=5) Tx for total aganglionosis (n=4), short bowel syndrome (SBS) (n=2), microvillous atrophy (n=2), epithelial dysplasia (n=2) or chronic intestinal pseudoobstruction (CIPOS) (n=2). All patients had a graft terminal ileostoma at time of transplant and during this follow up. Protein concentrations were assayed in the ileal output samples during the post-transplant days and during rejection episodes and were compared to 10 controls on ileostoma for SBS or CIPOS. An adapted pyrogallol red-molybdate method including a sample-blank determination, as for total urinary protein, has been used. Variations in protein concentrations versus degree of AGR were assessed by matching post-transplantation concentrations with patients grade of AGR at time of collection. Rejection was confirmed by biopsy and graded by standardized criteria.Statistical analysis was based on t test for unpaired data Results: Mean protein post-transplantation concentrations did not differ significantly between patients and controls (1.34 ± 0.82 versus 0.80 ± 0.47). During AGR, protein concentrations were significantly higher than post-transplantation samples at any rejection grade. The overall downward trend was statistically significant (p<0.001). In sequential measurements, protein levels decreased significantly over time with declining severity of rejection.Table 1Conclusion: Ileal output protein levels increase with increasing severity of AGR. Such high protein lossess are related to severe protein losing enteropathy with subsequent decrease in both plasma total protein and albumin, requiring albumin replacement during rejection episodes. Protein concentration assessment may be a useful, non invasive, costless tool for intestinal rejection monitoring. In addition, results may be obtained very rapidly at any time and before histological analysis.