Drains can be safely omitted for one-quarter of PDs. Drain amylase analysis identifies which moderate/high risk patients benefit from early drain removal. This data-driven, risk-stratified approach significantly decreases the occurrence of clinically relevant pancreatic fistula.

Selective interference with the CD45RB isoform by mAb (anti-CD45RB) reliably induces donor-specific tolerance. Although previous studies suggest participation of regulatory T cells, a mechanistic understanding of anti-CD45RB-induced tolerance is lacking. We report herein the unexpected finding that tolerance induced by this agent is not established in B cell-deficient mice but can be recovered by preemptive B lymphocyte transfer to B cell-deficient hosts. Using B cells from genetically modified donors to reconstitute B cell-deficient recipients, we evaluate the role of B lymphocyte-expressed CD45RB, T cell costimulatory molecules, and the production of Abs in this novel tolerance mechanism. Our data document an Ab-induced tolerance regimen that is uniquely B lymphocyte-dependent and suggest mechanistic contributions to tolerance development from the B cell compartment through interactions with T cells.

Regulatory T cells preserve tolerance to peripheral self-Ags and may control the response to allogeneic tissues to promote transplantation tolerance. Although prior studies have demonstrated prolonged allograft survival in the presence of regulatory T cells (T-reg), data documenting the capacity of these cells to promote tolerance in immunocompetent transplant models are lacking, and the mechanism of suppression in vivo remains unclear. We used a TCR transgenic model of allograft rejection to characterize the in vivo activity of CD4(+)CD25(+) T-reg. We demonstrate that graft Ag-specific T-reg effectively intercede in the rejection response of naive T cells to established skin allografts. Furthermore, CFSE labeling demonstrates impaired proliferation of naive graft Ag-specific T cells in the draining lymph node in the presence of T-reg. These results confirm the efficacy of T-reg in promoting graft survival and suggest that their suppressive action is accomplished in part through inhibition of proliferation.

Objective: The aim of this study was to investigate the relationship between drain fluid amylase value on the first postoperative day (DFA1) and clinically relevant fistula (CR-POPF) after distal pancreatectomy (DP), and to identify the cut-off of DFA1 that optimizes CR-POPF prediction. Background: DFA1 is a well-recognized predictor of CR-POPF after pancreatoduodenectomy, but its role in DP is largely unexplored. Methods: DFA1 levels were correlated with CR-POPF in 2 independent multi-institutional sets of DP patients: developmental (n = 338; years 2012 to 2017) and validation cohort (n = 166; years 2006 to 2016). Cut-off choice was based on Youden index calculation, and its ability to predict CR-POPF occurrence was tested in a multivariable regression model adjusted for clinical, demographic, operative, and pathological variables. Results: In the developmental set, median DFA1 was 1745 U/L and the CR-POPF rate was 21.9%. DFA1 correlated with CR-POPF with an area under the curve of 0.737 (P < 0.001). A DFA1 of 2000 U/L had the highest Youden index, with 74.3% sensitivity and 62.1% specificity. Patients in the validation cohort displayed different demographic and operative characteristics, lower values of DFA1 (784.5 U/L, P < 0.001), and reduced CR-POPF rate (10.2%, P < 0.001). However, a DFA1 of 2000 U/L had the highest Youden index in this cohort as well, with 64.7% sensitivity and 75.8% specificity. At multivariable analysis, DFA1 ≥2000 U/L was the only factor significantly associated with CR-POPF in both cohorts. Conclusion: A DFA1 of 2000 U/L optimizes CR-POPF prediction after DP. These results provide the substrate to define best practices and improve outcomes for patients receiving DP.

BACKGROUND:The literature investigating pancreatic invasive intraductal papillary mucinous neoplasm (IPMN) has largely come from small institutional studies, preventing adequately powered comparisons of adjuvant therapy versus surgery alone (SA) within specific patient subgroups. METHODS: Patients with resected, stage I through IV, invasive IPMN and conventional pancreatic ductal adenocarcinoma (PDAC) were identified in the National Cancer Data Base (1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010). Cox modeling of patients with invasive IPMN was used to compare overall survival (OS) between patients who received adjuvant therapy and those who underwent SA. A second model was used to compare OS between patients with invasive IPMN and those with PDAC. RESULTS: For the 1220 patients with invasive IPMN, the median OS was 28.9 months; the 1-year and 5-year actuarial survival rates were 76% and 17%, respectively; and 47% received adjuvant therapy. Cox modeling associated SA with worse OS (hazard ratio, 1.36; 95% confidence interval, 1.17-1.58; P 5.00005) as well as American Joint Committee on Cancer (AJCC) TNM stage III/IV disease, positive lymph node status, positive margins, and poor tumor differentiation (all P .05). In addition, Cox modeling stratified by the following characteristics demonstrated improved OS with adjuvant therapy: AJCC TNM stage II or III/IV, positive lymph node status, positive margins, and poorly differentiated tumors. There was no survival advantage from adjuvant therapy for patients who had AJCC TNM stage I or lymph node-negative disease. Patients who had invasive IPMN had improved risk-adjusted OS compared with those who had PDAC (hazard ratio, 0.73; 95% confidence interval, 0.68-0.78; P <.00001). CONCLUSIONS: Invasive IPMN appears to be more indolent than conventional PDAC. Adjuvant therapy is associated with improved OS compared with SA in patients with invasive