Hmc Shantha Kumara, PhD1, Neil Mitra, MD1, Dasuni Niyagama Gamage, MD1, Carl S Winkler, MD1, Jaspreet K Sandhu, MD2, Xiaohong Yan, PhD1, Vesna Cekic, RN1, Nipa D Gandhi, MD1, Richard L Whelan, MD1. 1Mount Sinai West Hospital, Department of Surgery, New York,USA, 2Brookdale University Hospital & Medical Center, Department of Surgery,Brooklyn,New York,USA
Introduction: The protein B7 Homolog 1 (B7-H1), also named Programmed cell Death Ligand 1 (PDL-1), has proangiogenic and immunosupressive effects. PDL-1 is a ligand for PD-1 which is expressed on activated T cells; PDL-1 binding renders activated lymphocytes senescent. Recently, it has been shown that PD-L1 plasma levels are elevated for 4 weeks after colorectal cancer (CRC) resection. Added “free” PDL-1 in the blood may contribute to surgery-related immunosuppression by binding to PD-1 expressing circulating T-lymphocytes. The source of the plasma B7-H1 increase is unknown. It has earlier been shown that plasma levels of VEGF and 11 other proangiogenic proteins are elevated x 3-5 weeks after surgery; the healing wounds may be the protein source since wound fluid (WF) levels are 3-40 x higher than blood levels. This study’s purpose is to determine perioperative PDL-1 levels in blood and WF taken after CRC resection.
Method: Consenting patients (pts) undergoing elective CRC enrolled in an IRB approved tissue /data bank in whom an intra-abdominal Jackson Pratt (JP) drain had been placed were studied. Demographic, Clinical and pathologic data were reviewed. Preoperative (preop) and post-operative (postop) blood and postop wound fluid (WF) samples were simultaneously collected at 1 or more postop time points, centrifuged and were stored at -80°C. Late samples (POD 7-20) were bundled into 7 day blocks and considered as single time points. PDL-1 levels were determined in duplicate via ELISA. The Wilcoxon and Mann and Whitney test were used for analysis (significance p<0.05).
Results: Preop and 1 or more late plasma and WF samples from 23 CRC patients (colon 4, rectal 19; mean age 65.2± 11.4years) were analyzed. The surgical methods were: laparoscopic, 13pts; hand assisted 7; open, 3. The mean incision length (cm) for the MIS and Open pts was 8.4±4.2 and 25.0±8.8, respectively. The mean length of stay was 8.9± 5.3days. Plasma PDL-1 levels on postop day (POD) 1, 3, and 7-13 were significantly higher than preop levels (p<0.001). Also, WF PDL-1 levels were significantly higher than the plasma levels at each postop time point (p=0.02-0.003).
Conclusion: PDL-1 WF levels were significantly higher than corresponding plasma levels (also elevated) for 3 weeks. The highest PDL-1 levels were noted POD7-13. A portion of the added PDL-1 in the plasma may originate in the healing wounds. Elevated plasma PDL-1 may suppress TIL’s which may facilitate tumor growth. Larger perioperative PDL-1 studies and studies investigating plasma PD-1 levels are warranted.
Presented at the SAGES 2017 Annual Meeting in Houston, TX.
Abstract ID: 93775
Program Number: P356
Presentation Session: Poster Session (Non CME)
Presentation Type: Poster