CXCL10 (IP-10) and anti-ZnT8 autoantibodies: Exploratory indicators of risk in pancreatic transplant rejection.

Background: Measurement of chemokine CXCL10 is a novel approach to assess the transplant rejection risk and to detect the rejection. While CXCL10 has shown itself to be useful in renal transplants, there are only a few studies on the association between pancreas transplantation and CXCL10. Furthermore, the importance of autoantibodies associated with type I diabetes in pancreas transplantation are relatively poorly understood. Objectives: To determine whether there is an association between CXCL10 plasma levels and graft rejection in simultaneous pancreas and kidney transplant recipients, and to assess the effects of pancreas autoantibodies on pancreatic transplant rejection. Design: A retrospective case-control study was conducted. Methods: In total of 23 individuals (11 male and 12 female, mean age 39.5 (SD ± 7.6) years) who underwent simultaneous pancreas and kidney transplantation, and in 8 healthy controls (evenly distributed in terms of gender, mean age 26.1 (SD ± 1.5) years) plasma samples were analyzed for CXCL10 and autoantibody levels using ELISA. The data was categorized into preoperative, perioperative and postoperative samples and were further juxtaposed in relation to rejection episodes. Results: Preoperative CXCL10 levels did not differ from those for healthy individuals, but they rose postoperatively (P = .02). The median preoperative plasma concentration of CXCL10 was 68 pg/ml and increased to 123 pg/ml postoperatively. A postoperative plasma CXCL10 cut-off value of 297 pg/ml was indicative of rejection. Postoperative autoantibodies were detected in 10 recipients, 4 of whom were positive for anti-ZnT8 autoantibodies, and 2 were positive for more than 1 type autoantibody. All recipients who were positive for anti-ZnT8 autoantibodies or for more than 1 type autoantibody experienced rejection. Conclusion: Elevated CXCL10 levels during the first 3 months after transplantation seem to be a risk factor for rejection. The post transplant presence of anti-ZnT8 autoantibodies was associated with transplant rejection.