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Abstract: TH-PO0885

Early Detection of Kidney Transplant Rejection Using a Soft Wireless Strain Biosensor in a Swine Model

Session Information

Category: Transplantation

  • 2101 Transplantation: Basic

Authors

  • Gessaroli, Elisa, Universita degli Studi di Bologna, Bologna, Emilia-Romagna, Italy
  • Minicucci, Carlo, Universita degli Studi di Bologna, Bologna, Emilia-Romagna, Italy
  • Rogers, John A., Northwestern University, Evanston, Illinois, United States
  • Gallon, Lorenzo G., University of Illinois Chicago, Chicago, Illinois, United States
  • La Manna, Gaetano, Universita degli Studi di Bologna, Bologna, Emilia-Romagna, Italy
Background

Serum creatinine (Scr) is neither sensitive nor specific for the diagnosis of rejection and it takes several days to rise following renal transplant injury. The inflammation that occurs during rejection is associated with edema and swelling of the renal transplant. Here, we hypothesized that an implanted strain biosensor could measure organ stretching, due to edema and swelling and could be an early biomarker for the diagnosis of rejection. Outbred swine pigs were used for kidney transplant (KTx) model.

Methods

a wireless linear soft biosensor designed to detect real-time changes in strain was placed on the allograft surface. We performed KTx between AB0 compatible donors and recipients selected based on SLA incompatibility. No immunosuppression was given. The first group of animals (n=4) received a single KTx with one strain sensor positioned on the allograft surface and the second one of the native kidneys as a control. In the second group of animals (n=4) bilateral nephrectomy was performed before KTx and serial Scr was measured as a marker for rejection.

Results

The sensors detected expansion due to edema and inflammation of the rejecting allografts, at post-operative day (POD) 1 (Figure a) without any measurable expansion on the native kidneys. In the second group of animals , Scr started rising at POD 5, while organ expansion was detected at POD2. Pigs euthanized at POD3 showed signs of inflammation and rejection in the allograft and a 4 cm of kidney transplant length difference was found between POD0 and POD3.

Conclusion

In our KTx model, strain sensors detected changes associated with edema/inflammation of rejecting allografts. This occurs earlier than the rise in serum creatinine, suggesting an important clinical use of our sensor in monitoring KTx rejection.
Future direction: We are developing a new concentric strain biosensor with a distinct circular design, aimed at enhancing sensitivity and improving both positioning and suturing on the kidney transplant surface (Figure b).

Figure a) Strain sensor data from kidney allograft
Figure b) New-designed circular strain sensor

Digital Object Identifier (DOI)