The AlloSure test is approved by the Centers for Medicare & Medicaid Services (CMS) for use in Medicare patients to assess the probability of allograft rejection in kidney transplant patients. The pivotal DART study discusses the use of the non-invasive AlloSure test to measure donor derived cell-free DNA (dd-cfDNA) and the Allosure test can by used to discriminate active rejection in renal transplant patients. Pancreas allograft rejection still remains a major clinical challenge and is a primary cause of death censored pancreas allograft loss. Pancreas transplant rejection is diagnosed by biopsy, however it is not commonly performed because of the complications such as pancreatic leak, graft loss and patient death. Currently at Rush surveillance biopsy of the pancreas are not performed routinely due to the above risks.

At RUMC, patients are followed post-transplant with series of labs at set intervals that include lipase, DSA, C-Peptide, and GAD65 for surveillance of rejection

The AlloSure test was introduced for routine use in kidney transplant recipients at Rush University Medical Center in October 2017, after CMS approval and then as part of the KOAR Study in May of 2018. AlloSure test has been included as part of the routine labs for surveillance of rejection in pancreas transplant recipients at RUMC since September 2018 after it was approved for compassionate use. The addition of AlloSure has helped to improve surveillance of rejection in pancreas transplant recipients and has reduced the need for the kidney biopsy as a surrogate marker of rejection in the pancreas.

Our goal is to determine if AlloSure can be used for surveillance for rejection in recipients of Simultaneous Pancreas and Kidney (SPK) Transplant recipients.

This is a prospective and retrospective cohort study of recipients of simultaneous pancreas and kidney transplant recipients (SPK).

New SPK transplant recipients and previous SPK transplant recipients from September 2012 will be enrolled in the study, expected duration of participation will therefore range from a minimum of 1 year to a maximum of 5 years for each participant.

The visits are incorporated into the current standard of care in our program and no extra visits are required. Mobile draw for AlloSure can be obtained if the patient is not due for a visit when the AlloSure draw is due.

AlloSure labs will be drawn on all new SPK patients and results obtained as well as retrospective results that have already been received on past SPK recipients. The AlloSure will be added to the standard of care schedule for all SPK patients.

The schedule will be the following:

For newly transplanted patients, AlloSure will be checked at 14 days post-transplant

For all subjects:

From 1 month to 12 months post transplant: AlloSure will be obtained monthly with their transplant date as the reference time point

From 12 months to 36 months: AlloSure will be obtained every 3 months

From 36 months to 60 months: AlloSure will be obtained every 6 months.

AlloSure may be obtained more frequently than the above schedule, with other clinical data or allograft biopsy, if there is graft dysfunction or suspicion for rejection.

Inclusion Criteria:

• Participant is willing and able to give informed consent for participation in the study.
• Male or Female, aged 18 years or above.
• New SPK transplant recipients
• SPK recipients from September 2012 with functioning kidney and pancreas, not on dialysis and/or insulin

Exclusion Criteria:

The participant may not enter the study if ANY of the following apply:

• Unwilling to participate in research study
• Recipients of other solid organ transplants apart from the SPK
• Recipients of pancreas and kidney allografts from separate donors
• Recipients with SLE
• Patients who have received a bone marrow transplant
• Recipients of a transplant form a monozygotic twin
• Patients who are pregnant
• Patients below the age of 18 years
• SPK recipient on insulin at enrolment
• SPK recipient on dialysis

Recipients of Simultaneous Pancreas and Kidney (SPK) transplant since 2012 and above the age of 18 will be enrolled.