Detection of Graft Versus Host Disease With [18F]F-AraG

This is a single-center imaging study to determine utility of in vivo imaging with \[18F\]F-AraG to identify sites of Graft Versus Host Disease (GVHD) in patients highly suspected of having acute GVHD who require systemic therapy, and patients at high risk for developing acute GVHD. \[18F\]F-AraG PET scans will be compared to biopsy results to correlate T cell accumulation which is implicated in the disease. High risk patients will be followed to verify predictive potential of \[18F\]F-AraG.

This single-center imaging study will enroll three cohorts of participants: healthy volunteers, patients highly suspected to have acute GVHD (aGVHD) and requiring systemic therapy, and patients at high risk for developing GVHD.

A total of 5 healthy volunteers will undergo \[18F\]F-AraG PET scans and blood sampling to better understand \[18F\]F-AraG biodistribution and stability in the body.

A total of 10 highly suspected acute GVHD patients will be scanned following biopsy taken to confirm aGVHD. The staging and grading of the disease using the Glucksberg grade and International Bone Marrow Transplant Registry Severity Index (IBMTR) at time of enrollment will be noted. Biopsy tissues of consented patients will be analyzed further for T cell involvement.

A total of 15 high-risk patients (recipients of myeloablative or reduced intensity allogeneic transplants using either bone marrow or peripheral blood stem cells from HLA-matched or HLA-mismatched related or unrelated donors-protocols 9142, 9022, 9924) will be recruited. All those that consent will undergo a PET-CT scan with \[18F\]FAraG on day 4 +/- 2 days post transplant. Additionally, these patients will be scanned again between day 14-21 post transplant. Follow up on these patients will note those that go on to develop aGVHD and the clinical end point will be correlated to the scans to verify the predictive potential of the radiotracer.

Eligibility Criteria:
Inclusion Criteria:

1. Must be 21 years of age or older.
2. Must understand and voluntarily have signed an Informed Consent after its contents have been fully explained.

   1. For patients highly suspected to have aGVHD and requiring systemic therapy, informed consent should be signed after biopsy taken to support clinical diagnosis.
   2. For patients at high risk for developing aGVHD, informed consent should be signed prior to transplant.
3. For healthy volunteers only: Must have no known medical problems that would make undergoing the scan hazardous to the health of the patient or interfere with the results. In particular subjects should not have any cardiac or immunological disorders as these would likely affect the scan results. Subjects should have had a full physical exam within 6 months of the study. If healthy volunteers have not had a full medical exam within 6 months of the study, one of the nuclear medicine physicians will conduct the medical exam prior to any study procedures.
4. For patients highly suspected to have aGVHD and requiring systemic therapy only: Taking steroid treatment for suspected aGVHD for 3 days or less.
5. For patients at high risk for developing aGVHD only: Recipients of myeloablative or reduced intensity allogeneic transplants using either bone marrow or peripheral blood stem cells from HLA-matched or HLA-mismatched related or unrelated donors (protocols 9142, 9022, 9924) who have not yet been placed on any therapy for acute GVHD.

Exclusion Criteria:

1. Pregnant or nursing
2. Individuals with known or suspected substance abuse, obtained by self-reporting.
3. Uncontrolled infection
4. Relapsed/persistent malignancy
5. Currently receiving immunotherapy