Polyomic Biomarker Verification in Adult Chronic Graft-Versus-Host Disease (ABLE3.0/CTTC2201)

320 adult transplant recipients will be enrolled in this study. The investigators will not recruit healthy participants. Only those undergoing treatments from blood cancers and will be having the transplant procedure will be offered to participate in this study. The control participant group will be determined 12 months post-transplant. This group will consist of those participants who did not develop either chronic or late acute GvHD one year after transplantation. The investigators will be enrolling allogeneic HCT patients before transplant up through Day -1, following these patients prospectively until 12-months post-transplant for the development of all forms of GvHD - classical acute (aGvHD), late acute (L-aGvHD), and chronic (cGvHD), collecting blood samples and clinical data at day +60, day +100, and at the onset of either L-aGvHD or chronic GvHD (but not classical acute GvHD before day +100). Two more blood samples and clinical data will be collected from transplant recipients who never developed any chronic or late-acute GVHD at the 6- and 12-month post-transplant time points. Case Report Forms (CRFs) will be completed on the REDCap platform. If chronic GvHD develops at any time after transplant (Day 0 to 1 year), or if any form of GvHD occurs at or after day +100 (whether late acute, chronic GvHD, or overlap syndrome), a blood sample will be drawn before escalating immune suppression, and the onset GvHD case report form will be completed following the protocol. If chronic GvHD is confirmed, an additional CRF will be submitted at 12-months post-transplant to document new cGvHD manifestations, severity, and response to therapy. A blood sample will not be collected and a CRF will not be completed if classical acute GvHD occurs before Day 100. Staging and grading of classical acute GvHD however will occur on the main case report forms. On average, patients will have up to 4 blood samples drawn over the course of 1-year post-transplant, depending upon their overall scenario, event and GvHD status. For clinicians and site PIs, the primary responsibility will be monitoring patients for the development of all forms of GvHD (classical acute, late acute, and chronic GvHD), including accurate documentation, and near real-time reporting of detailed clinical data capture of staging / grading / clinical features /severity and responses to therapy for patients with late-acute and chronic GvHD. Blood samples drawn from patients will be shipped to the Schultz Laboratory in Vancouver, BC, Canada, processed and analyzed for cGvHD biomarkers. Cell phenotyping by flow cytometry will be carried out on whole blood. Plasma will be used in ELISA, metabolomic analysis and enzymatic assays. Blood cells will be used for B- and T- cell receptors research. A statistical validation of the previously developed pediatric risk predictor in adult population will be be performed based on the estimated overall frequency of cGvHD at 20% or patients.