As outcomes for allogeneic hematopoietic cell transplantation (HCT) improve with treatment advances, grafts from unrelated donors (URD) are becoming more common. The success of HCT from URD has been studied for factors such as donor age, HLA-match degree, dose, graft source, and donor immune reconstitution, but no studies have assessed the immune profile in URD HCT recipients.
In a single-center study, researchers from the Roswell Park Comprehensive Cancer Center, Buffalo, New York, retrospectively reviewed the immune profiles from prospectively collected blood samples of patients undergoing URD HCT. They compared immune parameters with outcomes such as overall survival (OS), progression-free survival (PFS), transplant-related mortality (TRM), and acute graft-versus-host disease (aGVHD).
From 2007-2016, their institution performed URD HCT (10/10 HLA-matched or 8-9/10 HLA-mismatched) for 314 adult patients. Most (94%) received prophylaxis with tacrolimus and methotrexate with or without mycophenolate mofetil for a median follow-up of 8 years. Reduced-intensity conditioning was used for 86%. Immune cell ratios were calculated and classified into high, low, or intermediate groups by percentile (upper 25th, lower 25th, and 25th-75th, respectively).
“For URD, we found that a lower ratio of CD8+ naïve: CD8+ effector memory (EM), lower ratio of CD8+ naïve: CD8+ central memory, and higher ratio of CD8+EM: NK cells were significantly associated with worse OS and PFS,” the authors reported; whereas “a higher ratio of CD4+ naïve: CD8+ naïve was significantly associated with a worse PFS, and a trend towards worse OS.”
Regarding aGVHD, grade II-IV occurrence was significantly associated with a higher ratio of CD4+ EM: CD4+ cells. The authors noted “a trend towards worse OS and PFS.”
Ho CM, Herr M, Wallace PK, et al. Recipient Immune Parameters Are Associated with Outcomes after Unrelated Donor (URD) Allogeneic Hematopoietic Cell Transplant (alloHCT). Abstract #307. Presented at the 2023 Tandem Meetings of ASTCT and CIBMTR; February 15-19, 2023; Orlando, FL.