Analysis of Cell Subsets in Donor Lymphocyte Infusions from HLA Identical Sibling Donors after Allogeneic Hematopoietic Cell Transplant

Donor lymphocytes infusions (DLIs) are amajor therapeutic approach to treat relapse and mixed chimerism after allogeneic hematopoietic cell transplant (alloHCT). The impact of the composition regarding different cell subsets in the development of graft-versus-host disease (GVHD) is not fully understood. We performed a cell subsets analysis of 56 DLIs from fully HLA-compatible identical matched sibling donors (MSDs) in 36 alloHCT patients and studied its association with GVHD. A median of one DLIwas infused per patient. Fourteen patients (38%) developed GVHD. The cell composition analysis of the first DLI (DLI1) showed that a high dose of B cells (P =.03) and CD27(+) B cells (P <.01) was associated with GVHD. We identified DLI dose cutoff points for several cell populations above which GVHD was more frequent (CD8(+) T-N >3 x 10(6) cells/kg, CD27(+) B cells >2.6 x 10(6)/kg, CD27(+) NK >0.35 x 10(6) cells/kg, and mononuclear cells >0.83 x 10(8)/kg). Noteworthy, the proportion of CD4(+) naive T cells (T-N) or unselected T-N was not linked with GVHD and a DLI1 containing a higher dose of regulatory T cells was not protective for GVHD. We studied several transplant clinical variables and did not find any association with GVHD. Altogether, this study provides a comprehensive analysis of the cell populations in a DLI fromMSDs and identifies potential key cell subsets, which provides insight for the understanding of GVHD after DLI. (C) 2020 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.