Characterization of immune cell subsets in marrow over time after DLI. (A) IHC staining analysis of marrow immune populations from responders and nonresponders before and 3 to 6 and 9 to 12 months after DLI. For each immune cell subset, significant differences between 0 and 3 to 6- or 9 to 12-month time points are noted. (B) Representative IHC of marrow samples from one responder and one nonresponder demonstrates robust marrow infiltration by CD3⁺ T cells in the responder before and subsequent increase after DLI. Images were captured with an Olympus QColor 5 camera on an Olympus BX41 microscope with a x40/0.75 objective using Adobe Photoshop Software (vCS5). (C) Pairwise comparison of individual patients’ marrow before and after DLI therapy revealed significant upregulation of marrow CD8⁺ T cells in the responder cohort after treatment. *P < .05 using the Wilcoxon signed-rank test.