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Minor histocompatibility antigens (miHA) are responsible for the occurrence of graft-versus-host disease in the setting of a major histocompatibility complex matched sibling allogeneic stem cell transplantation. These miHA are peptide fragments that are associated with major histocompatibility complex class I or class II antigens. Elegant experiments have led to the molecular characterization of these antigens. Efforts to prevent graft-versus-host disease could be targeted through this pathway by matching for these miHA or by preventing antigen recognition. Alternatively, these miHA could be exploited as targets for a more potent graft-versus-malignancy effect. This area of miHA promises to continue to be an exciting area of continued research. [Copyright &y& Elsevier]

• Delirium is common following hematopoietic stem cell transplantation. • In this select sample, greater age, treatment regimen intensity, and greater white matter burden were all associated with greater delirium incidence. Delirium is common among adults undergoing hematopoietic stem cell transplantation (HCT), although the clinical and neuroimaging correlates of post-HCT delirium have not been adequately delineated. We therefore examined the frequency of delirium and neuroimaging correlates of post-transplant delirium in a retrospective cohort of 115 adults undergoing neuroimaging after allogeneic HCT. Delirium was established using previously validated methods for retrospective identification of chart-assessed postprocedural delirium. Chart reviews were independently conducted by a multidisciplinary team with expertise in HCT, psychiatry, and psychology on consecutive allogeneic HCT patients who underwent neuroimaging assessments and transplantation at a single center between January 2009 and December 2016. Neuroimaging markers of white matter damage and brain volume loss were also recorded. In total, 115 patients were included, ranging in age from 20 to 74 years (mean [SD] age, 49 [13]). Fifty-three patients (46%) developed post-HCT delirium. In an adjusted model, delirium incidence was associated with older age (odds ratio [OR], 1.92 [1.28, 2.87] per decade, P =.002), greater severity of white matter hyperintensities (OR, 1.95 [1.06, 3.57], P =.031), and conditioning intensity (OR, 6.37 [2.20, 18.45], P <.001) but was unrelated to cortical atrophy (P =.777). Delirium was associated with fewer hospital-free days (P =.023) but was not associated with overall survival (hazard ratio, 0.95 [0.56, 1.61], P =.844). Greater incidence of delirium following HCT was associated with greater age, microvascular burden, and conditioning intensity. Pre-HCT consideration of microvascular burden and other neuroimaging biomarkers of risk may be warranted. [ABSTRACT FROM AUTHOR]

Infusing natural killer (NK) cells following transplantation may allow less infections and relapse with little risk of acute graft-versus-host disease (aGVHD). We delivered 51 total NK cell-enriched donor lymphocyte infusions (DLIs) to 30 patients following a 3-6/6 HLA matched T cell-depleted nonmyeloablative allogeneic transplant. The primary endpoint of this study was feasibility and safety. Eight weeks following transplantation, donor NK cell-enriched DLIs were processed using a CD56+ selecting column with up to 3 fresh infusions allowed. Toxicity, relapse, and survival were monitored. T cell phenotype, NK cell functional recovery, and KIR typing were assessed for association with outcomes. Fourteen matched and 16 mismatched transplanted patients received a total of 51 NK cell-enriched DLIs. Selection resulted in 96% (standard deviation [SD] 8%) purity and 83% (SD 21%) yield in the matched setting and 97% (SD 3%) purity and 77% (SD 24%) yield in the mismatched setting. The median number of CD3− CD56+ NK cells infused was 10.6 (SD 7.91) × 106 cells/kg and 9.21 (SD 5.6) × 106 cells/kg, respectively. The median number of contaminating CD3+CD56− T cells infused was .53 (1.1) × 106 and .27 (.78) × 106 in the matched and mismatched setting, respectively. Only 1 patient each in the matched (n = 14) or mismatched (n = 16) setting experienced severe aGVHD with little other toxicity attributable to the infusions. Long-term responders with multiple NK cell-enriched infusions and improved T cell phenotypic recovery had improved duration of responses (p = .0045) and overall survival (OS) (P = .0058). A 1-step, high-yield process is feasible, and results in high doses of NK cells infused with little toxicity. NK cell-enriched DLIs result in improved immune recovery and outcomes for some. Future studies must assess whether the improved outcomes are the direct result of the high doses and improved NK cell function or other aspects of immune recovery. [Copyright &y& Elsevier]

Abstract: T-cell receptor variable β chain (TCRBV) repertoire spectratyping involves the estimation of CDR3 length distributions for monitoring T-cell receptor diversity and has proven useful for analyses of immune reconstitution and T-cell clonal expansions in graft-versus-host disease (GVHD) and graft-versus-leukemia after allogeneic stem cell transplantation. We performed a longitudinal spectratype analysis of 23 TCRBV families in 28 patients who underwent allogeneic T cell–depleted peripheral blood stem cell transplantation. Sixteen patients subsequently developed acute GVHD. We recently developed statistical methods that bring increased power and flexibility to spectratype analysis and allow us to analyze TCRBV repertoire development under appropriately complex statistical models. Applying these methods, we found that patients with acute GVHD demonstrated TCRBV repertoire development statistically distinct from that repertoire development in patients without GVHD. Specifically, GVHD patients showed spectratypes indicative of lower diversity and greater deviation from the spectratypes expected in healthy individuals at intermediate times. Most individual TCRBV subfamilies had spectratypes statistically distinguishable between GVHD and non-GVHD patients at 6 months after transplantation. These results suggest that the T-cell receptor repertoire perturbations associated with acute GVHD are widely spread throughout the TCRBV families. [Copyright &y& Elsevier]

Introduction Prophylactic, donor lymphocyte infusion (DLI) is used to augment immune recovery and graft vs. tumor effect following a T-cell depleted alloSCT. However, it carries the risk of inducing severe GvHD. Our pre-clinical murine studies have implicated the naive T-cell, defined by CD62L marker, as the primary driver of alloreactivity. We hypothesize that transferring selected memory T-cells without naive-T cells would endow the patient with cells that do not cause GvHD while augmenting host defense against infection and tumor recurrence. Objectives The goal of the study was to determine the maximum tolerated dose of a prophylactic, delayed DLI that has been depleted of naive T-cells. Methods We enrolled 16 adult patients, median age 54 who met following criteria; a. underwent an alemtuzumab or thymoglobulin-containing non-myeloablative allogeneic transplant from an HLA-identical family donor or an 8/8 HLA-matched unrelated donor (MUD), b. at least 60 days from day of transplantation, c. no active acute GvHD grade II or higher. Primary diseases were CLL; n=1, MM; n=2, MF; n=1, NHL; n=5, MDS; n=1, AML; n=6. A dedicated, non-mobilized donor apheresis procedure was performed following enrollment. Naive, CD45RA+ T-cells were depleted from the collection under an IND using the Miltenyi clinimacs system. A standard phase I, 3+3 dose escalation schema was employed. The dose-limiting toxicity of the DLI was defined as development of grade III/IV acute GvHD within 90 days of the DLI. Results The DLI was infused on median 112.5 days (76 to 280 days) following transplant. 8 patients received matched sibling grafts and 8 received MUD grafts. 3 patients each received naive T-cell depleted CD3+ dose of 1 × 105/kg, 1 × 106/kg, and 5 × 106/kg. The top dose of 1 × 107/kg was expanded to 7 patients. No dose limiting toxicity or adverse event attributable to the DLI was observed at any dose level. 1 patient developed grade 2 acute GvHD and 1 developed moderate chronic GvHD attributable to the DLI. 4 patients had relapsed disease; 2 in the lowest dose and 2 in the highest dose levels. With a median follow-up of 2.75 years, 2-year relapse free and overall survivals are 56.25% and 68.75%, respectively (Fig 1 and 2). NK cells, CD3+T lymphocytes, CD4+ T lymphocytes and CD8+ T lymphocytes show positive correlations of 0.24, 0.40, 0.42 and 0.38 respectively with time following the DLI (Fig 3). Conclusion A prophylactic, naive T-cell depleted DLI can be provided safely, without significant risk of acute GvHD at a dose of 1 × 10e7 CD3/kg. Larger studies in a more homogeneous patient population will be needed to confirm the impact on immune recovery and relapse prevention. [ABSTRACT FROM AUTHOR]

Delirium is common among adults undergoing hematopoietic stem cell transplant (HCT), although the clinical predictors and neuroimaging correlates of postoperative delirium have not been adequately delineated. We therefore examined the frequency of delirium and neuroimaging correlates of post-HCT delirium in a retrospective cohort of 115 adults undergoing BMT. Delirium was established using previously validated methods for retrospective identification of chart-assessed postoperative delirium. Chart reviews were independently conducted by a team including a HCT physician, a transplant psychiatrist, a transplant psychologist, and a psychiatry resident on consecutive allogeneic HCT patients who underwent neuroimaging assessments, transplanted between January, 2009 December, 2016Y. Neuroimaging markers of cortical volume loss and white matter hyperintensities were also recorded. One hundred fifteen patients were included, ranging in age from 20 to 74 (mean age = 49 [SD = 13]). Fifty-three patients (46%) developed post-HCT delirium. In an adjusted model, delirium incidence was associated with older age (OR = 1.92 [1.28, 2.87] per decade, P =.002), greater severity of white matter hyperintensities (OR = 1.95 [1.06, 3.57], P =.031), and treatment regimen intensity (OR = 6.37 [2.20, 18.45], P <.001) but was unrelated to cortical atrophy (P =.777). Greater incidence of delirium following BMT was associated with greater age, microvascular burden, and more severe treatment regimen. Pre-HCT consideration of microvascular burden and other neuroimaging biomarkers of risk may be warranted. [ABSTRACT FROM AUTHOR]