Matching at Human Leukocyte Antigen-C Improved the Outcomes after Double Umbilical Cord Blood Transplantation for Recipients of Two to Four of Six Human Leukocyte Antigen-Matched Grafts

We studied the effect of HLA-C matching in 515 patients after double umbilical cord blood (UCB) transplantation. After HLA matching HLA-A, -B, and -DRB1 at the allele level, we scored patients according to number of donor-recipient HLA-C matches at 4 possible loci: 2 from each donor unit, at the allele level. Given a direct interaction between HLA-A, -B, and -DRB1 matching and HLA-C score, we analyzed HLA-C matching in those receiving at least 1 2/6 to 4/6 HLA-matched unit (n = 389) versus those receiving only 5/6 or 6/6-matched units (n = 126). In those with at least 1 2/6 to 4/6 HLA-matched unit, a better HLA-C matching score was associated with significantly lower risk of death of any cause and nonrelapse mortality and better disease-free survival. There was no association with the risk of relapse, acute and chronic graft-versus-host disease, and hematopoietic recovery. In contrast, among patients receiving only allele-level 5/6 or 6/6 HLA-matched UCB units, HLA-C match had no demonstrable effect on any outcome. For patients receiving at least 1 allele-level 2/6 to 4/6 HLA-matched UCB unit, matching at HLA-C reduces nonrelapse mortality and improves survival.

Sirolimus and Mycophenolate Mofetil as Calcineurin Inhibitor-Free Graft-versus-Host Disease Prophylaxis for Reduced-Intensity Conditioning Umbilical Cord Blood Transplantation

The use of calcineurin inhibitors (CNIs) to reduce the risk of graft-versus-host disease (GVHD) after hematopoietic cell transplantation (HCT) requires intensive post-transplantation toxicity monitoring. Sirolimus-based GVHD prophylaxis is associated with a favorable toxicity profile and requires less intensive monitoring. However, the efficacy of sirolimus-based regimen compared with CNI-based regimen has not been evaluated in the setting of reduced-intensity conditioning (RIC) double umbilical cord blood (UCB) HCT. We compared outcomes of patients receiving sirolimus/mycophenolate mofetil (MMF) (n = 37) or cyclosporine (CSA)/MMF (n = 123) in an ongoing phase II study of RIC UCB transplantation. In multiple regression analysis, sirolimus/MMF did not influence the risk of grades II to IV or grades III and IV acute GVHD. In addition, there was no association between type of GVHD prophylaxis and hematopoietic engraftment. Infection density analysis found a significantly lower risk of infections with sirolimus/MMF between days +46 and +180 after HCT compared with CSA/MMF (3.4 versus 6.3 per 1000 patient-days, P = .03); however, no difference was observed before day +45. Sirolimus/MMF use resulted in no thrombotic microangiopathy, fewer instances of elevated serum creatinine >2 mg/dL (14% versus 45%; P <.01), and similar rates of sinusoidal obstruction syndrome (2.7% versus 4%; P = .68), compared with CSA/MMF. Disease-free survival at 1 year was 51% for sirolimus/MMF and 41% for CSA/MMF (P = .41), and sirolimus/MMF use did not influence the risk of nonrelapse mortality or survival. In conclusion, sirolimus/MMF GVHD prophylaxis was better tolerated and resulted in similar rates of GVHD and survival as compared to CSA/MMF after RIC double UCB transplantation.

Infection Rates among Acute Leukemia Patients Receiving Alternative Donor Hematopoietic Cell Transplantation

Alternative graft sources (umbilical cord blood [UCB], matched unrelated donors [MUD], or mismatched unrelated donors [MMUD]) enable patients without a matched sibling donor to receive potentially curative hematopoietic cell transplantation (HCT). Retrospective studies demonstrate comparable outcomes among different graft sources. However, the risk and types of infections have not been compared among graft sources. Such information may influence the choice of a particular graft source. We compared the incidence of bacterial, viral, and fungal infections in 1781 adults with acute leukemia who received alternative donor HCT (UCB, n= 568; MUD, n = 930; MMUD, n = 283) between 2008 and 2011. The incidences of bacterial infection at 1 year were 72%, 59%, and 65% (P < .0001) for UCB, MUD, and MMUD, respectively. Incidences of viral infection at 1 year were 68%, 45%, and 53% (P < .0001) for UCB, MUD, and MMUD, respectively. In multivariable analysis, bacterial, fungal, and viral infections were more common after either UCB or MMUD than after MUD (P < .0001). Bacterial and viral but not fungal infections were more common after UCB than MMUD (P = .0009 and <.0001, respectively). The presence of viral infection was not associated with an increased mortality. Overall survival (OS) was comparable among UCB and MMUD patients with Karnofsky performance status (KPS) ≥ 90% but was inferior for UCB for patients with KPS < 90%. Bacterial and fungal infections were associated with poorer OS. Future strategies focusing on infection prevention and treatment are indicated to improve HCT outcomes.

Human leukocyte antigen supertype matching after myeloablative hematopoietic cell transplantation with 7/8 matched unrelated donor allografts: a report from the Center for International Blood and Marrow Transplant Research

The diversity of the human leukocyte antigen (HLA) class I and II alleles can be simplified by consolidating them into fewer supertypes based on functional or predicted structural similarities in epitope-binding grooves of HLA molecules. We studied the impact of matched and mismatched HLA-A (265 versus 429), -B (230 versus 92), -C (365 versus 349), and -DRB1 (153 versus 51) supertypes on clinical outcomes of 1934 patients with acute leukemias or myelodysplasia/myeloproliferative disorders. All patients were reported to the Center for International Blood and Marrow Transplant Research following single-allele mismatched unrelated donor myeloablative conditioning hematopoietic cell transplantation. Single mismatched alleles were categorized into six HLA-A (A01, A01A03, A01A24, A02, A03, A24), six HLA-B (B07, B08, B27, B44, B58, B62), two HLA-C (C1, C2), and five HLA-DRB1 (DR1, DR3, DR4, DR5, DR9) supertypes. Supertype B mismatch was associated with increased risk of grade II-IV acute graft-versus-host disease (hazard ratio =1.78, P=0.0025) compared to supertype B match. Supertype B07-B44 mismatch was associated with a higher incidence of both grade II-IV (hazard ratio=3.11, P=0.002) and III-IV (hazard ratio=3.15, P=0.01) acute graft-versus-host disease. No significant associations were detected between supertype-matched versus -mismatched groups at other HLA loci. These data suggest that avoiding HLA-B supertype mismatches can mitigate the risk of grade II-IV acute graft-versus-host disease in 7/8-mismatched unrelated donor hematopoietic cell transplantation when multiple HLA-B supertype-matched donors are available. Future studies are needed to define the mechanisms by which supertype mismatching affects outcomes after alternative donor hematopoietic cell transplantation.

Proteome Profiling in Lung Injury after Hematopoietic Stem Cell Transplantation

Pulmonary complications due to infection and idiopathic pneumonia syndrome (IPS), a noninfectious lung injury in hematopoietic stem cell transplant (HSCT) recipients, are frequent causes of transplantation-related mortality and morbidity. Our objective was to characterize the global bronchoalveolar lavage fluid (BALF) protein expression of IPS to identify proteins and pathways that differentiate IPS from infectious lung injury after HSCT. We studied 30 BALF samples from patients who developed lung injury within 180 days of HSCT or cellular therapy transfusion (natural killer cell transfusion). Adult subjects were classified as having IPS or infectious lung injury by the criteria outlined in the 2011 American Thoracic Society statement. BALF was depleted of hemoglobin and 14 high-abundance proteins, treated with trypsin, and labeled with isobaric tagging for relative and absolute quantification (iTRAQ) 8-plex reagent for two-dimensional capillary liquid chromatography (LC) and data dependent peptide tandem mass spectrometry (MS) on an Orbitrap Velos system in higher-energy collision-induced dissociation activation mode. Protein identification employed a target-decoy strategy using ProteinPilot within Galaxy P. The relative protein abundance was determined with reference to a global internal standard consisting of pooled BALF from patients with respiratory failure and no history of HSCT. A variance weighted t-test controlling for a false discovery rate of ≤5% was used to identify proteins that showed differential expression between IPS and infectious lung injury. The biological relevance of these proteins was determined by using gene ontology enrichment analysis and Ingenuity Pathway Analysis. We characterized 12 IPS and 18 infectious lung injury BALF samples. In the 5 iTRAQ LC-MS/MS experiments 845, 735, 532, 615, and 594 proteins were identified for a total of 1125 unique proteins and 368 common proteins across all 5 LC-MS/MS experiments. When comparing IPS to infectious lung injury, 96 proteins were differentially expressed. Gene ontology enrichment analysis showed that these proteins participate in biological processes involved in the development of lung injury after HSCT. These include acute phase response signaling, complement system, coagulation system, liver X receptor (LXR)/retinoid X receptor (RXR), and farsenoid X receptor (FXR)/RXR modulation. We identified 2 canonical pathways modulated by TNF-α, FXR/RXR activation, and IL2 signaling in macrophages. The proteins also mapped to blood coagulation, fibrinolysis, and wound healing-processes that participate in organ repair. Cell movement was identified as significantly over-represented by proteins with differential expression between IPS and infection. In conclusion, the BALF protein expression in IPS differed significantly from infectious lung injury in HSCT recipients. These differences provide insights into mechanisms that are activated in lung injury in HSCT recipients and suggest potential therapeutic targets to augment lung repair.

Loss of T Follicular Helper Cells in the Peripheral Blood of Patients with Chronic Graft-versus-Host Disease

B cell antihost antibody production plays a central role in chronic graft-versus-host disease (cGVHD). T follicular helper (TFH) cells drive B cell responses and are implicated in this process. Given differences in cGVHD incidence between umbilical cord blood (UCB) and adult donor transplant recipients, we evaluated TFH cell reconstitution kinetics to define graft source differences and their potential pathogenic role in cGVHD. Although we observed significantly fewer TFH cells in the blood of UCB recipients (versus matched related donors [MRD]) early after transplantation, by 1 year the numbers of TFH cells were similar. Additionally, at both early (day 60) and late (1 year) time points, TFH cell phenotype was predominantly central memory cells in both cohorts. TFH cells were functional and able to produce multiple cytokines (INF-γ, TNF-α, IL-2, IL-17, and IL-21) after stimulation. In contrast to mouse models, where an enhanced frequency of splenic TFH cells contributes to cGVHD, patients with cGVHD showed significantly depleted circulating TFH cells after both UCB and MRD transplantation. Low numbers of TFH cells early after UCB transplantation could directly contribute to less cGVHD in this cohort. Additionally, systemic therapy (including steroids and calcineurin inhibitors) may contribute to decreases in TFH cells in patients with cGVHD. These data provide further evidence supporting the importance of TFH cells in cGVHD pathogenesis.

Late Acute Graft-versus-Host Disease after Allogeneic Hematopoietic Stem Cell Transplantation

There are little data regarding the incidence, clinical manifestations, risk factors, and outcomes of late acute graft-versus-host disease (aGVHD). We evaluated patients with late aGVHD after allogeneic hematopoietic cell transplantation (HCT) between 2007 and 2012 and compared their outcomes to patients with early-onset aGVHD. Of the 511 allogeneic HCT recipients, 75 developed late aGVHD (cumulative incidence: 14.7% (95% confidence interval [CI], 11.6% to 17.8%) versus 248 with early-onset aGVHD (cumulative incidence: 49% [95% CI, 45% to 53%]). Among those with late aGVHD, 52% had persistent, 39% had recurrent, and 9% had de novo late aGVHD. Advanced (grades III and IV) early-onset aGVHD was associated with a higher risk of developing late aGVHD (hazard ratio [HR], 1.9; 95% CI, 1.2 to 3.1; P = .01). Forty-eight percent (95% CI, 36% to 60%) of late aGVHD versus only 31% (95% CI, 26% to 37%) of early-onset aGVHD progressed to chronic GVHD by 2 years. Higher proportion of persistent (53%) as compared to recurrent (39%) and de novo (46%) late aGVHD progressed to cGVHD at 2 years. The overall survival was 59% (95% CI, 49% to 72%) in late aGVHD and 50% (95% CI, 44% to 57%) in early-onset aGVHD. Persistent late aGVHD had worse overall survival and nonrelapse mortality (45% and 39%, respectively) than recurrent (74% and 18%, respectively) and de novo (83% and 0%, respectively) late aGVHD. Compared with HLA-identical sibling HCT, unrelated donor transplantations were associated with a higher risk of mortality in patients developing late aGVHD (HR, 6.1; 95% CI, 2.3 to 16.2; P < .01). In a landmark analysis (evaluating 100-day survivors among early-onset aGVHD), no difference was seen in late mortality (after 100 days) between early-onset and late aGVHD (HR, .96; 95% CI, .59 to 1.55; P = .85); however, the risk of cGVHD was nearly doubled (HR, 1.81; 95% CI, 1.16 to 2.82; P = .01) in patients with late aGVHD. Late aGVHD is a relatively common complication after allogeneic HCT. Poorer outcomes in those with persistent late aGVHD imply need for more effective therapy in this group to improve transplantation outcomes. A higher risk of subsequent chronic GVHD needs further evaluation and close monitoring.

Improved graft-versus-host disease-free, relapse-free survival associated with bone marrow as the stem cell source in adults

We previously reported that bone marrow grafts from matched sibling donors resulted in best graft-versus-host disease-free, relapse-free survival at 1-year post allogeneic hematopoietic cell transplantation. However, pediatric patients comprised the majority of bone marrow graft recipients in that study. To better define this outcome in adults and pediatric patients at 1- and 2-years post- allogeneic hematopoietic cell transplantation, we pooled data from the University of Minnesota and the Hôpital Saint-Louis in Paris, France (n=1901). Graft-versus-host disease-free, relapse-free survival was defined as the absence of grade III-IV acute graft-versus-host disease, chronic graft-versus-host disease (requiring systemic therapy or extensive stage), relapse and death. In adults, bone marrow from matched sibling donors (n=123) had best graft-versus-host disease-free, relapse-free survival at 1- and 2-years, compared with peripheral blood stem cell from matched sibling donors (n=540) or other graft/donor types. In multivariate analysis, peripheral blood stem cells from matched sibling donors resulted in a 50% increased risk of events contributing to graft-versus-host disease-free, relapse-free survival at 1- and 2-years than bone marrow from matched sibling donors. With limited numbers of peripheral blood stem cell grafts in pediatric patients (n=12), graft-versus-host disease-free, relapse-free survival did not differ between bone marrow and peripheral blood stem cell graft from any donor. While not all patients have a matched sibling donor, graft-versus-host disease-free, relapse-free survival may be improved by the preferential use of bone marrow for adults with malignant diseases. Alternatively, novel graft-versus-host disease prophylaxis regimens are needed to substantially impact graft-versus-host disease-free, relapse-free survival with the use of peripheral blood stem cell.

Steroids Versus Steroids Plus Additional Agent in Frontline Treatment of Acute Graft-versus-Host Disease: A Systematic Review and Meta-Analysis of Randomized Trials

Despite extensive research in the last few decades, progress in treatment of acute graft-versus-host disease (aGVHD), a common complication of allogeneic hematopoietic cell transplantation (HCT), has been limited and steroids continue to be the standard frontline treatment. Randomized clinical trials (RCTs) have failed to find a beneficial effect of escalating immunosuppression using additional agents. Considering the small number of RCTs, limited sample sizes, and frequent early termination because of anticipated futility, we conducted a systematic review and an aggregate data meta-analysis to explore whether a true efficacy signal has been missed because of the limitations of individual RCTs. Seven reports met our inclusion criteria. The control arm in all studies was 2 mg/kg/day prednisone (or equivalent). The additional agent(s) used in the experimental arm(s) were higher-dose steroids, antithymocyte globulin, infliximab, anti-interleukin-2 receptor antibody (daclizumab and BT563), CD5-specific immunotoxin, and mycophenolate mofetil. Random effects meta-analysis revealed no efficacy signal in pooled response rates at various times points. Overall survival at 100 days was significantly worse in the experimental arm (relative risk [RR], .83; 95% confidence interval [CI], .74 to .94; P = .004, data from 3 studies) and showed a similar trend (albeit not statistically significantly) at 1 year as well (RR, .86; 95% CI, .68 to 1.09; P = .21, data from 5 studies). In conclusion, these results argue against the value of augmented generic immunosuppression beyond steroids for frontline treatment of aGVHD and emphasize the importance of developing alternative strategies. Novel forms of immunomodulation and targeted therapies against non-immune-related pathways may enhance the efficacy of steroids in this setting, and early predictive and prognostic biomarkers can help identify the subgroup of patients who would likely need treatments other than (or in addition to) generic immunosuppression.

Pediatric-inspired therapy compared to allografting for Philadelphia chromosome-negative adult ALL in first complete remission

For adults with Philadelphia chromosome-negative (Ph-) acute lymphoblastic leukemia (ALL) in first complete remission (CR1), allogeneic hematopoietic cell transplantation (HCT) is an established curative strategy. However, pediatric-inspired chemotherapy may also offer durable leukemia-free survival in the absence of HCT. We compared 422 HCT recipients aged 18-50 years with Ph-ALL in CR1 reported to the CIBMTR with an age-matched concurrent cohort of 108 Ph- ALL CR1 patients who received a Dana-Farber Consortium pediatric-inspired non-HCT regimen. At 4 years of follow-up, incidence of relapse after HCT was 24% (95% CI 19-28) versus 23% (95% CI 15-32) for the non-HCT (chemo) cohort (P=0.97). Treatment-related mortality (TRM) was higher in the HCT cohort [HCT 37% (95% CI 31-42) versus chemo 6% (95% CI 3-12), P<0.0001]. DFS in the HCT cohort was 40% (95% CI 35-45) versus 71% (95% CI 60-79) for chemo, P<0.0001. Similarly, OS favored chemo [HCT 45% (95% CI 40-50)] versus chemo 73% [(95% CI 63-81), P<0.0001]. In multivariable analysis, the sole factor predictive of shorter OS was the administration of HCT [hazard ratio 3.12 (1.99-4.90), P<0.0001]. For younger adults with Ph- ALL, pediatric-inspired chemotherapy had lower TRM, no increase in relapse, and superior overall survival compared to HCT. Am. J. Hematol. 91:322-329, 2016. © 2015 Wiley Periodicals, Inc.

Umbilical cord blood-derived T regulatory cells to prevent GVHD: kinetics, toxicity profile, and clinical effect

We studied the safety and clinical outcomes of patients treated with umbilical cord blood (UCB)-derived regulatory T cells (Tregs) that expanded in cultures stimulated with K562 cells modified to express the high-affinity Fc receptor (CD64) and CD86, the natural ligand of CD28 (KT64/86). Eleven patients were treated with Treg doses from 3-100 × 10(6) Treg/kg. The median proportion of CD4(+)FoxP3(+)CD127(-) in the infused product was 87% (range, 78%-95%), and we observed no dose-limiting infusional adverse events. Clinical outcomes were compared with contemporary controls (n = 22) who received the same conditioning regimen with sirolimus and mycophenolate mofetil immune suppression. The incidence of grade II-IV acute graft-versus-host disease (GVHD) at 100 days was 9% (95% confidence interval [CI], 0-25) vs 45% (95% CI, 24-67) in controls (P = .05). Chronic GVHD at 1 year was zero in Tregs and 14% in controls. Hematopoietic recovery and chimerism, cumulative density of infections, nonrelapse mortality, relapse, and disease-free survival were similar in the Treg recipients and controls. KT64/86-expanded UCB Tregs were safe and resulted in low risk of acute GVHD.

IL15 Trispecific Killer Engagers (TriKE) Make Natural Killer Cells Specific to CD33+ Targets While Also Inducing Persistence, In Vivo Expansion, and Enhanced Function

PURPOSE

The effectiveness of NK cell infusions to induce leukemic remission is limited by lack of both antigen specificity and in vivo expansion. To address the first issue, we previously generated a bispecific killer engager (BiKE) containing single-chain scFv against CD16 and CD33 to create an immunologic synapse between NK cells and CD33(+) myeloid targets. We have now incorporated a novel modified human IL15 crosslinker, producing a 161533 trispecific killer engager (TriKE) to induce expansion, priming, and survival, which we hypothesize will enhance clinical efficacy.

EXPERIMENTAL DESIGN

Reagents were tested in proliferation and functional assays and in an in vivo xenograft model of AML.

RESULTS

When compared with the 1633 BiKE, the 161533 TriKE induced superior NK cell cytotoxicity, degranulation, and cytokine production against CD33(+) HL-60 targets and increased NK survival and proliferation. Specificity was shown by the ability of a 1615EpCAM TriKE to kill CD33-EpCAM(+) targets. Using NK cells from patients after allogeneic stem cell transplantation when NK cell function is defective, the 161533 TriKE restored potent NK function against primary AML targets and induced specific NK cell proliferation. These results were confirmed in an immunodeficient mouse HL-60-Luc tumor model where the 161533 TriKE exhibited superior antitumor activity and induced in vivo persistence and survival of human NK cells for at least 3 weeks.

CONCLUSIONS

Off-the-shelf 161533 TriKE imparts antigen specificity and promotes in vivo persistence, activation, and survival of NK cells. These qualities are ideal for NK cell therapy of myeloid malignancies or targeting antigens of solid tumors. Clin Cancer Res; 22(14); 3440-50. ©2016 AACRSee related commentary by Talmadge, p. 3419.

Phase I study of a bispecific ligand-directed toxin targeting CD22 and CD19 (DT2219) for refractory B-cell malignancies

PURPOSE

The novel bispecific ligand-directed toxin (BLT) DT2219 consists of a recombinant fusion between the catalytic and translocation enhancing domain of diphtheria toxin (DT) and bispecific single-chain variable fragments (scFV) of antibodies targeting human CD19 and CD22. We conducted a phase I dose-escalation study to assess the safety, maximum tolerated dose, and preliminary efficacy of DT2219 in patients with relapsed/refractory B-cell lymphoma or leukemia.

EXPERIMENTAL DESIGN

DT2219 was administered intravenously over 2 hours every other day for 4 total doses. Dose was escalated from 0.5 μg/kg/day to 80 μg/kg/day in nine dose cohorts until a dose-limiting toxicity (DLT) was observed.

RESULTS

Twenty-five patients with mature or precursor B-cell lymphoid malignancies expressing CD19 and/or CD22 enrolled to the study. Patients received median 3 prior lines of chemotherapy and 8 failed hematopoietic transplantation. All patients received a single course of DT2219; one patient was retreated. The most common adverse events, including weight gain, low albumin, transaminitis, and fever were transient grade 1-2 and occurred in patients in higher dose cohorts (≥40 μg/kg/day). Two subjects experienced DLT at dose levels 40 and 60 μg/kg. Durable objective responses occurred in 2 patients; one was complete remission after 2 cycles. Correlative studies showed a surprisingly low incidence of neutralizing antibody (30%).

CONCLUSIONS

We have determined the safety of a novel immunotoxin DT2219 and established its biologically active dose between 40 and 80 μg/kg/day ×4. A phase II study exploring repetitive courses of DT2219 is planned.

Hematopoietic Cell Transplantation Outcomes in Monosomal Karyotype Myeloid Malignancies

The presence of monosomal karyotype (MK+) in acute myeloid leukemia (AML) is associated with dismal outcomes. We evaluated the impact of MK+ in AML (MK+AML, n = 240) and in myelodysplastic syndrome (MDS) (MK+MDS, n = 221) on hematopoietic cell transplantation outcomes compared with other cytogenetically defined groups (AML, n = 3360; MDS, n = 1373) as reported to the Center for International Blood and Marrow Transplant Research from 1998 to 2011. MK+ AML was associated with higher disease relapse (hazard ratio, 1.98; P < .01), similar transplantation-related mortality (TRM) (hazard ratio, 1.01; P = .90), and worse survival (hazard ratio, 1.67; P < .01) compared with those outcomes for other cytogenetically defined AML. Among patients with MDS, MK+ MDS was associated with higher disease relapse (hazard ratio, 2.39; P < .01), higher TRM (hazard ratio, 1.80; P < .01), and worse survival (HR, 2.02; P < .01). Subset analyses comparing chromosome 7 abnormalities (del7/7q) with or without MK+ demonstrated higher mortality for MK+ disease in for both AML (hazard ratio, 1.72; P < .01) and MDS (hazard ratio, 1.79; P < .01). The strong negative impact of MK+ in myeloid malignancies was observed in all age groups and using either myeloablative or reduced-intensity conditioning regimens. Alternative approaches to mitigate disease relapse in this population are needed.

Blood transfusions and pulmonary complications after hematopoietic cell transplantation

BACKGROUND

Transfusion of blood products is an essential component of the hematopoietic cell transplantation (HCT) process. Blood transfusion carries several risks including, but not limited to, lung injury. The effect of transfusions on lung complications after HCT has not been previously investigated.

STUDY DESIGN AND METHODS

We retrospectively studied 215 adult allogeneic HCT recipients at the University of Minnesota and examined the association between transfusion of blood components and development of lung complications after HCT. Patients without lung complications were used as the control group.

RESULTS

A total of 113 (58%) of the patients developed lung injury events before Day 180 after HCT. Six-month survival was significantly lower in the lung event group (52%) versus the controls (78%; p = 0.01). Patients who eventually developed lung events received more transfusion episodes per week in the first month after HCT (median, 4.3 vs. 2.7 for controls), platelet units per week (3.5 vs. 2.0), and RBC units per week (1.8 vs. 1.4; p < 0.01) for all. In a multivariable analysis, each additional transfusion before Day +30 was associated with a 2.7% higher risk of lung complication (95% confidence interval, 0.8-4.8; p = 0.01), adjusting for time to engraftment, conditioning intensity, and donor type. Blood utilization increased after the lung event and remained high for several months relative to controls.

CONCLUSION

Our data suggest that transfusion of blood products is associated with and may further complicate lung complications after HCT. Cautious use of blood components in the post HCT period is recommended.

Marrow damage and hematopoietic recovery following allogeneic bone marrow transplantation for acute leukemias: Effect of radiation dose and conditioning regimen

BACKGROUND AND PURPOSE

Total body irradiation (TBI) is a common component of hematopoietic cell transplantation (HCT) conditioning regimens. Preclinical studies suggest prolonged bone marrow (BM) injury after TBI could contribute to impaired engraftment and poor hematopoietic function.

MATERIALS AND METHODS

We studied the longitudinal changes in the marrow environment in patients receiving allogeneic HCT with myeloablative (MA, n=42) and reduced intensity (RIC, n=56) doses of TBI from 2003-2013, including BM cellularity, histologic features of injury and repair, hematologic and immunologic recovery.

RESULTS

Following MA conditioning, a 30% decrease in the marrow cellularity persisted at 1 year post-transplant (p=0.03). RIC HCT marrow cellularity transiently decreased but returned to baseline by 6 months even though the RIC group received mostly umbilical cord blood (UCB) grafts (82%, vs. 17% in the MA cohort, p<0.01). There was no evidence of persistent marrow vascular damage or inflammation. Recipients of more intensive conditioning did not show more persistent cytopenias with the exception of a tendency for minimal thrombocytopenia. Immune recovery was similar between MA and RIC.

CONCLUSIONS

These findings suggest that TBI associated with MA conditioning leads to prolonged reductions in marrow cellularity, but does not show additional histological evidence of long-term injury, which is further supported by similar peripheral counts and immunologic recovery.

Nonparametric methods for analyzing recurrent gap time data with application to infections after hematopoietic cell transplant

Infection is one of the most common complications after hematopoietic cell transplantation. Many patients experience infectious complications repeatedly after transplant. Existing statistical methods for recurrent gap time data typically assume that patients are enrolled due to the occurrence of an event of interest, and subsequently experience recurrent events of the same type; moreover, for one-sample estimation, the gap times between consecutive events are usually assumed to be identically distributed. Applying these methods to analyze the post-transplant infection data will inevitably lead to incorrect inferential results because the time from transplant to the first infection has a different biological meaning than the gap times between consecutive recurrent infections. Some unbiased yet inefficient methods include univariate survival analysis methods based on data from the first infection or bivariate serial event data methods based on the first and second infections. In this article, we propose a nonparametric estimator of the joint distribution of time from transplant to the first infection and the gap times between consecutive infections. The proposed estimator takes into account the potentially different distributions of the two types of gap times and better uses the recurrent infection data. Asymptotic properties of the proposed estimators are established.

Myeloablative, but not Reduced-Intensity, Conditioning Overcomes the Negative Effect of Flow-Cytometric Evidence of Leukemia in Acute Myeloid Leukemia

Stringent complete remission (CR) in acute myeloid leukemia (AML) requires the absence of both morphologic and flow cytometric evidence of disease. We have previously shown that persistent AML detected by flow cytometry (FC+) before reduced-intensity conditioning (RIC) allogeneic hematopoietic cell transplantation (alloHCT) was associated with significantly increased relapse, shorter disease-free survival (DFS), and poorer overall survival (OS), independent of morphologic blast count. We evaluated the effect of FC status on outcomes of alloHCT for AML after either myeloablative conditioning (MAC) or RIC regimens in 203 patients (MAC, n = 80, and RIC, n = 123) with no morphologic evidence of persistent AML pretransplant on marrow biopsy. The allografts included 130 umbilical cord blood (UCB) and 73 sibling donors. We performed central review of pretransplant standard sensitivity FC to identify detectable FC+. Twenty-five patients were FC+, including 15 (18.7%) receiving MAC and 10 (8.1%) RIC alloHCT. Among RIC patients FC+ was associated with significantly inferior relapse, DFS, and OS (multiple regression HR, 3.8; 95% CI, 1.7 to 8.7; P < .01 for relapse; HR, 2.9; 95% CI, 1.4 to 5.9; P < .01 for DFS; and HR, 3.4; 95% CI, 1.7 to 7; P < .01 for OS). In contrast, FC+ status was not associated with relapse or decreased OS after MAC. These data suggest that MAC, but not RIC, overcomes the negative effect of pretransplant FC+ after sibling or UCB alloHCT. Therefore, a deeper pretransplant leukemia-free state is preferred for those treated with RIC.

Impact of Allele-Level HLA Mismatch on Outcomes in Recipients of Double Umbilical Cord Blood Transplantation

The impact of allele-level HLA mismatch is uncertain in recipients of double umbilical cord blood (UCB) transplantation. We report a single-center retrospective study of the clinical effect of using allele-level HLA mismatch HLA-A, -B, -C, -DRB1, and -DQB1 of the 2 UCB units. We studied 342 patients with hematologic malignancy. Donor-recipient pairs were grouped according to the number of matched HLA alleles, with 32 matched at 9-10/10, 202 at 6-8/10, and 108 at 2-5/10 alleles. The incidence of hematopoietic recovery, acute and chronic graft-versus-host disease, and nonrelapse mortality and treatment failure was similar between groups. In an exploratory analysis of 174 patients with acute leukemia, after adjusting for length of first remission and cytogenetic risk group, a 2-5/10 HLA match was associated with lower risk of relapse and treatment failure. These data indicate that a high degree of allele-level HLA mismatch does not adversely affect transplant outcomes and may be associated with reduced relapse risk in patients with acute leukemia.

CD56dimCD57+NKG2C+ NK cell expansion is associated with reduced leukemia relapse after reduced intensity HCT

We have recently described a specialized subset of human natural killer (NK) cells with a CD56^dimCD57⁺NKG2C⁺ phenotype that expand specifically in response to cytomegalovirus (CMV) reactivation in hematopoietic cell transplant (HCT) recipients and exhibit properties characteristic of adaptive immunity. We hypothesize that these cells mediate relapse protection and improve post-HCT outcomes. In 674 allogeneic HCT recipients, we found that those who reactivated CMV had lower leukemia relapse (26% [17–35%], p=0.05) and superior disease-free survival (DFS) (55% [45–65%] p=0.04) 1 year after reduced intensity conditioning (RIC) compared to CMV seronegative recipients who experienced higher relapse rates (35% [27–43%]) and lower DFS (46% [38–54%]). This protective effect was independent of age and graft-versus-host disease (GvHD) and was not observed in recipients who received myeloablative (MA) regimens. Analysis of the reconstituting NK cells demonstrated that CMV reactivation is associated with both higher frequencies and greater absolute numbers of CD56^dimCD57⁺NKG2C⁺ NK cells, particularly after RIC HCT. Furthermore, expansion of these cells at 6 months post-transplant independently trended toward a lower 2-year relapse risk. Together, our data suggest that the protective effect of CMV reactivation on post-transplant relapse is in part driven by adaptive NK cell responses.

Infections after Transplantation of Bone Marrow or Peripheral Blood Stem Cells from Unrelated Donors

Infection is a major complication of hematopoietic cell transplantation. Prolonged neutropenia and graft-versus-host disease are the 2 major complications with an associated risk for infection, and these complications differ according to the graft source. A phase 3, multicenter, randomized trial (Blood and Marrow Transplant Clinical Trials Network [BMT CTN] 0201) of transplantation of bone marrow (BM) versus peripheral blood stem cells (PBSC) from unrelated donors showed no significant differences in 2-year survival between these graft sources. In an effort to provide data regarding whether BM or PBSC could be used as a preferential graft source for transplantation, we report a detailed analysis of the infectious complications for 2 years after transplantation from the BMT CTN 0201 trial. A total of 499 patients in this study had full audits of infection data. A total of 1347 infection episodes of moderate or greater severity were documented in 384 (77%) patients; 201 of 249 (81%) of the evaluable patients had received a BM graft and 183 of 250 (73%) had received a PBSC graft. Of 1347 infection episodes, 373 were severe and 123 were life-threatening and/or fatal; 710 (53%) of these episodes occurred on the BM arm and 637 (47%) on the PBSC arm, resulting in a 2-year cumulative incidence 84.7% (95% confidence interval [CI], 79.6 to 89.8) for BM versus 79.7% (95% CI, 73.9 to 85.5) for PBSC, P = .013. The majority of these episodes, 810 (60%), were due to bacteria, with a 2-year cumulative incidence of 72.1% and 62.9% in BM versus PBSC recipients, respectively (P = .003). The cumulative incidence of bloodstream bacterial infections during the first 100 days was 44.8% (95% CI, 38.5 to 51.1) for BM versus 35.0% (95% CI, 28.9 to 41.1) for PBSC (P = .027). The total infection density (number of infection events/100 patient days at risk) was .67 for BM and .60 for PBSC. The overall infection density for bacterial infections was .4 in both arms; for viral infections, it was .2 in both arms; and for fungal/parasitic infections, it was .04 and .05 for BM and PBSC, respectively. The cumulative incidence of infection before engraftment was 47.9% (95% CI, 41.5 to 53.9) for BM versus 32.8% (95% CI, 27.1 to 38.7) for PBSC (P = .002), possibly related to quicker neutrophil engraftment using PBSC. Infections remain frequent after unrelated donor hematopoietic cell transplantation, particularly after BM grafts.

Hemorrhagic cystitis after allogeneic hematopoietic cell transplantation: risk factors, graft source and survival

Although hemorrhagic cystitis (HC) is a common complication of allogeneic hematopoietic cell transplantation (alloHCT), its risk factors and effects on survival are not well known. We evaluated HC in a large cohort (n=1321, 2003-2012) receiving alloHCT from all graft sources, including umbilical cord blood (UCB). We compared HC patients with non-HC (control) patients and examined clinical variables at HC onset and resolution. Of these 1321 patients, 219 (16.6%) developed HC at a median of 22 days after alloHCT. BK viruria was detected in 90% of 109 tested HC patients. Median duration of HC was 27 days. At the time of HC diagnosis, acute GVHD, fever, severe thrombocytopenia and steroid use were more frequent than at the time of HC resolution. In univariate analysis, male sex, age <20 years, myeloablative conditioning with cyclophosphamide and acute GVHD were associated with HC. In multivariate analysis, HC was significantly more common in males and HLA-mismatched UCB graft recipients. Severe grade HC (grade III-IV) was associated with increased treatment-related mortality but not with overall survival at 1 year. HC remains hazardous and therefore better prophylaxis, and early interventions to limit its severity are still needed.

Adaptive Natural Killer Cell and Killer Cell Immunoglobulin-Like Receptor-Expressing T Cell Responses are Induced by Cytomegalovirus and Are Associated with Protection against Cytomegalovirus Reactivation after Allogeneic Donor Hematopoietic Cell Transplantation

Cytomegalovirus (CMV) reactivates in >30% of CMV-seropositive patients after allogeneic hematopoietic cell transplantation (HCT). Previously, we reported an increase of natural killer (NK) cells expressing NKG2C, CD57, and inhibitory killer cell immunoglobulin-like receptors (KIRs) in response to CMV reactivation after HCT. These NK cells persist after the resolution of infection and display "adaptive" or memory properties. Despite these findings, the differential impact of persistent/inactive versus reactivated CMV on NK versus T cell maturation after HCT from different graft sources has not been defined. We compared the phenotype of NK and T cells from 292 recipients of allogeneic sibling (n = 118) or umbilical cord blood (UCB; n = 174) grafts based on recipient pretransplantation CMV serostatus and post-HCT CMV reactivation. This cohort was utilized to evaluate CMV-dependent increases in KIR-expressing NK cells exhibiting an adaptive phenotype (NKG2C(+)CD57(+)). Compared with CMV-seronegative recipients, those who reactivated CMV had the highest adaptive cell frequencies, whereas intermediate frequencies were observed in CMV-seropositive recipients harboring persistent/nonreplicating CMV. The same effect was observed in T cells and CD56(+) T cells. These adaptive lymphocyte subsets were increased in CMV-seropositive recipients of sibling but not UCB grafts and were correlated with lower rates of CMV reactivation (sibling 33% versus UCB 51%; P < .01). These data suggest that persistent/nonreplicating recipient CMV induces rapid production of adaptive NK and T cells from mature cells from sibling but not UCB grafts. These adaptive lymphocytes are associated with protection from CMV reactivation.

Circulating angiogenic factors associated with response and survival in patients with acute graft-versus-host disease: results from Blood and Marrow Transplant Clinical Trials Network 0302 and 0802

Circulating angiogenic factors (AF) reflect tissue healing capacity, although some AF can also contribute to inflammation and are indicative of endothelial dysfunction. The AF milieu in acute graft-versus-host disease (aGVHD) has not been broadly characterized. We hypothesized that patients with abundant AF involved in repair/regeneration versus those mediating damage/inflammation would have improved outcomes. Circulating AF known predominantly for repair/regeneration (epidermal growth factor [EGF], fibroblast growth factor-1 and -2, heparin binding-EGF-like growth factor, and vascular endothelial growth factor-A [VEGF-A], -C, and -D) and for damage/inflammation (angiopoietin-2, endothelin-1, soluble endoglin [sEng], follistatin [FS], leptin, and placental growth factor [PlGF]) were measured in a discovery set of hematopoietic cell recipients with grade III and IV aGVHD and compared with controls, then validated in 2 aGVHD cohorts enrolled in Blood and Marrow Transplant Clinical Trials Network (BMT CTN) trials 0302 (n = 105, serum) and 0802 (n = 158, plasma) versus controls without aGVHD (n = 53, serum). Levels of EGF and VEGF-A were lower than in controls at the onset of aGVHD in both trials and higher with complete response to first-line aGVHD therapy in CTN 0802. FS and PlGF were elevated in aGVHD measured in either serum or plasma. At day 28 after initial aGVHD therapy, elevated FS was an independent negative prognostic factor for survival in both cohorts (hazard ratio, 9.3 in CTN 0302; 2.8 in CTN 0802). These data suggest that circulating AF are associated with clinical outcomes after aGVHD and, thus, may contribute to both pathogenesis and recovery.

A refined risk score for acute graft-versus-host disease that predicts response to initial therapy, survival, and transplant-related mortality

To develop a novel acute graft-versus-host disease (GVHD) risk score, we examined the GVHD clinical stage and grade of 1723 patients at the onset of treatment with systemic steroids. Using clinical grouping, descriptive statistics and recursive partitioning, we identified poorly responsive, high-risk (HR) acute GVHD by the number of involved organs and severity of GVHD at onset. The overall response (complete response/partial response) rate 28 days after initiation of steroid therapy for acute GVHD was lower in the 269 patients with HR-GVHD than in the 1454 patients with standard risk (SR)-GVHD (44% [95% confidence interval (CI) 38% to 50%] versus 68% [95% CI, 66% to 70%], P < .001). Patients with HR-GVHD were less likely to respond at day 28 (odds ratio [OR], .3; 95% CI, .2 to .4; P < .001) and had higher risks of mortality (relative risk, 2.1; 95% CI, 1.7 to 2.6; P < .001) and transplant-related mortality (relative risk, 2.5; 95% CI, 2.0% to 3.2%, P < .001) than patients with SR-GVHD. This refined definition of acute GVHD risk is a better predictor of response, survival, and transplant-related mortality than other published acute GVHD risk scores. Patients with HR-GVHD are candidates for studies investigating new treatment approaches. Likewise, patients with SR-GVHD are candidates for studies investigating less toxic therapy.

The Past, Present, and Future of NK Cells in Hematopoietic Cell Transplantation and Adoptive Transfer

Hematopoietic cell transplantation (HCT) has been used as a part of cancer therapy for over half a decade. Beyond the necessity for donor-derived cells to reconstitute hematopoiesis after radiation and chemotherapy, immunologic reconstitution from allogeneic cells is important for the elimination of residual tumor cells. Natural killer (NK) cells are first among lymphocytes to reconstitute post-transplant and protect against cancer relapse. In this review, we provide a historical perspective on the role of NK cells in cancer control in the transplant setting and focus on current research aimed at improving NK cell responses for therapeutic benefit.

A prognostic score for acute graft-versus-host disease based on biomarkers: a multicentre study

BACKGROUND

Graft-versus-host disease (GVHD) is the major cause of non-relapse mortality after allogeneic haemopoietic stem-cell transplantation (SCT). The severity of symptoms at the onset of GVHD does not accurately define risk, and thus most patients are treated alike with high dose systemic corticosteroids. We aimed to define clinically meaningful risk strata for patients with newly diagnosed acute GVHD using plasma biomarkers.

METHODS

Between April 13, 2000, and May 7, 2013, we prospectively collected plasma from 492 SCT patients with newly diagnosed acute GVHD and randomly assigned (2:1) using a random number generator, conditional on the final two datasets having the same median day of onset, into training (n=328) and test (n=164) sets. We used the concentrations of three recently validated biomarkers (TNFR1, ST2, and Reg3α) to create an algorithm that computed the probability of non-relapse mortality 6 months after GVHD onset for individual patients in the training set alone. We rank ordered the probabilities and identified thresholds that created three distinct non-relapse mortality scores. We evaluated the algorithm in the test set, and again in an independent validation set of an additional 300 patients who underwent stem cell transplant and were enrolled on multicentre clinical trials of primary therapy for acute GVHD.

FINDINGS

In all three datasets (training, test, and validation), the cumulative incidence of 6-month non-relapse mortality significantly increased as the Ann Arbor GVHD score increased. In the multicentre validation set, scores were 8% (95% CI 3-16) for score 1, 27% (20-34) for score 2, and 46% (33-58) for score 3 (p<0·0001). Conversely, the response to primary GVHD treatment within 28 days decreased as the GVHD score increased 86% for score 1, 67% for score 2, and 46% for score 3 in the multicentre validation set, p<0·0001).

INTERPRETATION

Biomarker-based scores can be used to guide risk-adapted therapy at the onset of acute GVHD. High risk patients with a score of 3 are candidates for intensive primary therapy, while low risk patients with a score of 1 are candidates for rapid tapers of systemic steroid therapy.

FUNDING

The National Cancer Institute, the National Heart, Lung, and Blood Institute, the National Institute of Allergy and Infectious Diseases, the Doris Duke Charitable Fund, the American Cancer Society, and the Judith Devries Fund.

Comparison of outcomes of allogeneic transplantation for chronic myeloid leukemia with cyclophosphamide in combination with intravenous busulfan, oral busulfan, or total body irradiation

Cyclophosphamide (Cy) in combination with busulfan (Bu) or total body irradiation (TBI) is the most commonly used myeloablative conditioning regimen in patients with chronic myeloid leukemia (CML). We used data from the Center for International Bone Marrow Transplantation Research to compare outcomes in adults who underwent hematopoietic cell transplantation for CML in first chronic phase after myeloablative conditioning with Cy in combination with TBI, oral Bu, or intravenous (i.v.) Bu. Four hundred thirty-eight adults received human leukocyte antigen (HLA)-matched sibling grafts and 235 received well-matched grafts from unrelated donors (URD) from 2000 through 2006. Important differences existed between the groups in distribution of donor relation, exposure to tyrosine kinase inhibitors, and year of transplantation. In multivariate analysis, relapse occurred less frequently among patients receiving i.v. Bu compared with TBI (relative risk [RR], .36; P = .022) or oral Bu (RR, .39; P = .028), but nonrelapse mortality and survival were similar. A significant interaction was detected between donor relation and the main effect in leukemia-free survival (LFS). Among recipients of HLA-identical sibling grafts, but not URD grafts, LFS was better in patients receiving i.v. Bu (RR, .53; P = .025) or oral Bu (RR, .64; P = .017) compared with TBI. In CML in first chronic phase, Cy in combination with i.v. Bu was associated with less relapse than TBI or oral Bu. LFS was better after i.v. or oral Bu compared with TBI.

Survival of patients with acute myeloid leukemia relapsing after allogeneic hematopoietic cell transplantation: a center for international blood and marrow transplant research study

Acute myeloid leukemia (AML) relapse after allogeneic hematopoietic cell transplantation (alloHCT) remains a major therapeutic challenge. We studied outcomes of 1788 AML patients relapsing after alloHCT (1990 to 2010) during first or second complete remission (CR) to identify factors associated with longer postrelapse survival. Median time to post-HCT relapse was 7 months (range, 1 to 177). At relapse, 1231 patients (69%) received intensive therapy, including chemotherapy alone (n = 660), donor lymphocyte infusion (DLI) ± chemotherapy (n = 202), or second alloHCT ± chemotherapy ± DLI (n = 369), with subsequent CR rates of 29%. Median follow-up after relapse was 39 months (range, <1 to 193). Survival for all patients was 23% at 1 year after relapse; however, 3-year overall survival correlated with time from HCT to relapse (4% for relapse during the 1- to 6-month period, 12% during the 6-month to 2-year period, 26% during the 2- to 3-year period, and 38% for ≥3 years). In multivariable analysis, lower mortality was significantly associated with longer time from alloHCT to relapse (relative risk, .55 for 6 months to 2 years; relative risk, .39 for 2 to 3 years; and relative risk, .28 for ≥3 years; P < .0001) and a first HCT using reduced-intensity conditioning (relative risk, .77; 95% confidence interval [CI], .66 to .88; P = .0002). In contrast, inferior survival was associated with age >40 years (relative risk, 1.42; 95% CI, 1.24 to 1.64; P < .0001), active graft-versus-host disease at relapse (relative risk, 1.25; 95% CI, 1.13 to 1.39; P < .0001), adverse cytogenetics (relative risk, 1.37; 95% CI, 1.09 to 1.71; P = .0062), mismatched unrelated donor (relative risk, 1.61; 95% CI, 1.22 to 2.13; P = .0008), and use of cord blood for first HCT (relative risk, 1.23; 95% CI, 1.06 to 1.42; P = .0078). AML relapse after alloHCT predicted poor survival; however, patients who relapsed ≥6 months after their initial alloHCT had better survival and may benefit from intensive therapy, such as second alloHCT ± DLI.

Allogeneic hematopoietic cell transplantation outcomes in acute myeloid leukemia: similar outcomes regardless of donor type

The use of alternative donor transplants is increasing as the transplantation-eligible population ages and sibling donors are less available. We evaluated the impact of donor source on transplantation outcomes for adults with acute myeloid leukemia undergoing myeloablative (MA) or reduced-intensity conditioning (RIC) transplantation. Between January 2000 and December 2010, 414 consecutive adult patients with acute myeloid leukemia in remission received MA or RIC allogeneic transplantation from either a matched related donor (n = 187), unrelated donor (n = 76), or umbilical cord blood donor (n = 151) at the University of Minnesota or Hôpital St. Louis in Paris. We noted similar 6-year overall survival across donor types: matched related donor, 47% (95% confidence interval [CI], 39% to 54%); umbilical cord blood, 36% (95% CI, 28% to 44%); matched unrelated donor, 54% (95% CI, 40% to 66%); and mismatched unrelated donor, 51% (95% CI, 28% to 70%) (P < .11). Survival differed based on conditioning intensity and age, with 6-year survival of 57% (95% CI, 47% to 65%), 39% (95% CI, 28% to 49%), 23% (95% CI, 6% to 47%), 47% (95% CI, 36% to 57%), and 28% (95% CI, 17% to 41%) for MA age 18 to 39, MA age 40+, or RIC ages 18 to 39, 40 to 56, and 57 to 74, respectively (P < .01). Relapse was increased with RIC and lowest in younger patients receiving MA conditioning (hazard ratio, 1.0 versus 2.5 or above for all RIC age cohorts), P < .01. Transplantation-related mortality was similar across donor types. In summary, our data support the use of alternative donors as a graft source with MA or RIC for patients with acute myeloid leukemia when a sibling donor is unavailable.

Increasing incidence of chronic graft-versus-host disease in allogeneic transplantation: a report from the Center for International Blood and Marrow Transplant Research

Although transplant practices have changed over the last decades, no information is available on trends in incidence and outcome of chronic graft-versus-host disease (cGVHD) over time. This study used the central database of the Center for International Blood and Marrow Transplant Research (CIBMTR) to describe time trends for cGVHD incidence, nonrelapse mortality, and risk factors for cGVHD. The 12-year period was divided into 3 intervals, 1995 to 1999, 2000 to 2003, and 2004 to 2007, and included 26,563 patients with acute leukemia, chronic myeloid leukemia, and myelodysplastic syndrome. Multivariate analysis showed an increased incidence of cGVHD in more recent years (odds ratio = 1.19, P < .0001), and this trend was still seen when adjusting for donor type, graft type, or conditioning intensity. In patients with cGVHD, nonrelapse mortality has decreased over time, but at 5 years there were no significant differences among different time periods. Risk factors for cGVHD were in line with previous studies. This is the first comprehensive characterization of the trends in cGVHD incidence and underscores the mounting need for addressing this major late complication of transplantation in future research.

Multi-institutional feasibility study of a fast patient localization method in total marrow irradiation with helical tomotherapy: a global health initiative by the international consortium of total marrow irradiation

PURPOSE

To develop, characterize, and implement a fast patient localization method for total marrow irradiation.

METHODS AND MATERIALS

Topographic images were acquired using megavoltage computed tomography (MVCT) detector data by delivering static orthogonal beams while the couch traversed through the gantry. Geometric and detector response corrections were performed to generate a megavoltage topogram (MVtopo). We also generated kilovoltage topograms (kVtopo) from the projection data of 3-dimensional CT images to reproduce the same geometry as helical tomotherapy. The MVtopo imaging dose and the optimal image acquisition parameters were investigated. A multi-institutional phantom study was performed to verify the image registration uncertainty. Forty-five MVtopo images were acquired and analyzed with in-house image registration software.

RESULTS

The smallest jaw size (front and backup jaws of 0) provided the best image contrast and longitudinal resolution. Couch velocity did not affect the image quality or geometric accuracy. The MVtopo dose was less than the MVCT dose. The image registration uncertainty from the multi-institutional study was within 2.8 mm. In patient localization, the differences in calculated couch shift between the registration with MVtopo-kVtopo and MVCT-kVCT images in lateral, cranial-caudal, and vertical directions were 2.2 ± 1.7 mm, 2.6 ± 1.4 mm, and 2.7 ± 1.1 mm, respectively. The imaging time in MVtopo acquisition at the couch speed of 3 cm/s was <1 minute, compared with ≥15 minutes in MVCT for all patients.

CONCLUSION

Whole-body MVtopo imaging could be an effective alternative to time-consuming MVCT for total marrow irradiation patient localization.

Impact of Chronic Graft-versus-Host Disease on Late Relapse and Survival on 7,489 Patients after Myeloablative Allogeneic Hematopoietic Cell Transplantation for Leukemia

PURPOSE

Malignancy relapse remains a major obstacle for successful allogeneic hematopoietic cell transplantation (HCT). Chronic graft-versus-host disease (cGVHD) is associated with fewer relapses. However, when studying effects of cGVHD on relapse, it is difficult to separate from acute GVHD effects as most cases of cGVHD occur within the first year after transplant at the time when acute GVHD is still active.

EXPERIMENTAL DESIGN

This study based on CIBMTR registry data investigated cGVHD and its association with the incidence of late relapse and survival in 7,489 patients with acute myelogenous leukemia (AML), acute lymphoblastic leukemia (ALL), chronic myelogenous leukemia (CML), and myelodysplastic syndromes (MDS), who were leukemia free at 12 months after myeloablative allogeneic HCT.

RESULTS

Forty-seven percent of the study population was diagnosed with cGVHD at 12 months after transplant. The protective effect of cGVHD on late relapse was present only in patients with CML [RR, 0.47; 95% confidence interval (CI), 0.37-0.59; P < 0.0001). cGVHD was significantly associated with higher risk of treatment-related mortality (TRM; RR, 2.43; 95% CI, 2.09-2.82; P < 0.0001) and inferior overall survival (RR, 1.56; 95% CI, 1.41-1.73; P < 0.0001) for all diseases. In patients with CML, all organ sites and presentation types of cGVHD were equally associated with lower risk of late relapse.

CONCLUSIONS

These results indicate that clinically relevant antileukemia effects of cGVHD on late relapses are present only in CML but not in AML, ALL, or MDS. Chronic GVHD in patients who are 1-year survivors after myeloablative allogeneic HCT is primarily associated with higher TRM and inferior survival.

Association of severity of organ involvement with mortality and recurrent malignancy in patients with chronic graft-versus-host disease

The National Institutes of Health global score for chronic graft-versus-host disease was devised by experts but was not based on empirical data. We hypothesized that analysis of prospectively collected data would enable derivation of a more accurate model for estimating mortality risk. We analyzed 574 adult patients with chronic graft-versus-host disease enrolled in a multicenter, observational study, using multivariate time-varying analysis accounting for serial changes in severity of involvement of eight individual organ sites over time. In the training set, severity of skin, mouth, gastrointestinal tract, liver and lung involvement were independently associated with the risk of non-relapse mortality. Weighted mortality points were assigned to individual organs based on the hazard ratios and were summed. The population was divided into three risk groups based on the total mortality points. The three new risk groups were validated in an independent validation set, but did not show better discriminative performance than the National Institutes of Health global score. As compared to a moderate or mild global score, a severe global score was associated with increased risks of non-relapse and overall mortality across time but not with a decreased risk of recurrent malignancy. The National Institutes of Health global score predicts patients' mortality risk throughout the course of their chronic graft-versus-host disease. Further research is required in order to improve outcomes in patients with severe chronic graft-versus-host disease, since their risk of mortality remains elevated.

Donor killer cell Ig-like receptor B haplotypes, recipient HLA-C1, and HLA-C mismatch enhance the clinical benefit of unrelated transplantation for acute myelogenous leukemia

Killer cell Ig-like receptors (KIRs) interact with HLA class I ligands to regulate NK cell development and function. These interactions affect the outcome of unrelated donor hematopoietic cell transplantation (HCT). We have shown previously that donors with KIR B versus KIR A haplotypes improve the clinical outcome for patients with acute myelogenous leukemia by reducing the incidence of leukemic relapse and improving leukemia-free survival (LFS). Both centromeric and telomeric KIR B genes contribute to the effect, but the centromeric genes are dominant. They include the genes encoding inhibitory KIRs that are specific for the C1 and C2 epitopes of HLA-C. We used an expanded cohort of 1532 T cell-replete transplants to examine the interaction between donor KIR B genes and recipient class I HLA KIR ligands. The relapse protection associated with donor KIR B is enhanced in recipients who have one or two C1-bearing HLA-C allotypes, compared with C2 homozygous recipients, with no effect due to donor HLA. The protective interaction between donors with two or more, versus none or one, KIR B motifs and recipient C1 was specific to transplants with class I mismatch at HLA-C (RR of leukemia-free survival, 0.57 [0.40-0.79]; p = 0.001) irrespective of the KIR ligand mismatch status of the transplant. The survival advantage and relapse protection in C1/x recipients compared with C2/C2 recipients was similar irrespective of the particular donor KIR B genes. Understanding the interactions between donor KIR and recipient HLA class I can be used to inform donor selection to improve outcome of unrelated donor hematopoietic cell transplantation for acute myelogenous leukemia.

Autologous is superior to allogeneic hematopoietic cell transplantation for acute promyelocytic leukemia in second complete remission

To identify favored choice of transplantation in patients with acute promyelocytic leukemia (APL) in second complete remission, we studied 294 patients with APL in second complete remission (CR2) receiving allogeneic (n = 232) or autologous (n = 62) hematopoietic cell transplantation (HCT) reported to the Center for International Blood and Marrow Transplantation Research (CIBMTR) from 1995 to 2006, including 155 with pre-HCT PML/RAR∝ status (49% of allogeneic and 66% of autologous). Patient characteristics and transplantation characteristics, including treatment-related mortality, overall survival (OS), and disease-free survival, were collected and analyzed for both univariate and multivariate outcomes. With median follow-up of 115 (allogeneic) and 72 months (autologous), 5-year disease-free survival (DFS) favored autologous with 63% (49% to 75%), compared with allogeneic at 50% (44% to 57%) (P = .10). OS was 75% (63% to 85%) versus 54% (48% to 61%) (P = .002), for autologous and allogeneic transplantation, respectively. Multivariate analysis showed significantly worse DFS after allogeneic HCT (hazard ratio [HR], 1.88; 95% confidence interval [CI], 1.16 to 3.06; P = .011) and age > 40 years (HR, 2.30; 95% CI, 1.44 to 3.67; P = .0005). OS was significantly worse after allogeneic HCT (HR, 2.66; 95% CI, 1.52 to 4.65; P= .0006); age > 40 (HR, 3.29; 95% CI, 1.95 to 5.54; P < .001), and first complete remission < 12 months (HR, 1.56; 95% CI, 1.07 to 2.26; P = .021). Positive pre-HCT PML-RAR∝ status in 17 of 114 allogeneic and 6 of 41 receiving autologous transplantation did not influence relapse, treatment failure, or survival in either group. The survival advantage for autografting was attributable to increased treatment-related mortality (TRM) in the allogeneic group of 30% compared to 2% in the autologous group, in addition to the added mortality associated with GVHD. We conclude that autologous HCT yields superior OS for APL in CR2. Long-term DFS in autologous recipients, even with minimal residual disease-positive grafts, remains an important subject for further study.