Infections after Allogenic Transplant with Post-Transplant Cyclophosphamide: Impact of Donor HLA Matching

Incidence and outcome of infections after allogeneic hematopoietic stem cell transplantation (HSCT) with post-transplant cyclophosphamide (PT-Cy) as graft-versus-host disease (GVHD) prophylaxis are largely unknown. Study aims were to estimate the incidence of pre-engraftment bloodstream infections (PE-BSIs) and viral infections (VIs; cytomegalovirus [CMV], adenovirus [ADV], human herpes virus 6 [HHV6], and BK-polyomavirus hemorrhagic-cystitis [BKPyV-HC]), their predictive factors, and infection-related mortality (IRM) after HSCT with PT-Cy. We analyzed 235 patients: 62%, 21%, and 17% received haploidentical (haplo), matched-unrelated donor (MUD), and matched-related donor, respectively. Overall, 72 patients had 77 PE-BSI episodes at a median time of 13 days after HSCT: cumulative incidence function (CIF) at 28 days was 32%, without differences among donor types (P = .988). By multivariate analysis, CIF of PE-BSI was higher in patients with severe neutropenia before HSCT (adjusted hazard ratio [AHR] = 2.90) and in multidrug-resistant Gram-negative bacteria rectal carriers (AHR = 2.68). IRM at 30 days was 5%, without differences by donor type (P = .106). Overall, 208 patients experienced ≥1 VIs (first occurrence among CMV, HHV6, ADV, BKPyV-HC) at a median time of 20 days after HSCT: CIF at 90 days was 91%, significantly higher in MUD and haplo (P = .0089). By multivariate analysis, also acute GVHD grade ≥2 (AHR = 1.32) and host/donor CMV-serology mismatch (positive/positive versus negative/negative: AHR = 2.95, positive/negative versus negative/negative: AHR = 2.41, negative/positive versus negative/negative: AHR = 2.35) affected VIs occurrence. IRM at 180 days was 8%, without differences among donor types (P = .106). In conclusion, study results did not show a significant impact of donor type on PE-BSI incidence; conversely, MUD and haploidentical transplants retained a higher occurrence of VIs in the early phase after HSCT.     

A Modified Intensive Strategy to Prevent Cytomegalovirus Disease in Seropositive Umbilical Cord Blood Transplantation Recipients

We previously demonstrated a lower rate of cytomegalovirus (CMV) reactivation and disease among seropositive umbilical cord blood transplantation (CBT) recipients receiving an intensive prophylaxis strategy consisting of ganciclovir on days ?8 to ?2 pretransplantation, high-dose valacyclovir post-transplantation, and twice-weekly serum CMV polymerase chain reaction testing. We hypothesized that a modified intensive strategy excluding pretransplantation ganciclovir would be similarly effective. We compared the risk of CMV reactivation, occurrence of CMV disease, and duration of anti-CMV therapy by day 100 post-CBT in patients receiving the modified intensive and intensive strategies. Forty patients received the modified intensive strategy, and 43 received the intensive strategy. There was no difference in the hazard for CMV reactivation (hazard ratio, 1.1; P?=?.77). No patients in the modified intensive cohort, but 2 patients in the intensive cohort, developed CMV disease (P?=?.53). There was no difference in the hazard for early (≤30 days post-CBT; P?=?.76) or high-level (>1000?IU/mL; P?=?.37) CMV reactivation. Patients in the modified intensive cohort had marginally higher CMV viral loads and percentage of days of CMV detection and treatment, although the contribution of pretransplantation ganciclovir to these differences is unclear. The overall percentage of treatment days was 32% in both cohorts after accounting for pretransplantation ganciclovir. In conclusion, exclusion of prophylactic ganciclovir before CBT did not impact the risk of CMV reactivation or disease, although CMV kinetics appeared to differ by prevention strategy. Best practices for CMV prevention will need further study as new prophylactic strategies become available.     

Impact of Cytomegalovirus Replication and Cytomegalovirus Serostatus on the Outcome of Patients with B Cell Lymphoma after Allogeneic Stem Cell Transplantation

Cytomegalovirus (CMV) replication after allogeneic hematopoietic stem cell transplantation (HSCT) was historically associated with increased nonrelapse mortality (NRM). More recently, different groups have reported an association between CMV replication and reduced risk of acute myeloid leukemia (AML) relapse. Given the conflicting results, we evaluated the impact of CMV replication and other covariates on the outcome of a retrospective cohort of 265 adults with B cell lymphoma receiving allogeneic HSCT from HLA-identical siblings or alternative donors. In time-dependent multivariate analysis, CMV replication, evaluated by pp65 antigenemia, had no independent effect on the risk of relapse (hazard ratio [HR], 1.0; 95% confidence interval [CI], .6 to 1.6; P = .9), although it was associated with a reduced overall survival (HR, 2.0; 95% CI, 1.3 to 3.2; P = .001) and an increased NRM (HR, 2.5; 95% CI, 1.1 to 5.3; P = .01). Consistently, donor and/or recipient CMV seropositivity were not associated with a different outcome relative to CMV double-negative serostatus. In multivariate models, a diagnosis of follicular lymphoma (P < .0001) and pretransplantation complete remission status (P < .0001) were the main independent predictors for improved relapse-free survival. In summary, contrary to what is observed in patients with AML, this report identifies no independent role for CMV replication or serostatus on the relapse of patients with B cell lymphomas undergoing allogeneic HSCT.     

Early Cytomegalovirus Reactivation Leaves a Specific and Dynamic Imprint on the Reconstituting T Cell Compartment Long-Term after Hematopoietic Stem Cell Transplantation

Human cytomegalovirus (CMV) reactivation frequently occurs during the early phase of immune recovery after allogeneic hematopoietic stem cell transplantation (HSCT). Whereas the recovery of virus-specific immunity in the early phase after HSCT is extensively studied, the impact of CMV on the reconstitution and composition of the T cell compartment long-term after HSCT is unknown. We analyzed T cell reconstitution 1 to 2 years after HSCT in 131 pediatric patients. One year after HSCT, patients with early CMV reactivation (n = 46) had 3-fold higher CD8⁺ T cell numbers (median, 1323 versus 424 cells/μL; P < .0001) compared with patients without CMV reactivation (n = 85). This effect, caused by a major expansion of CD8⁺ effector memory (EM) and end-stage effector (EMRA) T cells, was independent of pretransplantation donor and recipient CMV serostatus and not seen after Epstein-Barr virus or adenovirus reactivations. At 1 and 2 years after HSCT, the absolute numbers of CD8⁺ naive and central memory T cells, as well as CD4⁺ naive, CM, EM, and EMRA T cells, did not differ between patients with or without CMV reactivation. In the second year after HSCT, a significant contraction of the initially expanded CD8⁺ EM and EMRA T cell compartments was observed in patients with early CMV reactivation. In conclusion, CMV reactivation early after pediatric HSCT leaves a specific and dynamic imprint on the size and composition of the CD8⁺ T cell compartment without compromising the reconstitution of CD8⁺ and CD4⁺ naive and central memory T cells pivotal in the response to neo and recall antigens.     

Favorable Effect of Cytomegalovirus Reactivation on Outcomes in Cord Blood Transplant and Its Differences Among Disease Risk or Type

The effects of cytomegalovirus (CMV) reactivation on cord blood transplant (CBT) are unclear. We assessed the effect of CMV reactivation in adult single-unit CBT without in vivo T cell depletion. Of 3147 eligible cases, 2052 were acute myeloid leukemia (AML), 643 acute lymphoblastic leukemia (ALL), and 452 myelodysplastic syndrome (MDS). CMV reactivation up to 100 days after CBT was associated with better overall survival (OS) compared with no reactivation cases (57.3% versus 52.6% at 3 years after CBT), whereas nonrelapse mortality (NRM) was increased in ALL (16.2% versus 8.9%) and standard disease risk (17.1% versus 10.6%, P = .014) by CMV reactivation. On multivariate analysis, CMV reactivation had favorable effects on relapse in MDS (hazard ratio [HR], .55; P = .044) and high disease risk (HR, .77; P = .047). In NRM, only standard-risk cases showed adverse effects of CMV reactivation (HR, 1.56; P = .026). OS was significantly improved with CMV reactivation in a subgroup of patients with AML (HR, .84; P = .044), MDS (HR, .68; P = .048), and high disease risk (HR, .81; P = .013). This favorable effect of CMV reactivation on OS in AML and high disease risk cases was maintained even after considering the effect of grades II to IV acute graft-versus-host disease. Thus, CMV reactivation might have beneficial or adverse effects on relapse, NRM, and OS, depending on the disease type or disease risk.     

Unrelated Donor Transplant Recipients Given Thymoglobuline Have Superior GRFS When Compared to Matched Related Donor Recipients Undergoing Transplantation without ATG

Recipients of allogeneic hematopoietic stem cell transplantation (HSCT) from unrelated donors (URDs) and mismatched related donors (MMRDs) typically have a higher incidence of acute and chronic graft-versus-host disease (GVHD) compared with matched related donors (MRDs). Anti-T-cell globulins (ATGs) are often used to reduce GVHD in these recipients. We report the outcomes of 211 adult peripheral blood stem cell transplant recipients with myeloid malignancies who received a standardized transplant protocol, in which ATG (Thymoglobuline 4.5 mg/kg) was administered to recipients of URD and MMRD (n = 147) but not MRD (n = 64) transplant. For all patients, incidence of acute GVHD grades 2 to 4 was 21.4%, and chronic GVHD was 35.0%. Two-year overall survival was 63.2% (95% confidence interval, 55.8% to 71.5%), relapse-free survival was 55.3% (47.4% to 64.6%), and GVHD-free, relapse-free survival (GRFS) was 30.7% (23.2% to 40.8%). There were no differences between recipients of MRDs and other donors in relapse, nonrelapse mortality, and overall and relapse-free survival. However, compared with MRD, recipients from URDs and MMRDs had reduced moderate to severe chronic GVHD (10.4% versus 30.1%, P= .002), less chronic GVHD requiring systemic therapy (19.4% versus 38.9%, P = .006), and superior 2-year GRFS (35.5% versus 20.0%, P = .003). In this retrospective review of nonrandomized transplant groups, outcomes of HSCT performed using an URD with ATG during conditioning were superior to transplant from an MRD without ATG. The addition of Thymoglobuline to conditioning in HSCT from MRD should be further examined in prospective trials.     

Synergistic Effect of Major Histocompatibility Complex Class I–Related Chain A and Human Leukocyte Antigen–DPB1 Mismatches in Association with Acute Graft-versus-Host Disease after Unrelated Donor Hematopoietic Stem Cell Transplantation

The clinical relevance of mismatches at the MHC class I–related chain A (MICA) in hematopoietic stem cell transplantation (HSCT) remains unclear. We investigated the association of MICA donor/recipient mismatch and whether there is an interaction between these and HLA-DPB1 mismatch on clinical outcomes after unrelated donor HSCT. Our study included 227 patients who underwent unrelated donor allogeneic HSCT at our institution between 2000 and 2010. Among these, 177 (78%) received HSCT from a 10/10 HLA-matched donor. MICA genotyping was performed using commercially available kits. In univariable analysis, the risk of grade II to IV acute graft-versus-host disease (GVHD) was greater for patients with MICA mismatch (hazard ratio [HR], 1.73; P = .02) than for those with HLA-DPB1 mismatch (HR, 1.62; P = .07). When MICA and HLA-DPB1 were assessed simultaneously, patients mismatched at both loci had the greatest risk (HR, 2.51; P < .01) and those mismatched at only 1 locus had somewhat greater risk (HR, 1.53; P = .12) than patients matched at both loci; this remained significant in multivariable analysis. The 100-day incidence was 66%, 45%, and 31%, respectively (P = .03). Results were similar for grade III and IV acute GVHD, with 100-day incidence 34%, 16%, and 8% (P = .01). These results are clinically pertinent to donor selection strategies and indicate that patients with mismatch at both MICA and HLA-DPB1 are at increased risk for acute GVHD.     

The Complex Relationship between Human Herpesvirus 6 and Acute Graft-versus-Host Disease

The most frequent manifestation of human herpesvirus 6 (HHV-6) reactivation after allogeneic hematopoietic stem cell transplantation (HSCT) is febrile rash, raising the question of its relationship with graft-versus-host disease (GVHD). In this retrospective analysis of 365 patients who underwent allogeneic HSCT, HHV-6 reactivation was significantly associated with cord blood transplantation (hazard ratio [HR], 3.20; P < .0001) and the use of unrelated donors (HR, 2.02; P = .008). On multivariate analysis, previous GVHD was a predictive factor for HHV-6 reactivation (HR, 1.80; P = .01), and previous HHV-6 reactivation was a predictive factor for acute GVHD (HR, 1.66; P = .03). Nineteen patients with no pathological evidence of GVHD later developed severe clinical GVHD (grade III-IV), suggesting the role of HHV-6 as a trigger for severe GVHD. Furthermore, 17 patients without histopathological GVHD demonstrated a significant lymphoid infiltrate suggesting “pure” HHV-6–related manifestations, and these patients could have been spared steroid therapy.     

Differences in Graft-versus-Host Disease Characteristics between Haploidentical Transplantation Using Post-Transplantation Cyclophosphamide and Matched Unrelated Donor Transplantation Using Calcineurin Inhibitors

We assessed differences in presentation and response to therapy in 394 consecutive patients who developed acute or chronic graft-versus-host disease (GVHD) after receiving their first allogeneic transplantation (HSCT) from a 10/10 HLA allele-matched unrelated donor (MUD; n = 179) using calcineurin inhibitors or a T cell-replete haploidentical donor (haplo; n = 215) and post-transplantation cyclophosphamide at our center between 2005 and 2017. The median duration of follow-up for survivors was 52.5 months. The cumulative incidences for grade II-IV and grade III-IV acute GVHD at day 180 post HCT were similar, at 39% and 14%, respectively, for haplo-HSCT compared with 50% and 16% for MUD HSCT (P not significant). Haplo-HSCT recipients had a lower cumulative incidence of moderate to severe chronic GVHD, at 22% (severe, 19%), compared with 31% (severe, 29%) for MUD HSCT recipients (P = .026). The time to onset of moderate to severe chronic GVHD was faster for haplo-HSCT recipients (213 days versus 280 days; P = .011). Among patients with grade II-IV acute GVHD, there was no significant between-group difference in organ involvement, with skin the most affected (75% for haplo-HSCT versus 70% for MUD HSCT), followed by the gastrointestinal tract (71% versus 69%) and liver (14% versus 17% MUD). For chronic GVHD, haplo-HSCT recipients had less involvement of the eyes (46% versus 75% for MUD; P < .001) and of the joints/fascia (12% versus 36%; P = .001). Also for cGVHD patients, haplo-HSCT recipients and MUD HSCT recipients had similar all-cause mortality (22% versus 18%; P = .89), but the former were more likely to be off immunosuppression at 2 years post-HCT (63% versus 43%; P = .03) compared with MUD.     

Risk factors for cytomegalovirus DNAemia following haploidentical stem cell transplantation and its association with host hepatitis B virus serostatus

BackgroundThe risk factors associated with CMV DNAemia are not well known after haploidentical stem cell transplantation (SCT).ObjectivesThis study investigated the risk factors and prognosis for CMV DNAemia among CMV seromatched donors and recipients (D+/R+).Study designA retrospective study of patients undergoing haploidentical stem cell transplantation (SCT) between January 2010 and January 2012 was conducted. Cox regression analysis was performed to identify the risk factors for CMV DNAemia. These possible factors included recipient/donor age, recipient/donor gender, gender disparity, recipient HBsAg serostatus, diagnosis, risk stratification, anti-thymocyte globulin (ATG) dose (6 mg/kg,10 mg/kg), early neutrophil engraftment (≤12 days, >12 days), absolute lymphocyte count on day 30 (ALC30) and the occurrence of acute GVHD before CMV DNAemia.ResultsThe total number of patients was 248 with median age of 31 years (range, 14–56). The cumulative incidence of CMV DNAemia (146/248) was 59.5%. CMV DNAemia was first detected after a median of +35 days (range,12–82). Seventeen patients (17/146, 11.6%) developed CMV disease. Multivariate analysis identified HBsAg seropositivity (P = 0.002, hazard ratio (HR) = 1.833; 95%CI = 1.257–2.673) and the occurrence of acute GVHD before CMV DNAemia (P = 0.014; HR = 1.520; 95%CI = 1.088–2.124) as risk factors for CMV DNAemia. CMV DNAemia was associated with subsequent II-IV acute graft-versus-host disease (GVHD) (P = 0.014), III-IV aGVHD (P = 0.013) and chronic GVHD (P = 0.008). Totally, CMV DNAemia was found to be a poor prognostic factor in terms of non-relapse mortality (NRM) (P = 0.003, HR = 2.730; 95%CI = 1.406–5.197), and overall survival (OS) (P = 0.045, HR = 1.654; 95%CI = 1.012–2.701).ConclusionsOur data showed HBsAg seropositivity was associated with an increased risk of cytomegalovirus DNAemia. Detection of CMV DNAemia proved to be a poor prognostic factor for haploidentical patients.     

Cord Haploidentical Non-In Vitro T Cell Depletion Allogeneic Hematopoietic Stem Cell Transplantation Reduces Relapse of Refractory Acute Leukemia

Whether a graft-versus-graft (GVG) response in patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT) is associated with an enhanced graft-versus-leukemia (GVL) effect remains highly controversial. Furthermore, it is unknown if the GVG response overwhelms the impact of refractory acute leukemia. We aimed to compare the characteristics and therapeutic outcomes between patients undergoing a modified haploidentical cord blood (cord-haplo) HSCT protocol (n?=?97) and those undergoing haploidentical HSCT (n?=?42) for refractory acute leukemia. A reliable and stable predominant haploidentical donor chimerism was established. The 2-year relapse rate was more favorable in patients undergoing cord-haplo HSCT than in those undergoing haploidentical HSCT (25.9% versus 53.2%; P = .007), as was progression-free survival (PFS; 35.5% versus 17.9%; P = .049). Meanwhile, nonrelapse mortality at 2 years was not significantly different (38.0% versus 24.6%; P = .367). We also found that a higher number of mutual haploidentical donor-mismatched antigens, a concept similar to HLA mismatching, was associated with better disease control. Multivariate analysis identified cord-haplo HSCT as an independent significant predictor of reduced relapse (hazard ratio [HR], .44; P = .028) and improved PFS (HR, .58; P = .033), as was chronic graft-versus-host disease (GVHD) (relapse: HR, .42; P ?= .013; PFS: HR, .63: P = .052). However, the incidences of neutrophil and platelet engraftment, GVHD, and virus reactivation were comparable in the 2 groups. This study demonstrates that cord-haplo HSCT significantly enhances the GVL effect and improves PFS, providing a reliable and efficient therapeutic platform for patients with refractory acute leukemia.     

Superior Survival of Unmanipulated Haploidentical Hematopoietic Stem Cell Transplantation Compared with Chemotherapy Alone Used as Post-Remission Therapy in Adults with Standard-Risk Acute Lymphoblastic Leukemia in First Complete Remission

We wanted to compare the efficacy of haploidentical hematopoietic stem cell transplantation (HSCT) with chemotherapy alone in adults with standard-risk acute lymphoblastic leukemia (ALL) in first complete remission (CR1). One hundred thirty-eight consecutive adult patients with standard-risk ALL in CR1 were retrospectively investigated. Of these patients, 59 received chemotherapy alone (group A) and 79 received unmanipulated haploidentical HSCT (group B). Cumulative incidence of relapse at 5 years in group A was significantly higher than that in group B (66.3% versus 29.9%, P < .0001). Overall and disease-free survival in group A were significantly inferior to group B (P < .0001). Moreover, multivariate analyses demonstrated that central nervous system leukemia (P = .002), T cell immunophenotype (P = .044), expression of E2A-PBX1 (P = .007), and positive minimal residual disease after the first cycle of consolidation (P = .004) were correlated with relapse. Patients with 1 of 4 risk factors were assigned to the high-risk group. Otherwise, patients without risk factors were assigned to the low-risk group. In the high-risk group, HSCT had lower relapse rates and superior DFS compared with chemotherapy (P < .05), but in the low-risk group, there were no differences between HSCT and chemotherapy (P > .05). This study is the first to demonstrate that compared with chemotherapy alone, haploidentical HSCT is a better postremission therapy in adults with standard-risk ALL in CR1. Moreover, based on the 4 risk factors, the establishment of risk stratification could identify the subgroup of patients with a higher risk of relapse in adults with standard-risk ALL in CR1. Furthermore, risk stratification–directed postremission therapies using haploidentical HSCT or chemotherapy alone not only reduce relapse rate but also avoid unnecessary treatment-related mortality and improve survival.     

Impact of CD34 Cell Dose and Conditioning Regimen on Outcomes after Haploidentical Donor Hematopoietic Stem Cell Transplantation with Post-Transplantation Cyclophosphamide for Relapsed/Refractory Severe Aplastic Anemia

Severe aplastic anemia (SAA) is a life-threatening disease that can be cured with allogeneic cell transplantation (HCT). Haploidentical donor transplantation with post-transplantation cyclophosphamide (haplo-PTCy) is an option for patients lacking an HLA-matched donor. We analyzed 87 patients who underwent haplo-PTCy between 2010 and 2019. The median patient age was 14 years (range, 1 to 69 years), most were heavily transfused, and all received previous immunosuppression (25% without antithymocyte globulin). Almost two-thirds (63%) received standard fludarabine (Flu)/cyclophosphamide (Cy) 29/total body irradiation (TBI) 200 cGy conditioning, and the remaining patients received an augmented conditioning: Flu/Cy29/TBI 300-400 (16%), Flu/Cy50/TBI 200 (10%), or Flu/Cy50/TBI 400 (10%). All patients received PTCy-based graft-versus-host disease (GVHD) prophylaxis. Most grafts (93%) were bone marrow (BM). The median duration of follow-up was 2 years and 2 months. The median time to neutrophil recovery was 17 days. Primary graft failure occurred in 15% of the patients, and secondary or poor graft function occurred in 5%. The incidences of grade II-IV acute GVHD was 14%, and that of chronic GVHD was 9%. Two-year overall survival and event-free survival (EFS) were 79% and 70%, respectively. EFS was higher for patients who received augmented Flu/Cy/TBI (hazard ratio [HR], .28; P = .02), and those who received higher BM CD34 cell doses (>3.2 × 10E6/kg) (HR, .29; P = .004). The presence of donor-specific antibodies before HSCT was associated with lower EFS (HR, 3.92; P = .01). Graft failure (HR, 7.20; P < .0001) was associated with an elevated risk of death. Cytomegalovirus reactivation was frequent (62%). Haploidentical HCT for SAA is a feasible procedure; outcomes are improved with augmented conditioning regimens and BM grafts with higher CD34 cell doses.     

Comparative Study of Mizoribine and Mycophenolate Mofetil Combined with a Calcineurin Inhibitor-Based Immunosuppressive Regimen in Patients with Alternative Donor Hematopoietic Cell Transplantation

Cytomegalovirus (CMV) infection and graft-versus-host disease (GVHD) remain the major causes of nonrelapse mortality (NRM) in patients following alternative donor hematopoietic stem cell transplantation (HCT). Mizoribine (MZR) showed an anti-CMV effect in addition to its immunosuppressive effect in patients with renal transplantation. In this study, we aimed to evaluate the efficacy and safety of MZR combined with a calcineurin inhibitor (CNI) as a method of prophylactic immunosuppression in recipients following alternative donor HCT. Eighty patients were enrolled in the study and randomized to the MZR (n = 40) or MMF (n = 40) cohort before transplantation conditioning. Analyses involved a comparison of the outcomes between the 2 cohorts, as well as risk analyses of early nonrelapse mortality (NRM) and severe CMV infection. In contrast to MMF, MZR was associated with a lower but statistically nonsignificant median CMV DNA peak load (P = .075), significantly fewer episodes of persistent/refractory infection (odds ratio [OR], .12), and a lower failure rate of CMV treatment (OR, .82), but a significantly higher rate of hyperuricemia (OR, 2.75). Transplantation efficacy was comparable in the 2 cohorts regarding engraftment, the development of secondary poor graft function and GVHD, and the estimated OS and PFS. The 1-year NRM of the MZR cohort did not differ from that of the MMF cohort, whereas the rate of 1-year NRM caused by viral infections was reduced in the MZR cohort and was of borderline statistical significance (P = .05). In the multivariate analysis, lower doses of CD34⁺ cells in grafts (hazard ratio [HR], 3.65) and persistent/refractory CMV infections (versus no CMV infection: HR, 7.31; versus CMV infection that was not persistent/refractory: HR, 4.46) were predictors of increased 1-year NRM. The use of MMF (versus MZR cohort: OR, 11.54) and grade II-IV acute GVHD (OR, 15.32) were independent risk factors for developing persistent/refractory CMV infection. When combined with CNIs, MZR functioned well in terms of both immunosuppression and reduced severity of CMV infection; however, further studies are warranted to verify its use as a potential immunosuppressant for alternative donor HCT.     

Impact of Pretransplantation Risk Factors on Post Transplantation Outcome of Patients with Acute Myeloid Leukemia in Remission after Haploidentical Hematopoietic Stem Cell Transplantation

The impact of risk-related parameters has not been defined in transplantation settings. We wondered whether the currently recognized predictors could be used to categorize acute myeloid leukemia (AML) patients who underwent transplantation during remission into risk groups. We analyzed the data of 255 consecutive patients (median age, 26) with AML in their first or second remission (CR1 or CR2) after haploidentical hematopoietic stem cell transplantation (HSCT). Three parameters were found to be predictive of outcome: response after induction therapy, white blood cell count at diagnosis, and cytogenetics. These three factors were combined to yield two risk groups. The 2-year cumulative incidences of relapse for patients at low and high risk were 8% and 36% (P = .001), respectively. The 3-year probabilities of leukemia-free survival for these two groups were 80% and 52% (P = .001), respectively. Multivariate analysis for relapse and for leukemia-free survival showed that not achieving CR after two courses of therapy was the strongest independent prognostic factor (P = .001 and P = .028, respectively). In addition, in a subgroup of patients with quantification of minimal residual disease at the time of HSCT, positive minimal residual disease at this time point was correlated with a poor outcome. Our results suggest that the pretransplantation risk factors influence posttransplantation outcomes of patients with AML in CR after haploidentical HSCT and might be applicable to assist with risk-directed posttransplantation therapy.     

Alternative Donor Transplantation for Older Patients with Acute Myeloid Leukemia in First Complete Remission: A Center for International Blood and Marrow Transplant Research-Eurocord Analysis

We studied patients with acute myeloid leukemia (AML) over age 50 and in first complete remission (CR1) after adult unrelated donor (URD) (n = 441, 8/8 HLA matched; n = 94, 7/8 HLA matched) or umbilical cord blood (UCB; n = 205) transplantations. UCB recipients achieved CR1 within 8 weeks less often, and received reduced-intensity conditioning and cyclosporine-based graft-versus-host disease (GVHD) prophylaxis more often. Neutrophil recovery was slower in UCB (69% by day 28) compared with 8/8 HLA-matched URD (97%) and 7/8 HLA-matched (91%) (P < .001) recipients. Three-year transplantation-related mortality (TRM) was higher and leukemia-free survival (LFS) lower with UCB (35% and 28%, respectively) versus 8/8 HLA-matched URD (27% and 39%, respectively). TRM was higher in 7/8 HLA-matched URD (41%, P = .01), but LFS was similar at 34% (P = .39). Three-year chronic GVHD was the lowest in UCB (28%) versus 53% and 59% in 8/8 and 7/8 HLA-matched URD recipients, respectively. Three-year survival was 43% in 8/8 HLA-matched URD (95% confidence interval [CI], 38% to 48%), 30% in UCB (95% CI, 23% to 37%) (P = .002) and 37% in 7/8 URD (95% CI, 27 to 46). Allotransplantation for AML in CR1 with any of these grafts extends LFS for over one third of older patients. In the absence of an 8/8 HLA-matched URD or when transplantation is needed urgently, UCB can provide extended survival. Less frequent chronic GVHD with UCB transplantation may be of particular value for older patients.     

Comparable Outcomes of First-Line Hematopoietic Stem Cell Transplantation from Unrelated and Matched Sibling Donors in Adult Patients with Aplastic Anemia: A Retrospective Single-Center Study

To explore the feasibility of upfront unrelated donor (URD) hematopoietic stem cell transplantation (HSCT) in the treatment of adult aplastic anemia (AA), we conducted a retrospective, single-center study and compared the outcomes of adult patients who underwent first-line URD HSCT or matched sibling donor (MSD) HSCT between August 2012 and June 2018. In all, 23 URD HSCT recipients had an increased cumulative incidence of grade II acute graft-versus-host disease (aGVHD) (21.7% versus 3.4%; P =.007), but similar rates of secondary graft failure (8.7 ± 6.0% versus 6.9 ± 3.4%; P = .764), chronic GVHD (cGVHD) (18.2% versus 8.8%; P = .285), extensive cGVHD (9.1% versus 3.5%; P = .328), 5-year estimated overall survival (87.0% versus 94.2%; P = .501), and 5-year estimated failure-free survival (82.0% versus 89.3%; P = .404) compared with 58 MSD HSCT recipients treated during the same period. After using propensity score matching to reduce the influence of potential confounders, the 2 groups were well balanced in terms of pretransplantation clinical factors. The median survival time was similar, and no significant differences in the aforementioned outcomes were observed between the 2 groups. Our results suggest that URD HSCT may be an effective and feasible option for first-line therapy in adult AA patients who lack an MSD.     

Phase I Study of Urate Oxidase in the Reduction of Acute Graft-Versus-Host Disease after Myeloablative Allogeneic Stem Cell Transplantation

Graft-versus-host disease (GVHD) is a donor T cell driven response against host tissue that can complicate allogeneic hematopoietic stem cell transplantation (HSCT). During acute GVHD, endogenous adjuvants such as uric acid are released by damaged host tissue, activating alloreactive donor T cells. A phase I study was conducted at the Massachusetts General Hospital between 2007 and 2010 to test the hypothesis that reduction of uric acid levels during allogeneic HSCT can modulate the development of acute GVHD. Twenty-one patients with hematologic malignancies in complete remission undergoing myeloablative peripheral blood HSCT received recombinant urate oxidase at .20 mg/kg for 5 consecutive days during conditioning. Results were compared with all patients who underwent allogeneic HSCT at our institution during the same time period who met the same inclusion and exclusion criteria but were not enrolled in the study. The only major adverse event was a case of hemolytic anemia in a patient who had glucose-6-phosphate dehydrogenase deficiency. Primary outcome was the cumulative incidence of grades II to IV acute GVHD, which was significantly decreased in the treatment group in the intention-to-treat analysis (57% [12/21] versus 24% [5/21], P = .036) and in the per-protocol analysis (P = .017). Patients who developed acute GVHD had a higher level of serum uric acid during the pretransplantation period compared with those who did not (P < .001). There was no difference in disease-free or overall survival. Our study suggests that urate oxidase can be safely administered during myeloablative conditioning and may reduce the incidence of acute GVHD.     

Comparison of Characteristics of Bacterial Bloodstream Infection between Adult Patients with Allogeneic and Autologous Hematopoietic Stem Cell Transplantation

Although autologous and allogeneic hematopoietic stem cell transplantation (HSCT) are fundamentally different procedures, a tailored approach to bacterial bloodstream infection (BSI) according to the type of HSCT has not yet been suggested. We evaluated the characteristics of BSI after HSCT, with a focus on comparison of BSIs between recipients of autologous HSCT (auto-HSCT) and allogeneic HSCT (allo-HSCT). Among 134 patients (59 received allo-HSCT and 75 received auto-HSCT) who underwent HSCT, BSIs were reported earlier in patients who underwent auto-HSCT, compared with those who underwent allo-HSCT (mean 12.1 ± 3.4 days versus 32.8 ± 27.1 days, P = .006). Among patients receiving allo-HSCT, postneutrophil-engraftment bacterial BSI showed an association with grade ≥2 acute graft-versus-host disease (GVHD). In patients who underwent auto-HSCT, results of multivariate analysis showed that not receiving prophylactic antibiotics (P = .004) and having elevated serum C-reactive protein (P = .034) were risk factors of BSI. Elevated CRP (P = .01) and acute GVHD ≥ grade 2 (P = .002) were independent risk factors in patients who underwent allo-HSCT. Those differences originated mainly from the impact of acute GVHD-related postengraftment BSIs of patients who underwent allo-HSCT. To establish the best defense strategy against BSI, the distinctive natures of bacterial BSI after HSCT between auto-HSCT and allo-HSCT should be considered.