Impact of haploidentical hematopoietic cell transplantation conditioning intensity on the incidence and severity of post-transplantation viral infections

Severity and organ distribution of chronic graft-versus-host disease with posttransplant cyclophosphamide-based versus methotrexate/calcineurin inhibitor-based allogeneic hematopoietic cell transplantation

The reduced risk of chronic graft-versus-host-disease (GVHD) with posttransplant cyclophosphamide (ptCy) in the setting of haploidentical related donor and more recently, with HLA-matched related and matched and mismatched unrelated donor allogeneic transplantation has been established. There is, however, paucity of data to show if ptCy impacts chronic GVHD pathogenesis, its phenotype and evolution after HCT regardless of the donor status. We examined the differences in chronic GVHD incidence and presentation in 314 consecutive patients after receiving their first allogeneic transplantation (HCT) using ptCy-based GVHD prophylaxis (ptCy-HCT; n = 120; including 95 with haploidentical related donor) versus conventional calcineurin inhibitor-based prophylaxis (CNI-MUD; n = 194) between 2012 and 2019. The 1-year cumulative incidence of all-grade chronic GVHD and moderate/severe chronic GVHD was 24% and 12%, respectively, after ptCy-HCT and 40% and 23% in the CNI-MUD recipients (p = 0.0003 and 0.007). Multivariable analysis confirmed that use of CNI-based GVHD prophylaxis and peripheral blood stem cell graft as the risk factors for chronic GVHD. The cumulative incidence of visceral (involving ≥1 of the following organs: liver, lungs, gastrointestinal tract, serous membranes) chronic GVHD was significantly higher with CNI-MUD vs. ptCy-HCT (27% vs. 15% at 1 year, p = 0.009). The incidence of moderate/severe visceral chronic GVHD was 20% in CNI-MUD group vs. 7.7% in the ptCy-HCT group at 1 year (p = 0.002). In addition, significantly fewer ptCy-HCT recipients developed severe chronic GVHD in ≥3 organs (0.8%) vs. 8.8% in the CNI-MUD group at 1-year posttransplant (p = 0.004). There was no significant different in relapse, non-relapse mortality, and relapse-free and overall survival between the two groups. Further investigation is needed to confirm that reduced risk and severity of chronic GVHD, less visceral organ distribution with ptCy-HCT leads to improved quality of life.

Impact of cytomegalovirus immunodominant HLA-I donor-recipient matching on the incidence and features of virus DNAemia and virus-specific T-cell immune reconstitution in unmanipulated haploidentical hematopoietic stem cell transplantation

BACKGROUND

We investigated whether donor-recipient mismatch involving one or more cytomegalovirus (CMV) immunodominant (ID) human leukocyte antigen (HLA)-I alleles may impact on the degree of CMV pp65/immediate-early 1 (IE-1) T-cell reconstitution and the incidence of CMV DNAemia in patients undergoing unmanipulated haploidentical hematopoietic stem cell transplantation with high-dose posttransplant cyclophosphamide (PT/Cy-haplo).

METHODS

Multicenter observational study including 106 consecutive adult PT/Cy-haplo patients (34 CMV ID HLA-I matched and 72 mismatched). A real-time PCR was used for plasma CMV DNA load monitoring. Enumeration of CMV-specific (pp65/IE-1) interferon (IFN)-γ-producing T cells from several patients was performed by flow cytometry by days +30, +60, +90 and +180 after transplantation.

RESULTS

The cumulative incidence of CMV DNAemia, clinically significant CMV DNAemia episodes (cs-CMVi), and recurrent CMV DNAemia was comparable across CMV ID HLA-I matched and mismatched patients (71.8% vs. 80.9%, p = .95; 40.7% vs. 44.2%, p = .85; 16.4% vs. 28.1%; p = .43, respectively). The percentage of patients exhibiting detectable CMV-specific IFN-γ-producing T-cell responses (either CD8⁺ or CD4⁺ ) was similar across groups; nevertheless, significantly higher CMV-specific CD8⁺ T-cell counts were enumerated in the CMV ID HLA-I matched compared to mismatched patients by day +60 (p = .04) and +180 (p = .016) after transplantation.

CONCLUSION

CMV ID HLA-I matching may impact on the magnitude of CMV-pp65/IE-1-specific CD8⁺ T-cell reconstitution; yet, this effect seemed not to have an impact on the incidence of initial, recurrent CMV DNAemia, or cs-CMVi.

Features of Epstein–Barr Virus and Cytomegalovirus Reactivation in Acute Leukemia Patients After Haplo-HCT With Myeloablative ATG-Containing Conditioning Regimen

Background

Haploidentical donor hematopoietic cell transplantation (haplo-HCT) has become a preferred option for patients without HLA-matched donors, but it increases the risk of viral reactivations. Epstein–Barr virus (EBV) and cytomegalovirus (CMV) are common viruses post-HCT, but limited data have been reported in the setting of haplo-HCT.

Methods

We conducted a retrospective study enrolling acute leukemia patients who received haplo-HCT with myeloablative conditioning regimen employing ATG in our center from July 2014 to July 2017. All the patients enrolled were EBV-IgM and EBV-DNA negative but EBV-IgG positive, and so were their donors. The same went for CMV as well.

Results

In total, 602 patients were recruited consisting of 331 with acute myeloid leukemia (AML) and 271 with acute lymphoblastic leukemia (ALL). One-year cumulative incidences of EBV (22.9% ± 2.4% vs. 27.4% ± 2.8%, P = 0.169) and CMV (24.7% ± 2.4% vs. 29.4% ± 2.8%, P = 0.190) reactivation were comparable between AML and ALL. EBV and CMV were independent risk factors for each other. In the AML group, male recipients [HR = 1.275, 95% CI (1.001–1.624), P = 0.049] and acute graft-versus-host disease [HR = 1.592, 95% CI (1.001–2.533), P = 0.049] were independent risk factors for EBV reactivation and CMV reactivation, respectively. CMV rather than EBV reactivation was related to a trend of worsened treatment-related mortality (TRM) (15.6% ± 0.1% vs. 10.2% ± 0.0%, P = 0.067) and progression-free survival (PFS) (60.6% ± 4.1% vs. 70.3% ± 2.3%, P = 0.073), while significant impacts were revealed only in the subgroup analysis. CMV reactivation resulted in a remarkable inferior 2-year overall survival (OS) (64.2% ± 5.7% vs. 77.6% ± 3.2%, P = 0.038) and PFS (55.0% ± 5.9% vs. 71.9% ± 3.4%, P = 0.042) in ALL patients. On the other hand, in the EBV+/CMV− subgroup, relapse was lower in ALL patients (8.2% ± 0.2% vs. 32.4% ± 0.8%, P = 0.010) compared with AML patients, which led to a superior 2-year OS (82.0% ± 6.2% vs. 60.3% ± 8.8%, P = 0.016) and PFS (74.5% ± 7.0% vs. 57.5% ± 8.4%, P = 0.036).

Conclusion

We concluded that EBV and CMV reactivations were frequent in acute leukemia patients after haplo-HCT, with possibly distinctive risk factors from HLA-matched HCT. There could be a potential interaction between EBV and CMV, but impacts on transplant outcomes remained complex.

Is Haploidentical Hematopoietic Cell Transplantation Using Post-Transplantation Cyclophosphamide Feasible in Sub-Saharan Africa?

Identifying a suitable volunteer unrelated donor (UD) in South Africa is challenging due to the highly diverse ethnic groups and mixed-race populations in this region. Haploidentical hematopoietic cell transplantation (haploHCT) is thus an attractive procedure for patients with high-risk hematologic malignancies. This study was conducted to assess the safety and feasibility of haploHCT in South Africa. We retrospectively analyzed the outcome of 134 patients with hematologic malignancies who received unmanipulated haploHCT with post-transplantation cyclophosphamide at 2 high-volume HCT centers between 2014 and 2019. We assessed overall survival (OS), disease-free survival (DFS), nonrelapse mortality (NRM), relapse incidence (RI), and incidence of acute GVHD. The median recipient age was 44 years (range, 15 to 73 years) and the median donor age was 36 years (range, 9 to 68 years). Acute myelogenous leukemia or myelodysplastic syndrome (AML/MDS) and acute lymphoblastic leukemia (ALL) were the most common indications for haploHCT (61.2%). The European Society for Blood and Marrow Transplantation risk score was ≥5 in 44 patients (32.8%). Seventy-seven patients (57.4%) received a myeloablative conditioning regimen. The majority of patients received a sex-matched transplant (57.4%) and had peripheral blood stem cells (PBSCs) as the stem cell source (70.9%). Sixteen patients (11.9%) had an incongruent cytomegalovirus serostatus at transplantation. The median duration of follow-up was 10.8 months (range, 0.36 to 70.8 months). OS was 56% (95% confidence interval [CI], 47% to 64%) at 1 year and 37% (95% CI, 28% to 47%) at 3 years. DFS was 47% (95% CI, 38% to 55%) at 1 year and 32% (95% CI, 24% to 41%) at 3 years. The 100-day and 3-year cumulative incidence of NRM was 18% (95% CI, 11% to 25%) and 41% (95% CI, 32% to 50%), respectively, and the 1- and 3-year cumulative RI was 16% (95% CI, 11% to 24%) and 21% (95% CI, 14% to 29%), respectively. The 1-year OS was 55% (95% CI, 40% to 67%) for the patients with AML/MDS versus 41% (95% CI, 21% to 60%) for those with ALL. Forty-five patients (41.7%) developed acute GVHD by day +100; of these, 80% had grade I-II disease. Fifty patients (37.5%) developed cytomegalovirus infection that required therapy. On multivariable analysis, older donor age was an independent risk factor for lower DFS. RI was higher for diagnoses other than acute leukemia/MDS (relative risk [RR], 2.62; 95% CI, 1.12 to 6.15; P = .027), decreased for PBSC versus bone marrow (RR, 0.43; 95% CI, 0.19 to 0.95; P = .038) and decreased for offspring donors (RR, 0.25; 95% CI, 0.09 to 0.67; P = .006). These data support the feasibility of haploHCT and suggest that unmanipulated haploHCT using a younger parent or offspring donor is a viable option for adults in sub-Saharan Africa with acute leukemia and MDS who lack a suitable related or unrelated donor.

CMV Infection and CMV-Specific Immune Reconstitution Following Haploidentical Stem Cell Transplantation: An Update

Haploidentical stem cell transplantation (haploSCT) has advanced to a common procedure for treating patients with hematological malignancies and immunodeficiency diseases. However, cure is seriously hampered by cytomegalovirus (CMV) infections and delayed immune reconstitution for the majority of haploidentical transplant recipients compared to HLA-matched stem cell transplantation. Three major approaches, including in vivo T-cell depletion (TCD) using antithymocyte globulin for haploSCT (in vivo TCD-haploSCT), ex vivo TCD using CD34 + positive selection for haploSCT (ex vivo TCD-haploSCT), and T-cell replete haploSCT using posttransplant cyclophosphamide (PTCy-haploSCT), are currently used worldwide. We provide an update on CMV infection and CMV-specific immune recovery in this fast-evolving field. The progress made in cellular immunotherapy of CMV infection after haploSCT is also addressed. Groundwork has been prepared for the creation of personalized avenues to enhance immune reconstitution and decrease the incidence of CMV infection after haploSCT.

American Society for Transplantation and Cellular Therapy Series: #3-Prevention of Cytomegalovirus Infection and Disease After Hematopoietic Cell Transplantation

The Practice Guidelines Committee of the American Society for Transplantation and Cellular Therapy partnered with its Transplant Infectious Disease Special Interest Group to update its 2009 compendium-style infectious diseases guidelines for the care of hematopoietic cell transplant (HCT) recipients. A new approach was taken with the goal of better serving clinical providers by publishing each standalone topic in the infectious disease series as a concise format of frequently asked questions (FAQ), tables, and figures. Adult and pediatric infectious disease and HCT content experts developed and answered FAQs. Topics were finalized with harmonized recommendations that were made by assigning an A through E strength of recommendation paired with a level of supporting evidence graded I through III. The third topic in the series focuses on the prevention of cytomegalovirus infection and disease in HCT recipients by reviewing prophylaxis and preemptive therapy approaches; key definitions, relevant risk factors, and diagnostic monitoring considerations are also reviewed.

Clinical impact of multiple DNA virus infections in nondepleted haploidentical and unrelated allogeneic hematopoietic stem cell transplantation

Few studies have compared the clinical impact of multiple DNA-virus infections in haploidentical hematopoietic stem cell transplantation (haplo-HSCT) with posttransplant cyclophosphamide (PTCy) and unrelated donor allogeneic hematopoietic stem cell transplantation (UD-HSCT) with thymoglobulin, so we retrospectively analyzed viral infections in the first 6 mo posttransplant in these scenarios. Fifty-nine patients underwent to haplo-HSCT, and 68 to UD-HSCT. The most frequent infection was cytomegalovirus (CMV) (76.3% in haplo-HSCT and 69.1% in UD-HSCT) (P = .878) and in the group of patients with CMV reactivation, maximal CMV viral load over 2500 UI/ml correlated with worse overall survival-hazard ratio (HR) 1.93 (95% confidence interval [CI] 1.04-3.59) P = .03. The cumulative incidence of multiple DNA virus within 180 d of posttransplant was 78.7% for one virus and 28.4% for two or more viruses with no difference regarding the type of transplant. Viral infections, age, and acute graft versus host disease (GVHD) grades II-IV were risk factors for worse overall survival in multivariate analyses: one virus HR 2.53 (95% CI 1.03-6.17) P = .04, two or more viruses HR 3.51 (95% CI 1.37-9) P < .01, age HR 1.03 (95% CI 1.02-1.05) P < .01 and acute GVHD II-IV HR 1.97 (95% CI 1.13-3.43) P = .01. Also, age over 50 y HR 4.25 (95% CI 2.01-8.97) P < .001, second CMV reactivation or having both CMV and BK polyomavirus (BKV) HR 2.65 (95% CI 1.26-5.56) P = .01 and acute GVHD grades II-IV HR 2.23 (95% CI 1.12-4.43) P = .022 were risk factors for nonrelapse mortality in the multivariate analyses. In conclusion, multiple DNA-virus infections are frequent in both haplo-HSCT and UD-HSCT and a risk factor for worse overall survival.

Reconstitution of cytomegalovirus-specific T-cell immunity following unmanipulated haploidentical allogeneic hematopoietic stem cell transplantation with posttransplant cyclophosphamide

Cytomegalovirus (CMV) DNAemia and CMV disease have been reported as more frequent in patients undergoing haploidentical allogeneic hematopoietic stem cell transplantation (Haplo-HSCT) than in those receiving HLA-matched allografts. This could be due to impaired CMV-specific T-cell reconstitution. Here, we conducted a multicenter observational study to assess CMV pp65 and IE-1-specific T cells kinetics in patients undergoing unmanipulated Haplo-HSCT with posttransplant cyclophosphamide (PT/Cy-haplo) and compared it with patients allografted with HLA-matched donors. Plasma CMV DNA load was monitored by real-time PCR and enumeration of CMV-specific IFN-γ-producing CD8⁺ and CD4⁺ T cells was performed by flow cytometry for intracellular cytokine staining at days +30, +60, +90, and +180 after transplantation. CMV DNAemia developed in 62 patients, occurring with comparable frequency in PT/Cy-haplo and MRD/MUD recipients (P = 0.14). There were no significant differences across groups in the number of patients either displaying detectable CMV-specific CD8⁺ and CD4⁺ T-cell responses or acquiring CMV-specific T-cell levels conferring protection against subsequent infection. CMV-specific T-cell counts were comparable between groups at most time points examined, irrespective of whether CMV DNAemia occurred or not prior to monitoring. Collectively the data suggest that PT/Cy-haplo recipients may reconstitute CMV-specific T-cell immunity to the same extent as patients undergoing HLA-matched allo-HSCT.

Incidence, features, and outcomes of cytomegalovirus DNAemia in unmanipulated haploidentical allogeneic hematopoietic stem cell transplantation with post-transplantation cyclophosphamide

BACKGROUND

Conflicting data have been published as to the risk of cytomegalovirus (CMV) DNAemia and CMV disease in patients undergoing haploidentical hematopoietic stem cell transplantation (haplo-HSCT) with post-transplantation cyclophosphamide.

METHODS

We conducted a multicenter retrospective study including 118 patients subjected to unmanipulated haplo-HSCT to further clarify this issue. An historic cohort comprising 165 patients undergoing other transplant modalities (HLA-matched related, matched unrelated or mismatched) was built for comparison purposes. Plasma CMV DNA monitoring was performed using two highly sensitive real-time PCR assays.

RESULTS

Overall, the cumulative incidence of CMV DNAemia, recurrent CMV DNAemia, and CMV DNAemia requiring preemptive antiviral therapy in patients undergoing haplo-HSCT was 63.9%, 34.9%, and 50.1%, respectively. These figures were rather comparable for other transplant modalities (P = .22, P = .13 and P = .72, respectively). A trend toward longer duration of episodes and shorter CMV DNA doubling times was observed in haplo-HSCT patients in comparison with other transplant modalities. Furthermore, median CMV DNA peak load was significantly higher in haplo-HSCTs (P = .008), yet overall mortality by day 180 and 365 was the same across comparison groups. There were five cases of CMV disease, and all occurred in haplo-HSCT patients. This latter observation is worrying and merits further investigation.

CONCLUSIONS

The incidence of initial and recurrent episodes of CMV DNAemia either requiring or not antiviral therapy in unmanipulated haplo-HSCT was comparable to other transplant modalities in our cohort.

Guidelines for the management of cytomegalovirus infection in patients with haematological malignancies and after stem cell transplantation from the 2017 European Conference on Infections in Leukaemia (ECIL 7)

Cytomegalovirus is one of the most important infections to occur after allogeneic haematopoietic stem cell transplantation (HSCT), and an increasing number of reports indicate that cytomegalovirus is also a potentially important pathogen in patients treated with recently introduced drugs for hematological malignancies. Expert recommendations have been produced by the 2017 European Conference on Infections in Leukaemia (ECIL 7) after a review of the literature on the diagnosis and management of cytomegalovirus in patients after HSCT and in patients receiving other types of therapy for haematological malignancies. These recommendations cover diagnosis, preventive strategies such as prophylaxis and pre-emptive therapy, and management of cytomegalovirus disease. Antiviral drugs including maribavir and letermovir are in development and prospective clinical trials have recently been completed. However, management of patients with resistant or refractory cytomegalovirus infection or cytomegalovirus disease is a challenge. In this Review we summarise the reviewed literature and the recommendations of the ECIL 7 for management of cytomegalovirus in patients with haematological malignancies.

Comparison of Graft Acquisition and Early Direct Charges of Haploidentical Related Donor Transplantation versus Umbilical Cord Blood Transplantation

Alternative donor allogeneic hematopoietic cell transplants (HCTs), such as double umbilical cord blood transplants (dUCBT) and haploidentical related donor transplants (haplo-HCT), have been shown to be safe and effective in adult patients who do not have an HLA-identical sibling or unrelated donor available. Most transplant centers have committed to 1 of the 2 alternative donor sources, even with a lack of published randomized data directly comparing outcomes and comparative data on the cost-effectiveness of dUCBT versus haplo-HCT. We conducted a retrospective study to evaluate and compare the early costs and charges of haplo-HCT and dUCBT in the first 100 days at 2 US transplant centers. Forty-nine recipients of haplo-HCT (at 1 center) and 37 with dUCBT (at another center) were included in the analysis. We compared graft acquisition, inpatient/outpatient, and total charges in the first 100 days. The results of the analysis showed a significantly lower cost of graft acquisition and lower total charges (for 100-day HCT survivors) in favor of haplo-HCT. Importantly, to control for the obvious shortcomings of comparing costs at 2 different transplant centers, adjustments were made based on the current (2018) local wage index and inflation rate. In the absence of further guidance from a prospective study, the cost analysis in this study suggests that haplo-HCT may result in early cost savings over dUCBT and may be preferred by transplant centers and for patients with more limited resources.