Haploidentical allogeneic hematopoietic stem cell transplantation increases the risk of cytomegalovirus infection in adult patients with acute leukemia

Haploidentical and matched unrelated donor allogeneic hematopoietic stem cell transplantation offer similar survival outcomes for acute leukemia

BACKGROUND

Haploidentical hematopoietic stem cell transplantation (haplo-HSCT) has emerged as an effective approach for acute leukemia, primarily due to the inherent difficulty in finding human leukocyte antigen-matched unrelated donors (MUD). Nevertheless, it remains uncertain whether haplo-HSCT and MUD-HSCT can provide comparable outcomes in patients with acute leukemia.

AIMS

This study aimed to assess the overall survival (OS) and leukemia-free survival (LFS) outcomes between the MUD-HSCT and haplo-HSCT groups.

METHODS AND RESULTS

This retrospective analysis encompassed adult patients with acute leukemia undergoing the initial allo-HSCT. Among these 85 patients, we stratified 33 patients into the MUD-HSCT group and 52 to the haplo-HSCT group. The primary outcomes were OS and LFS. The median OS was not reached in the haplo-HSCT group, while it reached 29.8 months in patients undergoing MUD-HSCT (p = .211). Likewise, the median LFS periods were 52.6 months in the haplo-HSCT group and 12.7 months in the MUD-HSCT group (p = .212). Importantly, neither the OS nor LFS showed substantial differences between the MUD-HSCT and haplo-HSCT groups. Furthermore, univariate analyses revealed that haplo-HSCT did not demonstrate a significantly higher risk of worse LFS (hazard ratio [HR], 0.69; 95% confidence interval [CI], 0.38-1.25; p = .216) or OS (HR, 0.67; 95% CI, 0.36-1.26; p = .214) than MUD-HSCT. Notably, a high European Group for Blood and Marrow Transplantation risk score (HR, 1.44; 95% CI, 1.10-1.87; p = .007) and non-complete remission (HR, 2.48; 95% CI, 1.17-5.23; p = .017) were significantly correlated with worse OS.

CONCLUSION

Haplo-HSCT may serve as an alternative to MUD-HSCT for the treatment of acute leukemia, offering similar survival outcomes.

Ten-year epidemiology and risk factors of cytomegalovirus infection in hematopoietic stem cell transplantation patients in Taiwan

BACKGROUND

Cytomegalovirus (CMV) can cause infection and critical diseases in hematopoietic stem cell transplantation (HSCT) recipients. This study aimed to explore the cumulative incidence and risk factors for CMV infection and disease among HSCT recipients in Taiwan.

METHODS

This retrospective cohort study using the Taiwan Blood and Marrow Transplantation Registry (TBMTR) included HSCT recipients between 2009 and 2018 in Taiwan. The primary outcome was cumulative incidence of CMV infection or disease at day 100 after HSCT. Secondary outcomes included day 180 cumulative incidence of CMV infection or disease, infection sites, risk factors for CMV infection or disease, survival analysis, and overall survival after CMV infection and disease.

RESULTS

There were 4394 HSCT recipients included in the study (2044 auto-HSCT and 2350 allo-HSCT). The cumulative incidence of CMV infection and disease was significantly higher in allo-HSCT than in auto-HSCT patients at day 100 (53.7% vs. 6.0%, P < 0.0001 and 6.1% vs. 0.9%, P < 0.0001). Use of ATG (HR 1.819, p < 0.0001), recipient CMV serostatus positive (HR 2.631, p < 0.0001) and acute GVHD grades ≥ II (HR 1.563, p < 0.0001) were risk factors for CMV infection, while matched donor (HR 0.856, p = 0.0180) and myeloablative conditioning (MAC) (HR 0.674, p < 0.0001) were protective factors.

CONCLUSION

The study revealed a significant disparity in terms of the incidence, risk factors, and clinical outcomes of CMV infection and disease between auto and allo-HSCT patients. These findings underscore the importance of considering these factors in the management of HSCT recipients to improve outcomes related to CMV infections.

Refractory human cytomegalovirus infection without evidence of genetic resistance in the UL-54 and UL-97 genes in a pediatric hematopoietic stem cell transplant recipient: a case report

Cytomegalovirus (CMV) infection is a common complication in patients undergoing hematopoietic stem cell transplantation (HSCT). Management of refractory CMV infections, especially in developing countries, can be challenging due to the limited availability of second and third-line antiviral drugs or alternative treatments. Here, we present a case of an 8 years-old patient diagnosed with acute myeloid leukemia. Eight months post-diagnosis, the patient underwent TCR-αβ+/CD19+-depleted haploidentical HSCT. Both the donor and recipient tested positive for anti-CMV IgG and negative for IgM antibodies. Before transplantation, the patient received CMV prophylaxis in the form of intravenous ganciclovir. Post-transplantation, the patient exhibited oscillating CMV viral loads and was diagnosed with a refractory infection. Treatment with ganciclovir, foscarnet, and cidofovir was unsuccessful. Sequencing of UL-54 and UL-97 genes was performed to rule out potential resistance to first-line treatment. Ten months after the HSCT, the child died from hypovolemic shock due to gastrointestinal bleeding. This is the first case reported in Peru and Latin America of a refractory CMV infection in a pediatric HSCT recipient without evidence of clinical symptoms and CMV genetic resistance. This case demonstrates the need for alternative treatments to manage refractory CMV infections, especially in haploidentical HSCT cases where drug resistance is frequent (~15%). Furthermore, this case highlights the importance of using highly sensitive genetic tools to detect mutations associated with virus resistance in a broader range of the viral genome.

Does PTCY increase the risk of infections?

PTCY has been mainly used in haploidentical transplant (haploHSCT), but its use in matched donors allowed better evaluation of infectious risk conferred separately by PTCY or donor type. PTCY increased the risk of bacterial infections, both in haploidentical and matched donors, mainly pre-engraftment bacteremias. Bacterial infections, particularly due to multidrug-resistant Gram-negatives, were main causes of infection-related deaths. Higher rates of CMV and other viral infections were reported, mainly in haploHSCT. The role of donor might be more important than the role of PTCY. PTCY increased the risk of BK virus associated hemorrhagic cystitis, and seemed associated with higher risk of respiratory viral infections. Fungal infections were frequent in haploHSCT PCTY cohorts without mold active prophylaxis, but the exact role of PTCY needs to be established. Infections appear to be increased in patients receiving PTCY, although the exact role of GvHD prophylaxis and donor type can only be assessed in prospective trials.

[Efficacy and safety of allogeneic hematopoietic stem cell transplantation in the treatment of 28 patients with hepatitis-related aplastic anemia]

Objective: To evaluate the efficacy and safety of HLA-haploidentical hematopoietic stem cell transplantation (allo-HSCT) for hepatitis-related aplastic anemia (HRAA) patients. Methods: Retrospective analysis was performed on hepatitis-associated aplastic anemia patients who received haplo-HSCT at our center between January 2012 and June 2022. October 30, 2022 was the final date of follow-up. Results: This study included 28 HRAA patients receiving allo-HSCT, including 18 males (64.3% ) and 10 females (35.7% ), with a median age of 25.5 (9-44) years. About 17 cases of severe aplastic anemia (SAA), 10 cases of very severe aplastic anemia (VSAA), and 1 case of transfusion-dependent aplastic anemia (TD-NSAA) were identified. Among 28 patients, 15 patients received haplo-HSCT, and 13 received MSD-HSCT. The 2-year overall survival (OS) rate, the 2-year failure-free survival (FFS) rate, the 2-year transplant-related mortality (TRM) rate, the 100-day grade Ⅱ-Ⅳ acute graft-versus-host disease (aGVHD) cumulative incidence rate, and the 2-year chronic graft-versus-host disease (cGVHD) cumulative incidence rate were 81.4%, 81.4% (95% CI 10.5% -20.6% ), 14.6% (95% CI 5.7% -34.3% ), 25.0% (95% CI 12.8% -45.4% ), and 4.2% (95% CI 0.6% -25.4% ), respectively. After transplantation, all patients had no significant liver function damage. Compared with the MSD-HSCT group, only the incidence of cytomegaloviremia was significantly higher in the haplo-HSCT group [60.0% (95% CI 35.2% -84.8% ) vs 7.7% (95% CI 0-22.2% ), P=0.004]. No statistically significant difference in the Epstein-Barr virus was found in the 2-year OS, 2-year FFS, 2-year TRM, and 100-day grade Ⅱ-Ⅳ aGVHD cumulative incidence rates and 2-year cGVHD cumulative incidence rate. Conclusion: Allo-HSCT is safe and effective for HRAA, and haplo-HSCT can be used as a safe and effective alternative for newly diagnosed HRAA patients who cannot obtain HLA-matched sibling donors.

Epidemiology, treatment patterns, and disease burden of cytomegalovirus in hematopoietic cell transplant recipients in selected countries outside of Europe and North America: A systematic review

BACKGROUND

Cytomegalovirus (CMV) disease impacts morbidity and mortality in hematopoietic cell transplant (HCT) recipients. This systematic review summarized data on the epidemiology, management, and burden of CMV post-HCT outside of Europe and North America.

METHODS

The MEDLINE, Embase, and Cochrane databases were searched for observational studies and treatment guidelines in HCT recipients across 15 selected countries from Asia-Pacific, Latin America, and Middle East (search period: 1 January 2011-17 September 2021). Outcomes included incidence of CMV infection/disease, recurrence, risk factors, CMV-related mortality, treatments, refractory, resistant CMV, and burden.

RESULTS

Of 2708 references identified, 68 were eligible (67 studies and one guideline; 45/67 studies specific to adult allogeneic HCT recipients). The rates of CMV infection and disease within 1 year of allogeneic HCT were 24.9%-61.2% (23 studies) and 2.9%-15.7% (10 studies), respectively. Recurrence occurred in 19.8%-37.9% of cases (11 studies). Up to 10% of HCT recipients died of CMV-related causes. In all countries, first-line treatment for CMV infection/disease involved intravenous ganciclovir or valganciclovir. Conventional treatments were associated with serious adverse events such as myelosuppression (10.0%) or neutropenia only (30.0%, 39.8%) and nephrotoxicity (11.0%) (three studies), frequently leading to treatment discontinuation (up to 13.6%). Refractory CMV was reported in 2.9%, 13.0%, and 28.9% of treated patients (three studies) with resistant CMV diagnosed in 0%-10% of recipients (five studies). Patient-reported outcomes and economic data were scarce.

CONCLUSION

The incidence of CMV infection and disease post-HCT is high outside of North America and Europe. CMV resistance and toxicity highlight a major unmet need with current conventional treatments.

Total body irradiation-free haploidentical peripheral blood stem cell transplantation compared to related and unrelated donor transplantation in pediatrics with acute lymphoblastic leukemia

BACKGROUND

Acute lymphoblastic leukemia (ALL) is the most prevalent childhood cancer under the age of 15 years. Despite the recent advances in therapeutic regimens, relapse occurs in 15%-20% of pediatric patients after chemotherapy, and hematopoietic stem cell transplantation (HSCT) is the best treatment option. However, donor availability is one of the major challenges. Over the last decade, haploidentical donor (HID) transplantation has evolved as an alternative option. Herein, we aimed to compare the transplant outcomes in pediatric patients receiving total body irradiation (TBI)-free myeloablative regimens, between non-HID and HID transplant.

PATIENTS AND METHODS

The study included 60 pediatric ALL patients who had undergone HSCT from October 2016 until September 2020. Forty-three patients received non-HID HSCT, while 17 patients received HID. The sources of stem cells (SC) were peripheral blood stem cells (PBSC) for all the patients. The conditioning regimen was based on busulfan and cyclophosphamide. For graft-versus-host disease (GvHD) prophylaxis, patients received cyclosporine and methotrexate in the setting of non-HID transplantation, where HIDs received post-transplant cyclosporine and cyclophosphamide.

RESULTS

The cumulative incidences of 3-year overall survival (OS) were 73.1%, 66.6%, and 69.5%, for matched sibling donor-matched related donor (MSD-MRD), matched unrelated donor-mismatched unrelated donor (MUD-MMUD), and HID groups, respectively (p = .85). The cumulative incidences of grade II-IV acute GvHD for the MRD, MUD-MMUD, and HID groups were 29%, 41%, and 49%, respectively (p = .47). Furthermore, the 3-year cumulative incidence of chronic GvHD was MSD-MRD: 70% versus MUD-MMUD: 42% versus HID: 45% (p = .64). The 3-year cumulative incidence of relapse post transplantation was 45%, 18%, and 45%, respectively, for the MSD-MRD, MUD-MMUD, and HID groups, and the differences were not statistically significant (p = .55). There was a higher risk for cytomegalovirus (CMV) infection in patients receiving HID transplants compared to those of non-HIDs (p < .01).

CONCLUSION

Our results indicate that PBSC-HID transplant outcomes in the setting of non-TBI conditioning are comparable to those of non-HIDs in pediatric ALL patients.

Infection-related mortality after HLA-identical and haploidentical hematopoietic cell transplantation using reduced-intensity conditioning in an outpatient setting

BACKGROUND

Despite the improvements in supportive care for allogeneic-hematopoietic cell transplantation (allo-HCT) recipients, infectious complications and infection-related mortality (IRM) continue to be a major issue for transplantation centers.

METHODS

We herein report the infectious complications and IRM of 107 and 89 patients that underwent haploidentical (haplo-HCT) or HLA-identical HCT at a tertiary referral center during 2013-2020. Patients in the haplo-HCT group received post-transplant cyclophosphamide (PT-Cy), and all received reduced-intensity conditioning regimens.

RESULTS

More haplo-HCT recipients presented severe infections in the pre-engraftment period (22.4% vs. 6.7%, p = 0.003). Viral (14.9% vs. 4.5%, p = 0.016) and fungal (12.1% vs. 1.1%, p = 0.003) etiologies were more common in this period in this group. The 100-day and 2-year cumulative incidence of IRM was 15% and 21% for the haplo-HCT and 5.6% and 17% for the HLA-identical group; no significant differences were observed between the groups. Fungal pathogens mainly contributed to IRM (33.3%). Infections were the most common cause of mortality (40/81, 49.4%). There were significant differences in donor/recipient CMV serostatus between transplant groups (0.002).

CONCLUSIONS

No differences in IRM were observed based on allo-HCT type, with more haplo-HCT patients suffering from severe infections in the pre-engraftment period. Studies to assess future prevention, diagnostic, and treatment strategies to reduce IRM are warranted.

Prophylactic Pretransplant Ganciclovir to Reduce Cytomegalovirus Infection After Hematopoietic Stem Cell Transplantation

OBJECTIVE/BACKGROUND

Cytomegalovirus (CMV) reactivation remains a serious complication after allogeneic hematopoietic cell transplantation (HCT) occurring in approximately 60-70% of CMV-seropositive HCT recipients. CMV reactivation leads to adverse outcomes including end-organ damage, graft-versus-host disease, and graft failure.

METHODS

Ganciclovir was administered pretransplant at 5 mg/kg twice daily intravenously from the start of conditioning to Day T-2 to CMV-seropositive patients receiving their first allogeneic HCT. CMV DNA was monitored weekly until at least Day 100 posttransplant.

RESULTS

A total of 109 consecutive patients were treated, median age 57 (range 20-73) years. Of these, 36 (33%) patients had a CMV reactivation within the first 105 days posttransplant with a median time of reactivation of 52.5 (range 36-104) days posttransplant. The cumulative incidence of CMV reactivation at Day 105 posttransplant was 33.1% (95% confidence interval: 24.4-42.0). One patient developed CMV disease.

CONCLUSION

The use of pretransplant ganciclovir was associated with low incidence of CMV reactivation and disease. These data suggest that pretransplant ganciclovir with preemptive therapy for viral reactivation may be a useful strategy to reduce CMV reactivation. Future prospective trials are needed to compare strategies for CMV prophylaxis.

Letermovir as Cytomegalovirus Prophylaxis in a Pediatric Cohort: A Retrospective Analysis

Letermovir is an attractive cytomegalovirus (CMV) prophylactic agent, but published data in children are scarce. This retrospective chart review aimed to describe our experience using letermovir as CMV prophylaxis in pediatric hematopoietic cell transplantation (HCT) recipients. Pediatric patients (age <20 years) undergoing allogeneic HCT and receiving letermovir prophylaxis in the Mayo Clinic Pediatric Bone Marrow Transplant Program were eligible for inclusion in this retrospective chart review. Medical records were reviewed to evaluate letermovir dosing, CMV levels, laboratory values, and reports of adverse effects. Between October 2020 and April 2022, 9 patients age 4 to 19 years undergoing allogeneic HCT in the Pediatric Bone Marrow Transplant Program received letermovir prophylaxis, either 240 mg or 480 mg daily at a mean and median dose of 10 mg/kg/day. Letermovir was crushed and administered via nasogastric tube in 4 of 9 patients. Two patients received letermovir for secondary CMV prophylaxis after initial treatment with ganciclovir/valganciclovir, and the remaining 7 received letermovir for primary prophylaxis. One patient, a 20-kg 6-year-old female receiving 240 mg (12 mg/kg), experienced low-level CMV viremia while on letermovir. No other patients experienced CMV reactivation while on letermovir prophylaxis. In 2 patients, transient mild transaminitis was noted within the first weeks of letermovir therapy, which resolved without intervention, and its relationship to letermovir could not be clearly established. Letermovir administration was feasible and well tolerated as CMV prophylaxis in our small cohort of pediatric patients undergoing HCT. Larger, prospective studies are warranted to confirm the safety and efficacy of letermovir in children. © 2022 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

High dose valacyclovir for cytomegalovirus prophylaxis following allogeneic hematopoietic cell transplantation

INTRODUCTION

Cytomegalovirus (CMV) is one of the most common and clinically significant viral infections following allogeneic hematopoietic cell transplantation (HCT). Currently available options for CMV prophylaxis and treatment present challenges related to side effects and cost.

METHODS

In this retrospective medical record review, the incidence of clinically significant CMV infection (CMV disease or reactivation requiring preemptive treatment) following allogeneic HCT was compared in patients receiving valacyclovir 1 g three times daily versus acyclovir 400 mg every 12 h for viral prophylaxis.

RESULTS

Forty-five patients who received valacyclovir were matched based on propensity scoring to 35 patients who received acyclovir. All patients received reduced-intensity conditioning regimens containing anti-thymocyte globulin. Clinically significant CMV infection by day + 180 was lower in the valacyclovir group compared to the acyclovir group (18% vs. 57%, p = 0.0004). Patients receiving valacyclovir prophylaxis also had less severe infection evidenced by a reduction in CMV disease, lower peak CMV titers, delayed CMV reactivation, and less secondary neutropenia.

CONCLUSION

Prospective evaluation of valacyclovir 1 g three times daily for viral prophylaxis following allogeneic HCT is warranted. Due to valacyclovir's favorable toxicity profile and affordable cost, it has the potential to benefit patients on a broad scale as an option for CMV prophylaxis.

Features of cytomegalovirus infection and evaluation of cytomegalovirus-specific T cells therapy in children’s patients following allogeneic hematopoietic stem cell transplantation: A retrospective single-center study

Cytomegalovirus (CMV) infection remains a critical cause of mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT), despite improvement by pre-emptive antivirus treatment. CMV-specific cytotoxic T lymphocytes (CMV-CTL) are universally used and proven well-tolerance after allo-HSCT in adult clinical trials. However, it is not comprehensively evaluated in children’s patients. Herein, we conducted a retrospective study to determine the risk factors of CMV infection and evaluation of CMV-CTL in children patients who underwent allo-HSCT. As result, a significantly poor 5-year overall survival was found in the CMV infection group (87.3 vs. 94.6%, p=0.01). Haploidentical HSCT (haplo-HSCT) was identified as an independent risk factor for CMV infection through both univariate and multivariate analyses (p<0.001, p=0.027, respectively). Furthermore, the cumulative incidence of CMV infection was statistically higher in the haplo-HSCT group compared to the HLA-matched donor group (44.2% vs. 21.6%, p<0.001). Finally, the overall response rate of CMV-CTL was 89.7% (26/29 patients) in CMV infection after allo-HSCT. We concluded that CMV infection following allo-HSCT correlated with increased mortality in children’s patients, and haplo-HSCT was an independent risk factor for CMV infection. Adoptive CMV-CTL cell therapy was safe and effective in pediatric patients with CMV infection.

Diagnosis and treatment for the early stage of cytomegalovirus infection during hematopoietic stem cell transplantation

Cytomegalovirus (CMV) infection remains a frequent complication after hematopoietic stem cell transplantation (HSCT) and causes significant morbidity and mortality in transplantation recipients. In this review, we highlight the role of major risk factors that are associated with the incidence of CMV infection. Advances in immunosurveillance may predict CMV infection, allowing early interventions to prevent severe infection. Furthermore, numerous therapeutic strategies against CMV infection after HSCT are summarized. A comprehensive understanding of the current situation of CMV treatment may provide a hint for clinical practice and even promote the development of novel strategies for precision medicine.

Results of an Innovative Program for Surveillance, Prophylaxis, and Treatment of Infectious Complications Following Allogeneic Stem Cell Transplantation in Hematological Malignancies (BATMO Protocol)

Background

Infectious complications are a significant cause of morbidity and mortality in patients undergoing allogeneic haematopoietic stem cell transplantation (Allo-SCT). The BATMO (Best-Antimicrobial-Therapy-TMO) is an innovative program for infection prevention and management and has been used in our centre since 2019. The specific features of the BATMO protocol regard both prophylaxis during neutropenia (abandonment of fluoroquinolone, posaconazole use in high-risk patients, aerosolized liposomal amphotericin B use until engraftment or a need for antifungal treatment, and letermovir use in CMV-positive recipients from day 0 to day +100) and therapy (empirical antibiotics based on patient clinical history and colonization, new antibiotics used in second-line according to antibiogram with the exception of carbapenemase-producing K pneumoniae for which the use in first-line therapy is chosen).

Methods

Data on the infectious complications of 116 transplant patients before BATMO protocol (Cohort A; 2016 - 2018) were compared to those of 84 transplant patients following the introduction of the BATMO protocol (Cohort B; 2019 - 2021). The clinical and transplant characteristics of the 2 Cohorts were comparable, even though patients in Cohort B were at a higher risk of developing bacterial, fungal, and CMV infections, due to a significantly higher proportion of myeloablative regimens and haploidentical donors.

Results

No change in the incidence of infections with organ localization was observed between the two Cohorts. A significant reduction in Clostridioides difficile infections by day +100 was observed in Cohort B (47% vs. 15%; p=0.04). At day +30, a higher incidence of Gram-negative bloodstream infections (BSIs) was observed in Cohort B (12% vs. 23%; p=0.05). By day +100 and between days +100 and +180, the incidence of BSIs and of the various etiological agents, the mortality from Gram-negative bacteria, and the incidence of invasive fungal infections were not different in the two Cohorts. The incidence of CMV reactivations by day +100 dropped drastically in patients of Cohort B, following letermovir registration (51% vs. 15%; p=0.00001).

Discussion

The results of this study suggest that the BATMO program is safe. In particular, the choice to avoid prophylaxis with fluoroquinolone was associated with an increase in Gram-negative BSIs by day +30, but this did not translate into higher levels of mortality. Moreover, this strategy was associated with a significant reduction of Clostridiodes difficile infections. The efficacy of anti-CMV prophylaxis with letermovir was confirmed by a significant reduction in CMV reactivations. Even though patients in Cohort B were at higher risk of developing fungal infections (more haploidentical transplants with more myeloablative regimens), the extensive use of posaconazole for prophylaxis balanced this risk, and no increase in the incidence of fungal-associated complications was observed.

Risk factors for late cytomegalovirus infection after completing letermovir prophylaxis

Prophylactic use of letermovir (LMV) markedly reduces the incidence of early clinically significant cytomegalovirus (csCMV) infection within the first 100 days after allogeneic hematopoietic cell transplantation (allo-HCT), which improves transplant outcomes. However, some patients eventually develop late-csCMV infection (beyond day 100) after completing LMV prophylaxis. To assess the incidence of late-csCMV infection as well as its risk factors and impacts on transplant outcome, a total of 81 allo-HCT recipients who had not developed early csCMV infection during LMV prophylaxis were retrospectively analyzed. Among them, 23 (28.4%) patients developed late-csCMV infection (until day 180) at a median time of 131 days after transplantation and 30 days after LMV discontinuation, respectively. Late-csCMV infection was correlated with apparent delayed immune reconstitution: patients transplanted from HLA-mismatched donors (hazard ratio [HR] = 13.0, p = 0.011) or CMV-IgG-negative donors (HR = 2.39, p = 0.043) had a significantly higher risk. In this study, transplant outcomes did not differ between patients with and without late-csCMV infection. This suggests a need to clarify the efficacy of extended administration of LMV for preventing late-csCMV infection in a larger number of allo-HCT recipients, especially those with "high-risk" donors.

Revisit of the Association between Cytomegalovirus Infection and Invasive Fungal Infection after Allogeneic Hematopoietic Stem Cell Transplantation: A Real-World Analysis from a High CMV Seroprevalence Area

Infection is a major complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT) especially cytomegalovirus (CMV) infection and invasive fungal infection (IFI). Taiwan is a high CMV seroprevalence area. Our study aimed to evaluate the incidence, risk factors, the impact on survival of CMV infection (including reactivation and disease) and the association of CMV infection and IFI in recipients after allo-HSCT during the first 100 days after transplantation. This was a retrospective study including 180 recipients of allo-HSCT. A total of 99 patients had CMV reactivation, and nine patients had CMV diseases. There were more mismatched donors, more ATG usage and more transplantation from CMV IgG-negative donor in patients with CMV reactivation. There was no survival difference in patients with or without CMV reactivation. A total of 34 patients had IFIs, and IFI after allo-HSCT was associated with significantly inferior survival. Patients with CMV reactivation did not increase the incidence of overall IFI, but they did result in more late-onset (>40 days) IFI (p = 0.056). In this study, we demonstrated real-world data of CMV infection and IFI from a high CMV seroprevalence area.

The changing impact of cytomegalovirus among hematopoietic cell transplant recipients during the past decade: A single institutional cohort study

BACKGROUND

With advancements in allogeneic hematopoietic cell transplantation (alloHCT), the need for cytomegalovirus (CMV) surveillance persists.

METHODS

We present a retrospective analysis on the impact of CMV with preemptive therapy in 1,065 alloHCT patients with donor and/or recipient CMV seropositivity from 2009-2019.

RESULTS

51% developed clinically significant CMV infection (CMV-CSI); 6.5% had CMV disease. In multivariate analysis stratified by serostatus and preparative regimen the use of ATG (HR 2.97, 95% CI 2.00 to 4.42, P < 0.001) was associated with development of CMV-CSI. Median length of stay for index hospitalization was longer in patients with CMV-CSI (27 d vs 25 d, respectively; P = .002), as were rates (32.9% vs 17.7%; P < .001) and duration (9 d vs 6 d; P < .001) of rehospitalization, and median total inpatient days (28 d vs 26 d; P < .001). Patients with CMV-CSI had higher rates of neutropenia (47% vs 20%; P < .001) and transfusion support (PRBC, median 5 vs 3; P < .001; platelets, median 3 vs 3; P < .001).

CONCLUSION

Preemptive therapy does not negate the impact of CMV-CSI on peri-engraftment toxicity and healthcare utilization. This cohort represents a large single center study on the impact of CMV in the pre-letermovir era and serves as a real-world comparator for assessing the impact of future prophylaxis. This article is protected by copyright. All rights reserved.

Continuous High-Dose (6 mg) vs. Low-Dose (3 mg) Intravitreal Ganciclovir for Cytomegalovirus Retinitis After Haploidentical Hematopoietic Stem Cell Transplantation: A Randomized Controlled Study

Purpose: To evaluate the safety and efficacy of continuous high-dose (6 mg) intravitreal ganciclovir injections (IVG) for cytomegalovirus (CMV) retinitis (CMVR) after haploidentical hematopoietic stem cell transplantation (Haplo-HSCT), and to explore factors that may influence the treatment procedure.

Design: Prospective, randomized, single-blinded, positive-controlled, interventional, comparative study.

Methods: A total of 22 patients with CMVR (32 eyes) were randomized to either high-dose group (IVG 6 mg weekly) or low-dose group (IVG 3 mg given twice weekly for 2 weeks as induction phase and weekly thereafter as maintenance phase). Patients who were recorded any positive CMV DNAemia or other active CMV diseases and needed systemic anti-CMV treatment during the study period were excluded. The vision outcome, variables of the treatment procedure, and incidence of complication and CMVR recurrence were analyzed and compared. Logistic regression was applied to determine the factors that may have an impact on the treatment process at baseline.

Results: Compared to the low-dose group, the high-dose group resulted in a median of two less intravitreal injections (4 vs. 6 times, respectively, P = 0.016), while the rate of vision stability or improvement (81.2 vs. 87.5%), the incidence of complication (6.2 vs. 18.8%), and CMVR recurrence (12.5% vs. 6.2%) were similar (all P > 0.05). No drug-related toxicity was observed. Initial aqueous CMV-DNA load (OR: 6.872, 95% CI: 1.335–35.377, P = 0.021) and extension of lesion (OR: 0.942, 95% CI: 0.897 to .991, P = 0.020), but not dosing regimen (P = 0.162), were predictors of the treatment duration.

Conclusions: Continuous high-dose regimen was well tolerated and resulted in less intravitreal injections, with similar vision outcomes and safety profiles. The clinical course of CMVR after Haplo-HSCT was determined by its own nature at baseline and could not be modified by treatment protocols under consistent immune background.

Prevention and management of human cytomegalovirus in pediatric HSCT recipients: A review

Cytomegalovirus (CMV), like other herpesviruses, has the unique ability to establish latent infection with subsequent reactivation during periods of stress and immunosuppression. Herpesviruses cause potentially devastating disease, particularly in hematopoietic stem cell transplant (HSCT) recipients. CMV is especially of concern in HSCT recipients given the high community seroprevalence, high risk of reactivation and high risk of transmission from HSCT donors to recipients causing primary infection after transplantation. The risk of CMV infection and severity of CMV disease varies depending on the underlying disease of the HSCT recipient, donor and recipient CMV status prior to HSCT, type of conditioning therapy in preparation for HSCT, allogeneic versus autologous HSCT, donor graft source, timing of infection in relation to HSCT, and other patient comorbidities. Different strategies exist for prevention (e.g., preemptive therapy vs. universal prophylaxis) as well as management of CMV disease (e.g., antiviral therapy, augmenting immune reconstitution, cytotoxic T-cell therapy). The purpose of this narrative review is to discuss diagnosis, prevention, and management of CMV infection and disease at different stages of HSCT, including key points illustrated through presentations of complex cases and difficult clinical scenarios. Traditional and novel strategies for CMV management will be discussed in the context of these unique clinical cases.

Cidofovir, a choice for salvage treatment of CMV infection in patients with haploidentical hematopoietic stem cell transplantation

BACKGROUND

Cidofovir (CDV) is a nucleotide analogue with broad antiviral activities. It remains unclear about the CDV administration for anti-cytomegalovirus (CMV) treatment in patients with haploidentical hematopoietic stem cell transplantation (haplo-HSCT).

PATIENTS AND METHODS

In this study, 31 out of 101 haplo-HSCT recipients suffered CMV infection in the CT group (conventional treatment) were enrolled into the CDV-ST group (CDV-second-line treatment). These patients were treated with CDV as they failed conventional treatment or they were unavailable to the preemptive antiviral therapy. Nine patients with CMV infection were enrolled into the CDV-FT group (CDV-frontline treatment) and received CDV preemptive therapy.

RESULTS

In the CDV-ST group, 23/28(82.1%) patients were observed treatment response with a median time of 9 (2-23) days, and 20 (71.8%) among these patients obtained complete response (CR). In the CDV-FT group, 6/8 (75.0%) patients acquired CR with a median of 6 (4-25) days. The treatment response in CDV-treated groups was comparable with those in CT groups. Besides, there was no statistical difference in CMV-related mortality between the three groups (P>0.05). During the follow-up period (Median follow-up:10 (1-28) months), a total of 8/22 (36.4%) patients experienced CMV reactivation in the CDV-ST group, versus 23/62 (37.1%) in CT group (P>0.05). CDV-related toxicities occurred in 13/40 (32.5%) patients, including 6 (15%) reversible nephrotoxicity.

CONCLUSION

Our study suggests that CDV is potentially an option for the salvage treatment of CMV infection in the haplo-HSCT patients. This article is protected by copyright. All rights reserved.

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.

Haploidentical donor transplant is associated with secondary poor graft function after allogeneic stem cell transplantation: A single-center retrospective study

Background

Secondary poor graft function (sPGF) is a serious complication after allogeneic hematopoietic stem cell transplantation (allo‐HSCT) related to poor outcome. We aimed to retrospectively evaluate the morbidity and hazard elements of sPGF after allo‐HSCT.

Methods

Eight hundred and sixty‐three patients who achieved initial engraftment of both neutrophils and platelets were retrospectively reviewed in this study.

Results

Fifty‐two patients developed sPGF within 180 days post‐transplants, with the median onset time was 62 days (range, 34–121 days) post‐transplants. The overall cumulative incidence of sPGF within 180 days post‐transplantation was 6.0%, with 3.4%, 3.4%, and 10.1%, respectively, in matched sibling donor (MSD), matched unrelated donor (MUD), and haploidentical donor (HID) transplant (p < 0.0001). Multivariable analysis showed that HID (HID vs. MSD: hazard ratio [HR] 2.525, p = 0.004; HID vs. MUD: [HR] 3.531, p = 0.017), acute graft versus host disease (aGVHD) within +30 days ([HR] 2.323, p = 0.003), and cytomegalovirus (CMV) reactivation ([HR] 8.915, p < 0.0001) within +30 days post‐transplants were hazard elements of sPGF. The patients with sPGF had poorer survival than good graft function (51.7±8.1% vs. 62.9±1.9%, p < 0.0001). Our results also showed that only CMV reactivation was the hazard element for the development of PGF in HID transplant ([HR] 12.521 p < 0.0001).

Conclusion

HID transplant is also an independent hazard element of sPGF except for aGVHD and CMV reactivation.

Severe infections and infection-related mortality in a large series of haploidentical hematopoietic stem cell transplantation with post-transplant cyclophosphamide

Severe infections and their attributable mortality are major complications in recipients of allogeneic hematopoietic stem cell transplantation (alloSCT). We herein report 236 adult patients who received haploSCT with PTCy. The median follow-up for survivors was 37 months. The overall incidence of bloodstream infections by gram-positive and gram-negative bacteria at 37 months was 51% and 46%, respectively. The incidence of cytomegalovirus infection was 69%, while Epstein Barr virus infections occurred in 10% of patients and hemorrhagic cystitis in 35% of cases. Invasive fungal infections occurred in 11% at 17 months. The 3-year incidence of infection-related mortality was 19%. The median interval from transplant to IRM was 3 months (range 1-30), 53% of IRM occurred >100 days post-haploSCT. Risk factors for IRM included age >50 years, lymphoid malignancy, and developing grade III-IV acute GvHD. Bacterial infections were the most common causes of IRM (51%), mainly due to gram-negative bacilli BSI. In conclusion, severe infections are the most common causes of NRM after haploSCT with PTCy, with a reemergence of gram-negative bacilli as the most lethal pathogens. More studies focusing on the severe infections after haploSCT with PTCy and differences with other types of alloSCT in adults are clearly warranted.

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.

HLA-haploidentical vs matched unrelated donor transplants with posttransplant cyclophosphamide-based prophylaxis

Posttransplant cyclophosphamide (PTCy) graft-versus-host disease (GVHD) prophylaxis has enabled haploidentical (Haplo) transplantation to be performed with results similar to those after matched unrelated donor (MUD) transplantation with traditional prophylaxis. The relative value of transplantation with MUD vs Haplo donors when both groups receive PTCy/calcineurin inhibitor/mycophenolate GVHD prophylaxis is not known. We compared outcomes after 2036 Haplo and 284 MUD transplantations with PTCy GVHD prophylaxis for acute leukemia or myelodysplastic syndrome in adults from 2011 through 2018. Cox regression models were built to compare outcomes between donor types. Recipients of myeloablative and reduced-intensity regimens were analyzed separately. Among recipients of reduced-intensity regimens, 2-year graft failure (3% vs 11%), acute grades 2 to 4 GVHD (hazards ratio [HR], 0.70; P = .022), acute grades 3 and 4 GVHD (HR, 0.41; P = .016), and nonrelapse mortality (HR, 0.43; P = .0008) were lower after MUD than with Haplo donor transplantation. Consequently, disease-free (HR, 0.74; P = .008; 55% vs 41%) and overall (HR, 0.65; P = .001; 67% vs 54%) survival were higher with MUD than with Haplo transplants. Among recipients of myeloablative regimens, day-100 platelet recovery (95% vs 88%) was higher and grades 3 and 4 acute (HR, 0.39; P = .07) and chronic GVHD (HR, 0.66; P = .05) were lower after MUD than with Haplo donor transplantation. There were no differences in graft failure, relapse, nonrelapse mortality, and disease-free and overall survival between donor types with myeloablative conditioning regimens. These data extend and confirm the importance of donor-recipient HLA matching for allogeneic transplantation. A MUD is the preferred donor, especially for transplantations with reduced-intensity conditioning regimens.

NEOVASCULAR COMPLICATIONS FROM CYTOMEGALOVIRUS NECROTIZING RETINOPATHY IN PATIENTS AFTER HAPLOIDENTICAL HEMATOPOIETIC STEM CELL TRANSPLANTATION

PURPOSE

To report the incidence and clinical features of neovascular complications from cytomegalovirus (CMV) necrotizing retinopathy in patients after haploidentical hematopoietic stem cell transplantation.

METHODS

Thirty-nine patients (58 eyes) of CMV necrotizing retinopathy after haploidentical hematopoietic stem cell transplantation in our institute between January 2018 and June 2020 were retrospectively reviewed, and cases that developed neovascular complications during follow-up were identified and described.

RESULTS

Two (2 eyes) cases that developed neovascular glaucoma from CMV necrotizing retinopathy were identified. Both of them manifested as granular peripheral retinitis, panretinal occlusive vasculitis, and some degree of intraocular inflammation, which were consistent with chronic retinal necrosis. Insidious progression of isolated immune-mediated occlusive vasculitis that could only be observed on fundus fluorescein angiography without active retinitis or intraocular inflammation was recognized to be the cause in one of two cases.

CONCLUSION

Neovascular glaucoma developed in 5.1%/cases and 3.4%/eyes complicated by CMV chronic retinal necrosis and vasculitis in patients after haploidentical hematopoietic stem cell transplantation, which warrants the needs for long-term follow-up. Immune-mediated CMV vasculitis could be an isolated manifestation in patients with a minimal immune deviation and may only be found on fundus fluorescein angiography, which emphasizes the importance of fundus fluorescein angiography on a regular basis during follow-up.

Sirolimus versus cyclosporine in haploidentical stem cell transplantation with posttransplant cyclophosphamide and mycophenolate mofetil as graft-versus-host disease prophylaxis

Sirolimus has emerged as an alternative to calcineurin inhibitors-based (CNI) graft-versus-host disease (GVHD) prophylaxis. This retrospective study compares the outcome of 133 consecutive adult patients with haematological malignancies undergoing haploidentical stem cell transplantation with posttransplant cyclophosphamide (PTCy) and mycophenolate mofetil (MMF), combined with cyclosporine A (PTCy-CsA-MMF, n = 67) or sirolimus (PTCy-Sir-MMF, n = 66) as GVHD prophylaxis strategy. The median follow-up was 48 (range 22-83) and 13 (range 3-33) months, respectively. PTCy-CsA-MMF was associated in multivariate analyses with a higher risk of acute kidney injury (HR 2.1, 95% CI, 1.21-3.57, p = .008) and thrombotic microangiopathy (HR 12.5, 95% CI, 1.66-93.5, p = .014), whereas PTCy-Sir-MMF was associated with a higher risk of hepatic sinusoidal obstruction syndrome (SOS) (HR 10.8, 95% CI, 1.52-77, p = .018), especially late-onset forms, which totally resolved and none of the patients needed discontinuation of sirolimus. Two SOS-related deaths were detected, both in the PTCy-CsA-MMF subgroup. Both GVHD prophylaxis strategies were otherwise comparable in terms of engraftment, GVHD incidence and survival.

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.

Cytomegalovirus prophylaxis using low-dose valganciclovir in patients with acute leukemia undergoing allogeneic hematopoietic stem-cell transplantation

Background

Letermovir prophylaxis is currently the standard of care for the prevention of cytomegalovirus (CMV) infections in allogeneic hematopoietic stem-cell transplantation (allo-HSCT). However, drug-drug interactions between letermovir and azoles or calcineurin inhibitors and the high financial burden of letermovir remain problematic, especially in resource-limited countries. It has not been clarified whether a lower dose of valganciclovir would constitute an effective strategy for CMV prevention in patients with acute leukemia undergoing allo-HSCT.

Methods

We retrospectively assessed 84 consecutive adult patients with acute leukemia who underwent allo-HSCT. These 84 patients were stratified into a valganciclovir prophylaxis group (n = 20) and a non-valganciclovir prophylaxis group (n = 64).

Results

Patients in the valganciclovir prophylaxis group had a lower possibility of CMV DNAemia at week 14 after allo-HSCT than those in the non-valganciclovir prophylaxis group (15.0% versus 50.0%; p = 0.012). The cumulative incidence of CMV DNAemia at week 14 was also lower in patients with valganciclovir CMV prophylaxis than in those without (15.0% versus 50.4%; p = 0.006). Multivariate analysis validated these data, showing that a low dose of valganciclovir significantly reduced the risk of CMV DNAemia at week 14 by 88% (hazard ratio: 0.12; 95% confidence interval: 0.04-0.42; p = 0.001). However, these two groups had similar overall survival rates at week 48 (75.0% versus 76.6%; p = 0.805). Four of 20 (20%) patients discontinued valganciclovir prophylaxis because of adverse events.

Conclusion

Low-dose valganciclovir prophylaxis could be an alternative to letermovir to prevent CMV infection in allo-HSCT, especially in resource-limited countries.

Cytomegalovirus management after allogeneic hematopoietic stem cell transplantation: A mini-review

Because of the high incidence of cytomegalovirus (CMV) seropositivity in the population, CMV infection is a common and severe complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in Taiwan. Here we propose a CMV management strategy for patients undergoing allo-HSCT from the Taiwanese perspective, which focuses on the epidemiology, diagnosis, monitoring, prophylaxis, and treatment of CMV infection after allo-HSCT. In terms of CMV monitoring, weekly CMV monitoring with the COBAS® AmpliPrep system is the standard approach because the pp65 CMV antigenemia assay has a lower sensitivity than CMV monitoring with the COBAS® AmpliPrep system. However, pp65 CMV antigenemia assay has a better correlation with clinical symptoms in immunocompromised patients. A 14-week prophylactic course of letermovir is recommended for allo-HSCT recipients in Taiwan, especially for recipients of hematopoietic stem cells from mismatched unrelated and haploidentical donors. Preemptive ganciclovir therapy should be initiated when the CMV viral load exceeds 1000 copies/mL, and should not be discontinued until CMV DNA is no longer detected in the blood. For allo-HSCT recipients who have CMV-related diseases, ganciclovir with or without CMV-specific intravenous immunoglobulin is the standard of care. The limited availability of foscarnet, an alternative for patients who are not responsive to or cannot tolerate ganciclovir, is a crucial issue in Taiwan. For pediatric allo-HSCT recipients, more data are needed to propose a CMV management recommendation.

[Impact of poor graft function on cytomegalovirus pneumonia in patients who have undergone haploidentical stem cell transplantation]

Objective: To retrospectively analyze the impact of primary PGF on CMV pneumonia in patients who have undergone haplo-HSCT. Methods: The clinical data of 122 patients who underwent haplo-HSCT at the Peking University Institute of Hematology from 2011-2012 were retrospectively reviewed. The incidence rate of CMV pneumonia between PGF and good graft function (GGF) was compared, and the factors were analyzed. In addition, outcomes in PGF patients with CMV pneumonia have been described. Results: Total 122 patients were retrospectively reviewed, and of these, 26 (21.3% ) had PGF, while 96 (78.7% ) had GGF. In addition, 15 patients had CMV pneumonia, and the median time to the development of CMV pneumonia was 103 (31-262) days; the 1-year cumulative incidence of CMV pneumonia was 12.3% (95% CI 6.2% -18.4% ) . In patients with primary PGF and GGF after Haplo-HSCT, the incidence of CMV pneumonia was 30.8% (8/26) and 7.3% (7/96) , respectively (P=0.002) . Moreover, 24 patients had CMV viremia (92.3% ) , while of the 96 GGF patients, 79 (82.3% ) had CMV viremia (P=0.212) . In multivariate analysis, the results showed that primary PGF had a significant influence on CMV pneumonia (P=0.005) . Compared with those without CMV pneumonia, patients with CMV pneumonia had poorer overall survival 37.3% (95% CI 11.2% -63.4% ) vs. 78.9% (95% CI 72.0% -87.6% ) (χ(2)=16.361, P<0.001) . The 1-year overall survival (OS) was 25.0% (95% CI 0% -55.0% ) and 50.0% (95% CI 26.9% -73.1% ) (χ(2)=4.656, P=0.031) in PGF patients with (8/26) and without (18/26) CMV pneumonia. Conclusion: The incidence of cytomegalovirus pneumonia in patients with primary poor graft function increases and the survival rate decreases.

Letermovir Prophylaxis Decreases Burden of Cytomegalovirus (CMV) in Patients at High Risk for CMV Disease Following Hematopoietic Cell Transplant

Despite effective therapies, cytomegalovirus (CMV) continues to have a significant impact on morbidity and mortality in hematopoietic cell transplant recipients. At particular risk are recipients of alternative grafts such as umbilical cord blood (UCB), haploidentical transplants (haplo), or patients conditioned with T-cell depleting regimens such as anti-thymocyte globulin (ATG). With the approval of letermovir, its impact on high-risk patients is of particular interest. To evaluate the impact of letermovir prophylaxis at our center, we performed a retrospective analysis of 114 high-risk patients who received letermovir as prophylaxis (LET PPX) between January 2018 through December 2019, including 30 UCB and 22 haplo recipients, compared with 637 historical controls with comparable risk between January 2013 and December 2019. By post-transplant day 100 (D+100), letermovir prophylaxis significantly decreased the incidence of both CMV DNAemia compared with controls (45.37% versus 74.1%; P < .001) and clinically significant CMV infection (12.04% versus 48.82%; P < .001). The impact of LET PPX was even more profound on the incidence of clinically significant CMV infection (CSI), defined as the administration of antiviral therapy as preemptive therapy for CMV DNAemia or treatment for CMV disease. CSI was significantly lower in haplo recipients on LET PPX compared with controls (13.64% versus 73.33%; P= .02) and UCB recipients on LET PPX compared with controls (3.45% versus 37.5%; P < .001). No patients on LET primary PPX developed CMV disease in any treatment group by D+100 compared with controls (0% versus 5.34%, respectively; P = .006). Patients on LET PPX had fewer hospitalizations involving initiation of anti-CMV therapy compared with controls (0.93% versus 15.23%, respectively). Our analysis of the largest cohort of patients at high risk for CMV reactivation published to date demonstrates that letermovir prophylaxis significantly reduces the number of patients who receive CMV-active antiviral therapy for either DNAemia or disease due to CMV.

Incidence of viral and fungal complications after utilization of alternative donor sources in hematopoietic cell transplantation

Allogeneic hematopoietic cell transplantation (HCT) remains the only curable option for adult patients with hematologic malignancies. According to guidelines published by the American Society for Transplantation and Cellular Therapy, allogeneic HCT should be offered to all intermediate- and high-risk patients with acute leukemia. While matched-related donor (MRD) grafts continue to be the preferred stem cell source for allogeneic HCT, studies comparing MRD grafts to matched-unrelated donor (MUD) grafts showed comparable outcomes in patients with acute leukemia. Unfortunately, for those without a suitable matched-related graft, the probability of finding a suitable matched-unrelated donor varies significantly depending on racial and ethnic background. With allogeneic HCT procedures increasing year after year due to the increased availability of suitable donors, each of these alternative donor sources merits special clinical considerations, specifically with regard to infections. Infections remain a significant cause of morbidity and mortality after allogeneic transplant, especially in those receiving alternative donor grafts. Due to the high-risk nature associated with these donor grafts, it is important to understand the true risk of developing infectious complications. While there are a multitude of infections that have been described in patients post-allogeneic HCT, this review seeks to focus on the incidence of cytomegalovirus (CMV) and invasive fungal infections (IFI) in adult patients receiving alternative donor source transplantation for hematologic malignancies.

How we perform haploidentical stem cell transplantation with posttransplant cyclophosphamide

HLA-haploidentical hematopoietic stem cell transplantation is now one of the most commonly employed alternative donor techniques, with most centers applying T-cell-replete strategies such as that developed by the Baltimore group using high-dose posttransplant cyclophosphamide. HLA-haploidentical hematopoietic stem cell transplantation using posttransplant cyclophosphamide is associated with low rates of severe graft-versus-host disease and nonrelapse mortality and does not require graft manipulation or storage, which results in a low graft acquisition cost. Its remarkable safety when used with reduced-intensity conditioning has been demonstrated in patients up to 75 years old with outcomes similar to those of patients in their 50s. Several large, registry-based retrospective studies have confirmed the efficacy of HLA-haploidentical hematopoietic stem cell transplantation with posttransplant cyclophosphamide, achieving results comparable to those of HLA-matched hematopoietic stem cell transplantation. In this article, we describe our approach to this rapidly available and clinically simple platform and address some of the key clinical questions associated with its use.

How we perform haploidentical stem cell transplantation with posttransplant cyclophosphamide

HLA-haploidentical hematopoietic stem cell transplantation is now one of the most commonly employed alternative donor techniques, with most centers applying T-cell-replete strategies such as that developed by the Baltimore group using high-dose posttransplant cyclophosphamide. HLA-haploidentical hematopoietic stem cell transplantation using posttransplant cyclophosphamide is associated with low rates of severe graft-versus-host disease and nonrelapse mortality and does not require graft manipulation or storage, which results in a low graft acquisition cost. Its remarkable safety when used with reduced-intensity conditioning has been demonstrated in patients up to 75 years old with outcomes similar to those of patients in their 50s. Several large, registry-based retrospective studies have confirmed the efficacy of HLA-haploidentical hematopoietic stem cell transplantation with posttransplant cyclophosphamide, achieving results comparable to those of HLA-matched hematopoietic stem cell transplantation. In this article, we describe our approach to this rapidly available and clinically simple platform and address some of the key clinical questions associated with its use.

The Presence of a CMV Immunodominant Allele in the Recipient Is Associated With Increased Survival in CMV Positive Patients Undergoing Haploidentical Hematopoietic Stem Cell Transplantation

Specific major histocompatibility (MHC) class I alleles dominate anti-CMV responses in a hierarchal manner. These CMV immunodominant (IMD) alleles are associated with a higher magnitude and frequency of cytotoxic lymphocyte responses as compared to other human leukocyte antigen (HLA) alleles. CMV reactivation has been associated with an increased incidence of graft-vs.-host disease and non-relapse mortality, as well as protection from relapse in HLA-matched HSCT settings. Less is known about the impact of CMV reactivation on these major outcomes after haploidentical (HI) HSCT, an increasingly applied therapeutic option. In HI HSCT, the efficiency of the immune response is decreased due to the immune suppression required to cross the MHC barrier as well as MHC mismatch between presenting and responding cells. We hypothesized that the presence of a CMV IMD allele would increase the efficiency of CMV responses after HI HSCT potentially impacting CMV-related outcomes. In this retrospective, multivariable review of 216 HI HSCT patients, we found that CMV+ recipients possessing at least 1 of 5 identified CMV IMD alleles had a lower hazard of death (HR = 0.40, p = 0.003) compared to CMV+ recipients not possessing a CMV IMD allele, and an overall survival rate similar to their CMV- counterparts. The analysis delineated subgroups within the CMV+ population at greater risk for death due to CMV reactivation.