Cellular Therapeutic Approaches to Cytomegalovirus Infection Following Allogeneic Stem Cell Transplantation

Proteomics screening after pediatric allogenic hematopoietic stem cell transplantation reveals an association between increased expression of inhibitory receptor FCRL6 on γδ T cells and cytomegalovirus reactivation

We studied the associations between inflammation-related proteins in circulation and complications after pediatric allogenic hematopoietic stem cell transplantation (HSCT), to reveal proteomic signatures or individual soluble proteins associated with specific complications after HSCT. We used a proteomics method called Proximity Extension Assay to repeatedly measure 180 different proteins together with clinical variables, cellular immune reconstitution and blood viral copy numbers in 27 children (1-18 years of age) during a 2-year follow-up after allogenic HSCT. Protein profile analysis was performed using unsupervised hierarchical clustering and a regression-based method, while the Bonferroni-corrected Mann-Whitney U-test was used for time point-specific comparison of individual proteins against outcome. At 6 months after allogenic HSCT, we could identify a protein profile pattern associated with occurrence of the complications such as chronic graft-versus-host disease, viral infections, relapse and death. When protein markers were analyzed separately, the plasma concentration of the inhibitory and cytotoxic T-cell surface protein FCRL6 (Fc receptor-like 6) was higher in patients with cytomegalovirus (CMV) viremia [log2-fold change 1.5 (P = 0.00099), 2.5 (P = 0.00035) and 2.2 (P = 0.045) at time points 6, 12 and 24 months]. Flow cytometry confirmed that FCRL6 expression was higher in innate-like γδ T cells, indicating that these cells are involved in controlling CMV reactivation in HSCT recipients. In conclusion, the potentially druggable FCRL6 receptor on cytotoxic T cells appears to have a role in controlling CMV viremia after HSCT. Furthermore, our results suggest that system-level analysis is a useful addition to the studying of single biomarkers in allogenic HSCT.

Predictors of cytomegalovirus reactivation after allogeneic hematopoietic cell transplantation: Insights from a real-world experience

BACKGROUND

We aimed to investigate factors associated with cytomegalovirus (CMV) viremia and CMV disease and its impact on post-transplant outcomes including overall survival (OS) following allogeneic hematopoietic stem cell transplantation (Allo-SCT).

METHODS

We conducted a single-center retrospective study including 452 Allo-SCT recipients (matched unrelated donor, MUD 61%; haploidentical, haplo 39%) from 2016 to 2021. Data were analyzed using SPSS v28. Descriptive (chi-square and t-test), Kaplan-Meier and regression analyses were conducted.

RESULTS

The median age was 57 years. Sixty-one percent were males and 84.3% were Caucasians. CMV serostatus was positive in 59.1% of recipients. The median follow-up was 24.4 months. CMV viremia and CMV disease were observed in 181 (40%) and 32 (7%) patients, respectively. Among CMV seropositive recipients, 65% developed CMV viremia and 11% were noted to have CMV disease compared to 4% and 1% in seronegative recipients, respectively (p < 0.001). Patients with CMV disease had significantly lower OS than those without CMV disease (median 14.1 months vs. not reached, p = 0.024); however, OS was not associated with CMV viremia (median not reached in both groups, p = 0.640). Letermovir prophylaxis was used in 66% (n = 176/267) of CMV seropositive recipients, but no impact was observed on the incidence of CMV viremia or CMV disease and OS.

CONCLUSIONS

CMV disease leads to significantly inferior survival after an allogeneic hematopoietic cell transplantation. Recipient CMV seropositive status was associated with the risk of CMV viremia and CMV disease, and this was not abrogated with the use of Letermovir prophylaxis.

Approaches and Challenges in the Current Management of Cytomegalovirus in Transplant Recipients: Highlighting the Role of Advanced Practice Providers (Nurse Practitioners and Physician Assistants)

Cytomegalovirus (CMV) infection is associated with increased morbidity and mortality in hematopoietic cell transplant (HCT) and solid organ transplant (SOT) recipients, with traditional anti-CMV therapies limited by their associated toxicities and the development of resistance. Clinical providers are often faced with challenging and complicated CMV infections that require multiple courses of antiviral therapies. Increasingly, advanced practice providers (APPs) are playing an important role in the day-to-day management of transplant recipients with CMV infection, including resistant/refractory CMV and other complex CMV syndromes. Here, we provide an overview of current preventative and treatment strategies for CMV infection in HCT and SOT recipients, highlighting the challenging aspects of current management and the potential utility of newer antiviral agents. This article also focuses on how a multidisciplinary team, orchestrated by APPs, can improve CMV-associated patient outcomes. Protocols using antiviral agents for the prevention or treatment of CMV infections require carefully designed and meticulously implemented strategies to ensure the best clinical outcomes for patients. APPs, who have increasingly become the frontline providers of outpatient care for transplant recipients, are ideally positioned to design and carry out these protocols.

The Emerging Role of Induced Pluripotent Stem Cells as Adoptive Cellular Immunotherapeutics

Adoptive cell therapy (ACT) has transformed the treatment landscape for cancer and infectious disease through the investigational use of chimeric antigen receptor T-cells (CAR-Ts), tumour-infiltrating lymphocytes (TILs) and viral-specific T-cells (VSTs). Whilst these represent breakthrough treatments, there are subsets of patients who fail to respond to autologous ACT products. This is frequently due to impaired patient T-cell function or "fitness" as a consequence of prior treatments and age, and can be exacerbated by complex manufacturing protocols. Further, the manufacture of autologous, patient-specific products is time-consuming, expensive and non-standardised. Induced pluripotent stem cells (iPSCs) as an allogeneic alternative to patient-specific products can potentially overcome the issues outlined above. iPSC technology provides an unlimited source of rejuvenated iPSC-derived T-cells (T-iPSCs) or natural killer (NK) cells (NK-iPSCs), and in the context of the growing field of allogeneic ACT, iPSCs have enormous potential as a platform for generating off-the-shelf, standardised, "fit" therapeutics for patients. In this review, we evaluate current and future applications of iPSC technology in the CAR-T/NK, TIL and VST space. We discuss current and next-generation iPSC manufacturing protocols, and report on current iPSC-based adoptive therapy clinical trials to elucidate the potential of this technology as the future of ACT.

Expanding the scope of the infectious diseases pharmacist in HCT: Beyond antimicrobial stewardship

BACKGROUND

Infectious disease (ID) pharmacists and antimicrobial stewardship (AMS) programs are integral to the infection management of hematopoietic cell transplant (HCT) recipients demonstrating effective implementation of clinical pathways, de-escalation of empirical antibiotics for febrile neutropenia (FN), allergy assessments, and use of rapid diagnostic testing. The HCT procedure is complex, dynamic, and a high risk for infectious complications. Therefore, there is an important role for an ID and AMS pharmacist to collaborate with the primary treating team, with ongoing care, involving the optimal individual patient prophylactic, pre-emptive and treatment management of infections in this high-risk population.

CONCLUSION

This review highlights key factors for consideration of ID/AMS Pharmacists in relation to HCT, including important aspects in the evaluation of infection risk prior to transplant, risk from donor sources, length of, and changes in immunosuppression, and potential drug-drug interactions from other essential supportive care therapies.

Current Perspectives on the Management of Herpesvirus Infections in Solid Organ Transplant Recipients

Solid organ transplant recipients (SOTRs) are at high risk of human herpesvirus (HHV)-related morbidity and mortality due to the use of immunosuppressive therapy. We aim to increase awareness and understanding of HHV disease burden in SOTRs by providing an overview of current prevention and management strategies as described in the literature and guidelines. We discuss challenges in both prevention and treatment as well as future perspectives.

The Ten Most Common Questions on Cytomegalovirus Infection in Hematopoietic Stem Cell Transplant Patients

With the rising number of patients undergoing hematopoietic stem cell transplantation (HSCT), clinicians are more likely to encounter infectious complications in immunocompromised hosts, particularly cytomegalovirus (CMV) infection. Besides the high mortality of CMV end-organ disease, patients with detectable CMV viremia may have worse outcomes and decreased survival even in the absence of end-organ disease. In view of the implications on morbidity and mortality, clinicians should maintain a high index of suspicion and initiate antiviral drugs promptly when CMV infection is confirmed. High-risk patients should be identified in order to provide optimal management. Additionally, novel antiviral agents with a good safety profile and minor adverse events are now available for prophylaxis in high-risk patients and for treatment of resistant or refractory CMV infection. The following review provides concise, yet comprehensive, guidance on the burden and risk factors of CMV in this population, as well as an update on the latest evidence for the management of CMV infection.

Adoptive Immunotherapy for Prophylaxis and Treatment of Cytomegalovirus Infection

Cytomegalovirus (CMV), a member of the Herpesviridae family, is frequent among hematopoietic cell transplant (HCT) and solid organ transplant (SOT) recipients in absence of antiviral prophylaxis, and is a major cause of morbidity and mortality in these vulnerable populations. Antivirals such ganciclovir, valganciclovir, and foscarnet are the backbone therapies, however drug toxicity and antiviral resistance may render these agents suboptimal in treatment. Newer therapies such as letermovir and maribavir have offered additional approaches for antiviral prophylaxis as well as treatment of drug resistant CMV infection, though may be limited by cost, drug intolerance, or toxicity. Adoptive immunotherapy, the transfer of viral specific T-cells (VSTs), offers a new approach in treatment of drug-resistant or refractory viral infections, with early clinical trials showing promise with respect to efficacy and safety. In this review, we will discuss some of the encouraging results and challenges of widespread adoption of VSTs in care of immunocompromised patients, with an emphasis on the clinical outcomes for treatment and prophylaxis of CMV infection among high-risk patient populations.

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.

In-depth summary over cytomegalovirus infection in allogeneic hematopoietic stem cell transplantation recipients

In this study, we reviewed various aspects of cytomegalovirus infection, including pathophysiology, diagnosis methods, and antiviral treatments. Background: Infections continue to be a major reason of complications like high non-relapse morbidity and mortality rate after allogenic hematopoietic stem cell transplantation. Cytomegalovirus is the most common infection in immunocompromised patients or those with graft-versus-host disease. The Latent-cytomegalovirus disease could increase the risk of reactivation in allogenic hematopoietic stem cell transplantation patients and lead to profound adverse effects on transplantation outcomes. Cytomegalovirus-specific CD4 + and CD8 + T cells reconstitution is crucial for protection against the virus reactivation. Different prophylactic, pre-emptive, and therapeutic anti-viral drugs are available to prevent cytomegalovirus infection/reactivation and treat resistant infections. Conclusion: Although there has been introduced various CMV antiviral treatment strategies like antiviral drugs, Vaccination, passive immunotherapies and adoptive transfer of CMV-specific T cells, further clinical trials are required to approve current therapies.

Epstein-Barr virus and cytomegalovirus reactivation after allogeneic hematopoietic cell transplantation in patients with non-Hodgkin lymphoma: the prevalence and impacts on outcomes : EBV and CMV reactivation post allo-HCT in NHL

Epstein–Barr virus (EBV) and cytomegalovirus (CMV) reactivations are common complications after allogeneic hematopoietic cell transplantation (allo-HCT), but data focusing on non–Hodgkin lymphoma (NHL) are limited. We retrospectively analyzed the prevalence of EBV and CMV reactivation post-allo-HCT and the impacts on transplant outcomes in 160 NHL patients. The 1-year incidences of EBV and CMV reactivation were 22.58% and 25.55%, respectively. Independent impactors for EBV reactivation were more than 6 lines of chemotherapy (P = 0.030), use of rituximab (P = 0.004), and neutrophil recovery within 30 days post-HCT (P = 0.022). For T-cell lymphoblastic lymphoma patients, the International Prognostic Index (IPI) (P = 0.015) and chronic GVHD (P = 0.001) increased the risk of CMV reactivation. CMV reactivation was independently related to a lower risk of relapse (P = 0.027) but higher transplant-related mortality (TRM) (P = 0.038). Although viral reactivation had no significant impact on overall survival (OS) in the whole cohort, it led to an inferior 2-year OS (67.6% versus 92.5%, P = 0.005) and TRM (20.1% versus 4.7%, P = 0.020) in recipients surviving for more than 180 days. We concluded that EBV and CMV reactivation post-allotransplant still deserved concern particularly in NHL patients with high-risk factors, since it is generally related to a deteriorated prognosis. Large-scale studies are warranted to validate our findings.

CMV Infection in Hematopoietic Stem Cell Transplantation: Prevention and Treatment Strategies

Purpose of Review

Cytomegalovirus (CMV) remains a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (Allo-HSCT). New strategies and methods for prevention and management of CMV infection are urgently needed. We aim to review the new developments in diagnostics, prevention, and management strategies of CMV infection in Allo-HSCT recipients.

Recent Findings

The approval of the novel anti-CMV drug letermovir in 2017 has led to an increase in the use of antiviral prophylaxis as a preferred approach for prevention in many centers. Real-world studies have shown efficacy similar to the clinical trial. CMV-specific T cell-mediated immunity assays identify patients with immune reconstitution and predict disease progression. Phase 2 trials of maribavir have shown its efficacy as preemptive therapy and treatment of resistant and refractory CMV infections. Adoptive T cell therapy is an emerging option for treatment of refractory and resistant CMV. Of the different CMV vaccine trials, PepVax has shown promising results in a phase 1 trial.

Summary

CMV cell-mediated immunity assays have potential to be used as an adjunctive test to develop individualized management plan by identifying the patients who develop immune reconstitution; however, further prospective interventional studies are needed. Maribavir and adoptive T cell therapy are promising new therapies for treatment of CMV infections. CMV vaccine trials for prevention are also under way.