Impact of Cytomegalovirus Viral Load on Probability of Spontaneous Clearance and Response to Preemptive Therapy in Allogeneic Stem Cell Transplantation Recipients

Cost-effectiveness of maribavir versus conventional antiviral therapies for post-transplant refractory cytomegalovirus infection with or without genotypic resistance: A US perspective

This study evaluated the cost-effectiveness of maribavir versus investigator-assigned therapy (IAT; valganciclovir/ganciclovir, foscarnet, or cidofovir) for post-transplant refractory cytomegalovirus (CMV) infection with or without resistance. A two-stage Markov model was designed using data from the SOLSTICE trial (NCT02931539), real-world multinational observational studies, and published literature. Stage 1 (0-78 weeks) comprised clinically significant CMV (csCMV), non-clinically significant CMV (n-csCMV), and dead states; stage 2 (78 weeks-lifetime) comprised alive and dead states. Total costs (2022 USD) and quality-adjusted life years (QALYs) were estimated for the maribavir and IAT cohorts. An incremental cost-effectiveness ratio was calculated to determine cost-effectiveness against a willingness-to-pay threshold of $100 000/QALY. Compared with IAT, maribavir had lower costs ($139 751 vs $147 949) and greater QALYs (6.04 vs 5.83), making it cost-saving and more cost-effective. Maribavir had higher acquisition costs compared with IAT ($80 531 vs $65 285), but lower costs associated with administration/monitoring ($16 493 vs $27 563), adverse events (AEs) ($11 055 vs $16 114), hospitalization ($27 157 vs $33 905), and graft loss ($4516 vs $5081), thus making treatment with maribavir cost-saving. Maribavir-treated patients spent more time without CMV compared with IAT-treated patients (0.85 years vs 0.68 years), leading to lower retreatment costs for maribavir (cost savings: -$42 970.80). Compared with IAT, maribavir was more cost-effective for transplant recipients with refractory CMV, owing to better clinical efficacy and avoidance of high costs associated with administration, monitoring, AEs, and hospitalizations. These results can inform healthcare decision-makers on the most effective use of their resources for post-transplant refractory CMV treatment.

Baseline Cytomegalovirus Viremia at Cryptococcal Meningitis Diagnosis Is Associated With Long-term Increased Incident TB Disease and Mortality in a Prospective Cohort of Ugandan Adults With HIV

Background

Adults with HIV-associated cryptococcal meningitis have overlapping burdens of cytomegalovirus (CMV) and tuberculosis (TB) coinfections. CMV infection/reactivation is strongly associated with CMV-specific memory T-cell activation and upregulation of type 1 interferons, which may lead to increased risk of TB disease and poor outcomes.

Methods

We conducted a cohort study of 2-week survivors of cryptococcal meningitis during 2010-2021 to determine TB incidence and all-cause mortality over time stratified by baseline CMV status.

Results

We followed 497 Ugandans with HIV-associated cryptococcal meningitis for a median (interquartile range) of 4.6 (2.6-53.9) months. Overall, 42% (210/497) developed incident TB disease or died. One-fifth (98/497, 19.7%) developed incident TB disease, and 29% (142/497) of participants died during follow-up. Of 259 participants with CMV viral load measured at baseline, 37% (96/259) had concurrent CMV viremia (defined as anyone with detectable CMV DNA in plasma/serum by qualitative polymerase chain reaction [PCR] detection). Of 59 with measured CMV immunoglobulin G (IgG), 100% had positive CMV IgG antibody serology (≥10 enzyme-linked immunosorbent assay units/mL). CMV viremia was positively associated with higher HIV viral load (196 667 vs 73 295 copies/mL; P = .002) and higher cerebrospinal fluid fungal burden (68 500 vs 14 000 cfu/mL; P = .002) compared with those without. Participants with high-level CMV viremia (defined as CMV viral load ≥1000 IU/mL) had twice the risk of incident TB (subdistribution adjusted hazard ratio [aHR], 2.18; 95% CI, 1.11-4.27) and death (aHR, 1.99; 95% CI, 1.14-3.49) compared with participants with no or low-level CMV viremia. There was no association between the CMV IgG index and the incidence of TB/death (P = .75).

Conclusions

CMV viremia >1000 IU/mL at meningitis diagnosis was associated with increased incident TB disease and mortality during long-term follow-up. Future studies to determine the causal relationship and potential for therapeutic intervention are warranted.

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.

Human Cytomegalovirus (HCMV) - specific T-cell response after letermovir prophylaxis is predictive for subsequent HCMV reactivation in haematopoietic stem cell transplant recipients

BACKGROUND

Human Cytomegalovirus (HCMV) is still one of the major concerning infection in hematopoietic stem cell transplant (HSCT) recipients. Letermovir (LTV) has been recently introduced for HCMV prophylaxis in adult patients who received allogeneic HSCT. However, many aspects related to immune reconstitution need to be further explored. The aim of this study was to define the prognostic role of HCMV-specific T-cell frequency measured at the end of LTV prophylaxis in predicting the risk for clinically significant HCMV infection (i.e. infection requiring antiviral treatment) after the stop of the prophylaxis.

METHODS

Sixty-six adult patients who underwent allogeneic HSCT were enrolled and HCMV DNAemia was prospectively monitored. Additionally, HCMV-specific T-cell response was evaluated using ELISpot assay against two different antigens (HCMV infected cell lysate and pp65 peptide pool).

RESULTS

Ten patients (15.2%) developed at least one positive HCMV DNAemia episode during LTV prophylaxis, whereas 50/66 (75.8%) patients developed at least one positive HCMV DNA event after LTV prophylaxis. Of note, 25 of them (50%) experienced a clinically significant HCMV infection. The median HCMV-specific T-cell response measured against HCMV lysate but not against pp65 peptide pool was lower in patients who developed HCMV clinically significant infection after prophylaxis. A ROC analysis revealed that the level of 0.04 HCMV-specific T cells/µl should be used as cut-off for development of clinically significant HCMV reactivation after prophylaxis.

CONCLUSION

Assessment of HCMV-specific immunity upon discontinuation of universal prophylaxis with LTV should be considered as a method for identification of patients at risk for clinically significant HCMV infection.

Threshold of Quantitative Cytomegalovirus DNA PCR for Preemptive Treatment in Pediatric Hematopoietic Stem Cell Transplant Recipients

BACKGROUND

Consensus cytomegalovirus (CMV) DNA viral load thresholds for intervention in hematopoietic stem cell transplant (HSCT) recipients have not been established, especially in children. This study aimed at obtaining viral load thresholds of CMV DNA to guide preemptive management in pediatric HSCT recipients.

MATERIALS AND METHODS

A total of 465 blood samples from 177 children who received HSCT between 2015 and 2019 were included in a single center in Korea. The samples were analyzed for CMV infection by both antigenemia assay and quantitative DNA polymerase chain reaction. The 2 assay results were compared for the 233 samples which were collected when antiviral treatment has not been initiated. We determined the viral loads corresponding to the antigenemia of 5 pp65-positive cells/2×10 5 white blood cells (WBCs) as the level for initiating preemptive therapy.

RESULTS

Sixty percent of the samples were collected within 100 days (39.7% in 0 to 50 d, 60.2% in 0 to 100 d) from the graft infusion. The correlation between CMV DNA viral load and CMV antigenemia level increased significantly after 50 days from the graft infusion ( r =0.71 vs. r =0.93, P <0.0001). The correlation was greater in the antiviral treatment-naive group than the treatment group ( r =0.75 vs. r =0.66, P <0.0001). Under receiver operating characteristic curve analysis of the treatment-naive group, the estimated threshold CMV DNA viral loads corresponding to 5 pp65-positive cells/2×10 5 WBCs was 898 IU/mL.

CONCLUSIONS

The CMV DNA levels that corresponded to 5 pp65-positive cells/2×10 5 WBCs was 900 IU/mL in the HSCT group. The proposed viral load thresholds can be used to guide preemptive therapy in pediatric HSCT recipients, especially in the preengraftment period.

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.

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.

Early immune surveillance to predict cytomegalovirus outcomes after allogeneic hematopoietic stem cell transplantation

Background

There is no method of predicting human cytomegalovirus (HCMV) outcomes in allogeneic hematopoietic stem cell transplant recipients clinically, leading in some cases to excessive or insufficient antiviral therapy. We evaluated the early immune response of recipients with disparate HCMV outcomes.

Methods

The HCMV outcomes of recipients were determined by long-term monitoring of HCMV DNA levels posttransplant. HCMV IgG and IgM concentrations at 1 week before and 1 week after transplantation, absolute lymphocyte counts, and HCMV-specific IFN-γ secreting cells at 1 month posttransplant were evaluated based on HCMV outcome.

Results

All recipients were negative for HCMV IgM. Significant differences between recipients with and without HCMV reactivation were observed in pre- and post-transplant HCMV IgG antibody levels, absolute lymphocyte counts, and HCMV-specific IFN-γ secreting cells (P &lt; 0.05). HCMV IgG antibody levels significantly increased after transplantation in recipients with HCMV reactivation (P = 0.032), but not in those without reactivation. Multivariate analysis revealed that except for the absolute lymphocyte count these biomarkers were related to HCMV reactivation, independent of other clinical factors. In time-to-event analyses, lower levels of these biomarkers were associated with an increased 150-day cumulative incidence of HCMV reactivation (log-rank P &lt; 0.05). In recipients with HCMV reactivation, the duration of HCMV DNAemia had negative correlation with HCMV-specific IFN-γ-secreting cells (P = 0.015, r = -0.372). The relationships between the peak HCMV DNA load and absolute lymphocyte count and HCMV-specific IFN-γ-secreting cells followed the same trends (P = 0.026, r = -0.181 and P = 0.010, r = -0.317).

Conclusions

HCMV IgG, absolute lymphocyte count, and HCMV-specific IFN-γ secreting cells represent the humoral and cellular immune response. Early monitoring of these immune markers could enable prediction of HCMV outcomes posttransplant and assessment of the severity of HCMV DNAemia.

Immunoprofiling reveals cell subsets associated with the trajectory of cytomegalovirus reactivation post stem cell transplantation

Human cytomegalovirus reactivation is a major opportunistic infection after allogeneic haematopoietic stem cell transplantation and has a complex relationship with post-transplant immune reconstitution. Here, we use mass cytometry to define patterns of innate and adaptive immune cell reconstitution at key phases of human cytomegalovirus reactivation in the first 100 days post haematopoietic stem cell transplantation. Human cytomegalovirus reactivation is associated with the development of activated, memory T-cell profiles, with faster effector-memory CD4⁺ T-cell recovery in patients with low-level versus high-level human cytomegalovirus DNAemia. Mucosal-associated invariant T cell levels at the initial detection of human cytomegalovirus DNAemia are significantly lower in patients who subsequently develop high-level versus low-level human cytomegalovirus reactivation. Our data describe distinct immune signatures that emerged with human cytomegalovirus reactivation after haematopoietic stem cell transplantation, and highlight Mucosal-associated invariant T cell levels at the first detection of reactivation as a marker that may be useful to anticipate the magnitude of human cytomegalovirus DNAemia.

Human cytomegalovirus is a major cause of morbidity and mortality in transplant patients and multiple immune cells types are critical during infection and reactivation. Here the authors assess the immune cell compartments of haematopoietic stem cell recipients in the early period post transplantation and identify key features of effector memory CD4⁺ T cells and mucosal associated invariant T cells in this context.

Letermovir vs. high-dose valacyclovir for cytomegalovirus prophylaxis following haploidentical or mismatched unrelated donor allogeneic hematopoietic cell transplantation receiving post-transplant cyclophosphamide

Patients undergoing haploidentical or mismatched unrelated donor (haplo/MMUD) allogeneic hematopoietic cell transplantation (alloHCT) receiving post-transplant cyclophosphamide (PTCy) are at high risk of cytomegalovirus (CMV) infection. Experience with letermovir (LET) in this population is limited. This single center retrospective cohort study compared CMV and transplant outcomes between LET and a historical control with high-dose valacyclovir (HDV) prophylaxis in adults undergoing haplo/MMUD alloHCT. Thirty-eight CMV seropositive patients were included, 19 in each arm. LET reduced the incidence of CMV infection (5% vs. 53%, RR 0.01, 95% CI 0.014-0.71, p = .001) and need for CMV treatment by day +100 (5% vs. 37%, RR 0.14, 95% CI 0.18-0.99, p = .017) compared to HDV. Median CMV event-free-survival was improved with LET (not reached vs. 80 days, HR 0.114, 95% CI 0.07-0.61, p = .004). These data support the efficacy of LET in alternative donor transplants.

Impact of cytomegalovirus infection prior to hematopoietic stem cell transplantation in children with inborn errors of immunity

The presence of active viral infections has an impact on the prognosis of patients undergoing hematopoietic stem cell transplantation (HSCT). Nevertheless, the number of reports of cytomegalovirus infection in patients with inborn errors of immunity (IEI) who undergo HSCT is relatively low. To analyze the effect of cytomegalovirus infection acquired prior to curative treatment on patient survival in 123 children with IEI. An observational and retrospective study was performed with patients younger than 18 years diagnosed with IEI who were candidates for HSCT, gene therapy, or thymus transplantation at five hospitals in Spain between 2008 and 2019. We included 123 children, 25 infected by cytomegalovirus prior to undergoing curative treatment (20.3%). At IEI diagnosis, 24 of the patients were already infected, 21 of whom had symptomatic cytomegalovirus disease (87%), while the other three patients developed disease before undergoing curative treatment. The patients with cytomegalovirus infection had higher mortality than those without (p = 0.006). Fourteen patients developed refractory cytomegalovirus infection (56%), all of whom died, while no patients with non-refractory infection died (p = 0.001) All deaths that occurred before curative treatment and three of the five after the treatment were attributed to cytomegalovirus. Patients with refractory cytomegalovirus disease had the highest pre-HSCT mortality rate (64.3%), compared with the non-infected children and those with non-refractory cytomegalovirus disease (10.1%) (p < 0.0001).

CONCLUSION

Prevention and prompt control of cytomegalovirus infection, together with early HSCT/gene therapy, are crucial for improving the prognosis in children with IEI.

WHAT IS KNOWN

• Cytomegalovirus is the most frequent viral infection in children with inborn errors of immunity who are candidates to hematopoietic stem cell transplantation (HSCT). • Active viral infections at the time of HSCT lead to worse prognosis.

WHAT IS NEW

• In children with inborn errors of immunity and indication of HSCT, refractory cytomegalovirus disease is associated with a very high mortality rate, compared with non-infected children and those with non-refractory cytomegalovirus disease. • In patients with novel transplantation indications, the presence and treatment response of CMV infection should be considered to decide the best possible moment for HSCT.

OUP accepted manuscript

Hepatitis B virus (HBV) remains a global public health problem despite the availability of effective vaccine and antiviral therapy. Cytomegalovirus (CMV), another hepatotropic virus, is also very prevalent in the general population worldwide. Both HBV and CMV can persist in the host and have potential to reactivate especially with weakened host cellular immunity. Superimposed CMV infection can lead to severe HBV reactivation. The pathogenesis of the co-infection of HBV and CMV remains poorly understood. Studies reported conflicting results regarding the inhibitory effect of CMV on HBV replication. There is an unmet need on the management of co-infection of HBV and CMV; research initiatives dedicated to understanding their interactions are urgently needed.

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.

Impact of CMV reactivation on relapse of acute myeloid leukemia after HCT is dependent on disease stage and ATG

The impact of CMV reactivation on hematologic relapse after HCT is modulated by AML stage (CR1 or advanced) and in vivo T cell depletion.

Following CMV reactivation, NRM was increased in CR1 patients without ATG, but not in patients with ATG or advanced disease stages.

Cytomegalovirus (CMV) reactivation is a frequent complication after allogeneic hematopoietic cell transplantation (HCT), whose impact on clinical outcome, in particular on leukemic relapse, is controversial. We retrospectively analyzed 687 HCT recipients with acute myeloid leukemia (AML) and ciclosporin-based immunosuppression to better understand the differential impact of CMV on transplant outcomes depending on AML disease stage and in vivo T cell depletion with antithymocyte globulin (ATG). Without ATG, CMV reactivation associated with significantly reduced relapse, yet its effect was more pronounced for advanced disease AML (P = .0002) than for patients in first complete remission (CR1, P = .0169). Depending on the disease stage, ATG exposure abrogated relapse protection following CMV reactivation in advanced stages (P = .796), while it inverted its effect into increased relapse for CR1 patients (P = .0428). CMV reactivation was associated with significantly increased nonrelapse mortality in CR1 patients without ATG (P = .0187) but not in those with advanced disease and ATG. Following CMV reactivation, only patients with advanced disease had significantly higher event-free survival rates as compared with patients without CMV. Overall, our data suggest that both ATG and disease stage modulate the impact of post-HCT CMV reactivation in opposite directions, revealing a level of complexity that warrants future studies regarding the interplay between antivirus and antitumor immunity.

Lower Incidence of Cytomegalovirus Reactivation Following Post-Transplantation Cyclophosphamide HLA-Mismatched Unrelated Donor Transplantation

The use of haploidentical or HLA-mismatched unrelated donors (MMUD) allows allogeneic hematopoietic cell transplantation in individuals without suitable matched donors. Post-transplantation cyclophosphamide (PTCy) is used routinely for prevention of graft-versus-host disease in recipients of haploidentical transplants, and its use has been recently explored in MMUD transplantation. We compared the incidence of cytomegalovirus (CMV) reactivation and rate of lymphocyte recovery between PTCy MMUD and alternative transplantation modalities. Single-center retrospective study of 22 consecutive PTCy MMUD recipients transplanted between April 2017 and January 2019. Patients undergoing anti-thymocyte globulin (ATG) MMUD (n = 37) and PTCy haploidentical transplantation (n = 19) between January 2015 and July 2018 served as historical controls. We assessed the incidence of CMV (any viremia) and clinically significant CMV reactivation (cs-CMVi; defined as CMV disease or CMV viremia leading to preemptive treatment) in these 3 groups. Immune reconstitution was assessed by absolute lymphocyte count (ALC) at days 30, 90, 180, and 360 after transplantation. Statistical analyses included Kaplan-Meier plots with a log-rank test, Kruskal-Wallis test, and Fisher's exact test where appropriate, and logistic regression analyses. For PTCy MMUD, PTCy haploidentical and ATG MMUD groups, the 100-day and 200-day incidence of CMV (any viremia) were 41%, 63%, and 77% (P = .02), and 64%, 68%, and 86% (P = .049), respectively. The rate of cs-CMVi was also lower in PTCy MMUD compared to PTCy haploidentical and ATG MMUD (14% versus 53% and 54% at day 100 [P = .01] and 25% versus 53% and 58% at day 200 [P = .03]). There was a trend toward lower 200-day incidence of cs-CMVi in PTCy MMUD compared to ATG MMUD, even after excluding letermovir-treated patients from the analysis (25% versus 58% [P = .06]). The association between PTCy MMUD and lower risk of cs-CMVi remained significant even after adjusting for letermovir prophylaxis (odds ratio = 0.23, 95% confidence interval, 0.07-0.81 [P = .02]). Day 30 ALC was lower in PTCy MMUD compared to PTCy haploidentical and ATG MMUD (0.14, 0.33, 0.44 × 10⁹/L, respectively [P = .005) but similar across groups at other time points. PTCy MMUD transplantation was associated with lower incidence of CMV events, independent of the use of CMV prophylaxis. Larger studies are needed.

CMV viral load kinetics as surrogate endpoints after allogeneic transplantation

BACKGROUNDViral load (VL) surrogate endpoints transformed development of HIV and hepatitis C therapeutics. Surrogate endpoints for CMV-related morbidity and mortality could advance development of antiviral treatments. Although observational data support using CMV VL as a trial endpoint, randomized controlled trials (RCTs) demonstrating direct associations between virological markers and clinical endpoints are lacking.METHODSWe performed CMV DNA PCR on frozen serum samples from the only placebo-controlled RCT of ganciclovir for early treatment of CMV after hematopoietic cell transplantation (HCT). We used established criteria to assess VL kinetics as surrogates for CMV disease or death by weeks 8, 24, and 48 after randomization and quantified antiviral effects captured by each marker. We used ensemble-based machine learning to assess the predictive ability of VL kinetics and performed this analysis on a ganciclovir prophylaxis RCT for validation.RESULTSVL suppression with ganciclovir reduced cumulative incidence of CMV disease and death for 20 years after HCT. Mean VL, peak VL, and change in VL during the first 5 weeks of treatment fulfilled the Prentice definition for surrogacy, capturing more than 95% of ganciclovir's effect, and yielded highly sensitive and specific predictions by week 48. In the prophylaxis trial, the viral shedding rate satisfied the Prentice definition for CMV disease by week 24.CONCLUSIONSOur results support using CMV VL kinetics as surrogates for CMV disease, provide a framework for developing CMV preventative and therapeutic agents, and support reductions in VL as the mechanism through which antivirals reduce CMV disease.FUNDINGMerck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc.

Severe cytomegalovirus disease with encephalitis after CAR-T cell therapy: A rare but potentially fatal complication

Cytomegalovirus (CMV) is a ubiquitous herpes virus that develops lifelong latency following primary infection and can be reactivated following immune suppression. CMV encephalopathy has been described in few reports after hematopoietic stem cell transplantation and in patients with acquired immunodeficiency syndrome. To the best of our knowledge, CMV encephalopathy following CAR-T cells infusion had not been previously reported. Initial CMV viral load and monitoring are crucial in patients with CAR-T cells to allow early intervention with aggressive antiviral treatment without delay if needed.

Letermovir treatment of cytomegalovirus infection or disease in solid organ and hematopoietic cell transplant recipients

BACKGROUND

Few options are available for cytomegalovirus (CMV) treatment in transplant recipients resistant, refractory, or intolerant to approved agents. Letermovir (LET) is approved for prophylaxis in hematopoietic cell transplant (HCT) recipients, but little is known about efficacy in CMV infection. We conducted an observational study to determine the patterns of use and outcome of LET treatment of CMV infection in transplant recipients.

METHODS

Patients who received LET for treatment of CMV infection were identified at 13 transplant centers. Demographic and outcome data were collected.

RESULTS

Twenty-seven solid organ and 21 HCT recipients (one dual) from 13 medical centers were included. Forty-five of 47 (94%) were treated with other agents prior to LET, and 57% had a history of prior CMV disease. Seventy-seven percent were intolerant to other antivirals; 32% were started on LET because of resistance concerns. Among 37 patients with viral load < 1000 international units (IU)/ml at LET initiation, two experienced >1 log rise in viral load by week 12, and no deaths were attributed to CMV. Ten patients had viral load > 1000 IU/ml at LET initiation, and six of 10 (60%) had a CMV viral load < 1000 IU/ml at completion of therapy or last known value. LET was discontinued in two patients for an adverse event.

CONCLUSIONS

Patients treated with LET with viral load < 1000 IU/ml had good virologic outcomes. Outcomes were mixed when LET was initiated at higher viral loads. Further studies on combination therapy or alternative LET dosing are needed.

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.

CMV viral load kinetics predict CMV end-organ disease and mortality after hematopoietic cell transplant (HCT)

BACKGROUND

We investigated the association between time-averaged area under the curve (AAUC) of CMV viral load (VL) by D100 and overall survival (OS) at one-year post-hematopoietic cell transplantation (HCT).

METHODS

A retrospective cohort study, including patients receiving HCT between 2010.6 and 2017.12 from Memorial Sloan Kettering Cancer Center. AAUC was calculated for patients with detected VL. Patients were categorized into "non-controllers" (Q4) and "controllers" (Q1-3) using the highest AAUC quartile as cutoff. Kaplan-Meier analyses and Cox models were used to estimate the association between AAUC and OS. Patients with non-detected CMV VL were categorized into "elite-controllers" (R+ or R-/D+) and "R-/D-".

RESULTS

The study (N=952) included 282 controllers, 93 non-controllers, 275 elite-controllers, and 302 R-/D-. OS was 80.1% and 58.1% for controllers and non-controllers, respectively. In multivariable models, non-controllers had worse OS versus controllers (adjusted hazard ratio [HR] 2.65, 95% CI 1.71-4.12). In landmark analyses, CMV controllers had similar OS as elite-controllers (HR 1.26, 95% CI 0.83-1.91) or R-/D- (HR 0.98, 95% CI 0.64-1.5).

CONCLUSION

CMV non-controllers had worse OS at one-year post-HCT. CMV controllers had similar OS as elite-controllers or R-/D-. Future studies are needed to validate our AAUC cutoff across different cohorts and CMV management strategies.

STING and transplantation: can targeting this pathway improve outcomes?

Stimulator of interferon genes (STING) is an innate immune sensor of cytoplasmic dsDNA originating from microorganisms and host cells. STING plays an important role in the regulation of murine graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and may be similarly activated during other transplantation modalities. In this review, we discuss STING in allo-HSCT and its prospective involvement in autologous HSCT (auto-HSCT) and solid organ transplantation (SOT), highlighting its unique role in nonhematopoietic, hematopoietic, and malignant cell types.

Positive HCMV DNAemia in stem cell recipients undergoing letermovir prophylaxis is expression of abortive infection

Letermovir (LMV) inhibits HCMV replication by binding to components of the HCMV-terminase complex showing a potential role in prevention of HCMV-related complications in allogenic hematopoietic stem cell transplant recipients (allo-HSCTRs). However, little is known about breakthrough HCMV infection and the relevance of HCMV DNAemia during prophylaxis. We reported the results of a multicenter prospective study involving five Italian centers in the management of HCMV DNAemia in 75 adult HCMV-seropositive allo-HSCTRs undergoing LMV prophylaxis. The aim of the present study was to characterize the presence of real HCMV reactivation during LMV prophylaxis. Then, the presence of circulating infectious HCMV particles was determined by virus isolation and degradation of free-floating viral DNA. This report provides the first evidence that during LMV prophylaxis the clinical relevance of HCMV DNAemia should be critically considered.

Improving Outcomes in Hematopoietic Stem Cell Transplant: Recent Advances

During JADPRO Live Virtual 2020, Maritza Alencar, DNP, MBA, APRN-BC, BMTCN, described advances in the management and prevention of infectious disease complications and graft-vs.-host disease following transplant. Dr. Alencar also emphasized the role of advanced practitioners in post-transplant care.

Cytomegalovirus kinetics after hematopoietic cell transplantation reveal peak titers with differential impact on mortality, relapse and immune reconstitution

Even in the era of PCR-based monitoring, prophylaxis, and preemptive therapy, Cytomegalovirus (CMV) viremia remains a relevant cause of non-relapse mortality (NRM) after allogeneic hematopoietic cell transplantation (HCT). However, studies using binary analysis (presence/absence of CMV) reported contradicting data for NRM, overall survival and leukemia relapse. Here, we analyzed CMV replication kinetics in 11 508 whole blood PCR samples of 705 patients with HCT between 2012 and 2017. Using two independent models based on CMV peak titers and on the time point of first CMV reactivation, we stratified patients into risk cohorts. Each cohort had distinct cellular immune reconstitution profiles and differentiated for relevant clinical outcomes. Patients with high CMV peak titers had significantly reduced overall survival (HR 2.13, 95% CI 1.53-2.96; p < .0001), due to high NRM. Early impaired T cell reconstitution was a risk factor for high CMV peak titers, however relevant CMV viremia also related to boosted T cell reconstitution. Importantly, intermediate CMV peak titers associated with a significantly reduced relapse probability (HR 0.53, 95% CI 0.31-0.91; p = .022). In short, CMV kinetics models distinguished relevant clinical outcome cohorts beyond the R+ serostatus with distinct immune reconstitution patterns and resolve in part contradicting results of previous studies exclusively focused on the presence or absence of CMV.

Survey of HCMV in allogenic and autologous stem cell transplantation by real-time PCR in Kermanshah, west of Iran

INTRODUCTION

Human Cytomegalovirus (HCMV) is the most important viral pathogen in people undergoing bone marrow transplantation (BMT). HCMV detection in the early stages makes is possible to save the patients' lives through immediate and timely treatment. The aim of this study was to investigate the status of HCMV using the real-time PCR method in BMT patients in Kermanshah, west of Iran.

METHODS

HCMV monitoring was done in 120 patients who underwent BMT, 38 allogeneic cases and 82 autologous cases, using the ELISA serology test before transplantation. The participants were followed up 100 days after transplantation for HCMV detection in blood samples using real-time PCR. Preemptive therapy started with Ganciclovir and Foscarnet when the viral load was > 200 HCMV DNA copies/ml.

RESULTS

Despite preemptive therapy, infection recurred in less than 1 month. HCMV recurred more frequently in patients undergoing allogenic transplation versus those receiving autologous transplantation. Recurrence was seen in 5 patients receiving allogenic transplantation. HCMV recurrence occurred in five patients with allogeneic transplantation. Twelve patients undergoing allogeneic or autologous transplantation (83%) and a virus load of > 1000 copies/ml showed HCMV-related symptoms. Three patients died, two due to HCMV-related pneumonia and the other one due to a fungal infection.

CONCLUSION

Real-time PCR may be a useful method for quantification and monitoring of HCMV recurrence and may be helpful in choosing more efficient HCMV preemptive treatment in BMT recipients.

A Systematic Review of the Clinical Pharmacokinetics, Pharmacodynamics and Toxicodynamics of Ganciclovir/Valganciclovir in Allogeneic Haematopoietic Stem Cell Transplant Patients

BACKGROUND

Ganciclovir (GCV) and valganciclovir (VGCV) are the first-line agents used to prevent and treat cytomegalovirus (CMV) infection in allogeneic haematopoietic stem cell transplant (alloHCT) patients.

OBJECTIVE

The aim of this work was to describe available data for the clinical pharmacokinetics, pharmacodynamics and toxicodynamics of GCV and VGCV and the potential of a therapeutic drug monitoring strategy to improve outcomes in the alloHCT population.

METHODS

We systematically reviewed the pharmacokinetics (dose-exposure), pharmacodynamics (exposure-efficacy) and toxicodynamics (exposure-toxicity) of GCV and VGCV in alloHCT patients with CMV infection. Studies including alloHCT patients treated for CMV infection reporting the pharmacokinetics, pharmacodynamics and toxicodynamics of GCV or VGCV were searched for using the PUBMED and EMBASE databases from 1946 to 2019. Only studies involving participants > 12 years of age and available in the English language were included.

RESULTS

A total of 179 patients were included in the 14 studies that met the inclusion criteria, of which 6 examined GCV pharmacokinetics only, while 8 also examined GCV pharmacodynamics and toxicodynamics. Reported pharmacokinetic parameters showed considerable interpatient variability and were different from other populations, such as solid organ transplant and human immunodeficiency virus-infected patients. Only one study found a correlation between neutropenia and elevated peak and trough GCV concentrations, with no other significant pharmacodynamic and toxicodynamic relationships identified. While therapeutic drug monitoring of GCV is performed in some institutions, no association between GCV therapeutic drug monitoring and clinical outcomes was identified.

CONCLUSION

Further studies of the pharmacokinetics, pharmacodynamics and toxicodynamics of GCV/VGCV in alloHCT patients are required to identify a more robust therapeutic range and to subsequently quantify the potential value of therapeutic drug monitoring of GCV/VGCV in the alloHCT population.

Cytomegalovirus (CMV) management in allogeneic hematopoietic cell transplantation: Pre-transplant predictors of survival, reactivation, and spontaneous clearance

BACKGROUND

Cytomegalovirus (CMV) reactivation is a frequent complication after allogeneic hematopoietic cell transplant (alloHCT).

METHOD

We analyzed 159 alloHCT recipients with 4409 quantitative CMV viral loads to determine pre-transplant predictors of CMV reactivation, clinically significant CMV infection (cs-CMVi, defined as CMV viral load >1000 IU/mL), CMV disease, kinetics of spontaneous clearance of CMV, and survival using a standardized pre-emptive therapy approach to identify at-risk groups to target prevention strategies.

RESULTS

Cs-CMVi was most common in D-/R+ unrelated donor transplants (URD). Spontaneous CMV clearance occurred in 26% of patients who reached a viral load of 56-137 IU/mL, 6% at 138-250 IU/mL and in one patient >250 IU/mL. Median time between the first CMV reactivation (>56 IU/mL) and a viral load >250 IU/mL was 13 days, whereas the time from the first viral load >250 IU/mL to reach a vial load >1000 IU/mL was 4 days. Cs-CMVi was associated with a significant increase in non-relapse mortality (NRM) on multivariate analysis.

CONCLUSIONS

Overall, this study indicates that D-/R+ URD recipients are at high-risk for cs-CMVi- and CMV-related mortality, and are potential candidates for targeted CMV prophylaxis. Spontaneous clearance of CMV beyond a viral load of 250 IU/mL is uncommon, suggesting that this could be used as an appropriate threshold to initiate pre-emptive therapy.

Progress and Challenges in the Prevention, Diagnosis, and Management of Cytomegalovirus Infection in Transplantation

Hosts with compromised or naive immune systems, such as individuals living with HIV/AIDS, transplant recipients, and fetuses, are at the highest risk for complications from cytomegalovirus (CMV) infection. Despite substantial progress in prevention, diagnostics, and treatment, CMV continues to negatively impact both solid-organ transplant (SOT) and hematologic cell transplant (HCT) recipients. In this article, we summarize important developments in the field over the past 10 years and highlight new approaches and remaining challenges to the optimal control of CMV infection and disease in transplant settings.

Optimal pre-emptive cytomegalovirus therapy threshold in a patient population with high prevalence of seropositive status

INTRODUCTION

Preemptive therapy (PET) for cytomegalovirus (CMV) reactivation post allogeneic hematopoietic stem cell transplantation (SCT) was shown to decrease the incidence of CMV disease. However, the optimal PET threshold is elusive.

PURPOSE OF THE STUDY

To examine the efficacy of PET initiation at a viral threshold of 1000 copies/mL (1560 IU/mL) in a patient population with high prevalence of CMV seropositive status.

PATIENTS AND METHODS

A single center retrospective review of patients that underwent allogeneic SCT was done.

RESULTS

A total of 195 allogeneic SCT recipients were included with median follow up of 18.1 (0.7-95.6) months. A total of 178 (91 %) of patients had a positive CMV PCR with median days to initial reactivation post SCT of 17 (1-1187); 129 patients had peak CMV titer < 1000 copies/mL (low titer) whereas the remaining 49 patients had a peak titer ≥ 1000 copies/mL (high titer). 120 (93 %) of patients with low titers cleared spontaneously with median time to clearance of 40 days (4-188). One patient in the high titer group developed CMV disease. At multivariable analysis; age at SCT HR 1.02 (1.004-1.04; 0.017), malignant vs. benign condition HR 9.4 (2.47-61; 0.0005) and cGVHD HR 0.37 (0.2-0.65; 0.0005) were significant for OS.

CONCLUSIONS

CMV reactivation post SCT was very common in patients with high prevalence of seropositive status. A PET threshold of 1000 copies/mL (1560 IU/mL) appears desirable as it was associated with spontaneous clearance in over 90 % of patients while minimizing treatment related toxicity. Validation of these observations is warranted.

CMV infection management in transplant patients in Italy

Transplant represents an effective strategy in the management of chronic organ dysfunction. Nonetheless, life threatening risks remain, especially in the post-transplant; among them, human cytomegalovirus (CMV) is a major concern, currently causing active infections in at least one-third of transplant recipients. Microbiologist and transplant scientific societies redefined guidance on CMV disease prevention and the best use for universal prophylaxis and pre-emptive virological monitoring. Developments in molecular diagnostic supported the spread of the pre-emptive strategy, and quantitative Real Time-PCR assays has unravelled the potential of viral load measurement as a predictor of the infection development in CMV post-transplant management. However, despite the WHO 1st CMV International Standard, the standardization of diagnostic and clinical practice has been limited by the absence of algorithms for calculating conversion factor to International Units and the lack of shared monitoring procedure, both at national and international level. At a regional level, the Italian scientific societies, AMCLI (Italian Clinical Microbiologist Association), SITO (Organ Transplant Italian Society), GITMO (Italian Group for Bone Marrow Transplant), recently tried to define a consensus for post-transplant monitoring. The concerted practice encompasses molecular quantitative PCR assays technical aspects and endorses the relevance of immunologic monitoring for improvement in patient risk stratification and prognosis. Here, we provide an overview of the state of the art of CMV management strategies, with a specific focus on the clinical practices and on the scientific societies' initiatives that aim to implement international standardization guidelines at a national level.

Cytomegalovirus retinitis in children and adolescents with acute leukemia following allogeneic hematopoietic stem cell transplantation

Cytomegalovirus retinitis (CMVR) may occur after allogeneic hematopoietic stem cell transplantation (HSCT). However, little is known about its incidence, strategies for ophthalmic surveillance, and timely implementation of adequate antiviral treatment in pediatric allogeneic HSCT recipients. We provide a retrospective analysis of the epidemiology and clinical features of CMVR in pediatric allogeneic HSCT patients transplanted at our center over a 16-year period. Two patients of this cohort with leukemia are presented. Our analysis is supplemented by a systematic review on pediatric patients with leukemia and CMVR in the setting of allogeneic HSCT. The overall incidence of CMVR in our cohort was 1% (4/338) and 14.2% (3/21) in leukemic patients. In published cases, CMVR occurred at a median of 143 days after transplantation, and, in the majority of patients, was preceded by CMV detection in blood by a median of 93 days. Continued immune suppression following engraftment likely triggers CMVR. Preemptive treatment with ganciclovir as standard is usually successful. Foscarnet is used in case of resistance to ganciclovir or drug-induced granulocytopenia. Overall, CMVR after HSCT in pediatric leukemic patients is rare, but a potentially higher vulnerability of this population for involvement of the eye warrants a standardized ophthalmological examination plan.

Cytomegalovirus disease in patients with hematopoietic stem cell transplantation, experience over 8 years

Objective

Cytomegalovirus infection and disease are significant causes of morbidity and mortality among patients with hematopoietic stem cell transplantation. The aim of this study was to assess the frequency of cytomegalovirus infection and characterize the patients who developed the disease.

Methods

A retrospective cohort study was performed among adult patients, recipients of allogeneic HSTC between 2008 and 2015. Taking into account the institutional protocol of prophylaxis infections in hematopoietic stem cell transplantation, patients received either preemptive therapy or prophylaxis with valganciclovir. Infection was defined as a positive pp65 antigenemia assay or PCR higher than 500 copies/mL. Disease was defined as viremia with evidence of end organ damage.

Results

Seventy patients were included, the median age was 36 years old (IQR 17–62). A total of 93% of the recipients had a positive serology. The Cytomegalovirus infection occurred in 59% of the patients. Eleven patients developed disease (16%), the most frequent manifestation being colitis, followed by pneumonitis and a single case of retinitis. There were no differences between the preemptive therapy or prophylaxis groups. The mean time of onset of the disease was day 94 post-transplant. Three patients developed disease with a viral load lower than 1000 copies/mL.

Conclusion

The incidence of cytomegalovirus infection after transplantation at our institution is high. It was found that the disease can occur with any level of viral load and is associated with high mortality.

Letermovir for prophylaxis of cytomegalovirus manifestations in adult allogeneic hematopoietic stem cell transplant recipients

Cytomegalovirus (CMV) manifestations remain important complications after allogeneic hematopoietic stem cell transplantation (HSCT), even in the current era. Unfortunately, available anti-CMV agents, mainly viral polymerase inhibitors, have a substantial risk of myelosuppression and nephrotoxicity. Letermovir, a novel anti-CMV drug that targets the viral terminase complex, has recently been approved for the prevention of clinically significant CMV infection in adult CMV seropositive hematopoietic stem cell transplantation recipients. This molecule could become a paradigm-shifting drug in preventing CMV manifestations based on its novel mechanism of action, lack of cross-resistance with available drugs, proven efficacy in a large randomized clinical trial, and its beneficial toxicity and tolerability profile. Drug-drug interactions and the lack of any activity against other viruses are the main shortcomings of letermovir.

Deep functional immunophenotyping predicts risk of cytomegalovirus reactivation after hematopoietic cell transplantation

Cytomegalovirus (CMV) is the most common viral infection in hematopoietic cell transplantation (HCT) recipients. We performed deep phenotyping of CMV-specific T cells to predict CMV outcomes following allogeneic HCT. By using 13-color flow cytometry, we studied ex vivo CD8⁺ T-cell cytokine production in response to CMV-pp65 peptides in 3 clinically distinct subgroups of CMV-seropositive HCT patients: (1) Elite Controllers (n = 19): did not have evidence of CMV DNAemia on surveillance testing; (2) Spontaneous Controllers (n = 16): spontaneously resolved low-grade CMV DNAemia without antiviral therapy; and (3) Noncontrollers (NC; n = 21): experienced clinically significant CMV. Two CMV-specific CD8⁺ T-cell functional subsets were strongly associated with risk of CMV: (i) the nonprotective signature (NPS; IL-2^-IFN-γ⁺TNF-α^-MIP-1β⁺), found at increased levels among NC; and (ii) the protective signature (PS; IL-2⁺IFN-γ⁺TNF-α⁺MIP-1β⁺) found at low levels among NC. High levels of the NPS and low levels of PS were associated with an increased 100-day cumulative incidence of clinically significant CMV infection (35% vs 5%; P = .02; and 40% vs 12%; P = .05, respectively). The highest predictive value was observed when these signatures were combined into a composite biomarker consisting of low levels of the PS and high levels of the NPS (67% vs 10%; P < .001). After adjusting for steroid use or donor type, this composite biomarker remained associated with a fivefold increase in the risk of clinically significant CMV infection. CMV-specific CD8⁺ T-cell cytokine signatures with robust predictive value for risk of CMV reactivation should prove useful in guiding clinical decision making in HCT recipients.