Treatment of CMV infection after allogeneic hematopoietic stem cell transplantation

The Histogenetic Origin of Malignant Cells Predicts Their Susceptibility towards Synthetic Lethality Utilizing the TK.007 System

BACKGROUND

Remarkable differences exist in the outcome of systemic cancer therapies. Lymphomas and leukemias generally respond well to systemic chemotherapies, while solid cancers often fail. We engineered different human cancer cells lines to uniformly express a modified herpes simplex virus thymidine kinase TK.007 as a suicide gene when ganciclovir (GCV) is applied, thus in theory achieving a similar response in all cell lines.

METHODS

Fifteen different cell lines were engineered to express the TK.007 gene. XTT-cell proliferation assays were performed and the IC50-values were calculated. Functional kinome profiling, mRNA sequencing, and bottom-up proteomics analysis with Ingenuity pathway analysis were performed.

RESULTS

GCV potency varied among cell lines, with lymphoma and leukemia cells showing higher susceptibility than solid cancer cells. Functional kinome profiling implies a contribution of the SRC family kinases and decreased overall kinase activity. mRNA sequencing highlighted alterations in the MAPK pathways and bottom-up proteomics showed differences in apoptotic and epithelial junction signaling proteins.

CONCLUSIONS

The histogenetic origin of cells influenced the susceptibility of human malignant cells towards cytotoxic agents with leukemias and lymphomas being more sensitive than solid cancer cells.

Clinical Insights: Antimicrobial Therapy for Infectious Uveitis

Infectious uveitis is a major global cause of vision impairment. Despite the eye's immune privilege, afforded by the blood-ocular barrier that restricts microbial entry, several pathogens such as bacteria, viruses, fungi, and parasites can still infiltrate and cause ocular infections and complications. Clinicians often encounter significant challenges in treating infectious uveitis due to limited or ineffective treatment options. Modern molecular techniques and imaging can aid in diagnosing and assessing intraocular infections. Various antimicrobial therapies exist, spanning topical and systemic treatments, but these are constrained by issues like drug concentration, penetration, effective duration, toxicity, and side effects. Treatment approaches also differ based on the infection's etiology. This review provides recent updates on antimicrobial therapies from a clinical perspective, covering topical, systemic, and regional treatments for infectious uveitis.

Letermovir for Cytomegalovirus infection in pediatric patients undergoing allogenic hematopoietic stem cell transplantation: a real-life study by the Infectious Diseases Working Group of Italian Association of Pediatric Hematology-Oncology (AIEOP)

Letermovir prophylaxis revolutionized the approach to Cytomegalovirus infection in adult hematopoietic stem cell transplant (HCT), while data in pediatric setting are still lacking. We retrospectively analyzed 87 HCT children transplanted in 11 AIEOP centers receiving letermovir as off-label indication between January 2020 and November 2022. Letermovir was used as primary, secondary prophylaxis or CMV treatment in 39, 26 and 22 cases, respectively; no discontinuation due to toxicity was reported. Median duration was 100 days (14-256) for primary and 96 days (8-271) for secondary prophylaxis, respectively. None of the patients experienced CMV-clinically significant reactivation during Letermovir primary prophylaxis; one patient developed breakthrough infection during secondary prophylaxis, and 10 and 1 patient experienced asymptomatic CMV-reactivation and CMV-primary infection after drug discontinuation, respectively. Median duration of letermovir in CMV treatment was 40 days (7-134), with 4/22 patients suffering CMV-pneumonia, with an overall response rate of 86.4%. With a median follow-up of 10.7 months (8.2-11.8), estimated 1-year overall survival was 86%; no CMV-related deaths were reported in prophylaxis groups. This is the largest report on Letermovir use in pediatric HCT; real-life data confirm an excellent toxicity profile, with high efficacy as CMV prophylaxis; results in CMV-infection treatment should be investigated in larger, prospective trials.

Torque teno virus-DNA load as individual cytomegalovirus risk assessment parameter upon allogeneic hematopoietic stem cell transplantation

BACKGROUND

Immune recovery following allogeneic hematopoietic stem cell transplantation (allo-HSCT) decisively influences the occurrence of opportunistic infections, one of the leading causes of death among this group of patients. Yet, today, there are no laboratory parameters mirroring immune function sufficiently. Torque teno virus (TTV) has already proven itself as a functional immune marker in other settings.

AIMS

In this analysis, we investigated whether monitoring of TTV-DNA load in whole blood is able to provide additional information on the capacity of the immune system to control cytomegalovirus (CMV) replication in allo-HSCT recipients.

METHODS

Whole blood samples from 59 patients were collected upon allo-HSCT (between Day -7 and +10), on Day +14, +21, +28, +56, +90, and +365 post-transplant. TTV-DNA loads and other relevant clinical information were correlated with the risk of CMV infections or reactivations, defined by evidence of viral replication in blood.

RESULTS

CMV serostatus of the recipient and a TTV load below 1000 copies/mL upon allo-HSCT were significantly associated with an increased incidence of CMV infection or reactivation.

CONCLUSIONS

Quantification of TTV load in the early phase of allo-HSCT procedure could provide additional information in order to identify patients at risk for CMV infection or reactivation.

Healthcare resource utilization of maribavir versus investigator-assigned therapy in transplant recipients with cytomegalovirus infection refractory (with or without genotypic resistance) to prior treatment: Exploratory analysis of the Phase 3 SOLSTICE trial

BACKGROUND

Cytomegalovirus (CMV), a common post-transplant infection, is associated with increased healthcare resource utilization. In the Phase 3 SOLSTICE trial, maribavir was superior to investigator-assigned therapy (IAT; valganciclovir/ganciclovir, foscarnet, and cidofovir) for CMV viremia clearance at Week 8 in transplant recipients with confirmed refractory CMV infection with/without resistance. This exploratory analysis evaluated hospital admissions of patients during the SOLSTICE trial.

METHODS

Patients were randomized to maribavir (400 mg twice daily) or IAT for an 8-week treatment phase with a 12-week follow-up. After ≥3 weeks of treatment, patients on IAT who met pre-specified criteria could enter a maribavir rescue arm (8-week maribavir treatment, 12-week follow-up). Adjusted hospitalization rates and length of hospital stay (LOS) were estimated using negative binomial models adjusting for the time in the relevant study phase. Subgroup analysis for the maribavir rescue arm was conducted.

RESULTS

Overall, 352 patients were randomized (maribavir: 235; IAT: 117); 22 entered the maribavir rescue arm. After adjusting for treatment exposure, patients on maribavir had a 34.8% reduction in hospitalization rate and 53.8% reduced LOS (days/person/year) versus IAT during the treatment phase. No significant differences between treatments were observed during the follow-up phase, although in both arms, hospitalization rates were lower than in the treatment phase. In the maribavir rescue arm, hospitalizations were 60.6% lower on/after maribavir rescue versus pre-rescue treatment (p = 0.008).

CONCLUSION

In patients requiring post-transplant CMV treatment, hospitalization rate and LOS were lower for maribavir than IAT, and hospitalization rates were lower on/after maribavir rescue than pre-rescue. Reducing hospitalizations can alleviate the burden on patients and healthcare systems.

Murine cytomegalovirus reactivation concomitant with acute graft-versus-host disease is controlled by antibodies

Reactivation of human cytomegalovirus (HCMV) from latency is a frequent complication following hematopoietic stem cell transplantation (HSCT). The development of acute graft-versus-host disease (GVHD) is a significant risk factor for HCMV disease. Using a murine GVHD model in animals latently infected with murine CMV (MCMV), we studied preventive and therapeutic interventions in this high-risk scenario of HSCT. Mice latently infected with MCMV experienced reactivated MCMV and developed disseminated MCMV infection concomitant with the manifestations of GVHD. Dissemination was accompanied by accelerated mortality. We demonstrate that MCMV reactivation and dissemination was modulated by MCMV-specific antibodies, thus demonstrating in vivo protective activity of antiviral antibodies. However, the efficacy of serum therapy required repetitive doses of high-titer immune serum secondary to the shortened serum half-life of IgG in animals with GVHD. In a complementary approach, treatment of GVHD by adoptive transfer of donor-derived Tregs facilitated production of MCMV-specific antibodies from newly developing donor-derived B cells. Together, our findings strongly suggest that antibodies play a major role in controlling recurrent MCMV infection that follows GVHD, and they argue for reassessing the potential of antibody treatments as well as therapeutic strategies that enhance de novo antibody development against HCMV.

ELISPOT assays with pp65 peptides or whole HCMV antigen are reliable predictors of immune control of HCMV infection in seropositive kidney transplant recipients

Human cytomegalovirus (HCMV) infection represents a major complication for solid organ transplant recipients. The aim of this study was to verify if the measurement of HCMV-specific T-cells could help to identify patients protected against HCMV disease cytokine flow cytometry using infected dendritic cells as stimulus (CFC-iDC, which discriminates between CD4⁺ and CD8⁺ T cells), and ELISPOT, using infected cell lysate (ELISPOT-iCL) or pp65 (ELISPOT-pp65) as stimulus, were adopted. Among the 47 kidney transplant recipients (KTR) enrolled, 29 had a self-resolving HCMV infection (Controllers) and 18 required antiviral treatment (Non-Controllers). HCMV-specific T-cell frequency at the peak of HCMV infection identified Controllers and Non-Controllers, although the diagnostic performance of CD8⁺ CFC-iDC (area under the curve [AUC] of the receiver-operator characteristic curve: 0.65) was lower than that of CD4⁺ CFC-iDC (AUC: 0.83), ELISPOT-iCL (AUC: 0.83) and ELISPOT-pp65 (AUC: 0.80). CFC-iDC detected a protective immune reconstitution significantly earlier (median time: 38 days) than ELISPOT-iCL and ELISPOT-pp65 (median time: 126 and 133 days, respectively). Time to protective immune reconstitution in Non-Controllers was significantly longer than in Controllers with the ELISPOT and the CD4⁺ CFC-iDC assays, but not with CD8⁺ CFC-iDC. The majority of patients did not require antiviral treatment after protective immune reconstitution, with the exception of five patients according to CFC-iDC assay, one patient according to ELISPOT-iCL assay and three patients according to ELISPOT-pp65 assay. Monitoring the HCMV-specific immunological reconstitution with is effective in discriminating KTR at risk of or protected from HCMV disease and the ELISPOT assays are suitable for implementation in the clinical setting.

Cytomegalovirus-Specific T Cells from Third-Party Donors Successfully Treated Refractory Cytomegalovirus Retinitis after Unrelated Umbilical Cord Blood Transplantation

Umbilical cord blood (UCB) transplants (UCBTs) are becoming increasingly common in the treatment of a variety of hematologic and nonhematologic conditions. The T cells from UCB are naïve T cells, which have not yet been exposed to antigens and therefore do not contain T cells with specific immune functions against viruses. Cytomegalovirus (CMV) infections occur in more than 80% of patients after UCBT compared to other types of transplantation. Anti-CMV medications are currently restricted, with ganciclovir, foscarnet, and valganciclovir being the most common in China; however, with limited efficacy and considerable side effects, all these drugs are susceptible to viral resistance. In recent years, cytomegalovirus-specific T cells (CMVST) have advanced the treatment of viral infections in immunodeficient patients. CMVST usually uses the same donor as hematopoietic stem cell transplantation. CMVST should be administered to UCBT patients because of the absence of donors after UCBT. In China, there is no report on the use of CMVST to treat CMV infection after UCBT, and foreign reports are also limited. This paper reported a 20-year-old male patient with acute myeloid leukemia who developed cytomegalovirus retinitis (CMVR) after umbilical cord blood transplantation. After ineffective viral treatment, he was treated with a third-party donor CMVST and was successfully transformed into CMV nucleic acid negative.

Natural killer cell infusion for cytomegalovirus infection in pediatric patients with Wiskott-Aldrich syndrome following cord blood transplantation: A case report and literature review

NK cells have important functions in resisting cytomegalovirus infection, as they proliferate after viral infection and have certain immunological memory. Here, we report infusion of haploid donor-derived natural killer cells to treat two pediatric patients with Wiskott-Aldrich syndrome (WAS) who were infected with cytomegalovirus after cord blood transplantation (CBT), which successfully cleared the viral infection in both patients.

A decade of approved first-in-class small molecule orphan drugs: Achievements, challenges and perspectives

In the past decade (2011-2020), there was a growing interest in the discovery and development of orphan drugs for the treatment of rare diseases. However, rare diseases only account for a population of 0.65‰-1‰ which usually occur with previously unknown biological mechanisms and lack of specific therapeutics, thus to increase the demands for the first-in-class (FIC) drugs with new biological targets or mechanisms. Considering the achievements in the past 10 years, a total of 410 drugs were approved by U.S. Food and Drug Administration (FDA), which contained 151 FIC drugs and 184 orphan drugs, contributing to make up significant numbers of the approvals. Notably, more than 50% of FIC drugs are developed as orphan drugs and some of them have already been milestones in drug development. In this review, we aim to discuss the FIC small molecules for the development of orphan drugs case by case and highlight the R&D strategy with novel targets and scientific breakthroughs.

Effects of Nursing Intervention Based on Health Belief Model on Self-Perceived Burden, Drug Compliance, and Quality of Life of Renal Transplant Recipients

Objective

To explore the effects of nursing intervention based on health belief model (HBM) on self-perceived burden, drug compliance, and quality of life of renal transplant recipients.

Methods

Sixty patients with renal transplantation treated in our hospital from February 2019 to July 2021 were enrolled. The patients were randomly assigned to control group and study group. The former received routine nursing and the latter received nursing intervention based on HBM.

Results

The nursing satisfaction in the study group was higher compared to the control group (P < 0.05). Secondly, we compared the scores of self-burdens. Before nursing, they exhibited no significant difference (P > 0.05); after nursing, they decreased. Moreover, the physical burden, economic burden, and emotional burden of the study group were lower compared to the control group (P < 0.05). In terms of drug compliance, the rates of no missed medication, noncontinuous missed medication, timely medication, dose-by-dose medication, and non-self-stopping medication in the study group were higher compared to the control group (P < 0.05). The scores of SAS and SDS exhibited no significant difference before nursing (P > 0.05). After nursing, they decreased. Furthermore, the scores of SAS and SDS of the study group were lower compared to the control group (P < 0.05). The self-management ability exhibited no significant difference before nursing (P > 0.05); after nursing, it increased. Moreover, the self-management ability of the study group at discharge and 1 month, 3 months, and 6 months after discharge was higher compared to the control group (P < 0.05). Finally, we compared the scores of quality of life. Before nursing, there was no significant difference (P > 0.05). The scores of physiological function, psychological function, social function, and health self-cognition in the study group were lower compared to the control group (P < 0.05).

Conclusion

The nursing intervention based on HBM can enhance the medication compliance of renal transplant recipients, and the intervention effect is long-lasting. Meanwhile, it can effectively enhance the negative emotion of patients, reduce the burden of self-feeling, promote the quality of life, strengthen the self-management of patients, and facilitate the prognosis.

Maribavir for Refractory Cytomegalovirus Infections With or Without Resistance Post-Transplant: Results From a Phase 3 Randomized Clinical Trial

BACKGROUND

Therapies for refractory cytomegalovirus infections (with or without resistance [R/R]) in transplant recipients are limited by toxicities. Maribavir has multimodal anti-cytomegalovirus activity through the inhibition of UL97 protein kinase.

METHODS

In this phase 3, open-label study, hematopoietic-cell and solid-organ transplant recipients with R/R cytomegalovirus were randomized 2:1 to maribavir 400 mg twice daily or investigator-assigned therapy (IAT; valganciclovir/ganciclovir, foscarnet, or cidofovir) for 8 weeks, with 12 weeks of follow-up. The primary endpoint was confirmed cytomegalovirus clearance at end of week 8. The key secondary endpoint was achievement of cytomegalovirus clearance and symptom control at end of week 8, maintained through week 16.

RESULTS

352 patients were randomized (235 maribavir; 117 IAT). Significantly more patients in the maribavir versus IAT group achieved the primary endpoint (55.7% vs 23.9%; adjusted difference [95% confidence interval (CI)]: 32.8% [22.80-42.74]; P < .001) and key secondary endpoint (18.7% vs 10.3%; adjusted difference [95% CI]: 9.5% [2.02-16.88]; P = .01). Rates of treatment-emergent adverse events (TEAEs) were similar between groups (maribavir, 97.4%; IAT, 91.4%). Maribavir was associated with less acute kidney injury versus foscarnet (8.5% vs 21.3%) and neutropenia versus valganciclovir/ganciclovir (9.4% vs 33.9%). Fewer patients discontinued treatment due to TEAEs with maribavir (13.2%) than IAT (31.9%). One patient per group had fatal treatment-related TEAEs.

CONCLUSIONS

Maribavir was superior to IAT for cytomegalovirus viremia clearance and viremia clearance plus symptom control maintained post-therapy in transplant recipients with R/R cytomegalovirus. Maribavir had fewer treatment discontinuations due to TEAEs than IAT. Clinical Trials Registration. NCT02931539 (SOLSTICE).

Characterization of a thiourea derivative that targets viral transactivators of cytomegalovirus and herpes simplex virus type 1

Although currently available antivirals against certain herpesviruses are effective, the development of resistance during long-term use has necessitated the search for seed compounds that work against novel target molecules. In this report, we identified a thiourea derivative compound, 147B3, that inhibits the infection of human cytomegalovirus (HCMV) in fibroblasts and herpes simplex virus type 1 (HSV-1) in Vero cells at a 50% effective concentration of 0.5 μM and 1.9 μM, respectively. Characterization of the compound provided the following clues regarding its mode of action. 1) Time-of-addition and block-release assays showed that 147B3 behaved similarly to ganciclovir. 2) 147B3 reduced the expression of early and late but not immediate-early gene products and the accumulation of viral genomic DNA in both HCMV-infected and HSV-1-infected cells. 3) 147B3 inhibited the HCMV IE2-dependent activation of viral early gene promoters. 4) Four HSV-1 clones resistant to 147B3 were isolated and next-generation sequencing analysis of their genome DNA revealed that all of them had a mutation(s) in the infected cell protein 4 (ICP4) gene, which encodes a viral transcriptional factor. 5) Although 147B3 did not reduce the amount of ICP4 in an immunoblotting analysis, it changed the localization of the ICP4 from the speckles in the nuclei to diffused dots in the cytoplasm. 6) 147B3 did not affect the localization of promyelocytic leukemia (PML) bodies. Our findings suggest that 147B3 targets viral transactivators, potentially through their interaction with factors required for the viral gene expression system.

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.

Mesenchymal stem/stromal cell therapy in atopic dermatitis and chronic urticaria: immunological and clinical viewpoints

Allergic diseases are immune-mediated diseases. Allergies share a common immunopathogenesis, with specific differences according to the specific disease. Mesenchymal stem/stromal cells (MSCs) have been applied to people suffering from allergic and many other diseases. In this review, the immunologic roles of MSCs are systemically reviewed according to disease immunopathogenesis from a clinical viewpoint. MSCs seem to be a promising therapeutic modality not only as symptomatic treatments but also as causative and even preventive treatments for allergic diseases, including atopic dermatitis and chronic urticaria.

Letermovir Prophylaxis for Cytomegalovirus Infection in Allogeneic Stem Cell Transplantation: A Real-World Experience

Despite effective treatments, cytomegalovirus (CMV) continues to have a significant impact on morbidity and mortality in allogeneic stem cell transplant (allo-SCT) recipients. This multicenter, retrospective, cohort study aimed to evaluate the reproducibility of the safety and efficacy of commercially available letermovir for CMV prophylaxis in a real-world setting. Endpoints were rates of clinically significant CMV infection (CSCI), defined as CMV disease or CMV viremia reactivation within day +100-+168. 204 adult CMV-seropositive allo-SCT recipients from 17 Italian centres (median age 52 years) were treated with LET 240 mg/day between day 0 and day +28. Overall, 28.9% of patients underwent a haploidentical, 32.4% a matched related, and 27.5% a matched unrelated donor (MUD) transplant. 65.7% were considered at high risk of CSCI and 65.2% had a CMV seropositive donor. Low to mild severe adverse events were observed in 40.7% of patients during treatment [gastrointestinal toxicity (36.3%) and skin rash (10.3%)]. Cumulative incidence of CSCI at day +100 and day +168 was 5.4% and 18.1%, respectively, whereas the Kaplan-Meier event rate was 5.8% (95% CI: 2.4-9.1) and 23.3% (95% CI: 16.3-29.7), respectively. Overall mortality was 6.4% at day +100 and 7.3% at day +168. This real-world experience confirms the efficacy and safety of CMV.

Immunotherapy with adoptive cytomegalovirus-specific T cells transfer: Summarizing latest gene engineering techniques

Cytomegalovirus (CMV) infection remains a major complication following allogeneic hematopoietic stem cell transplantation (HSCT). T cell response plays a critical role in inducing long-term immunity against CMV infection/reactivation that impairs during HSCT. Adoptive T cell therapy (ACT) via transferring CMV-specific T cells from a seropositive donor to the recipient can accelerate virus-specific immune reconstitution. ACT, as an alternative approach, can restore protective antiviral T cell immunity in patients. Different manufacturing protocols have been introduced to isolate and expand specific T cells for the ACT clinical setting. Nevertheless, HLA restriction, long-term manufacturing process, risk of alloreactivity, and CMV seropositive donor availability have limited ACT broad applicability. Genetic engineering has developed new strategies to produce TCR-modified T cells for diagnosis, prevention, and treatment of infectious disease. In this review, we presented current strategies required for ACT in posttransplant CMV infection. We also introduced novel gene-modified T cell discoveries in the context of ACT for CMV infection. It seems that these innovations are enabling to improvement and development of ACT utilization to combat posttransplant CMV infection.

Epidemiological changes in cytomegalovirus end-organ diseases in a developed country: A nationwide, general-population-based study

BACKGROUND

Cytomegalovirus (CMV) can cause tissue-invasive diseases in various organs after primary infection or through reactivation of latent-to-lytic switch over a lifetime. The number of individuals who are at risk of CMV diseases, such as elderly or immunocompromised patients, is constantly increasing; however, recent epidemiological changes associated with CMV disease have not been fully evaluated.

METHODS

We used claims data of about 50 million individuals between 2010 and 2015 from the Korean Health Insurance Review and Assessment Service nationwide database. The code for CMV end-organ diseases in the 'Relieved Co-payment Policy' program matches the ICD-10 code of B25, except for congenital CMV infection and mononucleosis. A 628 cases of CMV and 3140 controls (without CMV disease), matched for age and sex, were selected from this dataset in order to evaluate the effect of adult CMV diseases on all-cause death.

RESULTS

The overall unadjusted incidence rate (IR) of CMV end-organ diseases was 0.52/100,000 individuals. The standardized IR, adjusted for age and sex, have continuously increased from 0.32/100,000 in 2010 to 0.75/100,000 in 2015. The overall unadjusted IR in adult population was highest in 70-79 years for six years (0.96/100,000). In the model adjusted for age, sex, immunocompromised status including solid-organ or hematopoietic stem cell transplant recipients, hematologic malignancies, and human immunodeficiency virus diseases, the hazard ratio of case group was 5.2 (95% confidence interval, 3.6-7.4) for all-cause mortality.

CONCLUSION

Nationwide data indicates that CMV end-organ disease has steadily increased in the past six years and is associated with higher mortality.

Therapeutic Vaccination of Hematopoietic Cell Transplantation Recipients Improves Protective CD8 T-Cell Immunotherapy of Cytomegalovirus Infection

Reactivation of latent cytomegalovirus (CMV) endangers the therapeutic success of hematopoietic cell transplantation (HCT) in tumor patients due to cytopathogenic virus spread that leads to organ manifestations of CMV disease, to interstitial pneumonia in particular. In cases of virus variants that are refractory to standard antiviral pharmacotherapy, immunotherapy by adoptive cell transfer (ACT) of virus-specific CD8+ T cells is the last resort to bridge the "protection gap" between hematoablative conditioning for HCT and endogenous reconstitution of antiviral immunity. We have used the well-established mouse model of CD8+ T-cell immunotherapy by ACT in a setting of experimental HCT and murine CMV (mCMV) infection to pursue the concept of improving the efficacy of ACT by therapeutic vaccination (TherVac) post-HCT. TherVac aims at restimulation and expansion of limited numbers of transferred antiviral CD8+ T cells within the recipient. Syngeneic HCT was performed with C57BL/6 mice as donors and recipients. Recipients were infected with recombinant mCMV (mCMV-SIINFEKL) that expresses antigenic peptide SIINFEKL presented to CD8+ T cells by the MHC class-I molecule Kb. ACT was performed with transgenic OT-I CD8+ T cells expressing a T-cell receptor specific for SIINFEKL-Kb. Recombinant human CMV dense bodies (DB-SIINFEKL), engineered to contain SIINFEKL within tegument protein pUL83/pp65, served for vaccination. DBs were chosen as they represent non-infectious, enveloped, and thus fusion-competent subviral particles capable of activating dendritic cells and delivering antigens directly into the cytosol for processing and presentation in the MHC class-I pathway. One set of our experiments documents the power of vaccination with DBs in protecting the immunocompetent host against a challenge infection. A further set of experiments revealed a significant improvement of antiviral control in HCT recipients by combining ACT with TherVac. In both settings, the benefit from vaccination with DBs proved to be strictly epitope-specific. The capacity to protect was lost when DBs included the peptide sequence SIINFEKA lacking immunogenicity and antigenicity due to C-terminal residue point mutation L8A, which prevents efficient proteasomal peptide processing and binding to Kb. Our preclinical research data thus provide an argument for using pre-emptive TherVac to enhance antiviral protection by ACT in HCT recipients with diagnosed CMV reactivation.

Immunodominant Cytomegalovirus Epitopes Suppress Subdominant Epitopes in the Generation of High-Avidity CD8 T Cells

CD8⁺ T-cell responses to pathogens are directed against infected cells that present pathogen-encoded peptides on MHC class-I molecules. Although natural responses are polyclonal, the spectrum of peptides that qualify for epitopes is remarkably small even for pathogens with high coding capacity. Among those few that are successful at all, a hierarchy exists in the magnitude of the response that they elicit in terms of numbers of CD8⁺ T cells generated. This led to a classification into immunodominant and non-immunodominant or subordinate epitopes, IDEs and non-IDEs, respectively. IDEs are favored in the design of vaccines and are chosen for CD8⁺ T-cell immunotherapy. Using murine cytomegalovirus as a model, we provide evidence to conclude that epitope hierarchy reflects competition on the level of antigen recognition. Notably, high-avidity cells specific for non-IDEs were found to expand only when IDEs were deleted. This may be a host’s back-up strategy to avoid viral immune escape through antigenic drift caused by IDE mutations. Importantly, our results are relevant for the design of vaccines based on cytomegaloviruses as vectors to generate high-avidity CD8⁺ T-cell memory specific for unrelated pathogens or tumors. We propose the deletion of vector-encoded IDEs to avoid the suppression of epitopes of the vaccine target.

Development of a Vaccine against Human Cytomegalovirus: Advances, Barriers, and Implications for the Clinical Practice

Human cytomegalovirus (hCMV) is one of the most common causes of congenital infection in the post-rubella era, representing a major public health concern. Although most cases are asymptomatic in the neonatal period, congenital CMV (cCMV) disease can result in permanent impairment of cognitive development and represents the leading cause of non-genetic sensorineural hearing loss. Moreover, even if hCMV mostly causes asymptomatic or pauci-symptomatic infections in immunocompetent hosts, it may lead to severe and life-threatening disease in immunocompromised patients. Since immunity reduces the severity of disease, in the last years, the development of an effective and safe hCMV vaccine has been of great interest to pharmacologic researchers. Both hCMV live vaccines-e.g., live-attenuated, chimeric, viral-based-and non-living ones-subunit, RNA-based, virus-like particles, plasmid-based DNA-have been investigated. Encouraging data are emerging from clinical trials, but a hCMV vaccine has not been licensed yet. Major difficulties in the development of a satisfactory vaccine include hCMV's capacity to evade the immune response, unclear immune correlates for protection, low number of available animal models, and insufficient general awareness. Moreover, there is a need to determine which may be the best target populations for vaccine administration. The aim of the present paper is to examine the status of hCMV vaccines undergoing clinical trials and understand barriers limiting their development.

Performance evaluation of the Roche cobas 6800 system for quantifying cytomegalovirus DNA in plasma and urine samples

INTRODUCTION

Cytomegalovirus (CMV) nucleic acid amplification testing is important for CMV infection diagnosis and management. CMV DNA is found in plasma and various other fluids, including urine. If CMV can be reliably detected in urine, it may be considered a non-invasive alternative to blood tests. The cobas 6800 system (Roche Diagnostics, Mannheim, Germany) is a Food and Drug Administration-approved testing platform for measuring CMV DNA in plasma.

OBJECTIVE

To evaluate the analytical performance of the cobas 6800 system and compare the clinical feasibility of CMV detection in plasma and urine samples.

STUDY DESIGN

Imprecision, linearity, limit of quantitation (LOQ), and cross-reactivity of the cobas 6800 system were assessed, and reference interval verification was performed. Plasma CMV DNA quantification was compared to CMV DNA values in urine samples obtained from 129 pediatric patients (<18 years of age) from March 2020 to May 2020 at a tertiary hospital.

RESULTS

The assay precision was within the acceptable range. Linearity was observed within the tested concentration range (2.36-6.33 log IU/mL) with a coefficient of determination of 0.9972. The LOQ was 34.5 IU/mL. The assay did not show cross-reactivity with 15 other viruses. Plasma and urine detection results were stratified into three categories: negative, <LOQ, and positive to analyze the degree of agreement with the results. The quadratic weighted kappa value was 0.623 (P = 0.000), showing substantial concurrence.

CONCLUSION

The cobas 6800 system offers good sensitivity, precision, and linearity and is suitable for monitoring CMV viral loads in the plasma and urine samples.

Human cytomegalovirus infection: A considerable issue following allogeneic hematopoietic stem cell transplantation

Cytomegalovirus (CMV) is an opportunistic virus, whereby recipients are most susceptible following allogeneic hematopoietic stem cell transplantation (allo-HSCT). With the development of novel immunosuppressive agents and antiviral drugs, accompanied with the widespread application of prophylaxis and preemptive treatment, significant developments have been made in transplant recipients with human (H)CMV infection. However, HCMV remains an important cause of short- and long-term morbidity and mortality in transplant recipients. The present review summarizes the molecular mechanism and risk factors of HCMV reactivation following allo-HSCT, the diagnosis of CMV infection following allo-HSCT, prophylaxis and treatment of HCMV infection, and future perspectives. All relevant literature were retrieved from PubMed and have been reviewed.

Cytomegalovirus reactivation after hematopoietic stem cell transplant with CMV-IG prophylaxis: A monocentric retrospective analysis

Human cytomegalovirus (CMV) represents the most common viral infection after hematopoietic stem cell transplant (HSCT), mainly occurring as reactivation from latency in seropositive patients, with a different prevalence based on the extent and timing of seroconversion in a specific population. Here, we retrospectively analyzed a cohort of patients who underwent HSCT at our Institution between 2013 and 2018, all of whom were prophylactically treated with CMV-IG (Megalotect Biotest®), to define the incidence and clinical outcomes of CMV reactivation and clinically significant infection. CMV infection occurred in 69% of our patient series, mainly resulting from reactivation, and CMV clinically significant infection (CS-CMVi) occurred in 48% of prophylactically treated patients. CMV infection and CS-CMVi impacted neither on relapse incidence nor on overall survival nor on relapse-free survival. Moreover, a very low incidence of CMV end-organ disease was documented. CMV-IG used alone as prophylactic therapy after HSCT does not effectively prevent CMV reactivation.

DNA Encapsidation and Capsid Assembly Are Underexploited Antiviral Targets for the Treatment of Herpesviruses

Although there are effective nucleoside analogs to treat HSV, VZV, and HCMV disease, herpesvirus infections continue to contribute to significant morbidity and mortality. Acyclovir is the drug of choice for HSV encephalopathy, yet there is an estimated 6-19% mortality rate with half of the survivors experiencing moderate to severe chronic neurological deficits. For VZV, current treatments are inadequate to prevent acute and persistent pain due to zoster. Treatment of HCMV with GCV requires close monitoring particularly in patients with impaired renal function and there are no approved treatments for congenital HCMV infections. New therapeutic options to control cytomegalovirus reactivation in bone marrow and stem cell transplant patients are needed to improve patient outcome. No successful chemotherapeutic options are available for EBV, HHV-6, 7, and 8. Drug resistance is a concern for HCMV, HSV, and VZV since approved drugs share common mechanisms of action. Targeting DNA encapsidation or capsid assembly provide additional options for the development of non-nucleoside, small molecule anti-herpesviral drugs.

[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.

Viral Infections in Burns

Background: Viral infections after burns are less common than bacterial infections but usually occur in the more severely burned patients and have been associated with poor outcomes. Methods: Retrospective reviews and case series were examined to provide an overview of the management of viral infections in the burn patient. Results: The most common viral pathogens in these patients are the herpesviruses, which include herpes simplex, varicella zoster, cytomegalovirus, and human herpesvirus 6. Established viral infections that may complicate patient management include human immunodeficiency virus, hepatitis B and C, and, more recently, the novel coronavirus SARS-CoV-2. Herpesvirus infections can occur as primary or nosocomial pathogens but clinical manifestations most commonly are re-activation of latent viral infection. Because of the paucity of data in the burn population, much of the evidence for specific treatments is extrapolated from patients with severe immunosuppression or critical illness. Antiviral therapy is employed for the burn patient with herpesvirus infections. This is an area of active study, and further research is needed to better understand the risks, clinical manifestations, and attributable morbidity and mortality of viral infections. Conclusions: Major burn injury results in immunosuppression and viral infection in a small number of patients. Recognition and antiviral therapy are employed, but additional studies are necessary to improve outcomes in these patients.

Cytomegalovirus-Associated Inhibition of Hematopoiesis Is Preventable by Cytoimmunotherapy With Antiviral CD8 T Cells

Reactivation of latent cytomegalovirus (CMV) in recipients of hematopoietic cell transplantation (HCT) not only results in severe organ manifestations, but can also cause “graft failure” resulting in bone marrow (BM) aplasia. This inhibition of hematopoietic stem and progenitor cell engraftment is a manifestation of CMV infection that is long known in clinical hematology as “myelosuppression.” Previous studies in a murine model of sex-chromosome mismatched but otherwise syngeneic HCT and infection with murine CMV have shown that transplanted hematopoietic cells (HC) initially home to the BM stroma of recipients but then fail to further divide and differentiate. Data from this model were in line with the hypothesis that infection of stromal cells, which constitute “hematopoietic niches” where hematopoiesis takes place, causes a local deficiency in essential hematopoietins. Based on this understanding, one must postulate that preventing infection of stromal cells should restore the stroma's capacity to support hematopoiesis. Adoptively-transferred antiviral CD8⁺ T cells prevent lethal CMV disease by controlling viral spread and histopathology in vital organs, such as liver and lungs. It remained to be tested, however, if they can also prevent infection of the BM stroma and thus allow for successful HC engraftment. Here we demonstrate that antiviral CD8⁺ T cells control stromal infection. By tracking male donor-derived sry⁺ HC in the BM of infected female sry⁻ recipients, we show the CD8⁺ T cells allow for successful donor HC engraftment and thereby prevent CMV-associated BM aplasia. These data provide a further argument for cytoimmunotherapy of CMV infection after HCT.

Safety profile of the concomitant use of foscarnet and aerosolized pentamidine in allogeneic hematopoietic stem cell transplantation recipients

BACKGROUND

Concomitant use of foscarnet and intravenous pentamidine can very frequently cause severe hypocalcemia. However, it is unknown whether aerosolized pentamidine has a similar adverse interaction with foscarnet. The present study was aimed at examining the safety profile of concomitantly used foscarnet and aerosolized pentamidine in patients receiving allogeneic hematopoietic stem cell transplantation.

METHODS

Data from allogeneic hematopoietic stem cell recipients who had been administered foscarnet therapy for over 7 days were analyzed. We compared electrolyte abnormalities and serum creatinine level between patients who received aerosolized pentamidine concomitantly and those who did not.

RESULTS

A total of 84 consecutive patients and 135 episodes of foscarnet therapy between May 2011 and April 2016 were evaluable. Of these 135 episodes, 25 episodes of therapy included concurrent therapy with 300 mg dose of aerosolized pentamidine once a month (pentamidine group) and 110 episodes did not (non-pentamidine group). The incident rates of grade 3/4 hypocalcemia did not significantly differ between the pentamidine and non-pentamidine groups (P = .207; 0/25 [0%] vs 10/110 [9.1%], respectively). In addition, we observed no significant difference in the incident rates of grade 3/4 serum creatinine increase between the two groups (P = 1.00; 0/25 [0%] vs 4/110 [3.6%], respectively).

CONCLUSION

Our results suggest that the drug interactions between foscarnet and aerosolized pentamidine may not be clinically significant.

An update on the treatment of cytomegalovirus infection after allogeneic hematopoietic stem cell transplantation

Introduction: Human Cytomegalovirus (CMV) remains a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation. Standard treatment options have for long been limited to a small number of effective drugs with significant toxicities.Areas covered: In this manuscript, the authors update a previous review summarizing recent developments in the virology lab and their possible implications for treatment strategies at bedside. In particular, the authors focused on new antiviral drugs already available and under investigation in clinical trials and innovative immunotherapeutic approaches, including adoptive T-cell therapy and vaccines.Expert opinion: Broader knowledge of CMV biology and its relationship with the host immune system is greatly contributing to the development of novel therapeutic approaches. The availability of new drugs, the improved techniques for virological testing and the more accurate patient risk stratification allow to better individualize treatment, limiting toxicity while sparing antiviral effects. The role of immunotherapy is clearly emerging and will further expand our treatment armamentarium.

The prognostic impact of the cytomegalovirus serostatus in patients with chronic hematological malignancies after allogeneic hematopoietic stem cell transplantation: a report from the Infectious Diseases Working Party of EBMT

It has been shown recently that donor and/or recipient cytomegalovirus (CMV) seropositivity is associated with a significant overall survival (OS) decline in acute leukemia patients who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT). We now analyzed the prognostic impact of the donor/recipient CMV serostatus in 6968 patients with chronic hematological malignancies who underwent allo-HSCT. Donor and/or recipient CMV seropositivity was associated with a significantly reduced 2-year progression-free survival (PFS, 50% vs. 52%, p = 0.03) and OS (62% vs. 65%, p = 0.01). Multivariate Cox regression analyses showed an independent negative prognostic impact of donor and/or recipient CMV seropositivity on PFS (HR, 1.1; 95% CI, 1.0-1.2; p = 0.03), OS (HR, 1.1; 95% CI, 1.0-1.2; p = 0.003), and non-relapse mortality (HR, 1.2; 95% CI, 1.0-1.3; p = 0.02). OS decline was strongest for CMV-seropositive recipients with a CMV-seronegative donor (HR, 1.2; 95% CI, 1.1-1.3), followed by CMV-seropositive patients with a CMV-seropositive donor (HR, 1.1; 95% CI, 1.0-1.2). Conversely, OS did not differ significantly between CMV-seronegative recipients allografted from a CMV-seropositive donor (HR, 1.0; 95% CI, 0.9-1.2) and patients with donor/recipient CMV seronegativity (p = 0.001 for the four groups together). Non-relapse mortality was also significantly (p = 0.01) higher for CMV-seropositive patients with a CMV-seronegative graft (HR, 1.2; 95% CI, 1.1-1.4) than for CMV-seropositive patients with a CMV-seropositive graft (HR, 1.1; 95% CI, 0.9-1.2) or CMV-seronegative recipients with a CMV-seropositive graft (HR, 1.0; 95% CI, 0.8-1.2). Donor and/or recipient CMV seropositivity still results in an OS decline in patients with chronic hematological malignancies who have undergone allo-HSCT. However, this OS decline seems to be lower than that described for acute leukemia patients previously.

Robust Identification of Suitable T-Cell Subsets for Personalized CMV-Specific T-Cell Immunotherapy Using CD45RA and CD62L Microbeads

Viral infections and reactivations remain a serious obstacle to successful hematopoietic stem cell transplantation (HSCT). When antiviral drug treatment fails, adoptive virus-specific T-cell transfer provides an effective alternative. Assuming that naive T cells (T_N) are mainly responsible for GvHD, methods were developed to generate naive T-cell-depleted products while preserving immune memory against viral infections. We compared two major strategies to deplete potentially alloreactive T cells: CD45RA and CD62L depletion and analyzed phenotype and functionality of the resulting CD45RA^-/CD62L^- naive T-cell-depleted as well as CD45RA⁺/CD62L⁺ naive T-cell-enriched fractions in the CMV pp65 and IE1 antigen model. CD45RA depletion resulted in loss of terminally differentiated effector memory T cells re-expressing CD45RA (T_EMRA), and CD62L depletion in loss of central memory T cells (T_CM). Based on these differences in target cell-dependent and target cell-independent assays, antigen-specific T-cell responses in CD62L-depleted fraction were consistently 3⁻5 fold higher than those in CD45RA-depleted fraction. Interestingly, we also observed high donor variability in the CD45RA-depleted fraction, resulting in a substantial loss of immune memory. Accordingly, we identified donors with expected response (DER) and unexpected response (DUR). Taken together, our results showed that a naive T-cell depletion method should be chosen individually, based on the immunophenotypic composition of the T-cell populations present.

Donor NKG2C Copy Number: An Independent Predictor for CMV Reactivation After Double Cord Blood Transplantation

Cytomegalovirus (CMV) remains a major cause of morbidity following allogeneic hematopoietic stem cell transplant. Natural killer cells expressing NKG2C have been shown to play a role in the immune surveillance of human CMV. We studied NKG2C copy number in the donor graft and the risk of CMV reactivation after double umbilical cord blood transplantation (DUCBT) in 100 CMV seropositive DUCBT recipients and their corresponding cord blood (CB) grafts (n = 200). In the setting of DUCBT, the combined graft may contain 0-4 functional copies of NKG2C gene. Sixteen patients received a combined graft with 1 or 2 NKG2C copies and 84 patients were recipients of a combined graft with 3 or 4 NKG2C copies. The 6-month cumulative incidence of CMV reactivation for the two groups was 93.7 and 58.4%, respectively (p = 0.0003). In multivariate analysis, low NKG2C copies in the graft was an independent predictor of CMV reactivation (HR = 2.72, CI = 1.59-4.64; p < 0.0001). Our study points to an important role for donor NKG2C for protection against CMV reactivation after DUCBT. These novel findings may help identify patients at a higher risk of CMV reactivation after DUCBT. Donor NKG2C genotype may be used as a potential criterion in the algorithm for graft selection for DUCBT.

Cytomegalovirus infection and progressive differentiation of effector-memory T cells

Primary cytomegalovirus (CMV) infection leads to strong innate and adaptive immune responses against the virus, which prevents serious disease. However, CMV infection can cause serious morbidity and mortality in individuals who are immunocompromised. The adaptive immune response to CMV is characterized by large populations of effector-memory (EM) T cells that are maintained lifelong, a process termed memory inflation. Recent findings indicate that infection with CMV leads to continuous differentiation of CMV-specific EM-like T cells and that high-dose infection accelerates this progression. Whether measures that counteract CMV infection, such as anti-viral drugs, targeting of latently infected cells, adoptive transfer of CMV-specific T cells, and vaccination strategies, are able to impact the progressive differentiation of CMV-specific EM-like cells is discussed.

Cytomegalovirus reactivation and disease amongst patients with allogeneic haematopoietic stem cell transplantation in Eastern India: Epidemiology, outcome and healthcare cost

Purpose

Data from developing countries about incidence, prognosis and healthcare cost of cytomegalovirus (CMV) reactivation amongst patients with allogeneic hematopoietic stem cell transplantation (AHSCT) remain scarce. The purpose of the study was to describe the epidemiology, outcome and cost implications of CMV reactivation and CMV disease amongst patients with AHSCT in cancer hospital in Eastern India.

Materials and Methods

The study design was a retrospective audit of clinical records.

Results

Ninety-nine per cent of patients and 94% of the donors were found to be CMV seropositive. CMV reactivation rate was 43.8% amongst patients with AHSCT (n = 130 patients). CMV reactivation occurred 118 days after AHSCT (median; range: 28-943 days). Patients with any grade of graft-versus-host disease (GVHD) had higher CMV reactivation rate than patients without GVHD. Patients with CMV reactivation had more frequent GVHD than patients without CMV reactivation. Use of steroids was associated with CMV reactivation. We found no differences in overall survival of patients with or without CMV reactivation. The cost of in-house CMV-polymerase chain reaction at our centre was USD $57 (Rs. 3650), cost for intravenous ganciclovir was USD $26 (Rs. 1665) per infusion and oral valganciclovir USD $8 (Rs. 512)/900 mg tablet. The median duration of anti-CMV therapy was 14 days (interquartile range: 14-28 days) and the average cost per patient per month directed towards CMV management ranged between USD $800 and USD $1,300 (Rs. 51,238-Rs. 83,264). Three patients (2.3%) in this series had CMV disease, all of whom died.

Conclusion

In an increasingly globalised world, where medical tourism is common, data from developing countries regarding cost and outcome of CMV infections in AHSCT patients are of relevance.

Cytomegalovirus induces HLA-class-II-restricted alloreactivity in an acute myeloid leukemia cell line

Cytomegalovirus (HCMV) reactivation is found frequently after allogeneic hematopoietic stem cell transplantation (alloSCT) and is associated with an increased treatment-related mortality. Recent reports suggest a link between HCMV and a reduced risk of cancer progression in patients with acute leukemia or lymphoma after alloSCT. Here we show that HCMV can inhibit the proliferation of the acute myeloid leukemia cell line Kasumi-1 and the promyeloid leukemia cell line NB4. HCMV induced a significant up-regulation of HLA-class-II-molecules, especially HLA-DR expression and an increase of apoptosis, granzyme B, perforin and IFN-γ secretion in Kasumi-1 cells cocultured with peripheral blood mononuclear cells (PBMCs). Indolamin-2,3-dioxygenase on the other hand led only to a significant dose-dependent effect on IFN-γ secretion without effects on proliferation. The addition of CpG-rich oligonucleotides and ganciclovir reversed those antiproliferative effects. We conclude that HCMV can enhance alloreactivity of PBMCs against Kasumi-1 and NB4 cells in vitro. To determine if this phenomenon may be clinically relevant further investigations will be required.

Reactivated cytomegalovirus proctitis in an immunocompetent patient presenting as nosocomial diarrhea: a case report and literature review

BACKGROUND

Reactivated cytomegalovirus (CMV) infection has been known to cause significant morbidity and mortality in immunocompromised patients. However, CMV disease rarely develops in immunocompetent patients, and reported cases often present with a mild, self-limiting course, without severe life-threatening sequelae. While the colon is the most common gastrointestinal site affected by CMV disease in immunocompetent patients, rectal involvement is rarely reported. CMV proctitis can present in two distinct forms, primary and reactivated. However, reactivated CMV proctitis is rarely reported as a causative etiology of nosocomial diarrhea, except in transplant patients. Herein we present a case of reactivated CMV proctitis in an immunocompetent patient, presenting as nosocomial diarrhea. Previously reported cases of reactivated CMV proctitis in immunocompetent patients are also reviewed.

CASE PRESENTATION

A 79-year-old female was admitted because of metabolic encephalopathy caused by dehydration and hypernatremia. The patient's consciousness level returned rapidly after fluid supplementation. However, she subsequently presented with abdominal pain and diarrhea on day 8 of admission. Abdominal contrast-enhanced computed tomography on day 10 of admission demonstrated inflammation around the rectum, suggesting proctitis. Colonoscopy on day 16 of admission showed a giant ulcer at the rectum. Pathology of rectal biopsy confirmed CMV infection. The patient recovered without sequelae after 38 days of valganciclovir treatment. Follow-up colonoscopy revealed a healed ulcer over the rectum. Ten cases in the literature, plus our case, with reactivated CMV proctitis in immunocompetent patients were reviewed. We found that most patients were elderly (mean, 72 years) with a high prevalence of diabetes mellitus (54.5%). Cardinal manifestations are often non-specific (diarrhea, hematochezia, tenesmus), and eight (72.7%) developed CMV proctitis following a preceding acute, life-threatening disease, rather than as an initial presentation on admission. These manifestations frequently develop during hospitalization, and are thus often regarded as nosocomial diarrhea.

CONCLUSIONS

Clinicians should be aware of the possibility of nosocomial onset of reactivated CMV proctitis in patients hospitalized due to a preceding critical illness, although the benefits of antiviral therapy remain unclear.

CMV in Hematopoietic Stem Cell Transplantation

Due to its negative impact on the outcome of stem cell transplant (SCT) and solid organ transplant patients (SOT) CMV has been called “the troll of transplantation”. One of the greatest advances in the management of SCT has been the introduction of the preemptive strategy. Since its introduction, the incidence of the viremia, as expected, remains unchanged but there has been a marked decline in the incidence of early CMV disease. However, in spite of the advances in prevention of CMV disease, CMV is still today an important cause of morbidity and mortality. Late CMV disease is still occurring in a significant proportion of patients and the so-called indirect effects of CMV are causing significant morbidity and mortality. Fortunately there have been several advances in the development of new antivirals, adoptive immunotherapy and DNA-CMV vaccines that might transform the management of CMV in the near future.