Pulmonary cytomegalovirus (CMV) DNA shedding in allogeneic hematopoietic stem cell transplant recipients: Implications for the diagnosis of CMV pneumonia

Consensus Definitions of Cytomegalovirus (CMV) Infection and Disease in Transplant Patients Including Resistant and Refractory CMV for Use in Clinical Trials: 2024 Update From the Transplant Associated Virus Infections Forum

Cytomegalovirus (CMV) infection and disease are important causes of morbidity and mortality in transplant recipients. For the purpose of developing consistent reporting of CMV outcomes in clinical trials, definitions of CMV infection and disease were developed and most recently published in 2017. Since then, there have been major developments, including registration of new antiviral agents. Therefore, the Transplant Associated Virus Infections Forum, which consists of scientists, clinicians, regulators, and industry representatives, has produced an updated version of these definitions that incorporates recent knowledge with the aim of supporting clinical research and drug development. This also includes an update regarding the definition of resistant and refractory CMV infections previously published in 2019. As the field evolves, the need for updates of these definitions is clear, and collaborative efforts among clinicians, scientists, regulators, and industry representatives can provide a platform for this work.

Update on Cytomegalovirus Infection Management in Allogeneic Hematopoietic Stem Cell Transplant Recipients. A Consensus Document of the Spanish Group for Hematopoietic Transplantation and Cell Therapy (GETH-TC)

Background

Cytomegalovirus (CMV) infection is a common complication following allogeneic hematopoietic stem cell transplantation (allo-HSCT) and in patients receiving novel hematological therapies. Its impact on morbidity and mortality necessitates effective management strategies. Despite recent advances in diagnostics and treatment, unresolved questions persist regarding monitoring and treatment, prompting the need for updated recommendations.

Methods

A consensus was reached among a panel of experts selected for their expertise in CMV research and clinical practice. Key clinical areas and questions were identified based on previous surveys and literature reviews. Recommendations were formulated through consensus and graded using established guidelines.

Results

Recommendations were provided for virological monitoring, including the timing and frequency of CMV DNAemia surveillance, especially during letermovir (LMV) prophylaxis. We evaluated the role of CMV DNA load quantification in diagnosing CMV disease, particularly pneumonia and gastrointestinal involvement, along with the utility of specific CMV immune monitoring in identifying at-risk patients. Strategies for tailoring LMV prophylaxis, managing breakthrough DNAemia, and implementing secondary prophylaxis in refractory cases were outlined. Additionally, criteria for initiating early antiviral treatment based on viral load dynamics were discussed.

Conclusion

The consensus provides updated recommendations for managing CMV infection in hematological patients, focusing on unresolved issues in monitoring, prophylaxis, treatment, and resistance. These recommendations aim to guide clinical practice and improve outcomes in this high-risk population. Further research is warranted to validate these recommendations and address ongoing challenges in CMV management with emerging antiviral combinations, particularly in pediatric populations.

Antiviral Agents for Preventing Cytomegalovirus Disease in Recipients of Hematopoietic Cell Transplantation

This systematic review discusses the use of prophylaxis to prevent cytomegalovirus (CMV) infection in recipients who have undergone hematopoietic cell transplantation. It highlights the need for new approaches to control and prevent CMV infection. The approval of the anti-CMV drug letermovir has made antiviral prophylaxis more popular. CMV-specific T cell-mediated immunity tests are effective in identifying patients who have undergone immune reconstitution and predicting disease progression. Maribavir (MBV) has been approved for the treatment of post-transplant CMV infection/disease in adolescents. Adoptive T-cell therapy and the PepVax CMV vaccine show promise in tackling refractory and resistant CMV. However, the effectiveness of PepVax in reducing CMV viremia/disease was not demonstrated in a phase II trial. Cell-mediated immunity assays are valuable for personalized management plans, but more interventional studies are needed. MBV and adoptive T-cell therapy are promising treatments, and trials for CMV vaccines are ongoing.

The plasma viral communities associate with clinical profiles in a large-scale haematological patients cohort

BACKGROUND

Haematological patients exhibit immune system abnormalities that make them susceptible to viral infections. Understanding the relationship between the virome in the blood plasma of haematological patients and their clinical characteristic is crucial for disease management. We aimed to explore the presence of viral pathogens and identify close associations between viral infections and various clinical features.

RESULTS

A total of 21 DNA viruses and 6 RNA viruses from 12 virus families were identified from 1383 patients. Patients with haematological diseases exhibited significantly higher diversity, prevalence, and co-detection rates of viral pathogens. During fever episodes, pathogen detection was notably higher, with Epstein-Barr virus (EBV) and Mucorales infections being the most probable culprits for fever symptoms in non-haematological patients. The detection rate of torque teno virus (TTV) significantly increases in haematological patients after transplantation and during primary lung infections. Additionally, TTV-positive patients demonstrate significantly higher absolute neutrophil counts, while C-reactive protein and procalcitonin levels are notably lower. Furthermore, TTV, cytomegalovirus, and parvovirus B19 (B19V) were found to be more prevalent in non-neutropenic patients, while non-viral pathogenic infections, such as Gram-negative bacteria and Mucorales, were more common in neutropenic patients. Pegivirus C (HPgV-C) infection often occurred post-transplantation, regardless of neutropenia. Additionally, some viruses such as TTV, B19V, EBV, and HPgV-C showed preferences for age and seasonal infections.

CONCLUSIONS

Analysis of the plasma virome revealed the susceptibility of haematological patients to plasma viral infections at specific disease stages, along with the occurrence of mixed infections with non-viral pathogens. Close associations were observed between the plasma virome and various clinical characteristics, as well as clinical detection parameters. Understanding plasma virome aids in auxiliary clinical diagnosis and treatment, enabling early prevention to reduce infection rates in patients and improve their quality of life. Video Abstract.

Performance evaluation of the Alinity m system for quantifying cytomegalovirus DNA in samples of the respiratory, gastrointestinal, and urinary tract

Quantitation of cytomegalovirus (CMV) DNA load in specimens other than blood such as bronchoalveolar lavages, intestinal biopsies, or urine has become a common practice as an ancillary tool for the diagnosis of CMV pneumonitis, intestinal disease, or congenital infection, respectively. Nevertheless, most commercially available CMV PCR platforms have not been validated for CMV DNA detection in these specimen types. In this study, a laboratory-developed test based on Alinity m CMV ("Alinity LDT") was evaluated. Reproducibility assessment using spiked bronchial aspirate (BAS) or urine samples showed low standard deviations of 0.08 and 0.27 Log IU/mL, respectively. Evaluating the clinical performance of Alinity LDT in comparison to a laboratory-developed test based on RealTime CMV ("RealTime LDT") showed good concordance across 200 clinical specimens including respiratory specimens, intestinal biopsies, urine, and stool. A high Pearson's correlation coefficient of r = 0.92, a low mean bias of -0.12 Log IU/mL, a good qualitative agreement of 90%, and a Cohen's kappa value of 0.76 (substantial agreement) were observed. In separate analyses of the sample types BAS, tracheal aspirates, bronchoalveolar lavage, biopsies, and urine, the assay results correlated well between the two platforms with r values between 0.88 and 0.99 and a bias <0.5 Log IU/mL. Overall, the fully automated, continuous, random access Alinity LDT yielded good reproducibility, high concordance, and good correlation to RealTime LDT in respiratory, gastrointestinal, and urine samples and may enhance patient management with rapid result reporting.IMPORTANCEIn transplant recipients, a major cause for morbidity and mortality is end-organ disease by primary or secondary CMV infection of the respiratory or gastrointestinal tract. In addition, sensorineural hearing loss and neurodevelopmental abnormalities are frequent sequelae of congenital CMV infections in newborns. Standard of care for highly sensitive detection and quantitation of the CMV DNA load in plasma and whole blood specimens is real-time PCR testing. Beyond that, there is a need for quantitative determination of CMV DNA levels in respiratory, gastrointestinal, and urinary tract specimens using a highly automated, random access CMV PCR assay with a short turnaround time to enable early diagnosis and treatment. In the present study, clinical performance of the fully automated Alinity m analyzer in comparison to the current RealTime LDT assay was evaluated in eight different off-label sample types.

Evaluation of Alinity m CMV assay performance for detecting CMV in plasma, cerebrospinal fluid, and bronchoalveolar lavage specimens

Accurate detection and quantification of cytomegalovirus (CMV) is crucial to preventing adverse outcomes in immunocompromised individuals. Current assays were developed for use with plasma specimens, but CMV may be present in bronchoalveolar lavage (BAL) fluid and cerebrospinal fluid (CSF). We evaluated the performance of the Abbott Alinity m CMV assay compared to the Abbott RealTime CMV assay for quantification of CMV in plasma, BAL, and CSF specimens. To evaluate clinical performance, 190 plasma, 78 BAL, and 20 CSF specimens were tested with the Alinity m assay and compared to the RealTime assay. The Alinity m CMV assay showed high precision (SD <0.01 to 0.13) for all 3 specimen types. Clincal plasma and BAL specimens with quantifiable CMV DNA demonstrated strong correlation to RealTime CMV assay results (r2 = 0.9779 for plasma, r2 = 0.9373 for BAL). The Alinity m CMV assay may be useful for quantification of CMV in plasma, BAL, and CSF specimens.

Respiratory failure in a tofacitinib treated patient with ulcerative colitis

Tofacitinib is an oral Janus Kinase (JAK) inhibitor recently approved for the management of moderate to severe ulcerative colitis (UC). Safety data on tofacitinib has suggested a moderately increased risk for venous thromboembolism (VTE) as well as non-opportunistic infections and non-infectious drug-related lung disease. We faced a diagnostic dilemma between an infectious and non-infectious cause of acute respiratory insufficiency in a patient on recent tofacitinib therapy. A lung CT scan showed bilateral interstitial pneumonic infiltrates and a PCR on bronchoalveolar lavage fluid was positive for cytomegalovirus (CMV). The patient’s condition improved after discontinuation of tofacitinib and treatment with anti-viral drugs and high dose corticosteroids. A CMV primary infection was suspected, however a drug-induced interstitial lung disease cannot be excluded in the differential diagnosis of patients with autoimmune disorders under tofacitinib therapy who present with fever, hypoxia and pulmonary infiltrates.

A Systematic Literature Review to Identify Diagnostic Gaps in Managing Immunocompromised Patients With Cancer and Suspected Infection

Patients with cancer are increasingly vulnerable to infections, which may be more severe than in the general population. Improvements in rapid and timely diagnosis to optimize management are needed. We conducted a systematic literature review to determine the unmet need in diagnosing acute infections in immunocompromised patients with cancer and identified 50 eligible studies from 5188 records between 1 January 2012 and 23 June 2022. There was considerable heterogeneity in study designs and parameters, laboratory methods and definitions, and assessed outcomes, with limited evaluation of diagnostic impact on clinical outcomes. Culture remains the primary diagnostic strategy. Fewer studies employing molecular technologies exist, but emerging literature suggests that pathogen-agnostic molecular tests may add to the diagnostic armamentarium. Well-designed clinical studies using standardized methodologies are needed to better evaluate performance characteristics and clinical and economic impacts of emerging diagnostic techniques to improve patient outcomes.

Detection of cytomegalovirus in bronchoalveolar lavage fluid from immunocompromised patients with pneumonitis by viral culture and DNA quantification

PURPOSE

To compare the detection of human cytomegalovirus (HCMV) in bronchoalveolar lavage (BAL) fluid by viral culture and quantitative polymerase chain reaction (qPCR), and to establish a viral load threshold that can identify cases of HCMV replication indicative of pneumonitis. There is currently no universal viral load cut-off to differentiate between patients with and without pneumonitis, and the interpretation of qPCR results is challenging.

METHODS

176 consecutive BAL samples from immunosuppressed hosts with signs and/or symptoms of respiratory infection were prospectively studied by viral culture and qPCR.

RESULTS

Concordant results were obtained in 81.25% of the BAL samples. The rest were discordant, as only 34% of the qPCR-positive BAL samples were positive by culture. The median HCMV load was significantly higher in culture-positive than in culture-negative BAL samples (5,038 vs 178 IU/mL). Using a cut-off value of 1,258 IU/mL of HCMV in BAL, pneumonia was diagnosed with a sensitivity of 76%, a specificity of 100%, a VPP of 100% and VPN of 98%, and HCMV was isolated in 100% of the BAL cultures.

CONCLUSION

We found that a qPCR-negative was a quick and reliable way of ruling out HCMV pneumonitis, but a positive result did not always indicate clinically significant replication in the lung. However, an HCMV load in BAL fluid of ≥1,258 IU/mL was always associated with disease, whereas <200 IU/mL rarely so.

Quantitative PCR for the Diagnosis of HCMV Pneumonia in HSCT Recipients and Other Immunocompromised Hosts

Pneumonia is among the most serious manifestations of HCMV infection, with high morbidity and mortality. Probable pneumonia is defined as the detection of HCMV in bronchoalveolar lavage (BAL) by viral isolation or DNA quantification (qPCR) combined with symptoms and/or signs of respiratory infection. However, currently, there is no reproducible and well-defined viral load (VL) from BAL that can reliably differentiate patients with pneumonia from the much more common detection of viral DNA in seropositive patients without true HCMV pneumonia. Several studies have been published with the aim of establishing an optimal VL for differentiating pneumonia from viral lung shedding. The aim of this review is to collect and analyze the methodology and the conclusions obtained in studies whose objectives included the correlation between HCMV VL in BAL and/or the plasma and the occurrence of HCMV pneumonia. For this purpose, a total of 14 articles have been included. There are some conclusions on which they all agree. PCR techniques were more sensitive and had a higher NPV than culture techniques but were less specific and had a low PPV. The mean HCMV loads in both BAL and the plasma were significantly higher in patients with pneumonitis than in those without. The HCMV load in patients with pneumonitis was higher in BAL than in the plasma, making qPCR in BAL a better predictor of HCMV pneumonitis than in the plasma. Nevertheless, this review highlights the difficulty of establishing a universal VL value, both in BAL and in the blood, to differentiate patients with HCMV pneumonia from those without. To complete the information available in these studies, prospective multicentre studies would be required. Methodologically, a large number of patients with HCMV pneumonitis would have to be included, and a subclassification of the type of immunosuppression of each patient should be made in order to obtain an optimal VL threshold in different host groups.

Optimizing the treatment of cytomegalovirus infection in allo-HSCT recipients

INTRODUCTION

Cytomegalovirus (CMV) infection continues to negatively impact the prognosis after allogeneic hematopoietic stem cell transplantation (allo-HSCT), even with active monitoring and preemptive strategies. Recent progress in pharmacology, immunotherapy, and vaccines has improved the strategy of CMV management.

AREAS COVERED

We summarized recent advances in managing CMV infection post allo-HSCT, including diagnosis, prophylaxis, and treatment. In this review, we mainly focused on approaches that have optimized or might optimize the management of CMV infection after allo-HSCT.

EXPERT OPINION

In our opinion, optimized management covers aspects including the serial monitoring of CMV-DNA and CMI, an accurate diagnosis, effective prophylaxis, and a rational preemptive therapy integrating antiviral drugs and cell therapies. Strategies based on the understanding of CMV pathogenesis and CMV-related immune reconstitution after allo-HSCT will be a direction in future studies.

Impact of Post-Transplantation Cyclophosphamide on Transfusion Requirements in HLA-Matched Sibling Peripheral Blood Stem Cell Transplantation

Post-transplantation cyclophosphamide (PTCy)-based graft-versus-host disease (GVHD) prophylaxis is being increasingly used in allogeneic hematopoietic stem cell transplantation (allo-HSCT) from HLA-matched related donors (MRDs); however, information regarding the transfusion needs in this setting is lacking. This study compared RBC and platelet units transfused and time to transfusion independence according to the GVHD prophylaxis regimen in MRD HSCT. We performed a matched-pair analysis comparing the transfusion requirements and the clinical outcomes of patients who underwent MRD peripheral blood HSCT using PTCy between January 2017 and June 2021 (n = 100) with historical MRD HSCTs using standard cyclosporine A (CsA)-based prophylaxis (n = 100). Neutrophil engraftment was significantly delayed in the PTCy group compared with the CsA group (16 days versus 13 days; P = .003). PTCy was associated with increased RBC (median, 5 units versus 4 units; P = .04) and platelet (median, 6 units versus 3 units; P = .01) transfusion requirements during the first 30 days after transplantation. The proportion of patients requiring platelet transfusion during days 31 to 90 after transplantation was also higher in the PTCy group (55% versus 25%; P < .0001). In multivariate analysis, PTCy was associated with delayed RBC and platelet transfusion independence (hazard ratio, .61 [P = .007] and .51 [P < .0001], respectively). The cumulative incidence (CuI) of BK polyomavirus-associated hemorrhagic cystitis grade ≥2 at 100 days was higher in the PTCy group (34% versus 12%; P < .0001); however, the PTCy group had lower rates of grade II-IV acute GVHD (100-day CuI, 57% versus 23%; P < .0001) and moderate to severe chronic GVHD (1-year CuI, 49% versus 28%; P = .003), as well as better 2-year overall survival (74% versus 56%; P = .01). Our study shows that although PTCy increases the transfusion burden in MRD HSCT, it is associated with a low incidence of severe GVHD and with encouraging survival outcomes.

Delayed Onset of COVID-19 in an Immunosuppressed Patient

We report on a case of delayed presentation of COVID-19 in a postpartum immunosuppressed patient with the confounding variable of cytomegalovirus viremia. This case highlights the importance of maintaining high suspicion for COVID-19 disease even with delayed onset of symptoms, as this diagnosis as important treatment and public health implications.

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

Purpose of Review

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

Recent Findings

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

Summary

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

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.

Increasing Cytomegalovirus Detection Rate from Respiratory Tract Specimens by a New Laboratory-Developed Automated Molecular Diagnostic Test

Lots of automated molecular methods for detecting cytomegalovirus (CMV) DNA in the blood are available, but seldom for various clinical specimens. This study was designed to establish a highly sensitive automated assay to detect CMV DNA in non-blood specimens. We designed a new QMT assay using QIAGEN artus CMV RG polymerase chain reaction (Q-CMV PCR) kit applied on the BD MAX system and compared with the other assays, including an RGQ assay (LabTurbo auto-extraction combined Q-CMV PCR kit on Rotor-Gene-Q instrument), and in-house PCR assay. A total of 1067 various clinical samples, including 426 plasma, 293 respiratory tract specimens (RTS), 127 stool, 101 cerebral spinal fluid, 90 vitreous humours were analysed. Examining CMV DNA in simultaneous specimens of the same immunocompromised patient with respiratory symptoms, the detection rate of RTS (93.6%, 88/94) was significant higher than plasma (65.9%, 62/94). The positive rates for plasma samples with a low CMV viral load (<137 IU/mL) and diagnostic sensitivity of QMT, RGQ, and in-house assays were 65% and 99.1%, 45% and 100%, 5% and 65.5%, respectively. The QMT assay performs better, with shorter operational and turnaround time than the other assays, enabling the effective and early detection of CMV infection in various clinical specimens, particularly for RTS.

Opportunistic bacterial, viral and fungal infections of the lung

Opportunistic infections are a major cause of morbidity and mortality in severely immunocompromised patients, such as those given chemotherapy or biological therapies, and those with haematological malignancy, aplastic anaemia or HIV infection, or recipients of solid organ or stem cell transplants. The type and degree of immune defect dictates the profile of potential opportunistic pathogens; T-cell-mediated defects increase the risk of viral (cytomegalovirus, respiratory viruses) and Pneumocystis jirovecii infections, whereas neutrophil defects are associated with bacterial pneumonia and invasive aspergillosis. However, patients often have combinations of immune defects, and a wide range of other opportunistic infections can cause pneumonia. Importantly, conventional non-opportunistic pathogens are frequently encountered in immunocompromised hosts and should not be overlooked The radiological pattern of disease (best assessed by computed tomography) and speed of onset help identify the likely pathogen(s); this can then be supported by targeted investigation including early use of bronchoscopy in selected patients. Rapid and expert clinical assessment can identify the most likely pathogens, allowing timely appropriate therapy.

Uniform graft-versus-host disease prophylaxis with posttransplant cyclophosphamide, sirolimus, and mycophenolate mofetil following hematopoietic stem cell transplantation from haploidentical, matched sibling and unrelated donors

Following the success of posttransplant cyclophosphamide (PT-CY) as graft-versus-host disease (GVHD) prophylaxis in haploidentical transplantation, this prevention strategy has progressively been used for allogeneic hematopoietic stem cell transplantation (allo-HSCT) from HLA-matched sibling (MSD) and unrelated donor (MUD). We have introduced PT-CY plus sirolimus and micophenolate mofetil (PT-CY-Sir-MMF) as GVHD prophylaxis in allo-HSCT, irrespective of donor type. This study reports on the safety and efficacy of PT-CY-Sir-MMF in 158 consecutive allo-HSCT from MSD (n = 52), MUD (n = 64), and haploidentical (n = 42) donor. Median age was 53 years and 66% had acute leukemia or myelodysplastic syndrome. Cumulative incidences of acute GHVD grade II-IV, III-IV and moderate to severe cGVHD were 27%, 9% and 27%, respectively. The incidence of hepatic sinusoidal obstruction syndrome was 9.5%. The 1-year cumulative incidence of non-relapse mortality, relapse and event-free survival were 14%, 12% and 75%, respectively. Compared with MSD and MUD, haploidentical transplantation had a higher incidence of CMV DNAemia requiring therapy (34% vs 35% and 52%, respectively, p = 0.04) and was a risk factor for grade III-IV acute GVHD (RR 2.8, p = 0.05). Our study shows that PT-CY-Sir-MMF is not only feasible and effective in preventing GVHD after haploidentical HSCT, but also in allo-HSCT from MSD and MUD.

Cytomegalovirus (CMV) Pneumonitis: Cell Tropism, Inflammation, and Immunity

Human cytomegalovirus (HCMV) is an opportunistic pathogen causing disease mainly in immunocompromised patients or after congenital infection. HCMV infection of the respiratory tract leads to pneumonitis in the immunocompromised host, which is often associated with a bad clinical course. The related mouse cytomegalovirus (MCMV) likewise exhibits a distinct tropism for the lung and thus provides an elegant model to study host-pathogen interaction. Accordingly, fundamental features of cytomegalovirus (CMV) pneumonitis have been discovered in mice that correlate with clinical data obtained from humans. Recent studies have provided insight into MCMV cell tropism and localized inflammation after infection of the respiratory tract. Accordingly, the nodular inflammatory focus (NIF) has been identified as the anatomical correlate of immune control in lungs. Several hematopoietic cells involved in antiviral immunity reside in NIFs and their key effector molecules have been deciphered. Here, we review what has been learned from the mouse model with focus on the microanatomy of infection sites and antiviral immunity in MCMV pneumonitis.