Quantitative PCR Is Faster, More Objective, and More Reliable Than Immunohistochemistry for the Diagnosis of Cytomegalovirus Gastrointestinal Disease in Allogeneic Stem Cell Transplantation

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.

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.

Clinical characteristics and outcomes of immunocompromised critically ill patients with cytomegalovirus end-organ disease: a multicenter retrospective cohort study

BACKGROUND

Cytomegalovirus (CMV) infection in patients with cellular immune deficiencies is associated with significant morbidity and mortality. However, data on CMV end-organ disease (CMV-EOD) in critically ill, immunocompromised patients are scarce. Our objective here was to describe the clinical characteristics and outcomes of CMV-EOD in this population.

METHODS

We conducted a multicenter, international, retrospective, observational study in adults who had CMV-EOD and were admitted to any of 18 intensive care units (ICUs) in France, Israel, and Spain in January 2010-December 2021. Patients with AIDS were excluded. We collected the clinical characteristics and outcomes of each patient. Survivors and non-survivors were compared, and multivariate analysis was performed to identify risk factors for hospital mortality.

RESULTS

We studied 185 patients, including 80 (43.2%) with hematologic malignancies, 55 (29.7%) with solid organ transplantation, 31 (16.8%) on immunosuppressants, 16 (8.6%) with solid malignancies, and 3 (1.6%) with primary immunodeficiencies. The most common CMV-EOD was pneumonia (n = 115, [62.2%] including 55 [47.8%] with a respiratory co-pathogen), followed by CMV gastrointestinal disease (n = 64 [34.6%]). More than one organ was involved in 16 (8.8%) patients. Histopathological evidence was obtained for 10/115 (8.7%) patients with pneumonia and 43/64 (67.2%) with GI disease. Other opportunistic infections were diagnosed in 69 (37.3%) patients. Hospital mortality was 61.4% overall and was significantly higher in the group with hematologic malignancies (75% vs. 51%, P = 0.001). Factors independently associated with higher hospital mortality were hematologic malignancy with active graft-versus-host disease (OR 5.02; 95% CI 1.15-27.30), CMV pneumonia (OR 2.57; 95% CI 1.13-6.03), lymphocytes < 0.30 × 109/L at diagnosis of CMV-EOD (OR 2.40; 95% CI 1.05-5.69), worse SOFA score at ICU admission (OR 1.18; 95% CI 1.04-1.35), and older age (OR 1.04; 95% CI 1.01-1.07).

CONCLUSIONS

Mortality was high in critically ill, immunocompromised patients with CMV-EOD and varied considerably with the cause of immunodeficiency and organ involved by CMV. Three of the four independent risk factors identified here are also known to be associated with higher mortality in the absence of CMV-EOD. CMV pneumonia was rarely proven by histopathology and was the most severe CMV-EOD.

Diagnostic Utility of Cytomegalovirus (CMV) DNA Quantitation in Ulcerative Colitis

Cytomegalovirus (CMV) colitis is a critical condition associated with severe complications in ulcerative colitis (UC). This study aimed to investigate the diagnostic value of the presence of CMV DNA in intestinal mucosa tissue and blood samples in patients with active UC. This study included 81 patients with exacerbated symptoms of UC. Patient data were obtained from the Hospital Information Management System. CMV DNA in colorectal tissue and plasma samples were analyzed using a real-time quantitative PCR assay. CMV markers were detected using immunohistochemistry and hematoxylin-eosin staining. Immunohistochemistry positivity was observed in tissue samples from eight (9.9%) patients. Only one (1.2%) patient showed CMV-specific intranuclear inclusion bodies. CMV DNA was detected in 63.0% of the tissues (median: 113 copies/mg) and in 58.5% of the plasma samples (median: 102 copies/mL). For tissues, sensitivity and the negative predictive value (NPV) for qPCR were excellent (100.0%), whereas specificity and the positive predictive value (PPV) were low (41.9% and 15.7%, respectively). For plasma, sensitivity and NPV were high (100.0%) for qPCR, whereas specificity and PPV were low (48.6% and 24.0%, respectively). CMV DNA ≥392 copies/mg in tissue samples (sensitivity 100.0% and specificity 83.6%) and ≥578 copies/mL (895 IU/mL) in plasma samples (sensitivity 66.7% and specificity 100.0%) provided an optimal diagnosis for this test. The qPCR method improved patient management through the early detection of CMV colitis in patients with UC. However, reliance on qPCR positivity alone can lead to overdiagnosis. Quantification of CMV DNA can improve diagnostic specificity, although standardization is warranted.

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

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

Impact of letermovir prophylaxis in CMV reactivation and disease after allogenic hematopoietic cell transplantation: a real-world, observational study

Letermovir for CMV prevention in CMV-seropositive adults undergoing allo-HCT was implemented at our program in 2021. This study investigates the results from the use of letermovir. The study includes all the 140 CMV-seropositive patients who underwent an allo-HCT during the years 2020, 2021, and 2022 at our institution. Thirty-eight (27.4%) of these patients received letermovir, administered from day + 7 to day + 100 and restarted if patients were on treatment with steroids. The day + 180 and 1-year cumulative incidences of CMV reactivation were 5.3% and 12.1% for patients who received letermovir and 52.9% and 53.9% for those who did not (P < 0.001) (HR 0.19, P < 0.001). Four (10.5%) of these thirty-eight patients had a CMV reactivation, but only 2 (5.3%) cases occurred during the administration of letermovir. During the first year after allo-HCT, 13 (9.2%) patients had CMV disease; the day + 180 and 1-year cumulative incidences were 2.6% and 6.0% for patients who received letermovir and 9.9% and 12.3% for those who did not (P = 0.254) (HR 1.01, P = 0.458). Two (4.2%) of the patients included in the letermovir group had CMV disease, but both of them after letermovir discontinuation. Letermovir induced a protective effect on CMV reactivation risk, but its use was not associated with a significant reduction of CMV disease. The fact that the CMV disease in patients who received letermovir occurred after the discontinuation of the drug, questions whether CMV prophylaxis should be used in patients with high risk for CMV reactivation or disease.

Comparison of Infectious Bronchitis Virus (IBV) Pathogenesis and Host Responses in Young Male and Female Chickens

Infectious bronchitis virus (IBV) is an avian coronavirus that causes a disease in chickens known as infectious bronchitis (IB). The pathogenesis of IBV and the host immune responses against it depend on multiple factors such as the IBV variant, breed and age of the chicken, and the environment provided by the management. Since there is limited knowledge about the influence of the sex of chickens in the pathogenesis of IBV, in this study we aim to compare IBV pathogenesis and host immune responses in young male and female chickens. One-week-old specific pathogen-free (SPF) White Leghorn male and female chickens were infected with Canadian Delmarva (DMV)/1639 IBV variant at a dose of 1 × 106 embryo infectious dose (EID)50 by the oculo-nasal route while maintaining uninfected controls, and these chickens were euthanized and sampled 4- and 11-days post-infection (dpi). No significant difference was observed between the infected male and female chickens in IBV shedding, IBV genome load in the trachea, lung, kidney, bursa of Fabricius (BF), thymus, spleen, and cecal tonsils (CT), and IBV-induced lesion in all the examined tissues at both 4 and 11 dpi. In addition, there was no significant difference in the percentage of IBV immune-positive area observed between the infected male and female chickens in all tissues except for the kidney, which expressed an increased level of IBV antigen in infected males compared with females at both 4 and 11 dpi. The percentage of B lymphocytes was not significantly different between infected male and female chickens in all the examined tissues. The percentage of CD8+ T cells was not significantly different between infected male and female chickens in all the examined tissues except in the trachea at 11 dpi, where female chickens had higher recruitment when compared with male chickens. Overall, although most of the findings of this study suggest that the sex of chickens does not play a significant role in the pathogenesis of IBV and the host immune response in young chickens, marginal differences in viral replication and host responses could be observed to indicate that IBV-induced infection in male chickens is more severe.

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.

Immunohistochemistry Staining-Proven Cytomegalovirus Colitis in Living Donor Liver Transplantation

Background and Aims: Cytomegalovirus (CMV) infection is a common occurrence in liver transplantation (LT) even in an era of preventive strategies. However, the diagnosis of CMV colitis remains challenging. This study aimed to focus on the clinical significance of endoscopic biopsy-proven CMV colitis in patients following living donor liver transplantation (LDLT). Methods: From January 2007 to December 2021, a total of 55 CMV colitis cases were retrospectively enrolled and divided into a non-LDLT group in 53 and an LDLT group in 2 cases. Clinical demographics, diagnostic measurement, histopathology, and anti-viral therapy were investigated. Results: There were 1630 cases undergoing LDLT in the period 2007-2021, with only 2 recipients being confirmed to have CMV colitis in 2021 (2/114, 1-year incidence: 1.75%). Comparisons between the 53 non-LDLT cases and 2 LDLT cases are as follows: Serum anti-CMV immunoglobulin M (IgM) was shown to be positive (n = 3, 5.5% vs. n = 0, p = 1.0) and negative (n = 20, 37.7% vs. n = 2, 100%, p = 0.16); anti-CMV immunoglobulin G (IgG) was positive (n = 19, 35.8% vs. n = 2, 100%, p = 0.14) and none were negative; CMV DNAemia was shown to be detectable (n = 14, 26.4% vs. n = 1, 50%, p = 0.47) and undetectable (n = 14, 26.4% vs. n = 1, 50%, p = 0.47). Among the two recipients with CMV colitis, one had CMV DNAemia and the other had no CMV DNAemia upon the development of symptoms; negative anti-CMV-IgM and positive anti-CMV-IgG were observed both pre-transplant and post-transplant; finally, CMV colitis was documented based on the presence of inclusion bodies and positive immunohistochemistry (IHC) staining in histology. Conclusion: Patients with immunocompromised status, in particular organ transplantation, may have positive serum anti-CMV IgM/IgG antibodies both before and after transplantation. This study emphasized the fact that endoscopic biopsy with IHC staining may be a more powerful tool for making an accurate diagnosis of CMV colitis in the setting of living donor liver transplantation.

Assessment of PD-L1 mRNA expression in gastrointestinal tumors and the response to immunotherapy

Background

Programmed death ligand 1 (PD-L1) immunohistochemistry (IHC) has been proposed as a predictive biomarker to predict response to immunotherapy. Given the limitations of IHC test in PD-L1 detection, this study aimed to investigate the technical feasibility of using quantitative RT-PCR (qRT-PCR) to replace IHC in PD-L1 detection in gastrointestinal tumors.

Materials and methods

The Cancer Genome Atlas database was used to evaluate the relationship between PD-L1 expression in tumor tissue and the patient prognosis. In addition, 52 patients with gastrointestinal cancer were enrolled and divided into the stomach (STAD), colon (COAD), and rectum (READ) adenocarcinoma cohorts. IHC test was used to determine the PD-L1 level of the tissue specimens, and the qRT-PCR test was used to analyze the mRNA expression in both blood and tissue specimens. Moreover, the correlation between blood PD-L1 mRNA expression and immunotherapy efficacy was investigated in additional 15 patients with gastric cancer that further enrolled.

Results

The expression level of PD-L1 in tumor tissue is related to the tumor stage of COAD (p-value = 0.001) and primary therapy outcomes in patients with READ (p-value = 0.003) but not significantly correlated to the overall survival (OS) time of patients with gastrointestinal cancer. Moreover, the concordance of PD-L1 mRNA expression level of tissue and paired blood samples is low, despite a weak linear relationship that was found in the STAD cohort (r = 0.43, p-value = 0.049). We further demonstrated that qRT-PCR results in both tissue and blood specimens were numerically but not statistically significant consistent with IHC results (corresponding to a p-value of 0.84 and 0.55, respectively). Remarkably, high PD-L1 expression in blood of patients with STAD shows a better response to immunotherapy (p-value = 0.04), which could be well identified at the relative expression cutoff of 1.5 (sensitivity of 85.7%, specificity of 75.0%, and AUC of 0.82).

Conclusions

Our study established a novel strategy for rapidly distinguishing patients with gastrointestinal cancer with the response to immunotherapy and has potential clinical benefits.

Routine Histology-Based Diagnosis of CMV Colitis Was Rare in Pediatric Patients

Cytomegalovirus (CMV) induced or complicated colitis is important to identify, yet its incidence is unknown among pediatric patients. We aimed to establish the incidence of routine histology-confirmed CMV colitis among pediatric patients with colitis. Pathology reports at Texas Children's Hospital (TCH) between January 1, 2011 and November 6, 2019 were reviewed. Of 1801 cases of histologic colitis, 11 patients had CMV found by histology (mean age 15.4, 72.7% female), with an incidence of 0.6%. Nine out of these 11 (81.8%) patients were immunocompromised and 4 (36.4%) had inflammatory bowel disease (IBD) as an underlying diagnosis of whom 2 had new-onset ulcerative colitis. At an average follow-up of 3.7 years, none of the CMV colitis cases experienced recurrence or severe complications (such as colectomy). An independent analysis of 54 consecutive IBD-associated colectomy cases at TCH showed no histologic evidence of CMV. We conclude that routine histology proven CMV-associated colitis in pediatric patients and IBD-colon explants was rare.Key Words: cytomegalovirus; colitis; children; histopathology; ulcerative colitis.

Cytomegalovirus Diseases of the Gastrointestinal Tract

Cytomegalovirus (CMV) infection of the gastrointestinal (GI) tract can be fatal. However, very few studies have provided comprehensive analyses and specified the differences in symptoms observed in different parts of the GI tract. This study aimed to comprehensively analyze clinical manifestations and management of GI CMV disease. This retrospective cohort study enrolled the patients who had CMV diseases of the GI tract proved by CMV immunohistochemistry stain from the pathology database in a 4000-bed tertiary medical center between January 2000 and May 2021. The patient characteristics, clinical manifestations, endoscopic features, treatments, outcomes, and prognostic factors were analyzed. A total of 356 patients were enrolled, including 46 infected in the esophagus, 76 in the stomach, 30 in the small intestine, and 204 in the colon. In total, 49.4% patients were immunocompromised. The overall in-hospital mortality rate was 20.8%: CMV enteritis had the highest rate (23.3%). Sixty percent of patients received antiviral treatment and 16% were administered both intravenous and oral anti-viral drugs (Combo therapy, minimal and mean treatment duration were 14 and 39.9 ± 25 days). Prognostic factors of in-hospital mortality included age, immune status, albumin level, platelet count, GI bleeding, time-to-diagnosis, and Combo therapy. In the survival analysis, immunocompetent patients receiving Combo therapy had the best survival curve, and immunocompromised patients receiving non-Combo therapy had the worst survival curve. Combo therapy ≥14 days resulted in a better outcome for both immunocompromised and immunocompetent patients. In conclusion, CMV GI diseases affect both immunocompromised and immunocompetent hosts, and a complete treatment course should be considered for patients with poor prognostic factors.

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.

Role of highly sensitive nucleic acid amplification testing for plasma cytomegalovirus DNA load in diagnosis of cytomegalovirus gastrointestinal disease among kidney transplant recipients

BACKGROUND

High plasma cytomegalovirus (CMV) DNA load is generally associated with CMV tissue-invasive disease in solid organ transplant recipients. However, some tissue-invasive diseases, especially CMV gastrointestinal (GI) disease, have undetectable to very low plasma CMV DNA loads. Highly sensitive nucleic acid amplification testing (NAAT) has been increasingly used to quantify low-level CMV DNA loads. Our primary objective was to investigate the epidemiology of CMV GI disease and evaluate the validity of plasma CMV NAAT for the diagnosis of CMV GI disease in kidney transplant (KT) recipients.

METHODS

We conducted a retrospective study of all KT recipients who developed CMV GI disease from January 2016 to December 2018. Plasma CMV DNA load was measured using real-time PCR. The cut-off value of plasma CMV DNA load for diagnosing and risk factors of CMV GI disease were analyzed.

RESULTS

A total 17 (3.4%) cases of CMV GI disease occurred in 494 KT recipients. Fifteen (88%) patients had CMV D ⁺ /R ⁺ serostatus. Fourteen (82%) patients developed CMV GI disease within 6 months after KT. Plasma CMV DNA loads were detectable in all (100%) patients with a median load 11,102 (IQR 2,935-107,160) IU/ml. A plasma CMV DNA load of 4,063 IU/ml was established as al cut-off for diagnosing CMV GI disease (AUC 0.74, sensitivity 76.5%, specificity 70%, PPV 68, NPV 78). In multivariate analysis, prolonged cold ischemic time (HR 1.14, 95% CI 1.05-1.23, P = .002) and CMV D ⁺ /R ^- serostatus (HR 9.31, 95% CI 2.12-40.74, P = .003) were associated with CMV GI disease.

CONCLUSIONS

Using highly sensitive NAAT could potentially assist in the diagnosis of CMV GI disease in a CMV D ⁺ /R ⁺ serostatus setting. KT recipients with CMV seromismatch and prolonged cold ischemic time are at higher risk of CMV GI disease.

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.

Cytomegalovirus and Inflammatory Bowel Diseases (IBD) with a Special Focus on the Link with Ulcerative Colitis (UC)

Cytomegalovirus (CMV) infects approximately 40% of adults in France and persists lifelong as a latent agent in different organs, including gut. A close relationship is observed between inflammation that favors viral expression and viral replication that exacerbates inflammation. In this context, CMV colitis may impact the prognosis of patients suffering from inflammatory bowel diseases (IBDs), and notably those with ulcerative colitis (UC). In UC, the mucosal inflammation and T helper cell (T_H) 2 cytokines, together with immunomodulatory drugs used for controlling flare-ups, favor viral reactivation within the gut, which, in turn, increases mucosal inflammation, impairs corticoid and immunosuppressor efficacy (the probability of steroid resistance is multiplied by more than 20 in the case of CMV colitis), and enhances the risk for colectomy. This review emphasizes the virological tools that are recommended for exploring CMV colitis during inflammatory bowel diseases (IBD) and underlines the interest of using ganciclovir for treating flare-ups associated to CMV colitis in UC patients.