The Association Between Cytomegalovirus Infection and Cardiac Allograft Vasculopathy in the Era of Antiviral Valganciclovir Prophylaxis

Cytomegalovirus infection and cardiovascular outcomes in abdominal organ transplant recipients: A systematic review and meta-analysis

INTRODUCTION

Despite advancements in Cytomegalovirus (CMV) management, its impact on graft function, mortality, and cardiovascular (CV) health of organ transplant recipients (OTR) remains a significant concern. We investigated the association between CMV infection and CV events (CVE) in organ (other than heart) transplant recipients.

METHODS

We conducted a comprehensive literature search in PubMed and EMBASE, including studies that reported on CMV infection or disease and post-transplantation CVE. Studies of heart transplant recipients were excluded.

RESULTS

We screened 3875 abstracts and 12 clinical studies were included in the final analysis, mainly in kidney and liver transplant recipients. A significant association was observed between CMV infection and an increased risk of CVE, with a pooled unadjusted hazard ratio (HR) of 1.99 (95% Confidence Intervals [CI] 1.45-2.73) for CMV infection and 1.59 (95% CI 1.21-2.10) for CMV disease. Pooled adjusted HR were 2.17 (95% CI 1.47-3.20) and 1.77 (95% CI 0.83-3.76), respectively. Heterogeneity was low (I2 = 0%) for CMV infection, suggesting consistent association across studies, and moderate-to-high for CMVdisease (I2 = 50% for unadjusted, 53% for adjusted HR).

DISCUSSION

We found a significant association between CMV infection and CV risk in abdominal OTR, underscoring the importance of proactive CMV surveillance and early treatment. Future research should aim for more standardized methodologies to fully elucidate the relationship between CMV and CV outcomes, potentially informing novel preventive and therapeutic strategies that could benefit the CV health of OTR.

Cytomegalovirus infection is associated with impaired myocardial flow reserve after heart transplantation

BACKGROUND

Cardiac allograft vasculopathy (CAV) limits long-term survival after heart transplantation (HT). This study evaluates the relationship between clinically significant cytomegalovirus infection (CS-CMVi) and CAV using cardiac positron emission tomography (PET).

METHODS

We retrospectively evaluated HT patients from 2005 to 2019 who underwent cardiac PET for CAV evaluation. Multivariable linear and logistic regression models were used to evaluate the association between CS-CMVi and myocardial flow reserve (MFR). Kaplan-Meier and Cox regression analyses were used to assess the relationship between CS-CMV, MFR, and clinical outcomes.

RESULTS

Thirty-two (31.1%) of 103 HT patients developed CS-CMVi at a median 9 months after HT. Patients with CS-CMVi had a significantly lower MFR at year 1 and 3, driven by reduction in stress myocardial blood flow. Patients with CS-CMVi had a faster rate of decline in MFR compared to those without infection (-0.10 vs -0.06 per year, p < 0.001). CS-CMVi was an independent predictor of abnormal MFR (<2.0) (odds ratio: 3.8, 95% confidence intervals (CI): 1.4-10.7, p = 0.001) and a lower MFR (β = -0.39, 95% CI: -0.63 to -0.16, p = 0.001) at year 3. In adjusted survival analyses, both abnormal MFR (log-rank p < 0.001; hazard ratio [HR]: 5.7, 95% CI: 4.2-7.2) and CS-CMVi (log-rank p = 0.028; HR: 3.3, 95% CI: 1.8-4.8) were significant predictors of the primary outcome of all-cause mortality, retransplantation, heart failure hospitalization, and acute coronary syndrome.

CONCLUSIONS

CS-CMVi is an independent predictor of reduced MFR following HT. These findings suggest that CMV infection is an important risk factor in the development and progression of CAV.

Role of Preemptive Cytomegalovirus Hyperimmunoglobulin in Cytomegalovirus Viremia Following Stem Cell Transplant: An Integrative Review

Introduction

Cytomegalovirus (CMV) is a major cause of morbidity and mortality in stem cell transplant (SCT) patients. Cytomegalovirus hyperimmunoglobulin (CMV-HIG) therapy has been described in the solid organ transplant setting. However, no review has focused on preemptive use of intravenous CMV immunoglobulins in the SCT setting. This review aims to consolidate findings regarding the preemptive use of CMV-HIG for CMV viremia in SCT patients.

Methods

PubMed and Scopus were searched using specific search criteria for publications from 2011 to 2021. Search terms were: cytomegalovirus, CMV, immunoglobulins, immunoglobulin, IVIG, CMVIG, hematopoietic stem cell transplantation, and stem cell. Included studies discussed stem cell transplantation, immunoglobulins, and cytomegalovirus. 366 articles were identified from the search. Five articles met the inclusion and exclusion criteria.

Results

Preemptive CMV-HIG resulted in an overall response in 65% to 100% of patients with a clearance time of 14 to 21 days. Early use of CMV-HIG may shorten clearance time. No treatment-related mortality or serious adverse events were associated.

Conclusion

CMV-HIG is an effective treatment option in SCT patients that is as safe as antivirals alone. Preemptive CMV-HIG with antivirals may provide the added advantage of reduced time to viremia clearance without adding renal injury. Larger, prospective studies are needed to evaluate CMV-HIG's impact on time to viremia clearance and the effectiveness of preemptive CMV-HIG use with antivirals.

Immunological profiling in long COVID: overall low grade inflammation and T-lymphocyte senescence and increased monocyte activation correlating with increasing fatigue severity

Background

Many patients with SARS-CoV-2 infection develop long COVID with fatigue as one of the most disabling symptoms. We performed clinical and immune profiling of fatigued and non-fatigued long COVID patients and age- and sex-matched healthy controls (HCs).

Methods

Long COVID symptoms were assessed using patient-reported outcome measures, including the fatigue assessment scale (FAS, scores ≥22 denote fatigue), and followed up to one year after hospital discharge. We assessed inflammation-related genes in circulating monocytes, serum levels of inflammation-regulating cytokines, and leukocyte and lymphocyte subsets, including major monocyte subsets and senescent T-lymphocytes, at 3-6 months post-discharge.

Results

We included 37 fatigued and 36 non-fatigued long COVID patients and 42 HCs. Fatigued long COVID patients represented a more severe clinical profile than non-fatigued patients, with many concurrent symptoms (median 9 [IQR 5.0-10.0] vs 3 [1.0-5.0] symptoms, p<0.001), and signs of cognitive failure (41%) and depression (>24%). Immune abnormalities that were found in the entire group of long COVID patients were low grade inflammation (increased inflammatory gene expression in monocytes, increased serum pro-inflammatory cytokines) and signs of T-lymphocyte senescence (increased exhausted CD8+ TEMRA-lymphocytes). Immune profiles did not significantly differ between fatigued and non-fatigued long COVID groups. However, the severity of fatigue (total FAS score) significantly correlated with increases of intermediate and non-classical monocytes, upregulated gene levels of CCL2, CCL7, and SERPINB2 in monocytes, increases in serum Galectin-9, and higher CD8+ T-lymphocyte counts.

Conclusion

Long COVID with fatigue is associated with many concurrent and persistent symptoms lasting up to one year after hospitalization. Increased fatigue severity associated with stronger signs of monocyte activation in long COVID patients and potentially point in the direction of monocyte-endothelial interaction. These abnormalities were present against a background of immune abnormalities common to the entire group of long COVID patients.

Incidence and severity of cytomegalovirus infection in seropositive heart transplant recipients

BACKGROUND

The frequency and significance of cytomegalovirus (CMV) infection in seropositive (R+) heart transplant recipients (HTR) is unclear, with preventative recommendations mostly extrapolated from other groups. We evaluated the incidence and severity of CMV infection in R+ HTR, to identify risk factors and describe outcomes.

METHODS

R+ HTR from 2010 to 2019 were included. Antiviral prophylaxis was not routinely used, with clinically guided monitoring the local standard of care. The primary outcome was CMV infection within one-year post-transplant; secondary outcomes included other herpesvirus infections and mortality.

RESULTS

CMV infection occurred in 27/155 (17%) R+ HTR. Patients with CMV had a longer hospitalization (27 vs. 20 days, unadjusted HR 1.02, 95% CI 1.00-1.02, p = .01), higher rate of intensive care readmission (26% vs. 9%, unadjusted HR 3.46, 1.46-8.20, p = .005), and increased mortality (33% vs. 8%, unadjusted HR 10.60, 4.52-24.88, p < .001). The association between CMV and death persisted after adjusting for multiple confounders (HR 24.19, 95% CI 7.47-78.30, p < .001). Valganciclovir prophylaxis was used in 35/155 (23%) and was protective against CMV (infection rate 4% vs. 27%, adjusted HR .07, .01-.72, p = .025), even though those receiving it were more likely to have received thymoglobulin (adjusted OR 10.5, 95% CI 2.01-55.0, p = .005).

CONCLUSIONS

CMV infection is common in R+ HTR and is associated with a high burden of disease and increased mortality. Patients who received valganciclovir prophylaxis were less likely to develop CMV infection, despite being at higher risk. These findings support the routine use of antiviral prophylaxis following heart transplantation in all CMV R+ patients.

Cytomegalovirus in the transplant setting: Where are we now and what happens next? A report from the International CMV Symposium 2021

The CMV Symposium in September 2021 was an international conference dedicated to cytomegalovirus (CMV) infection after solid organ or hematopoietic stem cell transplantation. This review provides an overview of the presentations given by the expert faculty, supplemented with educational clinical cases. Topics discussed include CMV epidemiology and diagnosis, the burden of CMV infection and disease, CMV-specific immunity and management of CMV in transplant settings. Major advances in the prevention and treatment of CMV in the past decade and increased understanding of CMV immunity have led to improved patient outcomes. In the future, management algorithms may be individualized based on the transplant recipient's immune profile, which will mark the start of a new era for patients with CMV.

Long-term efficacy of everolimus as de novo immunosuppressant on the cardiac allograft vasculopathy in heart transplant recipients

BACKGROUND AND AIMS

Data on the long-term effects of everolimus (EVL) on the de novo immunosuppression of heart transplant (HT) recipients with progressive cardiac allograft vasculopathy (CAV) and vascular remodeling are lacking. Hence, in this study, we aimed to determine the long-term safety and efficacy of EVL as a de novo immunosuppressant therapy for CAV progression and the clinical outcomes after HT.

METHODS

We retrospectively reviewed the medical records of 144 HT recipients who survived for at least one year after HT. CAV progression was assessed via serial coronary intravascular ultrasonography (IVUS) in recipients who underwent at least two IVUS studies.

RESULTS

A significant attenuation in the percentage of the atheroma volume progression was observed in those who took EVL (1.2%) compared with those who took cyclosporin (CSA; 7.3%; p = 0.005 vs. EVL) or tacrolimus (TAC; 6.6%; p = 0.0052 vs. EVL) at 1 year after HT. This trend persisted for the next 3 and 5 years after HT. Moreover, the remodeling index was greater in the EVL (1.08) group than in the CSA (0.23) or TAC (-0.25) groups 1 year after HT. The results of the Kaplan-Meier analysis over a median follow-up period of 8 years revealed that there was no statistical difference in the primary endpoint between the three groups.

CONCLUSIONS

De novo immunosuppression with EVL is associated with attenuated CAV progression for the first 5 years of follow-up via IVUS. Moreover, EVL has comparable long-term clinical outcomes to those of CSA- or TAC-based protocols.

Role of cytomegalovirus infection after kidney transplantation on the subsequent risk of atherosclerotic and thrombotic events

Background and aims

Whether cytomegalovirus (CMV) infection increases the risk of cardiovascular complications after kidney transplantation (KT) through different indirect effects remains controversial.

Methods

We analyzed the incidence of post-transplant atherosclerotic (PAEs) and thrombotic events (PTEs) in 465 KT recipients according to the previous exposure to any level or high-level (≥1,000 IU/mL) CMV viremia (either asymptomatic or clinical disease) by means of landmark analysis beyond days 30, 180 and 360 after transplantation. Proportional hazards models were constructed with death and graft loss as competing risks.

Results

After a median of 722 days, the cumulative incidences of PAE and PTE were 6.0% each. Most PAEs (53.6%) occurred beyond post-transplant day 360, whereas most PTEs (60.7%) were diagnosed between days 30-180.The incidence of PAE beyond day 180 was higher among patients with previous CMV viremia compared to those without (two-year rates: 4.7% versus 0.4%; P-value = 0.035). This difference was more pronounced in recipients developing high-level viremia (6.3% versus 0.7%, respectively; P-value = 0.013). After multivariate adjustment for age, pre-transplant cardiovascular risk, antiplatelet and statin therapy and graft function, however, associations were not maintained either for any-level (hazard ratio [HR]: 1.84; 95% confidence interval [CI]: 0.48-7.05) or high-level CMV viremia (HR: 2.84; 95% CI: 0.78-10.36). No significant differences were found in the remaining landmark analyses (days 30 or 360) or for the outcome of PTE either.

Conclusions

Our study does not support that CMV infection independently contributes to the risk of PAE or PTE after KT.

Cardiac allograft vasculopathy: current review and future research directions

Cardiac allograft vasculopathy (CAV) is a pathologic immune-mediated remodelling of the vasculature in transplanted hearts and, by impairing perfusion, is the major cause of late graft loss. Although best understood following cardiac transplantation, similar forms of allograft vasculopathy occur in other vascularized organ grafts and some features of CAV may be shared with other immune-mediated vasculopathies. Here, we describe the incidence and diagnosis, the nature of the vascular remodelling, immune and non-immune contributions to pathogenesis, current therapies, and future areas of research in CAV.

In-hospital outcomes after percutaneous coronary interventions in cardiac allograft recipients

Introduction

The average age and survival of heart transplant recipients have improved significantly over the last 10 years. In these long-term survivors, coronary allograft vasculopathy is one of the most common causes of death. There is a paucity of large-data research highlighting the short-term outcomes of percutaneous coronary interventions in cardiac allograft recipients.

Methods

We compared the in-hospital outcomes of heart transplant recipient and non-transplant recipients following percutaneous coronary intervention using data from the National inpatient sample (NIS). All adult patients (age ⩾ 18 years) who had percutaneous coronary intervention in the index admissions from January of 2005 to December of 2014 were included in the analysis. They were then divided into two groups based on their heart transplant status. The primary outcome was in-hospital mortality. Secondary outcomes were stroke, cardiac arrest, duration of hospitalization, and total hospital charges. Logistic regression models were used to compare in-hospital outcomes between the two groups.

Results

Of 1,316,528 patients who had percutaneous coronary intervention, 618 (0.05%) were heart transplant recipients and 1,315,910 (99.95%) were not. The heart transplant recipient group was significantly younger with lower rates of obesity and peripheral vascular disease but higher rate of chronic kidney disease, iron deficiency anemia, and chronic liver disease. There was significantly higher in-hospital mortality in transplant recipients below 65 years of age (adjusted odds ration = 2.3, p value < 0.0001). Subjects in the heart transplant recipient group also had longer hospital stays (p value = 0.002).

Conclusion

Heart transplant recipients younger than 65 years had higher in-hospital mortality. Subjects in the heart transplant recipient group were also younger and had longer duration of hospitalization than the non-transplant cohorts.

Post-transplant absolute lymphocyte count predicts early cytomegalovirus infection after heart transplantation

Immunosuppressive therapy can decrease rejection episodes and increase the risk of severe and fatal infections in heart transplantation (HT) recipients. Immunosuppressive therapy can also decrease the absolute lymphocyte count (ALC), but the relationship between early post-transplant ALC and early cytomegalovirus (CMV) infection is largely unknown, especially in HT. We retrospectively analyzed 58 HT recipients who tested positive for CMV IgG antibody and received basiliximab induction therapy. We collected preoperative and 2-month postoperative data on ALC and CMV load. The CMV load > 1200 IU/mL was used as the cutoff value to define early CMV infection. Post-transplant lymphopenia was defined as an ALC of < 500 cells/μL at postoperative day (POD) #7. On POD #7, 29 (50.0%) patients had post-transplant lymphopenia and 29 (50.0%) patients did not. The incidence of CMV infection within 1 or 2 months of HT was higher in the post-transplant lymphopenia group than in the non-lymphopenia group (82.8% vs. 48.3%, P = 0.013; 89.7% vs. 65.5%, P = 0.028, respectively). ALC < 500 cells/μL on POD #7 was an independent risk factor for early CMV infection within 1 month of HT (odds ratio, 4.14; 95% confidence interval, 1.16-14.77; P = 0.029). A low ALC after HT was associated with a high risk of early CMV infection. Post-transplant ALC monitoring is simple and inexpensive and can help identify patients at high risk of early CMV infection.

The Incidence and Effect of Cytomegalovirus Disease on Mortality in Transplant Recipients and General Population: Real-world Nationwide Cohort Data

Background: In addition to the conventional opportunistic infections in solid organ transplantation (SOT) and hematopoietic stem cell transplantation (HSCT) recipients, cytomegalovirus (CMV) infection is associated with various chronic inflammatory diseases or poor outcomes in non-immunocompromised critically ill patients. To evaluate the burden or outcome of CMV replication in non-transplant individuals, we compared the incidence rates (IRs) for CMV disease and all-cause mortality between SOT recipients, HSCT recipients, and non-transplant population. Methods: The SOT (N=16,368) and HSCT (N=10,206) cohorts between 2010 and 2015 were established using the WHO ICD-10 from the whole population-based large database of the Health Insurance Review & Assessment Service (HIRA). CMV cases, defined as symptomatic disease with isolation of virus, DNA, pp65 antigen, and pathology except CMV syndrome, were extracted with the unique codes for relief of medical costs of HIRA in the same dataset. Cox's proportional hazard regression analyses and log-rank test in the Kaplan-Meier curves were performed to compare all-cause mortality between the three groups. Results: The CMV IRs adjusted by age and sex were significantly higher in the SOT (adjusted IR [95% confidence intervals], 33.1 [28.8-38.0] per 1,000 person-years) and HSCT recipients (5.1 [4.6-6.1] per 1,000 person-years) than in the whole population (0.58 [0.49-0.67] per 100,000 person-years). However, SOT recipients with CMV (18/283, 6.4%) had significantly lower all-cause mortality than non-transplant individuals with CMV (207/1,258, 16.5%) (adjusted hazard ratio [95% CI], 0.42 [0.25-0.67], log-rank P < 0.001). Conclusion: These data suggest that CMV disease in patients without transplants is associated with poor outcomes.

The pharmaceutical management of cardiac allograft vasculopathy after heart transplantation

INTRODUCTION

Cardiac allograft vasculopathy (CAV) is a major limitation to long-term survival after heart transplantation. Its peculiar pathophysiology involves multifactorial pathways including immune-mediated and metabolic risk factors, which are associated with the development of specific pathological lesions. The often diffuse and chronic nature of the disease reduces the effectiveness of revascularization procedures, and pharmacological prevention of the disease is the sole therapeutic approach with some proven efficacy.

AREAS COVERED

In this article, after briefly outlining the risk factors for CAV, the authors revise the potential pharmacological approaches that may reduce the burden of CAV. While several therapies have shown convincing efficacy in terms of CAV prevention diagnosed by coronary imaging, very few have been reported to improve prognosis with any meaningful level of evidence.

EXPERT OPINION

The authors believe that a customizable approach is necessary for clinical practice given the currently available evidence. Furthermore, it is important, in the future, to address the glaring therapeutic gap of an effective treatment against donor-specific antibodies, whose effect on endothelial injury is currently one of the major mechanisms of CAV development and for which no pharmacological treatment is currently available.