Cytomegalovirus infection and disease reduce 10-year cardiac allograft vasculopathy-free survival in heart transplant recipients

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.

Multicenter study of universal prophylaxis versus pre-emptive therapy for patients at intermediate risk (R+) for CMV following heart transplantation

INTRODUCTION

Heart transplant (HT) recipients with prior exposure to cytomegalovirus (CMV R+) are considered intermediate risk for CMV-related complications. Consensus guidelines allow for either universal prophylaxis (UP) or preemptive therapy (PET) (serial CMV testing) approaches to CMV prevention in such patients. Whether an optimal approach to mitigate CMV related risks exists in this setting remains uncertain. We therefore assessed the utility of PET as compared to UP in CMV R+ HT recipients.

METHODS

Retrospective analysis of all CMV R+ HT recipients from 6 U.S. centers between 2010 and 2018 was performed. The primary outcome was the development of CMV DNAemia or end-organ disease resulting in the initiation/escalation of anti-CMV therapy. The secondary outcome was CMV-related hospitalization. Additional outcomes included incidence of acute cellular rejection (ACR) ≥ grade 2R, death, cardiac allograft vasculopathy (CAV), and leukopenia.

RESULTS

Of 563 CMV R+ HT recipients, 344 (61.1%) received UP. PET was associated with increased risk for the primary (adjusted HR 3.95, 95% CI: 2.65-5.88, p < .001) and secondary (adjusted HR 3.19, 95% CI: 1.47-6.94, p = .004) outcomes, and with increased ACR ≥ grade 2R (PET 59.4% vs. UP 34.4%, p < .001). Incidence of detectable CAV was similar at 1 year (PET 8.2% vs. UP 9.5%, p = .698). UP was associated with increased incidence of leukopenia within 6 months post-HT (PET 34.7% vs. UP 43.6%, p = .036).

CONCLUSION

The use of a PET CMV prophylaxis strategy in intermediate risk HT recipients associated with increased risk of CMV infection and CMV-related hospitalization, and may associate with worse post-HT graft outcomes.

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.

The Viral G-Protein-Coupled Receptor Homologs M33 and US28 Promote Cardiac Dysfunction during Murine Cytomegalovirus Infection

Human cytomegalovirus (HCMV) is a ubiquitous pathogen that infects the majority of the world population and causes lifelong latent infection. HCMV has been shown to exacerbate cardiovascular diseases, including myocarditis, vascular sclerosis, and transplant vasculopathy. Recently, we have shown that murine CMV (MCMV) recapitulates the cardiovascular dysfunction observed in patients with HCMV-induced myocarditis. To understand the viral mechanisms involved in CMV-induced heart dysfunction, we further characterized cardiac function in response to MCMV and examined virally encoded G-protein-coupled receptor homologs (vGPCRs) US28 and M33 as potential factors that promote infection in the heart. We hypothesized that the CMV-encoded vGPCRs could exacerbate cardiovascular damage and dysfunction. Three viruses were used to evaluate the role of vGPCRs in cardiac dysfunction: wild-type MCMV, a M33-deficient virus (∆M33), and a virus with the M33 open reading frame (ORF) replaced with US28, an HCMV vGPCR (i.e., US28+). Our in vivo studies revealed that M33 plays a role in promoting cardiac dysfunction by increasing viral load and heart rate during acute infection. During latency, ΔM33-infected mice demonstrated reduced calcification, altered cellular gene expression, and less cardiac hypertrophy compared with wild-type MCMV-infected mice. Ex vivo viral reactivation from hearts was less efficient in ΔM33-infected animals. HCMV protein US28 expression restored the ability of the M33-deficient virus to reactivate from the heart. US28+ MCMV infection caused damage to the heart comparable with wild-type MCMV infection, suggesting that the US28 protein is sufficient to complement the function of M33 in the heart. Altogether, these data suggest a role for vGPCRs in viral pathogenesis in the heart and thus suggest that vGPCRs promote long-term cardiac damage and dysfunction.

Epidemiology and long-term outcomes of cytomegalovirus DNAemia and disease in pediatric solid organ transplant recipients

Despite prevention strategies, cytomegalovirus (CMV) remains a common infection in pediatric solid organ transplant recipients (SOTR). We sought to determine the frequency, associations with, and long-term outcomes of CMV DNAemia in pediatric SOTR. We performed a single-center retrospective cohort study, including 687 first time SOTR ≤21 years receiving universal prophylaxis from 2011 to 2018. Overall, 159 (23%) developed CMV DNAemia, the majority occurring after completing primary prophylaxis. CMV disease occurred in 33 (5%) SOTR, 25 (4%) with CMV syndrome and 10 (1%) with proven/probable tissue-invasive disease. CMV contributed to the death of three (0.4%) patients (all lung). High-risk (OR 6.86 [95% CI, 3.6-12.9]) and intermediate-risk (4.36 [2.3-8.2]) CMV status and lung transplantation (4.63 [2.33-9.2]) were associated with DNAemia on multivariable analysis. DNAemia was associated with rejection in liver transplant recipients (p < .01). DNAemia was not associated with an increase in graft failure, all-cause mortality, or other organ-specific poor outcomes. We report one of the lowest rates of CMV disease after SOTR, showing that universal prophylaxis is effective and should be continued. However, we observed CMV morbidity and mortality in a subset of patients, highlighting the need for research on optimal prevention strategies. This study was IRB approved.

Cytomegalovirus Donor Seropositivity Negatively Affects Survival After Heart Transplantation

OBJECTIVES

Prior studies have shown that cytomegalovirus(CMV) infection is a risk factor for the development of cardiac allograft vasculopathy(CAV) and is associated with reduced long-term survival after heart transplantation. The aim of this ISHLT Transplant Registry study was to compare post-transplant survival in different CMV donor:recipient serologic combinations.

METHODS

We performed a retrospective cohort study, using the ISHLT Thoracic Transplant Registry, on 15,885 adult primary heart transplant recipients with known CMV serologic status between 7/2004 and 6/2014. Post-transplant survival and risk of developing CAV were compared across 4 groups: CMV-seronegative recipients(R-) receiving CMV-positive grafts(D+), intermediate-risk patients(D+R+ and D-R+), and low-risk patients(D-R-).

RESULTS

Baseline characteristics (donor/recipient age, BMI, recipient serum creatinine, blood group, donor cause of death, recipient diagnosis and ischemic time) were mostly balanced between the groups. Kaplan Meier survival analyses over a follow up of 10 years revealed significantly worse survival for both D+ groups as compared to the CMV low risk group (D+R+:56.61% (95%CI 53.94,59.41) vs. D-R-:63.09% (59.74,66.64) p<.01 and D+R-:57.69% (56.03,59.39) vs. D-R-; p<.001), whereas recipient seropositivity alone was not associated with reduced survival (D-R+ vs. D-R- p=.178). The risk of developing CAV after HTx was not significantly increased in D+ as compared to D- groups.

CONCLUSION

In a large contemporary cohort, CMV status at the time of heart transplantation was not associated with CAV development. However, there was a significant association between donor CMV seropositivity and reduced short- and long-term survival after heart transplantation. Approaches to mitigate the impact of CMV on post-transplant survival are needed.Supplemental Visual Abstract; http://links.lww.com/TP/C292.

Cytomegalovirus mismatch after heart transplantation: Impact of antiviral prophylaxis and intravenous hyperimmune globulin

Objective

Cytomegalovirus (CMV) infections are correlated with complications following heart transplantation (HTx) and impaired outcome. The impact of a serologic mismatch between donor and recipient and the necessity of prophylactic virostatic medication is still a matter of concern.

Methods

We retrospectively reviewed all patients that underwent HTx between 2010 and 2020 in our department. The recipients (n = 176) could be categorized into four risk groups depending on their serologic CMV matching (D⁺/R⁻ = donor CMV‐IgG positive and recipient CMV‐IgG negative, n = 32; D⁻/R⁺, n = 51; D⁻/R⁻, n = 35; D⁺/R⁺, n = 58). All patients followed the same protocol of CMV prophylaxis with application of ganciclovir/valganciclovir and intravenous CMV hyperimmune globulin.

RESULTS

Incidence of postoperative morbidity such as primary graft dysfunction, neurological events, infections, and graft rejection were comparable between all groups (p > .05). However, the incidence of postoperative acute kidney injury with hemodialysis was by trend increased in the D⁻/R⁺ group (72.0%) compared to the other groups. In‐hospital CMV‐DNAemia was observed in serologic positive recipients only (D⁺/R⁻: 0.0%, D⁻/R⁺: 25.0%, D⁻/R⁻: 0.0%, D⁺/R⁺: 13.3%, p < .01). During the first year, a total of 18 patients developed CMV‐DNAemia (D⁺/R⁻: 31.6%, D⁻/R⁺: 31.9%, D⁻/R⁻: 3.4%, D⁺/R⁺: 11.1%, p = .03).

Conclusions

Seropositive recipients carry an important risk for CMV‐DNAemia. However, we did not observe differences in perioperative morbidity and mortality regarding CMV matching, which might be related to regularly administer prophylactic virostatics and additional CMV‐IVIG for risk constellations. For high‐risk constellation, long‐term application of CMV‐IVIG during the first year after transplant may be beneficial.

Cardiac allograft vasculopathy after heart transplantation: Pathophysiology, detection approaches, prevention, and treatment management

Cardiac allograft vasculopathy (CAV) continues to be a significant risk factor for the recipient's long-term survival following heart transplantation. Our knowledge of its etiology is constantly changing as new imaging techniques provide direct insight into the disease's natural history. CAV identification continues to be difficult since symptoms may be varied or nonexistent. Due to the irreversible nature of the disease, early diagnosis is critical to halting development. Prognostic tools and biomarkers have proliferated as a result of advancements in diagnostic techniques. Simultaneously, pharmaceutical advancements have aided in the amelioration of the disease's progressive progression.

Don't Go Breaking My Heart: MCMV as a Model for HCMV-Associated Cardiovascular Diseases

Human Cytomegalovirus (HCMV) is a widespread pathogen that causes lifelong latent infection and is associated with the exacerbation of chronic inflammatory diseases in seropositive individuals. Of particular impact, HCMV infection is known to worsen many cardiovascular diseases including myocarditis, atherosclerosis, hypertension, and transplant vasculopathy. Due to its similarity to HCMV, murine CMV (MCMV) is an appropriate model to understand HCMV-induced pathogenesis in the heart and vasculature. MCMV shares similar sequence homology and recapitulates much of the HCMV pathogenesis, including HCMV-induced cardiovascular diseases. This review provides insight into HCMV-associated cardiovascular diseases and the murine model of MCMV infection, which has been used to study the viral pathogenesis and mechanisms contributing to cardiovascular diseases. Our new functional studies using echocardiography demonstrate tachycardia and hypertrophy in the mouse, similar to HCMV-induced myocarditis in humans. For the first time, we show long term heart dysfunction and that MCMV reactivates from latency in the heart, which raises the intriguing idea that HCMV latency and frequent virus reactivation perturbs long term cardiovascular function.

Cytomegalovirus Disease, Short-Term Cardiovascular Events and Graft Survival in a Cohort of Kidney Transplant Recipients With High CMV IgG Seroprevalence

INTRODUCTION

Both cytomegalovirus (CMV) infection and CMV disease have been linked with several long-term indirect effects in kidney transplant recipients. Research questions: We conducted a retrospective study to assess the association between cytomegalovirus disease and risks of death, shortterm cardiovascular events and graft loss in a cohort of renal transplant recipients.

DESIGN

The associations between CMV disease and death and cardiovascular events were determined using Cox regression models, while the association between viral disease and graft loss risk was analyzed through a competing risks regression according to the Fine and Gray method. Death with a functioning graft was considered as a competing risk event.

RESULTS

A total of 865 consecutive renal transplant recipients were included. The prevalence of seropositive donor/seronegative recipient (D+/R-) group was 89.9% with the remaining patients classified as seropositive recipient (R+). After median follow-up time of 24.4 months, CMV disease was not a risk factor for all-causes mortality (HR = 1.75; 95% CI 0.94-3.25), early cardiovascular events (HR = 0.54; 95% CI 0.16-1.82) or graft loss (subhazard ratio [the HR adjusted for competing risk of death with functioning graft] = 0.99; 95% CI 0.53-1.84).

CONCLUSIONS

In this cohort with high prevalence of CMV IgG antibodies, we found no association between cytomegalovirus disease and risk of death or graft loss. The relationship between CMV and cardiovascular disease remains to be unraveled and probably corresponds to a multifactorial phenomenon involving individual risk factors and the immune response to infection rather than the virus effect itself.

Early renal function trajectories, cytomegalovirus serostatus and long-term graft outcomes in kidney transplant recipients

BACKGROUND

Improved recognition of factors influencing graft survival has led to better short-term kidney transplant outcomes. However, efforts to prevent long-term graft decline and improve graft survival have seen more modest improvements. The adoption of electronic health records has enabled better recording and identification of donor-recipient factors through the use of modern statistical techniques. We have previously shown in a prevalent renal transplant population that episodes of rapid deterioration are associated with graft loss.

METHODS

Estimated glomerular filtration rates (eGFR) between 3 and 27 months after transplantation were collected from 310 kidney transplant recipients. We utilised a Bayesian approach to estimate the most likely eGFR trajectory as a smooth curve from an average of 10,000 Monte Carlo samples. The probability of having an episode of rapid deterioration (decline greater than 5 ml/min/1.73 m2 per year in any 1-month period) was calculated. Graft loss and mortality data was collected over a median follow-up period of 8 years. Factors associated with having an episode of rapid deterioration and associations with long-term graft loss were explored.

RESULTS

In multivariable Cox Proportional Hazard analysis, a probability greater than 0.8 of rapid deterioration was associated with long-term death-censored graft loss (Hazard ratio 2.17; 95% Confidence intervals [CI] 1.04-4.55). In separate multivariable logistic regression models, cytomegalovirus (CMV) serostatus donor positive to recipient positive (Odds ratio [OR] 3.82; 95%CI 1.63-8.97), CMV donor positive (OR 2.06; 95%CI 1.15-3.68), and CMV recipient positive (OR 2.03; 95%CI 1.14-3.60) were associated with having a greater than 0.8 probability of an episode of rapid deterioration.

CONCLUSIONS

Early episodes of rapid deterioration are associated with long-term death-censored graft loss and are associated with cytomegalovirus seropositivity. Further study is required to better manage these potentially modifiable risks factors and improve long-term graft survival.

Does reactivation of cytomegalovirus contribute to severe COVID-19 disease?

The majority of people infected with SARS-CoV-2 are asymptomatic or have mild to moderate symptoms. However, for unknown reasons, about 15 % have severe pneumonia requiring hospital care and oxygen support, and about 5 % develop acute respiratory distress syndrome, septic shock, and multiorgan failure that result in a high mortality rate. The risk of severe COVID-19 is highest among those who are over 70 years of age. Why severe COVID-19 develops in some people but not others is not understood. Could some cases involve reactivation of latent cytomegalovirus (CMV)?

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 Role of Microbiologic Agents in the Progression of the Atherosclerosis: a Comprehensive Review

Atherosclerosis is a leading cause of disability, morbidity and mortality in the world. Atherosclerosis is accepted as a chronic progressive inflammatory disease. The inflammatory cascade in the vascular wall is well-defined. However, the predictors and contributors of the inflammatory response in atherosclerosis are not completely understood. Systemic and local inflammation, which enhance the burden of inflammation in the vascular wall, have been proposed as risk factors for the progression of atherosclerosis. Infectious micro-organisms are one of the major triggering factors for local and systemic inflammation. In this review, we aimed to emphasize the linkage between micro-organisms and the progression of atherosclerosis. We briefly summarize the current medical literature and discuss the future perspectives of the linkage between microbial agents and atherosclerosis representing cause and effect.

Cytomegalovirus infection and allograft rejection among pediatric heart transplant recipients in the era of valganciclovir prophylaxis

CMV infection remains a significant cause of morbidity among pediatric HTx recipients We explored the implications of CMV infection on post-transplant outcomes among CMV risk-stratified pediatric HTx recipients receiving VGC prophylaxis. Children who underwent HTx between January 2010 and October 2016 were stratified according to CMV risk at time of transplant and evaluated for evidence of post-transplant CMV infection, rejection, CAV, and graft loss. Among 97 children, 41 (42%) were considered HR or IR risk for CMV infection and received VGC prophylaxis. CMV DNAemia was observed in 34% of children, including 71% HR, 40% IR, and 18% LR individuals. Median time to CMV DNAemia following VGC prophylaxis was 32D among HR vs 277D in IR subjects (P = .042). No difference in overall graft loss was noted among groups, but CMV HR children had decreased rejection-free survival (3.5 years) compared to IR (6 years, P = .015) and LR children (8 years, P = .0003). CMV was noted on EMB in 13% of children but was not associated with increased CAV, rejection or graft loss. High-risk CMV status was associated with decreased time to CMV infection despite VGC prophylaxis, compared to IR, and decreased rejection-free survival times compared to both IR and LR recipients. Detection of CMV on EMB was not associated with increased rejection, CAV or graft loss. Additional studies are needed to explore the impact of CMV infection on rejection-free survival in HTx recipients.

Rat Cytomegalovirus Virion-Associated Proteins R131 and R129 Are Necessary for Infection of Macrophages and Dendritic Cells

Cytomegalovirus (CMV) establishes persistent, latent infection in hosts, causing diseases in immunocompromised patients, transplant recipients, and neonates. CMV infection modifies the host chemokine axis by modulating chemokine and chemokine receptor expression and by encoding putative chemokine and chemokine receptor homologues. The viral proteins have roles in cellular signaling, migration, and transformation, as well as viral dissemination, tropism, latency and reactivation. Herein, we review the contribution of CMV-encoded chemokines and chemokine receptors to these processes, and further elucidate the viral tropism role of rat CMV (RCMV) R129 and R131. These homologues of the human CMV (HCMV)-encoded chemokines UL128 and UL130 are of particular interest because of their dual role as chemokines and members of the pentameric entry complex, which is required for entry into cell types that are essential for viral transmission and dissemination. The contributions of UL128 and UL130 to acceleration of solid organ transplant chronic rejection are poorly understood, and are in need of an effective in vivo model system to elucidate the phenomenon. We demonstrated similar molecular entry requirements for R129 and R131 in the rat cells, as observed for HCMV, and provided evidence that R129 and R131 are part of the viral entry complex required for entry into macrophages, dendritic cells, and bone marrow cells.

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

Supplemental Digital Content is available in the text.

Previous studies on the association between cytomegalovirus (CMV) infection and cardiac allograft vasculopathy (CAV) were conducted on patients transplanted in the prevalganciclovir prophylaxis era. The aim of our study is to evaluate this relation in heart transplantation (HTx) recipients treated according to current prophylactic and immunosuppressive regimens.

Prognostic Value of Biomarkers in Cardiac Allograft Vasculopathy following Heart Transplantation: A Literature Review

Cardiac allograft vasculopathy (CAV), also known as cardiac transplant vasculopathy, is a major determinant of long-term survival among cardiac transplantation recipients. Histologically, CAV is featured by diffuse, concentric thickening of the vascular wall, and primarily affects large and small epicardial coronary arteries, intramyocardial arteries, and veins. Owing to graft denervation, CAV typically follows an insidious course, and patients may not experience classic angina symptoms but instead present with progressive heart failure or ventricular arrhythmias. Recent studies on biomarkers have furthered the knowledge concerning the prediction and prognosis of CAV. Given its association with metabolic, thrombotic, inflammatory, and immunologic markers, CAV is likely to represent a complex multifactorial process that involves both immune-mediated and non-immune-mediated pathways. In order to identify the high-risk patients that would benefit from early intervention, future research is warranted to examine the usefulness of a biomarker panel in CAV risk stratification.

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.

Impact of cytomegalovirus serologic status on heart transplantation

BACKGROUND

Cytomegalovirus (CMV) infection has been associated with increased risk of mortality, cardiac allograft vasculopathy, and de novo malignancy following heart transplantation in prior institutional reports. This study examines the impact of the recipient and donor CMV status on heart recipients in the United States.

METHODS

Adult heart transplant recipients were identified in the OPTN registry between 2005-2016. Recipients were stratified based on the recipient (R) and donor (D) CMV serologic status (+/-). The primary endpoint was survival 5-years after transplantation. The secondary endpoint was cardiac allograft vasculopathy 5-years after transplantation. Separate Cox proportional hazards regression models were developed to evaluate independent associations between CMV status and each of the study endpoints.

RESULTS

A total of 21 878 recipients met the inclusion criteria. The breakdown of study arms by CMV serologic status was R-/D- = 3412, R+/D- = 4939; R-/D+ = 5230, and R+/D+ = 8,297. Five-year survival estimates were similar across groups (77-79%). CMV status was associated with increased mortality at 5-years (23%-41% increased risk) which was most evident in the first 3 months. The use of valganciclovir was associated with decreased risk of mortality (HR 0.56; 95% CI, 0.52-0.60). The cumulative incidence of cardiac allograft vasculopathy (R-/D- = 31%, R+/D- = 30%, R-/D+ = 31%, and R+/D+ = 30%) was similar across groups.

CONCLUSIONS

CMV seropositivity at the time of transplantation is associated with increased long-term risk of mortality. Chemoprophylaxis with antivirals seems to mitigate this risk. There was no association with an increased risk of allograft vasculopathy.

Human Cytomegalovirus Infection in Women With Preexisting Immunity: Sources of Infection and Mechanisms of Infection in the Presence of Antiviral Immunity

Human cytomegalovirus (HCMV) infection remains an important cause of neurodevelopmental sequelae in infants infected in utero. Unique to the natural history of perinatal HCMV infections is the occurrence of congenital HCMV infections (cCMV) in women with existing immunity to HCMV, infections that have been designated as nonprimary maternal infection. In maternal populations with a high HCMV seroprevalence, cCMV that follows nonprimary maternal infections accounts for 75%-90% of all cases of cCMV infections as well as a large proportion of infected infants with neurodevelopmental sequelae. Although considerable effort has been directed toward understanding immune correlates that can modify maternal infections and intrauterine transmission, the source of virus leading to nonprimary maternal infections and intrauterine transmission is not well defined. Previous paradigms that included reactivation of latent virus as the source of infection in immune women have been challenged by studies demonstrating acquisition and transmission of antigenically distinct viruses, a finding suggesting that reinfection through exposure to an exogenous virus is responsible for some cases of nonprimary maternal infection. Additional understanding of the source(s) of virus that leads to nonprimary maternal infection will be of considerable value in the development and testing of interventions such as vaccines designed to limit the incidence of cCMV in populations with high HCMV seroprevalence.

Impact of valganciclovir prophylaxis duration on cytomegalovirus disease in high-risk donor seropositive/recipient seronegative heart transplant recipients

BACKGROUND

Few data support use of 6 over 3 months of antiviral prophylaxis for cytomegalovirus (CMV) disease prevention in donor seropositive/recipient seronegative (D+R-) heart transplant recipients (HTR).

METHODS

We retrospectively assessed CMV disease and outcomes in 310 adult HTR between July 5, 2005, and December 30, 2016, at our center. Valganciclovir (VGCV) prophylaxis was given for 3-6 months in the D+R- group. Multivariable models evaluated risk factors for CMV disease in patients who received 3 vs 6 months (±1 month) of prophylaxis, with investigation of inverse probability weighting to correct for confounding variables.

RESULTS

The incidence of CMV disease among all patients and the D+R- group was 8.7% (27/310) and 26.5% (22/83), respectively, and included syndrome in 22.2% (6/27) and end-organ involvement in 77.8% (21/27). In a multivariable model, 6 vs 3 months of antiviral prophylaxis was not associated with reduced risk for CMV disease (OR 2.28 [95% CI 0.66, 7.91], P = .19). CMV disease in D+R- HTR was associated with higher rates of hospitalization (87.5% [14/16] vs 6.3% [1/16], P < .001) and for a longer duration than in matched D+R- controls without disease.

CONCLUSIONS

Cytomegalovirus disease remains a major cause of morbidity in D+R- HTR. In contrast to documented benefit in D+R- lung and kidney recipients, VGCV duration of 6 months was not associated with a lower incidence of CMV disease in D+R- HTR compared to 3-month duration and should be reconsidered in this patient population.

HIV infection and coronary heart disease: mechanisms and management

Antiretroviral therapy has largely transformed HIV infection into a chronic disease condition. As such, physicians and other providers caring for individuals living with HIV infection need to be aware of the potential cardiovascular complications of HIV infection and the nuances of how HIV infection increases the risk of cardiovascular diseases, including acute myocardial infarction, stroke, peripheral artery disease, heart failure and sudden cardiac death, as well as how to select available therapies to reduce this risk. In this Review, we discuss the epidemiology and clinical features of cardiovascular disease, with a focus on coronary heart disease, in the setting of HIV infection, which includes a substantially increased risk of myocardial infarction even when the HIV infection is well controlled. We also discuss the mechanisms underlying HIV-associated atherosclerotic cardiovascular disease, such as the high rates of traditional cardiovascular risk factors in patients with HIV infection and HIV-related factors, including the use of antiretroviral therapy and chronic inflammation in the setting of effectively treated HIV infection. Finally, we highlight available therapeutic strategies, as well as approaches under investigation, to reduce the risk of cardiovascular disease and lower inflammation in patients with HIV infection.

Infectious complications following heart transplantation in the era of high-priority allocation and extracorporeal membrane oxygenation

Background

Infectious complications are a major cause of morbidity and mortality after heart transplantation (HT). However, the epidemiology and outcomes of these infections in the recent population of adult heart transplant recipients have not been investigated.

Methods

We conducted a single-center retrospective study on infectious complications occurring within 180 days following HT on consecutive heart transplant recipients, from January 2011 to June 2015 at Bichat University Hospital in Paris, France. Risk factors for non-viral infections occurring within 8, 30 and 180 days after HT were investigated using competing risk analysis.

Results

Overall, 113 patients were included. Fifty-eight (51%) HTs were high-priority allocations. Twenty-eight (25%) patients had an extracorporeal membrane oxygenation (ECMO) support at the time of transplantation. Ninety-two (81%) patients developed at least one infection within 180 days after HT. Bacterial and fungal infections (n = 181 episodes) occurred in 80 (71%) patients. The most common bacterial and fungal infections were pneumonia (n = 95/181 episodes, 52%), followed by skin and soft tissue infections (n = 26/181, 14%). Multi-drug-resistant bacteria were responsible for infections in 21 (19%) patients. Viral infections were diagnosed in 44 (34%) patients, mostly Cytomegalovirus infection (n = 39, 34%). In multivariate subdistribution hazard model, prior cardiac surgery (subdistribution hazard ratio sHR = 2.7 [95% CI 1.5–4.6] p < 0.01) and epinephrine or norepinephrine at the time of HT (sHR = 2.3 [95% CI 1.1–5.2] p  = 0.04) were significantly associated with non-viral infections within 8 days after HT. Prior cardiac surgery (sHR = 2.5 [95% CI 1.4–4.4] p < 0.01), recipient age over 60 years (sHR = 2.0 [95% CI 1.2–3.3] p < 0.01) and ECMO following HT (sHR = 1.7 [95% CI 1.0–2.8] p = 0.04) were significantly associated with non-viral infection within 30 days after HT, as well as within 180 days after HT.

Conclusion

This study confirmed the high rate of infections following HT. Recipient age, prior cardiac surgery and ECMO following HT were independent risk factors for early and late bacterial and fungal infections.

Electronic supplementary material

The online version of this article (10.1186/s13613-019-0490-2) contains supplementary material, which is available to authorized users.

The Human Cytomegalovirus UL38 protein drives mTOR-independent metabolic flux reprogramming by inhibiting TSC2

Human Cytomegalovirus (HCMV) infection induces several metabolic activities that are essential for viral replication. Despite the important role that this metabolic modulation plays during infection, the viral mechanisms involved are largely unclear. We find that the HCMV UL38 protein is responsible for many aspects of HCMV-mediated metabolic activation, with UL38 being necessary and sufficient to drive glycolytic activation and induce the catabolism of specific amino acids. UL38's metabolic reprogramming role is dependent on its interaction with TSC2, a tumor suppressor that inhibits mTOR signaling. Further, shRNA-mediated knockdown of TSC2 recapitulates the metabolic phenotypes associated with UL38 expression. Notably, we find that in many cases the metabolic flux activation associated with UL38 expression is largely independent of mTOR activity, as broad spectrum mTOR inhibition does not impact UL38-mediated induction of glycolysis, glutamine consumption, or the secretion of proline or alanine. In contrast, the induction of metabolite concentrations observed with UL38 expression are largely dependent on active mTOR. Collectively, our results indicate that the HCMV UL38 protein induces a pro-viral metabolic environment via inhibition of TSC2.

Impact of donor and recipient cytomegalovirus serology on long-term survival of heart transplant recipients

BACKGROUND

Some studies have shown that pre-transplant cytomegalovirus (CMV) serostatus is associated with heart transplant patient survival while others have not. We analyzed the relationship between pre-transplant donor/recipient CMV serostatus and long-term mortality in a retrospective cohort of heart transplant recipients at our center.

METHODS

Adult (Age >17 years) heart recipients transplanted between July 1985-December 2015 were analyzed. Variables included age, sex, pre-transplant donor (D)/recipient (R) serostatus [D-/R-, D-/R+, D+/R+, D+/R-], CMV infection within 2 years of transplant and transplant eras divided by changes in CMV prevention strategies: Era 1 (Pre-ganciclovir, July 1985-April 1998), Era 2 (Oral ganciclovir, May 1998-December 2004), Era 3 (Valganciclovir, January 2005-December 2015). Survival analysis and Cox regression were performed at 10 years.

RESULTS

A total of 620 heart transplants were included in our analysis; 20% were CMV mismatched pre-transplant. Thirty-eight percent of patients were infected with CMV within the first two post-transplant years. Survival analysis showed D/R CMV serostatus did not significantly impact survival of heart recipients at 10 years (P = 0.11). Survival was significantly different across eras for D-/R+, D+/R+, and D+/R+ (P = 0.043) but not D-/R- patients (P = 0.8). Cox regression revealed that patients transplanted in the valganciclovir era have an estimated 29% reduced risk of death (P = 0.047) compared to patients transplanted in the pre-ganciclovir era after controlling for age at transplantation, D/R CMV serostatus and CMV infection.

CONCLUSION

Our review of the impact of CMV managed differently across eras suggests in heart transplantation there is no influence of D/R CMV serostatus on 10 year survival.

New therapies for human cytomegalovirus infections

The recent approval of letermovir marks a new era of therapy for human cytomegalovirus (HCMV) infections, particularly for the prevention of HCMV disease in hematopoietic stem cell transplant recipients. For almost 30 years ganciclovir has been the therapy of choice for these infections and by today's standards this drug exhibits only modest antiviral activity that is often insufficient to completely suppress viral replication, and drives the selection of drug-resistant variants that continue to replicate and contribute to disease. While ganciclovir remains the therapy of choice, additional drugs that inhibit novel molecular targets, such as letermovir, will be required as highly effective combination therapies are developed not only for the treatment of immunocompromised hosts, but also for congenitally infected infants. Sustained efforts, largely in the biotech industry and academia, have identified additional highly active lead compounds that have progressed into clinical studies with varying levels of success and at least two have the potential to be approved in the near future. Some of the new drugs in the pipeline inhibit new molecular targets, remain effective against isolates that have developed resistance to existing therapies, and promise to augment existing therapeutic regimens. Here, we will describe some of the unique features of HCMV biology and discuss their effect on therapeutic needs. Existing drugs will also be discussed and some of the more promising candidates will be reviewed with an emphasis on those progressing through clinical studies. The in vitro and in vivo antiviral activity, spectrum of antiviral activity, and mechanism of action of new compounds will be reviewed to provide an update on potential new therapies for HCMV infections that have progressed significantly in recent years.

Elevated serum vascular endothelial growth factor and development of cardiac allograft vasculopathy in children

BACKGROUND

Cardiac allograft vasculopathy (CAV) is a leading cause of retransplantation and death in pediatric heart transplant recipients. Our aim was to evaluate the association between serum vascular endothelial growth factor-A (VEGF) and CAV development in the pediatric heart transplant population.

METHODS

In this retrospective study performed at a university hospital, VEGF concentrations were measured by enzyme-linked immunosorbent assay in banked serum from pediatric heart transplant recipients undergoing routine cardiac catheterization. In subjects with CAV (n = 29), samples were obtained at 2 time-points: before CAV diagnosis (pre-CAV) and at the time of initial CAV diagnosis (CAV). In subjects without CAV (no-CAV, n = 16), only 1 time-point was used. VEGF concentrations (n = 74) were assayed in duplicate.

RESULTS

Serum VEGF is elevated in pediatric heart transplant recipients before catheter-based diagnosis of CAV (no-CAV mean: 144.0 ± 89.05 pg/ml; pre-CAV mean: 316.2 ± 118.3 pg/ml; p = 0.0002). Receiver-operating characteristic curve analysis of pre-CAV VEGF levels demonstrated an area under the curve of 87.7% (p = 0.0002), with a VEGF level of 226.3 pg/ml predicting CAV development with 77.8% sensitivity and 91.7% specificity. VEGF is similarly elevated in subjects with angiographically diagnosed CAV and in those with normal angiography but intravascular ultrasound (IVUS) evidence of CAV.

CONCLUSIONS

The increase in serum VEGF before onset of detectable CAV is fundamental to its utility as a predictive biomarker and suggests further investigations of VEGF in the pathogenesis of CAV are warranted in the pediatric heart transplant population.

Progression of cardiac allograft vasculopathy assessed by serial three-vessel quantitative coronary angiography

Background

The purpose of the present study was to assess the short- and long-term progression of cardiac allograft vasculopathy (CAV) using serial 3-vessel quantitative coronary angiography (QCA).

Methods

CAV progression was assessed using serial 3-vessel QCA analysis at baseline, 1-year and long-term angiographic follow-up (8.5±3.7 years) after heart transplantation. The change in minimal lumen diameter (MLD) and percent diameter stenosis (%DS) was serially assessed within matched segments. Patients were graded according to the ISHLT-CAV classification and grouped as ISHLT-CAV₀ and ISHLT-CAV_1-3. The primary endpoint was mean change in MLD and %DS.

Results

A total of 41 patients and 520 matched segments were available for serial 3-vessel QCA. Overall, MLD decreased non-significantly from baseline to 1-year follow-up and significantly from 1-year to the long-term angiographic follow-up (Δ-0.08mm/year [95%CI -0.11 to -0.05], P<0.001). %DS increased significantly from baseline to 1-year (Δ+0.96%/year [95%CI 0.04 to 1.88], P = 0.041) and from 1-year to long-term angiographic follow-up (Δ+0.61%/year [95%CI 0.33 to 0.88], P<0.001). ISHLT-CAV_1-3 at 1 year and at long-term angiographic follow-up was observed in 22% and 61%, respectively. Between baseline and long-term angiographic follow-up, a significant reduction in MLD was observed within both groups without a significant difference in the reduction between the two groups (ISHLT-CAV₀: median -0.49mm [IQR -0.54 to -0.43] vs. ISHLT-CAV_1-3: median -0.40mm [IQR -0.44 to -0.35], P = 0.4).

Conclusion

The current data suggest that QCA can’t predict CAV beyond 1 year, but, QCA affirmed that CAV progresses to a similar extent in patients who do not develop visual CAV during long-term follow-up.

Cardiovascular disease after transplantation: an emerging role of the immune system

Cardiovascular disease (CVD) after transplantation remains a major concern. Little is known about what drives the increased cardiovascular risk in transplant recipients apart from traditional risk factors. The immune system is involved in the pathogenesis of hypertension, atherosclerosis, and coronary artery disease in the general population. Recently, inhibition of interleukin 1 - β by canakinumab versus placebo decreased the incidence of cardiovascular events. Emerging evidence points to a role of adaptive cellular immunity in the development of CVD. Especially, expansion of pro-inflammatory and antiapoptotic cytotoxic CD4⁺ CD28^null T cells is closely associated with incident CVD in various study populations including transplant recipients. The association of cytomegalovirus exposure with increased cardiovascular mortality might be explained by its capacity to upregulate these cytotoxic cells. Also, humoral immunity seems to be relevant for cardiovascular outcome in transplant recipients. Panel-reactive antibodies at baseline and donor-specific antibodies are independently associated with poor cardiovascular outcome after kidney transplantation. Cardiovascular effects of immunosuppressive drugs and statins do not only imply indirect positive or negative effects on traditional cardiovascular risk factors but also intrinsic immunological effects. How immunosuppressive drugs modify atherosclerosis largely remains elusive.

Cytomegalovirus infection in heart transplantation: A single center experience

BACKGROUND

Cytomegalovirus (CMV) infection remains a major complication after heart transplantation with varying prophylaxis strategies employed. We sought to determine the impact of valganciclovir (VGC) duration on the epidemiology of CMV infections after heart transplantation.

METHODS

We performed a prospective cohort study of CMV donor (D) or recipient (R) seropositive heart transplant recipients from 2005 to 2012 who completed VGC prophylaxis, ranging from 3 to 12 months according to serostatus and induction immunosuppression. Univariate and multivariate logistic regression was performed.

RESULTS

Among 159 heart transplant recipients during the study period, 130 (82%) were eligible for VGC prophylaxis. CMV D/R serostatus was as follows: 24% D+/R-, 30% D+/R+, and 29% D-/R+. 65% and 21% received basiliximab and thymoglobulin induction, respectively, followed by maintenance tacrolimus, mycophenolate mofetil, and prednisone. Twenty-one (16%) recipients suffered CMV infection. There was no association with comorbidities including diabetes mellitus, chronic kidney disease, or mechanical assist devices, nor were there associations with rejection, treatments of rejection, or mortality. When VGC prophylaxis duration was stratified by ≤6 vs ≥12 months, time from heart transplantation to CMV infection was delayed (median 247 vs 452 days, P = .002) but there was no difference in days from VGC discontinuation to onset of CMV infection (median 72 vs 83 days, P = .31). CMV infection occurred most frequently within 6-16 weeks of VGC cessation, and 95% of infections occurred during the 6 months post-prophylaxis period.

CONCLUSIONS

Relative to ≤6 months, ≥12 months of VGC did not reduce incidence of CMV infection and only delayed time to onset. 95% of CMV infection occurs within 6 months after cessation of VGC.

Cytomegalovirus reactivation in liver transplant recipients due to hepatitis C cirrhosis is associated with higher cardiovascular risk - an observational, retrospective study

The association between cytomegalovirus (CMV) reactivation and cardiovascular risk has been reported in solid organ transplant populations; however, it has yet to be assessed in liver transplantation (LT). We aim to evaluate whether CMV reactivation is associated with cardiovascular events (CVE) in HCV-LT patients. LT patients (2010 and 2014) due to HCV cirrhosis were included. Clinically significant CMV (CS-CMV) was defined as viral load (VL) >5000 copies/ml, need of therapy or CMV disease. Baseline variables and endpoint measures (CVE, survival, severe recurrent hepatitis C, de novo tumors, and diabetes) were collected. One hundred and forty patients were included. At LT, a history of AHT was present in 23%, diabetes 22%, tobacco use 45%, obesity 20%, and renal impairment (eGFR < 60 ml/min) in 26.5%. CS-CMV reactivation occurred in 25% of patients. Twenty-six patients (18.5%) developed a CVE. Cox regression analysis revealed two factors significantly associated with CVE: Pre-LT DM [HR = 4.6 95% CI (1.6, 13), P = 0.004] and CS-CMV [HR = 4.7 95% CI (1.8, 12.5), P = 0.002]. CS-CMV was not independently associated with the remaining endpoints except for survival (P = 0.03). In our series, CS-CMV reactivation was associated with a greater risk of developing CVE, thus confirming data from other solid organ transplant populations and emphasizing the need for adequate CMV control.

Heart Transplantation and Risk of Cardiac Vasculopathy Development: What Factors Are Important?

BACKGROUND The aim of this study was to find the main risk factors for development of cardiac allograft vasculopathy (CAV), especially factors identified before the surgical procedure and factors related to the recipient profile and the medical history of the donor. MATERIAL AND METHODS There were 147 patients who had heart transplantation (HT) included in this study: mean age was 45.8±15.3 years. All study patients had coronary angiography after HT. Analyzed risk factors were: non-immunologic recipient risk factors (age of transplantation, smoking, hypertension, lipids, diabetes, obesity and weight gain after HT), immunologic recipient risk factors (acute cellular rejection (ACR), acute humoral rejection (AMR), cytomegalovirus (CMV) episodes), and donor-related risk factors (age, sex, catecholamine usage, ischemic time, compatibility of sex and blood groups, cause of death, cardiac arrest). RESULTS CAV was recognized in 48 patients (CAV group); mean age 53.6±13.6 years. There were 99 patients without CAV (nonCAV group); mean age 48.3±15.5 years. A univariate Cox analysis of the development of coronary disease showed statistical significance (p<0.05) for baseline high-density lipid (HDL), ACR, AMR, CMV, and donor age. Multivariate Cox regression model confirmed that only baseline HDL, episodes of ACR, donor age, and CMV infection are significant for the frequency of CAV after HT. CONCLUSIONS Older donor age is highly associated with CAV development. Older donor age and low level of HDL in heart recipients with the strongest influence of immunologic risk factors (ACR, CMV infection) were linked with development of CAV.

Recent advances in allograft vasculopathy

PURPOSE OF REVIEW

Despite considerable advances in controlling acute rejection, the longevity of cardiac and renal allografts remains significantly limited by chronic rejection in the form of allograft vasculopathy. This review discusses recently reported mechanistic insights of allograft vasculopathy pathogenesis as well as recent clinical evaluations of new therapeutic approaches.

RECENT FINDINGS

Although adaptive immunity is the major driver of allograft vasculopathy, natural killer cells mediate vasculopathic changes in a transplanted mouse heart following treatment with donor-specific antibody (DSA). However, natural killer cells may also dampen chronic inflammatory responses by killing donor-derived tissue-resident CD4 T cells that provide help to host B cells, the source of DSA. DSA may directly contribute to vascular inflammation by inducing intracellular signaling cascades that upregulate leukocyte adhesion molecules, facilitating recruitment of neutrophils and monocytes. DSA-mediated complement activation additionally enhances endothelial alloimmunogenicity through activation of noncanonical NF-κB signaling. New clinical studies evaluating mammalian target of rapamycin and proteasome inhibitors to target these pathways have been reported.

SUMMARY

Allograft vasculopathy is a disorder resulting from several innate and adaptive alloimmune responses. Mechanistic insights from preclinical studies have identified agents that are currently being investigated in clinical trials.