Coronary artery disease after heart transplantation and its relation to cytomegalovirus

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.

Cyclosporine Versus Tacrolimus: Which Calcineurin Inhibitor Has Influence on Cytomegalovirus Infection in Cardiac Transplantation?

INTRODUCTION

Cytomegalovirus (CMV) infection is a relevant cause of morbidity and mortality in transplantation patients. Its major incidence is in the first year and viral replication is related to acute rejection, survival reduction, and graft vascular disease.

OBJECTIVE

This study aims to evaluate retrospectively whether a high dose of calcineurin inhibitors correlates with CMV-positive polymerase chain reaction (PCR), need for treatment, and death in cardiac transplantation patients.

METHODS

This is a case-control study including patients who underwent transplantation between 2014 and 2016. They were separated into two groups (positive or negative PCR) and evaluated for dosage serum levels of cyclosporine and tacrolimus. Patients were classified with adequate dose of immunosuppressant or high dose, and was analyzed that there was any association with those and positive CMV-PCR, need for treatment for CMV, and deaths. For statistical analysis, the Student t test was used for the quantitative variables and the Fisher's Exact Test for qualitative variables. To show CMV-free survival, the Kaplan-Meier curve was used. The level of significance was set at 5%.

RESULTS

CMV-positive PCR in the sample was 72% for a total of 50 individuals. Positive PCR correlated with a high dose of calcineurin inhibitors in a statistically significant way (P = .002), as did a high dose of cyclosporine (P = .004); however, a high dose of tacrolimus had no such association (P = .17). When a high dose was assessed with a need for treatment, the chance of needing treatment increased more than eight times (P = .024; odds ratio = 8.25; 95% CI = 1.33 to 51.26), which was different from results found with high-dose tacrolimus (P = 1.0). However, no significant association was found in relation to deaths.

CONCLUSIONS

Tacrolimus serum levels showed no association with CMV-PCR, which was different from serum cyclosporine, which showed association with CMV-PCR positivity, increasing the need for treatment approximately 8-fold, without association with death.

Adverse effects of immunosuppression in pediatric solid organ transplantation

Solid organ transplantation is a life-saving treatment for end-stage organ failure in children. Immunosuppressant medications are used to prevent rejection of the organ transplant. However, these medications are associated with significant adverse effects that impact growth and development, quality of life (QOL), and sometimes long-term survival after transplantation. Adverse effects can differ between the immunosuppressants, but many result from the overall state of immunosuppression. Strategies to manage immunosuppressant adverse effects often involve minimizing exposure to the drugs while balancing the risk for rejection. Early recognition of immunosuppressant adverse effects may help to reduce morbidities associated with solid organ transplantation, improve QOL, and possibly increase overall patient survival.

Manifestations of human cytomegalovirus infection: proposed mechanisms of acute and chronic disease

Infections with human cytomegalovirus (HCMV) are a major cause of morbidity and mortality in humans with acquired or developmental deficits in innate and adaptive immunity. In the normal immunocompetent host, symptoms rarely accompany acute infections, although prolonged virus shedding is frequent. Virus persistence is established in all infected individuals and appears to be maintained by both a chronic productive infections as well as latency with restricted viral gene expression. The contributions of the each of these mechanisms to the persistence of this virus in the individual is unknown but frequent virus shedding into the saliva and genitourinary tract likely accounts for the near universal incidence of infection in most populations in the world. The pathogenesis of disease associated with acute HCMV infection is most readily attributable to lytic virus replication and end organ damage either secondary to virus replication and cell death or from host immunological responses that target virus-infected cells. Antiviral agents limit the severity of disease associated with acute HCMV infections, suggesting a requirement for virus replication in clinical syndromes associated with acute infection. End organ disease secondary to unchecked virus replication can be observed in infants infected in utero, allograft recipients receiving potent immunosuppressive agents, and patients with HIV infections that exhibit a loss of adaptive immune function. In contrast, diseases associated with chronic or persistent infections appear in normal individuals and in the allografts of the transplant recipient. The manifestations of these infections appear related to chronic inflammation, but it is unclear if poorly controlled virus replication is necessary for the different phenotypic expressions of disease that are reported in these patients. Although the relationship between HCMV infection and chronic allograft rejection is well known, the mechanisms that account for the role of this virus in graft loss are not well understood. However, the capacity of this virus to persist in the midst of intense inflammation suggests that its persistence could serve as a trigger for the induction of host-vs-graft responses or alternatively host responses to HCMV could contribute to the inflammatory milieu characteristic of chronic allograft rejection.

Valganciclovir as preemptive therapy for cytomegalovirus in cytomegalovirus-seronegative liver transplant recipients of cytomegalovirus-seropositive donor allografts

The efficacy of valganciclovir as preemptive therapy for the prevention of cytomegalovirus (CMV) disease and its impact on indirect sequelae of CMV were assessed in recipient-negative/donor-positive (R-/D+) liver transplant recipients. Of 187 consecutive liver transplant recipients at our institution since July 2001, 36 (19.2%) belonged to the R-/D+ group. Surveillance tests for CMV were performed on all patients at weeks 2, 4, 6, 8, 10,12, and 16. In all, 27 patients with asymptomatic viremia received preemptive therapy with valganciclovir. At a total follow-up of 62.8 patient years (median: 19 months, range: 3 months to 5.6 years), no episodes of CMV disease were documented in these patients. The incidence of rejection, retransplantation, and bacterial or fungal infections and the probability of survival did not differ for R-/D+ patients and all non-R-/D+ patients treated preemptively with valganciclovir (P > 0.20 for all variables). Thus, preemptive therapy with valganciclovir in R-/D+ patients was not associated with CMV disease during the period of surveillance monitoring or at anytime thereafter (late-onset CMV disease). The indirect outcomes with the use of valganciclovir in R-/D+ patients were comparable to the outcomes of other subgroups of liver transplant recipients receiving preemptive therapy.

Acute cytomegalovirus infection and venous thrombosis: role of antiphospholipid antibodies

Cytomegalovirus (CMV)-induced thrombosis has been reported in immunocompromised patients, such as transplant recipients and patients with AIDS. Recent cases also describe thrombotic phenomena in immunocompetent patients with CMV infection. Various mechanisms may explain the role of CMV in thrombosis: this virus can damage endothelial cells, activate coagulation factors, and induce production of antiphospholipid (aPL) antibodies. We present a case report of a previously healthy white woman with a pulmonary embolism associated with CMV infection and the presence of aPL antibodies, and we discuss the role of the aPL antibodies associated with CMV infection in the pathogenesis of thrombosis.

Dobutamine myocardial scintigraphy for the prediction of cardiac events after heart transplantation

BACKGROUND

The long-term outcome after heart transplantation (HTx) is essentially influenced by the occurrence and extent of cardiac allograft vasculopathy (CAV). Single photon emission computed tomography-myocardial perfusion imaging (SPECT-MPI) has been shown to be a useful and cost-effective non-invasive method in patients with known or suspected coronary artery disease, but its role in detecting CAV remains unclear.

AIM

To evaluate the accuracy and predictive value of dobutamine MPI in patients after HTx during a 12-month follow-up.

METHODS

Seventy-seven patients (60 males, 17 females) underwent a total of 216 dobutamine MPI examinations over a period of 5 years. Examinations were obtained an average of 89+/-42 months after orthotopic HTx according to a 1-day protocol using 99mTc-methoxyisobutylisonitrile (99mTc-MIBI) with and without attenuation correction. For the present study, findings from 77 MPI examinations (one MPI examination per patient) were analysed visually and semiquantitatively using a 20-segment model. Summed stress scores (SSS) and summed rest scores (SRS) were calculated and receiver operating characteristic (ROC) analysis was performed to detect optimum threshold values. Patients were followed up for 12 months and cardiac events were registered.

RESULTS

Cardiac events were observed in 10 of the 77 patients. Good interobserver agreement was found for global visual and SRS-/SSS-based analysis (kappa=0.74 and 0.66, respectively). SSS was superior to SRS in the detection of cardiac events. ROC analysis showed an optimized SSS threshold value of three. For predicting a cardiac event during the 12-month follow-up, global visual and semiquantitative analysis reached sensitivities of 90% and 90%, specificities of 72% and 88%, accuracies of 74% and 87%, positive predictive values of 32% and 53% and negative predictive values of 98% and 98%, respectively. The sensitivity, specificity, accuracy and positive and negative predictive values for MPI to detect clinically relevant coronary artery stenoses (> or =50%) at conventional coronary angiography were 83%, 87%, 86%, 56% and 96%, respectively.

CONCLUSIONS

Non-invasive dobutamine MPI reliably identifies patients at risk for subsequent cardiac events in cases of CAV, with a high negative predictive value of 98% and an accuracy of 87%.

Small vessel disease after heart transplantation: impact of immunologic and nonimmunologic risk factors*

To determine risk factors for small vessel disease after heart transplantation (HTx), characteristics of donors and organ harvesting were evaluated in 246 HTx patients (205 male, 41 female, mean survival 5.4 years). In right ventricular endomyocardial biopsies (EMB, n = 5421) evidence of microvascular disease [endothelial cell (EC) swelling/vessel wall thickening] was evaluated by light microscopy (hematoxylin and eosin staining, x 200). Mild EC swelling/vessel wall thickening were found in 204 and 213 patients, severe EC swelling/vessel wall thickening were present in 23 and 142 patients respectively. Evidences of mild and severe acute cellular rejection were found in 2064 and 421 EMB respectively. Microvascular disease was positively correlated with mild acute rejection episodes (P < 0.05). EC swelling was more frequent in patients with donors dying of craniocerebral trauma. No correlations were present to further demographical data. Microvascular alterations after HTx seem to be the result of an immunologic conflict rather than to depend on nonimmunologic factors.

Cyclosporine-induced coronary endothelial dysfunction: is tetrahydrobiopterin the solution?

BACKGROUND

Coronary endothelial dysfunction after heart transplantation is predictive of cardiac allograft vasculopathy. Immunosuppressive drugs, particularly cyclosporine may contribute to this dysfunction by a direct effect. Tetrahydrobiopterin (BH(4)) is a potent antioxidant and an essential cofactor of nitric oxide biosynthesis. The purpose of this study was to investigate whether BH(4) could reverse the endothelial dysfunction induced by cyclosporine.

METHODS

A previously described in vitro model of drug incubation in Krebs-bicarbonate solution (4 degrees C, 48 hours) of porcine epicardial coronary arteries was used. Coronary endothelial function studies were performed in organ chamber experiments after incubation with cyclosporine (10(-4) mol/L) in the presence or absence of 6-methyltetrahydropterin (MH(4) [0.1 mol/L], a BH(4) analog) to assess its effect on the cyclosporine-induced endothelial dysfunction.

RESULTS

The average doses of PGF2(alpha) required to attain 50% of the maximal contraction to KCl was significantly lower (P < .001) in the cyclosporine group (8.6 +/- 1.94 x 10(-6) mol/L) compared to the control group (24.8 +/- 5.2 x 10(-6) mol/L). Exposure to cyclosporine induced a significant decrease in endothelium-dependent relaxations to serotonin (5HT) (% E(max) [5HT]: 77% +/- 4%; P < .05). Addition of MH(4) significantly reversed this impaired response (% E(max) [5HT]: 62% +/- 4%; P < .05). No alterations of relaxation were observed with bradykinin in both groups. Endothelium-independent relaxations to sodium nitroprussiate were fully preserved.

CONCLUSIONS

These results suggest a significant protective role of BH(4) on coronary endothelial function following exposure to cyclosporine, which could reduce the incidence of endothelial dysfunction and cardiac allograft vasculopathy following cardiac transplantation.

Cytomegalovirus infection in heart transplant recipients is associated with impaired endothelial function

BACKGROUND

Cardiac allograft vasculopathy (CAV) is initiated by allograft endothelial injury. We hypothesized that a major mechanism by which cytomegalovirus (CMV) could contribute to CAV is by dysregulation of the endothelial vasomotor response.

METHODS

Coronary endothelial vasomotor function was determined in 183 consecutive patients (24+/-33 months after transplantation), and was correlated with recipient and donor CMV serological status before transplantation and with documented CMV infection episodes (CMVpp65Ag+). Serial endothelial function measurements were performed in a subgroup of 53 transplant recipients (1 month and 12 months after transplantation). The composite endpoint of cardiovascular related events and death during a follow-up of 66+/-41 months was analyzed based on the CMV serological status before transplantation.

RESULTS

The medium event-free time for CMV-negative recipients of CMV-positive hearts was 8.1 years compared with 13.3 years for the other groups (P<0.05). Distal epicardial but not microvascular endothelial function was significantly impaired in CMV seronegative recipients of seropositive donor hearts (n=48) compared with all other groups (P<0.01 versus seronegative recipient/seronegative donor; P<0.05 versus seropositive recipient/seronegative donor; P<0.05 versus seropositive recipient/seropositive donor). Distal epicardial endothelial dysfunction was more pronounced in heart transplant recipients with a history of documented CMV infection compared with patients without any documented CMV infection (P<0.01). In a longitudinal subgroup analysis, distal epicardial and microcirculatory endothelial vasomotor response deteriorated significantly in recipients with documented CMV infection (P<0.05 versus baseline) but not in patients without previous CMV infection.

CONCLUSIONS

Documented CMV infection episodes in heart transplant recipients are associated with impaired coronary endothelial function. CMV-negative recipients of CMV-positive donor hearts have an impaired distal epicardial endothelial function and an increased incidence of cardiovascular-related events and death during follow-up. CMV infection may contribute to allograft failure by accelerating coronary endothelial dysfunction.

Efficacy of valganciclovir administered as preemptive therapy for cytomegalovirus disease in liver transplant recipients: impact on viral load and late-onset cytomegalovirus disease

BACKGROUND

The efficacy of valganciclovir used as preemptive therapy for cytomegalovirus (CMV) disease in liver transplant recipients is not known.

METHODS

Between 1996 and 2004, surveillance testing using CMV antigenemia was performed at weeks 2, 4, 6, 8, 10, 12, and 16 posttransplant. A total of 28.8% (17/59) of the patients from 2001 to 2004 with antigenemia who received valganciclovir as preemptive therapy were compared with 26.2% (21/80) of the patients from 1996 to 2000 who received oral ganciclovir as preemptive therapy.

RESULTS

The mean decline in the antigenemia level after initiation of valganciclovir and oral ganciclovir was 80.5% versus 50.7% at 1 week, 99.5% versus 89.4% at 2 weeks, and 100% versus 97.7% at 4 weeks, respectively. A higher proportion of patients who received valganciclovir (64.7%) belonged to the high-risk group (R-/D+) than patients who received oral ganciclovir (33.3%, P=0.10). Recurrent shedding was documented in 47.1% (8/17) of the patients in the valganciclovir group and 28.6% (6/21) of the patients in the oral ganciclovir group (P>0.20). Recurrent shedding correlated significantly with R-/D+ CMV serostatus and baseline CMV antigenemia level, regardless of the study group. No patient in either group developed CMV disease during or after the period of surveillance monitoring. The incidence of opportunistic infections and patient outcome did not differ for the valganciclovir group versus the oral ganciclovir group or patients without CMV infection (P>0.20).

CONCLUSION

Antigenemia-directed valganciclovir as preemptive therapy seems to be effective for the prevention of CMV disease in liver transplant recipients, including high-risk patients.

Human cytomegalovirus: clinical aspects, immune regulation, and emerging treatments

After initial infection, human cytomegalovirus remains in a persistent state with the host. Immunity against the virus controls replication, although intermitent viral shedding can still take place in the seropositive immunocompetent person. Replication of cytomegalovirus in the absence of an effective immune response is central to the pathogenesis of disease. Therefore, complications are primarily seen in individuals whose immune system is immature, or is suppressed by drug treatment or coinfection with other pathogens. Although our increasing knowledge of the host-virus relationship has lead to the development of new pharmacological strategies for cytomegalovirus-associated infections, these strategies all have limitations-eg, drug toxicities, development of resistance, poor oral bioavailability, and low potency. Immune-based therapies to complement pharmacological strategies for the successful treatment of virus-associated complications should be prospectively investigated.

Impact of Cytomegalovirus Match on Survival after Cardiac and Lung Transplantation

Acute cytomegalovirus (CMV) disease and indirect effects caused by the virus alter the outcome after solid organ transplantation. Long-term results after 54 lung and 139 cardiac transplants at a single center have been retrospectively analyzed with regard to CMV status. Standard CMV prophylaxis consisted of ganciclovir for 100 days. Lung recipients were pretransplant CMV negative in 32 per cent as compared to heart recipients with 23 per cent. Patient survival after mismatch transplants (donor positive, recipient negative) was significantly reduced as compared to the other match groups (42% vs 76% at five years, P = 0.01). In heart recipients, CMV positive patients receiving a CMV negative graft showed best survival, whereas in the group of lung recipients negative/negative matched transplants produced best results. In both groups, CMV negative grafts had a better outcome than CMV positive grafts, and a survival difference between heart and lung recipients was only observed in recipients of a CMV positive grafts. Despite ganciclovir prophylaxis, CMV match remains an important factor for survival follwing heart and, even more profoundly, lung transplantation. Because survival was least favorable in the mismatched group, prophylactic regimens warrant improvement. For CMV negative lung recipients, CMV matching might be considered.

Cytomegalovirus infection status predicts progression of heart-transplant vasculopathy

BACKGROUND

Transplant vasculopathy (TVP) is the most common cause of death and retransplantation after heart transplantation. Human cytomegalovirus (HCMV) infection has been linked to atherosclerosis and to the development of TVP. A prospective study evaluating the relation between CMV infection and progression of TVP is lacking thus far. The purpose of the present study was to investigate the influence of CMV infection status on the progression of TVP within 1 year.

METHODS

We enrolled 103 consecutive heart-transplant recipients who underwent routine cardiac catheterization and intracoronary ultrasound examination at study entry and after 1 year. Plaque progression determined by quantitative intracoronary ultrasound was used to define the severity of disease at baseline and at 1-year follow-up. At study entry, HCMV infection status was evaluated by immunological assays and reverse-transcriptase polymerase chain reaction (RT-PCR).

RESULTS

HCMV immunoglobulin (Ig)G/IgM seropositivity was found in 34 (33%) of transplant recipients, 11 of whom were HCMV PCR positive. The HCMV-positive group showed more advanced, calcified lesions (64.7% vs. 27.5%, P=0.002), and the maximal plaque thickness was significantly different from the HCMV IgG/IgM-negative group (median [quartile] 1.36 [0.85, 1.88] vs. 1.05 [0.58, 1.34], P=0.02). In a logistic regression model, we demonstrate that HCMV IgG/IgM positivity is a predictor for the progression of TVP independent of cardiovascular risk factors, inflammatory markers, and platelet activation (P=0.038). In addition, HCMV PCR positivity even increases the risk for accelerated TVP (P=0.017) and, consecutively, transplant failure.

CONCLUSIONS

HCMV infection status in transplant patients detects patients with increased risk for transplant failure caused by TVP.

Vascular thrombosis and acute cytomegalovirus infection in immunocompetent patients: report of 2 cases and literature review

Acute cytomegalovirus (CMV) infection in immunocompetent patients is common worldwide, with seroprevalence rates of 40%-100%, depending on the country, socioeconomic conditions, and the patient's age. Infection is most often asymptomatic, but acute cytomegalovirus infection is occasionally revealed by prolonged fever, cervical lymphadenitis, and arthralgia, and it is more rarely revealed by pneumonia, myocarditis, pericarditis, colitis, and hemolytic anemia. Here, we report 2 cases of acute CMV infection in nonimmunocompromised adults that were complicated by venous thrombosis with pulmonary embolism. We also review previously reported cases of vascular thrombosis and discuss the propensity of CMV to induce vascular damage with associated thrombosis.

Cardiac allograft vasculopathy and dysregulation of the NO synthase pathway

Cardiac allograft vasculopathy is the most aggressive form of atherosclerosis in humans and is the leading cause of death after the first year of heart transplantation. Endothelial dysfunction is a major contributing factor to the acceleration of coronary vascular disease in these individuals. A reflection of this endothelial dysfunction is the severe impairment in endothelium-dependent vasodilation that occurs early after transplantation. The etiology of this allograft endothelial alteration is multifactorial and may include preexisting atherosclerosis of the graft vessels, reperfusion injury during transplantation, denervation, disruption of the lymphatic system, and acute and chronic immune injury, as well as traditional risk factors for coronary artery disease (hyperlipidemia, diabetes, hypertension, or hyperhomocysteinemia) and pathogens, such as cytomegalovirus. The alteration in endothelial function affects vasomotor tone of the coronary arteries. Evidence indicates that there may be an impairment of endothelial production and/or activity of NO. Because NO is a potent vasodilator, its deficiency would explain the abnormal vasomotor tone in these individuals. In addition, because NO inhibits key processes in vascular inflammation and atherosclerosis, its absence may contribute to the acceleration of transplant vascular disease. Recent studies from our group and others have shed light on the mechanisms of endothelial dysfunction and its importance in cardiac allograft vasculopathy. In addition, the alteration in endothelial function contributes to vascular inflammation and progression of the disease.

Cytomegalovirus seropositivity is significantly associated with mycosis fungoides and Sézary syndrome

Although mycosis fungoides (MF) may arise through persistent antigen stimulation, cytomegalovirus (CMV) is not a known risk factor. To study the incidence of seropositivity to viral infections, we compared MF and Sézary Syndrome (SS) patients to healthy bone marrow donors and other historical control groups. Baseline screening serologies at baseline were performed on 116 biopsy-proven MF/SS patients at MD Anderson Cancer Center from 1992 to 2001 and on healthy bone marrow donors evaluated by the transplant service from 1988 to 2001. Antibodies to HTLV-I/II, HIV-1, EBV, and CMV were measured using standard enzyme-linked immunosorbent (ELISA) and membrane enzyme immunoassay (MEIA) assays. One hundred thirteen (97.4%) of all MF/SS patients had positive CMV IgG serologies at initial presentation. Early- and late-stage patients' seropositivity rates were significantly higher than healthy bone marrow donor controls (chi(2).05(df=1) = 71.79). By stage, 98.1% of early-stage MF patients (IA, IB, IIA; 52/53) and 96.8% of late-stage MF and SS patients (IIB-IVB; 61/63) were seropositive compared with healthy bone marrow donors whose seropositivity rate was 57.3% (757/1322). Because the rate of CMV seropositivity increases with age, a subset of cutaneous T-cell lymphoma (CTCL) patients 55 years or younger were compared to age-matched healthy donor controls; their seropositivity rate for CMV was also significantly higher (chi(2).05 05(df=1) = 20.4). EBV titers were positive by serology in 13 patients who were examined prospectively. CMV seropositivity is highly associated with MF and SS, even in the earliest stages of the disease, and is significantly higher than that of healthy and immunocompromised controls.

Humoral rejection in cardiac transplantation: risk factors, hemodynamic consequences and relationship to transplant coronary artery disease

BACKGROUND

Acute cellular rejection is the mechanism of most immune-related injury in cardiac transplant recipients. However, antibody-mediated humoral rejection (HR) has also been implicated as an important clinical entity following orthotopic heart transplantation. Humoral rejection has been reported to play a role in graft dysfunction in the early post-transplant period, and to be a risk factor for the development of transplant coronary artery disease. Some involved in transplantation pathology doubt the existence of clinically significant humoral rejection in cardiac allografts. Those who recognize its existence disagree on its possible role in graft dysfunction or graft coronary artery disease. In this study, we report clinical features of patients with the pathologic diagnosis of HR at our institution since July 1997, when we began systematic surveillance for humoral rejection.

METHODS

We reviewed medical records of patients with the pathologic diagnosis of HR without concurrent cellular rejection between July 1997 and January 2001. Diagnosis was based on routine histology ("swollen cells" distending capillaries, interstitial edema and hemorrhage) and immunofluorescence (capillary deposition of immunoglobulin and complement with HLA-DR positivity), or immunoperoxidase staining of paraffin-embedded tissue (numerous CD68-positive macrophages and fewer swollen endothelial cells distending capillaries).

RESULTS

A total of 44 patients (4 to 74 years old) showed evidence of HR without concurrent cellular rejection at autopsy or on one or more biopsies. Although females comprised only 26% of our transplant population, 23 patients (52%) with HR were female. A positive peri-operative flow cytometry T-cell crossmatch was observed in 32% of HR patients compared with 12% of controls (p = 0.02). Hemodynamic compromise consisting of shock, hypotension, decreased cardiac output/index and/or a rise in capillary wedge or pulmonary artery pressure was observed in 47% of patients at the time of diagnosis of HR. Six patients (5 females) died (14% mortality) with evidence of HR at or just before autopsy, 6 days to 16 months after transplantation. The incidence of transplant coronary artery disease was 10% greater at 1 year, and 36% greater at 5 years, in patients with HR when compared with non-HR patients.

CONCLUSIONS

Humoral rejection was associated with acute hemodynamic compromise in 47% of patients, and was the direct cause of death in 6 patients (13%). Humoral rejection is a clinicopathologic entity with a high incidence in women and is associated with acute hemodynamic compromise, accelerated transplant coronary artery disease and death.

Upregulation of CD40 expression on endothelial cells infected with human cytomegalovirus

CD40 has been identified as an important molecule for a number of processes, such as immune responses, inflammation, and the activation of endothelia. We investigated CD40 in endothelial cells (EC) following infection with an endotheliotropic strain of human cytomegalovirus (HCMV). Between 8 and 72 h postinfection, we observed a significant increase in CD40 levels on the surface of infected EC, as measured by fluorescence-activated cell sorting analysis. As a consequence of CD40 upregulation, increased levels of E-selectin were found on infected EC after stimulation with CD154-expressing T cells. Enhanced expression of CD40 was specific for EC, since infection of fibroblasts did not result in the upregulation of CD40. The addition of neutralizing antibodies as well as UV inactivation of virus completely prevented the upregulation of CD40 on EC. Also, laboratory-adapted HCMV strain AD169 was not able to induce CD40 on EC. De novo protein synthesis was necessary for the increased surface expression. At early times (4 to 24 h) postinfection, this change was not accompanied by increased levels of CD40 protein or mRNA. At late times (48 to 96 h) postinfection, increased amounts of CD40 protein and mRNA were detected. Immunohistochemical analysis of infected tissues demonstrated elevated levels of CD40 on HCMV-infected EC in vivo. Thus, infection of EC by HCMV may result in the activation of endothelia and in the augmentation of inflammatory processes.

Role of cytomegalovirus in cardiac allograft vasculopathy

Cardiac allograft vasculopathy is the most common cause of death and retransplantation following heart transplantation, and about 10% of patients per year have evidence of accelerated vascular disease; 50% at 5 years. Cytomegalovirus (CMV) infection has been associated with accelerated cardiac vasculopathy and decreased 5-year survival. Prophylactic therapy using ganciclovir has reduced the incidence of CMV disease, but not in the group at highest risk, namely the seronegative recipient of an allograft from a seropositive donor (D+/R-). Combination prophylaxis consisting of CMV hyperimmune globulin (CMV-IGIV) plus ganciclovir is associated with decreased intimal thickening, reduced coronary artery disease and obliterative bronchiolitis, and improved survival.

Clinical aspects and management of cytomegalovirus infection

The previous article discussed recent advances in understanding the biology of HCMV infection. Here we discuss current approaches to the clinical management of HCMV disease, and how understanding the biology of the virus may affect these.

[Inflammation and infection in stable coronary disease and acute coronary syndrome]

OBJECTIVE

To study whether inflammation and infection are related to coronary artery disease.

DESIGN

Sixty patients (44 males, mean age 62 +/- 13 years) with acute coronary syndrome and 40 with stable coronary artery disease (31 males, age 64 +/- 10 years) and a control group of 40 individuals (34 males, 53 +/- 5 years) were analyzed. IgG against Chlamydia pneumoniae, Cytomegalovirus and Helicobacter pylori plus C-reactive protein were assessed in all serum samples. In addition, IgM against C. pneumoniae and Cytomegalovirus on admission and C-reactive protein one month later were measured in acute patients.

RESULTS

No IgM seropositivity was observed. A high prevalence of IgG seropositivity with no significant differences among the groups was found: C. pneumoniae: acute group 44 (73%), stable group 29 (73%) and control group 25 (63%); Cytomegalovirus: 55 (92%), 37 (92%) and 38 (95%), respectively; and H. pylori, 43 (72%), 32 (80%) and 34 (85%) respectively. There was a high rate of positive C-reactive protein in the acute group: 48 (80%) vs 10 (25%) the stable group and 0% the control group (p < 0.001). C-reactive protein levels were higher in Q-wave infarction than in unstable angina/ non-Q-wave infarction (median 22.65 vs 7.69, p < 0.001). One month later, C-reactive protein levels decreased (median 22.65 vs 3.38, p < 0.001), but were still positive in 40%.

CONCLUSIONS

These data suggest that inflammation is detected by the commonly used methods in clinic practice in acute coronary syndromes and to a lesser extent in stable coronary artery disease. It seems that different mechanisms other than infection account for this inflammatory response, at least this being so when infection is assessed by serology. Serology does not appear to be an adequate method to determine the possible relationship among coronary syndromes, infection and inflammation.

Cardiovascular risk factors in kidney transplantation

Classical and non-classical cardiovascular risk factors are common after renal transplantation, and they are effectively associated with the development of cardiovascular disease. Despite the absence of large, controlled clinical trials examining the effect of prevention strategies, therapies should not be withheld from renal transplant recipients with significant risk factors, because their risk of developing cardiovascular disease is at least as high as that of the general population.

New developments in the management of cytomegalovirus infection and disease after renal transplantation

The clinical management of cytomegalovirus infection and disease in renal transplant recipients has recently been significantly improved with the availability of data on prophylaxis with oral ganciclovir and valacyclovir. In addition, significant progress in early diagnosis and the quantitation of viral load has been achieved. The influence of novel immunosuppressants on the clinical course of cytomegalovirus infection has been clarified to some extent by recent clinical data. The identification of risk factors for cytomegalovirus disease beyond seroconstellation and immunosuppression is an ongoing process that might lead to a more targeted use of antiviral agents, given the risk of ganciclovir resistance. The understanding of the effects of cytomegalovirus on long-term graft outcome still needs to be deepened in order to design cytomegalovirus-specific interventions to improve graft survival.

Preemptive therapy versus universal prophylaxis with ganciclovir for cytomegalovirus in solid organ transplant recipients

Whether preemptive therapy or universal prophylaxis with ganciclovir is the optimal approach against cytomegalovirus (CMV) remains unresolved. Controversy abounds with respect to the efficacy of preemptive therapy, the reliability of preemptive therapy tools, the logistical difficulties in conducting surveillance monitoring for CMV, the cost of prophylaxis, the effect of prophylaxis on indirect sequelae of CMV and epidemiology of CMV, and the potential for emergence of ganciclovir-resistant CMV. Although neither approach is wholly adequate, a discussion of the relative merits and limitations of the 2 approaches may guide the selection of a rational approach toward prevention of CMV infection in organ transplant recipients.

Transplant Coronary Vasculopathy

Because the transplanted heart is denervated, classic angina as a symptom of allograft coronary vasculopathy rarely is perceived. Any cardiac transplant patients who presents with decreased exercise capacity, shortness of breath, or syncope should be assessed thoroughly. Unfortunately, the initial presenting symptom of transplant vasculopathy may be acute myocardial infarction, heart failure, or even sudden death. Patients should be evaluated on an annual basis for the presence of transplant coronary vasculopathy in addition to when clinical suspicion warrants. Coronary angiography has been the main modality of invasive assessment, although it is insensitive. Recently, intracoronary ultrasound has been used in conjunction with angiography to detect the first evidence of transplant vasculopathy, manifested as thickening of the intimal layer of the vessel wall due to smooth muscle cell proliferation, which ultimately leads to luminal narrowing. Patients with evidence of vasculopathy should undergo functional evaluation with dobutamine echocardiography to document ischemic burden. Preventive measures include traditional coronary risk factor modification. Patients are started on statins early in the post-transplantation period and hypertension is treated aggressively using calcium channel blockers and angiotensin-converting enzyme (ACE) inhibitors. Because of their deleterious metabolic effects, steroids may be withdrawn under close surveillance for rejection. After transplant vasculopathy has developed, it is difficult to treat and options are limited. Patients with discrete luminal obstructions may undergo angioplasty, stenting, or coronary artery bypass. However, these procedures are palliative, and the only definitive therapy is retransplantation.

Potential infectious etiologies of atherosclerosis: a multifactorial perspective

Coronary heart disease (CHD) contributes substantially to illness and death worldwide. Experimental studies demonstrate that infection can stimulate atherogenic processes. This review presents a spectrum of data regarding the link between CHD and infection. In addition, the need for improved diagnostic tools, the significance of multiple pathogens, and potential intervention strategies are discussed.