Tiziana Lazzarotto

The “Silent” Global Burden of Congenital Cytomegalovirus

SUMMARY Human cytomegalovirus (CMV) is a leading cause of congenital infections worldwide. In the developed world, following the virtual elimination of circulating rubella, it is the commonest nongenetic cause of childhood hearing loss and an important cause of neurodevelopmental delay. The seroprevalence of CMV in adults and the incidence of congenital CMV infection are highest in developing countries (1 to 5% of births) and are most likely driven by nonprimary maternal infections. However, reliable estimates of prevalence and outcome from developing countries are not available. This is largely due to the dogma that maternal preexisting seroimmunity virtually eliminates the risk for sequelae. However, recent data demonstrating similar rates of sequelae, especially hearing loss, following primary and nonprimary maternal infection have underscored the importance of congenital CMV infection in resource-poor settings. Although a significant proportion of congenital CMV infections are attributable to maternal primary infection in well-resourced settings, the absence of specific interventions for seronegative mothers and uncertainty about fetal prognosis have discouraged routine maternal antibody screening. Despite these challenges, encouraging results from prototype vaccines have been reported, and the first randomized phase III trials of prenatal interventions and prolonged postnatal antiviral therapy are under way. Successful implementation of strategies to prevent or reduce the burden of congenital CMV infection will require heightened global awareness among clinicians and the general population. In this review, we highlight the global epidemiology of congenital CMV and the implications of growing knowledge in areas of prevention, diagnosis, prognosis, and management for both low (50 to 70%)- and high (>70%)-seroprevalence settings.

Neonatal Cytomegalovirus Blood Load and Risk of Sequelae in Symptomatic and Asymptomatic Congenitally Infected Newborns

OBJECTIVE. Human cytomegalovirus (CMV) is a ubiquitous human-specific DNA virus and is the main cause of congenital virus infection in developed countries leading to psychomotor impairment and deafness. Diagnostic techniques for CMV detection have greatly improved during recent years with the advent of sophisticated serological and virological methods. The aim of the present study was to assess the diagnostic and prognostic value of detection and quantification of virus in neonatal blood samples of symptomatic and asymptomatic newborns with CMV congenital infection. METHODS. Between January 1997 and December 2003, we studied 99 newborns who were born to women with primary, recurrent, and undefined CMV infection during pregnancy. CMV congenital infection was identified by isolation of the virus in urine within the second week of life. Fifty-eight of 99 infants were infected and were assessed clinically for disease in the newborn period and classified as having symptomatic or asymptomatic infection on the basis of physical, instrumental, and laboratory findings. The infants were followed up from birth according to a protocol of the tertiary NICU at the University of Bologna in a prospective study of long-term sequelae of congenital infection. Forty-seven blood samples were obtained from 47 infants in the neonatal period: 34 were examined for pp65 antigenemia test and 44 for qualitative and quantitative polymerase chain reaction (PCR and qPCR). Sequelae at 12 months were evaluated in a group of 50 infants. RESULTS. Antigenemia was positive in only 10 of 34 samples of infected newborns (29.4% sensitivity). PCR was performed in 44 samples of infected newborns and was positive in all (100% sensitivity). qPCR showed a finding of ≥100 copies per 105 of polymorphonuclear leukocytes (PMNLs) in 39 of 44 samples; in the other 5 cases, the number of copies per 105 PMNLs was <100. Between symptomatic and asymptomatic newborns, the mean values of viral blood load determined by qPCR turned out to be significantly higher in symptomatic newborns. Mean values of neonatal blood viral load were statistically higher in newborns who developed sequelae than in those who did not. Of 20 children with a neonatal viral blood load of <1000 copies per 105 PMNLs, 19 did not develop sequelae (negative predictive value: 95%), whereas 2 of 3 with a viral blood load of >10000 copies did develop sequelae. CONCLUSIONS. Different viremia value ranges are correlated to a different risk of sequelae: ∼70% sequelae were found in newborns with a qPCR higher than 10000 copies per 105 PMNLs. Low neonatal viral blood load detected by pp65 antigenemia test and qPCR was highly predictive of absence of sequelae: DNAemia <1000 copies per 105 PMNLs has a negative predictive value of 95%. As an independent predictive factor of outcome, neonatal viremia is another useful element for neonatal counseling and therapeutic choices in symptomatic and asymptomatic newborns.

Ultrasound prediction of symptomatic congenital cytomegalovirus infection

OBJECTIVE The objective of the study was to assess the effectiveness of ultrasound in the antenatal prediction of symptomatic congenital cytomegalovirus (CMV) infection. STUDY DESIGN The sonograms of 650 fetuses from mothers with primary CMV infection were correlated to fetal or neonatal outcome. Infection status was disclosed by viral urine isolation at birth or CMV tissue inclusions at autopsy. Classification of symptomatic disease was based on postnatal clinical or laboratory findings or macroscopic evidence of tissue damage at autopsy. RESULTS Ultrasound abnormalities were found in 51 of 600 mothers with primary infection (8.5%) and 23 of 154 congenitally infected fetuses (14.9%). Symptomatic congenital infection resulted in 1 of 23 and 68 of 131 cases with or without abnormal sonographic findings, respectively. Positive predictive values of ultrasound vs symptomatic congenital infection was 35.3% relating to all fetuses or infants from mothers with primary infection and 78.3% relating to fetuses or infants with congenital infection. CONCLUSION When fetal infection status is unknown, ultrasound abnormalities predict symptomatic congenital infection in only a third of cases.

Update on the prevention, diagnosis and management of cytomegalovirus infection during pregnancy.

Human cytomegalovirus (CMV) is the leading cause of congenital infection, with morbidity and mortality at birth and sequelae. Each year approximately 1-7% (Rev Med Virol 2010; 20: 311) of pregnant women acquire a primary CMV infection. Of these, about 30-40% transmit infection to their fetuses. The risk of serious fetal injury is greatest when maternal infection develops in the first trimester or early in the second trimester. Between 10 and 15% of congenitally infected infants are acutely symptomatic at birth and most of the survivors have serious long-term complications. Until a few years ago, laboratory testing was not possible to precisely define the maternal immune status, the recent development of advanced serological tests (IgG avidity test, IgM immunoblot and neutralizing antibody testing) allow us to identify, among pregnant women with suspected CMV, those with primary infection who are therefore at high risk of transmitting CMV to the fetus. This is done with the use of a screening test. As most maternal infections are asymptomatic, the only way to disclose primary infection is to implement specific serological testing as early in pregnancy as possible (before week 12-16 of gestation). Given the high risk of mother-fetus transmission and fetal damage, prenatal diagnosis is recommended to women with primary CMV infection contracted in the first half of pregnancy and in case of fetal abnormalities suggestive of infection. The correct interpretation of serological and virological tests followed by appropriate counselling by an expert physician is an effective tool to reduce the number of unnecessary pregnancy terminations by over 70%.

Hydroxymethyl-Glutaryl Coenzyme A Reductase Inhibition Limits Cytomegalovirus Infection in Human Endothelial Cells

Background—Statins exert anti-inflammatory effects independently of cholesterol-lowering properties. Cytomegalovirus (CMV) infection appears to be implicated in the pathophysiology of atherosclerosis by inducing inflammatory modifications in endothelial cells, especially in immunosuppressed patients. We investigated whether the activity of statins can inhibit replication of CMV in human endothelial cells. Methods and Results—Human umbilical vein endothelial cells (HUVECs) were infected with CMV and coincubated with fluvastatin at 0.1 and 0.2 &mgr;mol/L. Fluvastatin inhibited (P <0.001) CMV antigen expression, and this effect was dose related (P <0.001). Quantitative polymerase chain reaction showed that CMV DNA concentration was consistently lower in supernatants from fluvastatin-treated cells than in infected controls, and viral particle concentration was up to 30 times lower in 0.2 &mgr;mol/L fluvastatin-treated cells than in infected controls (10.5±0.9 versus 0.34±0.03 per 103 pfu/mL, P <0.001). Addition of mevalonate to treated cultures almost completely abolished fluvastatin inhibition of viral growth. Electrophoretic mobility shift assay showed that fluvastatin reduced nuclear factor-&kgr;B binding activity in CMV-infected cells. Conclusions—HMG-CoA inhibition by fluvastatin restrains CMV replication in HUVECs by inhibiting viral antigen expression, DNA synthesis, and viral particle production, conceivably by involving a reduction of nuclear factor-&kgr;B binding activity.

HHV-6A in Syncytial Giant-Cell Hepatitis

Syncytial giant-cell hepatitis is a rare but severe form of hepatitis that is associated with autoimmune diseases, drug reactions, and viral infections. We used serologic, molecular, and immunohistochemical methods to search for an infectious cause in a case of syncytial giant-cell hepatitis that developed in a liver-transplant recipient who had latent infection with variant B of human herpesvirus 6 (HHV-6B) and who had received the organ from a donor with variant A latent infection (HHV-6A). At the onset of the disease, the detection of HHV-6A (but not HHV-6B) DNA in plasma, in affected liver tissue, and in single micromanipulated syncytial giant cells with the use of two different polymerase-chain-reaction (PCR) assays indicated the presence of active HHV-6A infection in the patient. Expression of the HHV-6A-specific early protein, p41/38, but not of the HHV-6B-specific late protein, p101, was demonstrated only in liver syncytial giant cells in the absence of other infectious pathogens. The same markers of HHV-6A active infection were documented in serial follow-up samples from the patient and disappeared only at the resolution of syncytial giant-cell hepatitis. Neither HHV-6B DNA nor late protein was identified in the same follow-up samples from the patient. Thus, HHV-6A may be a cause of syncytial giant-cell hepatitis.

Intense Antiextracellular Adaptive Immune Response to Human Cytomegalovirus in Very Old Subjects with Impaired Health and Cognitive and Functional Status

Human aging is characterized by expanded and altered adaptive immune responses to human CMV (HCMV). It is unclear whether this expansion has its origins in age-related homeostatic disturbances or viral reactivation, whether anti-CMV immune surveillance may still be effective, and what are the consequences of this expanded immune response for health and longevity. We conducted an observational cross-sectional study in groups of HCMV-seropositive subjects aged ≥65 y of variable health status to compare the intensity of Ab responses against HCMV with those against EBV and with CD4+ and CD8+ T cell proinflammatory effector responses directed to HCMV-derived pp65 and immediate-early protein 1 synthetic peptides. Ab responses to HCMV, but not to EBV, and anti-HCMV CD4+, but not CD8+, T cell responses were more intense in elderly subjects aged ≥85 y in poor health and were inversely correlated with markers of functional activity and cognitive function. Therefore, humoral and CD4+ T cell anti-HCMV responses were specifically intensified in advanced aging associated with comorbidity and cognitive and functional impairments. Such a distinctive pattern of adaptive immunity indicates that immune responses targeting the extracellular phase of HCMV are increased in these elderly subjects and could represent an indirect effect of localized and undetectable HCMV reactivation. This study demonstrates that the oldest subjects in poor health with physical and mental impairment express intense functional immune responses to extracellular HCMV and suggests that they may be at risk for direct pathogenic effects by HCMV reactivation as well as indirect pathogenic effects linked to proinflammatory anti-HCMV effector responses.

Prophylaxis Versus Preemptive Anti-cytomegalovirus Approach for Prevention of Allograft Vasculopathy in Heart Transplant Recipients

BACKGROUND Cytomegalovirus (CMV) infection may influence the development of cardiac allograft vasculopathy (CAV). Prophylactic or preemptive administration of anti-CMV agents effectively prevents acute CMV manifestations. However, studies comparing allograft-related outcomes between these anti-CMV approaches are lacking. Herein we report a longitudinal observational study comparing CAV development between prophylactic and preemptive approaches. METHODS The 1-year change in maximal intimal thickening (MIT) assessed by intravascular ultrasound at 1 and 12 months after heart transplantation (the major surrogate for late survival) was compared in groups of patients routinely assigned to a preemptive strategy (from November 2004 to October 2005; n = 21) or receiving valganciclovir prophylaxis (from November 2005 to October 2006; n = 19). CMV infection was monitored with pp65 antigenemia. RESULTS The 1-year increase in MIT was significantly lower in patients receiving prophylaxis compared with those managed preemptively (0.15 +/- 0.17 vs 0.31 +/- 0.20 mm; p = 0.01). Prophylaxed recipients presented less frequently with MIT change > or =0.3 mm (p = 0.03) and > or =0.5 mm (p = 0.10) than those managed preemptively. Prophylaxis was also associated with later onset of CMV infection (p = 0.01), lower peak CMV detection (p < 0.01) and reduced incidence of CMV disease/syndrome (p = 0.04). After adjusting for metabolic risk factors and other possible confounders, prophylaxis remained independently associated with lower risk for MIT change > or =0.3 mm (odds ratio = 0.09, 95% confidence interval 0.01 to 0.93; p = 0.04). CONCLUSIONS Universal prophylaxis was associated with delayed onset of CMV infection, lower viral burden, reduced CMV disease/syndrome and less intimal thickening, as compared with a preemptive anti-CMV approach. Randomized studies are required to confirm the potential benefits of prophylaxis vs a preemptive approach in heart transplant recipients.

Relevance of cytomegalovirus infection and coronary-artery remodeling in the first year after heart transplantation: a prospective three-dimensional intravascular ultrasound study.

Background. Transplant coronary artery disease (TxCAD) is a major cause of long-term mortality after heart transplantation. Although vascular remodeling has been implicated in the pathophysiology of TxCAD, its determinants remain unknown. Methods. Twenty-nine consecutive heart-transplant recipients prospectively received intravascular ultrasound (IVUS) of the left-anterior descending artery 1 and 12 months after transplant, with volumetric reconstruction of the proximal 30 mm. Results. Overall, patients exhibited intimal volume increase (+83%, P <0.001), wheras vessel volume remained largely unchanged (+4%, P =0.270); consequently, overall lumen volume decreased (−6%, P =0.058). Among the clinical and laboratory variables, cytomegalovirus (CMV) infection requiring treatment (occurring in 12 patients), as assessed by pp65 antigenemia, was independently associated with the impaired ability of the vessel wall to enlarge in response to intimal volume increase, ultimately resulting in lumen loss (OR [95% CI]=0.098 [0.010–0.920];P =0.042). However, adequate vessel response to intimal hyperplasia with consequent lumen preservation was observed in the remaining 17 patients who did not present CMV infection requiring treatment. Conclusions. The present study demonstrates that either adequate or inadequate coronary remodeling may occur during the first year after transplantation. Moreover, for the first time, it strongly suggests that remodeling modalities may be negatively influenced by the occurrence of clinically relevant CMV infection. Randomized prospective trials are warranted to investigate whether aggressive treatment of CMV infection may help prevent TxCAD.

Cytomegalovirus (CMV)–Encoded UL144 (Truncated Tumor Necrosis Factor Receptor) and Outcome of Congenital CMV Infection

BACKGROUND Cytomegalovirus (CMV) is the most common congenital infection in humans. The effect of viral strains on the outcome of congenital CMV is debated. We evaluated whether UL144 polymorphisms in amniotic fluid from CMV-infected Italian women were associated with terminations of pregnancy, subsequent disease in their offspring, or viral load. METHODS The study was nested within a prenatal CMV program. We sequenced the UL144 gene from 66 amniotic-fluid samples, without knowledge of pregnancy outcome. We performed data analyses on 56 samples for which all information was available. RESULTS Genotype C was associated with termination of pregnancy (P=.03). Genotype B was associated with fewer terminations of pregnancy (P=.003). A possible association was found between genotype C and symptomatic disease in newborns (odds ratio, 8.81 [95% confidence interval, 0.48-164.02]; P=.05). There was no association between specific genotype and the viral load in amniotic fluid. Symptomatic newborns who had the most common UL144 genotype (B) were more likely to have higher viral loads than were asymptomatic infants (P=.003). CONCLUSIONS UL144 polymorphisms may be associated with the outcome of congenital CMV infection. Larger studies should be conducted to confirm this association, before genotype analysis can be used, along with other factors, in considering terminations of pregnancy.