Diagnostic Value of Cytomegalovirus IgM Antibodies at Birth in PCR-Confirmed Congenital Cytomegalovirus Infection

Congenital and Postnatal Cytomegalovirus: Case Series and State of the Science for Neonatal Providers

Cytomegalovirus (CMV), a beta-herpes virus, is the most common viral infection in infants. Transmission may occur congenitally (cCMV) or postnatally (pCMV). Early detection and intervention are crucial in reducing morbidities, notable developmental delays, and sensorineural hearing loss. However, more than 90% of infants are asymptomatic at birth. Treatment involves intravenous ganciclovir or the oral prodrug, valganciclovir, drugs usually reserved for use with symptomatic infants because of the toxicity profile. Research currently supports standardized antenatal CMV screening and treatment of affected pregnant patients with hyperimmune globulin as well as vaccination against CMV in unaffected pregnant patients, although widespread adoption is lacking. Standardized postnatal CMV screening is a proven, cost-effective way to detect and diagnose CMV and optimize outcomes across the lifespan. This article presents a case series of cCMV and pCMV and a review of the state of science of CMV as well as promising scientific advances that are on the horizon.

Clinical Characteristics of Infants with Symptomatic Congenital and Postnatal Cytomegalovirus Infection-An 11-Year Multicenter Cohort Study in Taiwan

(1) Background: Cytomegalovirus (CMV) infection is a prevalent viral disease among infants. The prevalence typically ranges from 0.2% to 2.4% among all newborns. There are limited data regarding the demographic characteristics of infants with symptomatic CMV infections. (2) Methods: In this retrospective cohort study using the Chang Gung Memorial Hospital multicenter database, infants with CMV infection determined by a positive urine culture, positive blood polymerase chain reaction assay or positive immunoglobulin M result for CMV from 2011 through 2021 were included. Clinical characteristics at initial diagnosis, management and outcomes were investigated. Congenital CMV (cCMV) infection is diagnosed within three weeks after birth; postnatal CMV (pCMV) is diagnosed when CMV is detected after the first 3 weeks of life. (3) Results: Among the 505 CMV-infected infants identified, 272 were included in the analysis. According to the age at initial presentation, 21 infants had cCMV infection and 251 had pCMV infection. Higher incidences of prematurity and being small for gestational age and a lower Z score for weight at diagnosis were observed in the cCMV group. While thrombocytopenia (61.9%) was the leading presentation in the cCMV group, hepatitis (59.8%) and prolonged jaundice (21.9%) were more common in the pCMV group. (4) Conclusions: Utilizing an 11-year multicenter database, we demonstrated the characteristics of infants with CMV infection in Taiwan and highlighted the demographic disparities and differing symptoms between the cCMV and pCMV groups. These findings emphasize the necessity for future research to refine screening policies, explore treatment options, and establish follow-up protocols for affected infants.

Effects of cytomegalovirus infection on the differential diagnosis between biliary atresia and intrahepatic cholestasis in a Chinese large cohort study

INTRODUCTION AND OBJECTIVES

Differentiating biliary atresia from other causes of neonatal cholestasis is challenging, particularly when cytomegalovirus (CMV) and biliary atresia occur simultaneously. We aimed to elucidate whether CMV infection would affect the differential diagnosis of biliary atresia and intrahepatic cholestasis.

PATIENTS AND METHODS

This retrospective study was conducted among patients with neonatal cholestasis admitted to three tertiary hospitals between January 2010 and August 2019. The clinical characteristics, laboratory, and imaging findings were recorded. On the basis of the CMV serology results, the infants were classified into CMV-IgM (+) and CMV-IgM (-) groups. The clinical differences and diagnostic performances of routine predictors between biliary atresia and intrahepatic cholestasis were analyzed in each group. Finally, we compared the diagnostic performances of various tests in the two groups.

RESULTS

A total of 705 patients with neonatal cholestasis were enrolled: 215 (30.5%) patients were positive for CMV-IgM, among whom 97 had biliary atresia and 118 had CMV hepatitis; 490 infants were CMV-IgM (-), among whom 240 had biliary atresia and 250 had intrahepatic cholestasis. The diagnostic performances of stool color, direct bilirubin level, γ-glutamyl transpeptidase level, abnormal gallbladder, triangular cord sign, and hepatobiliary scintigraphy between CMV hepatitis and CMV-IgM (+) biliary atresia were similar to those between CMV-IgM (-) biliary atresia and CMV-IgM (-) intrahepatic cholestasis groups.

CONCLUSIONS

Our large-scale study showed a high prevalence of CMV infection in patients with neonatal cholestasis in China. The presence of CMV infection did not affect the routine predictors to discriminate biliary atresia and intrahepatic cholestasis.

Change in Viral Load during Antiviral Therapy Is Not Useful for the Prediction of Hearing Dysfunction in Symptomatic Congenital Cytomegalovirus Infection

For symptomatic congenital cytomegalovirus infections (CCMVI), the usefulness of changes in viral load during valganciclovir (VGCV) treatment for the prediction of hearing dysfunction (HD) is unclear. To determine the utility of viral load change in the whole blood or urine for the prediction of HD, we performed a retrospective study to compare viral load changes during VGCV treatment between CCMVI infants with (n = 12) or without (n = 8) HD at six months of corrected age, whose blood and urine viral loads were measured continuously for eight weeks from April 2009 to December 2019. There was no significant difference in the changes in both the blood and urine viral loads after the initiation of VGCV treatment between CCMVI infants between the groups. Moreover, this negative result was maintained in the analysis for each six weeks or six months treatment period. In conclusion, the change in viral load during antiviral therapy is not useful for the prediction of HD at six months of corrected age in symptomatic CCMVI.

A Novel Strain-Specific Neutralizing Epitope on Glycoprotein H of Human Cytomegalovirus

Human cytomegalovirus (HCMV) is a ubiquitous pathogen that causes severe clinical disease in immunosuppressed patients and congenitally infected newborn infants. Viral envelope glycoproteins represent attractive targets for vaccination or passive immunotherapy. To extend the knowledge of mechanisms of virus neutralization, monoclonal antibodies (MAbs) were generated following immunization of mice with HCMV virions. Hybridoma supernatants were screened for in vitro neutralization activity, yielding three potent MAbs, 6E3, 3C11, and 2B10. MAbs 6E3 and 3C11 blocked infection of all viral strains that were tested, while MAb 2B10 neutralized only 50% of the HCMV strains analyzed. Characterization of the MAbs using indirect immunofluorescence analyses demonstrated their reactivity with recombinantly derived gH. While MAbs 6E3 and 3C11 reacted with gH when expressed alone, 2B10 detected gH only when it was coexpressed with gB and gL. Recognition of gH by 3C11 was dependent on the expression of the entire ectodomain of gH, whereas 6E3 required residues 1 to 629 of gH. The strain-specific determinant for neutralization by Mab 2B10 was identified as a single Met→Ile amino acid polymorphism within gH, located within the central part of the protein. The polymorphism is evenly distributed among described HCMV strains. The 2B10 epitope thus represents a novel strain-specific antibody target site on gH of HCMV. The dependence of the reactivity of 2B10 on the simultaneous presence of gB/gH/gL will be of value in the structural definition of this tripartite complex. The 2B10 epitope may also represent a valuable tool for diagnostics to monitor infections/reinfections with different HCMV strains during pregnancy or after transplantation. IMPORTANCE HCMV infections are life threatening to people with compromised or immature immune systems. Understanding the antiviral antibody repertoire induced during HCMV infection is a necessary prerequisite to define protective antibody responses. Here, we report three novel anti-gH MAbs that potently neutralized HCMV infectivity. One of these MAbs (2B10) targets a novel strain-specific conformational epitope on gH that only becomes accessible upon coexpression of the minimal fusion machinery gB/gH/gL. Strain specificity is dependent on a single amino acid polymorphism within gH. Our data highlight the importance of strain-specific neutralizing antibody responses against HCMV. The 2B10 epitope may also represent a valuable tool for diagnostics to monitor infections/reinfections with different HCMV strains during pregnancy or after transplantation. In addition, the dependence of the reactivity of 2B10 on the simultaneous presence of gB/gH/gL will be of value in the structural definition of this tripartite complex.

Cytomegalovirus Hepatitis in Immunocompetent and Immunocompromised Hosts

Human cytomegalovirus (HCMV) infection is common and affects between 40-100% of the worldwide population. However, the majority of cases are asymptomatic and when severe disease occurs, it is usually restricted to immunocompromised patients. Liver involvement by HCMV differs significantly, accordingly to the immune status of the host. In immunocompromised patients, particularly liver transplant patients, it often causes clinically significant hepatitis. On the other hand, in immunocompetent patients, HCMV hepatitis requiring hospitalization is extremely rare. This review aims to appraise studies regarding the pathophysiology of HCMV hepatitis, including mechanisms of latency and reactivation and its contribution to disease development, clinical presentation, diagnostic modalities and treatment, with a focus on comparing different aspects between immunocompromised and immunocompetent hosts.

Prediction of Neurodevelopmental Impairment in Congenital Cytomegalovirus Infection by Early Postnatal Magnetic Resonance Imaging

INTRODUCTION

Congenital cytomegalovirus infection (CCMVI) may result in neurodevelopmental impairments (NDIs) such as hearing loss, developmental delay, epilepsy, and cerebral palsy. We aimed to investigate the potential for brain magnetic resonance imaging (MRI) to predict NDI in patients with CCMVI.

METHODS

We studied infants with CCMVI who were referred to our hospital from April 2010 to October 2018 and underwent a brain MRI within 3 months since birth. We screened for 6 classic presentations of CCMVI including ventriculomegaly, periventricular cysts, hippocampal dysplasia, cerebellar hypoplasia, migration disorders, and white matter abnormalities. Images were interpreted by a blinded pediatric radiologist. NDI was defined as having a developmental quotient <80, hearing dysfunction, blindness, or epilepsy requiring anti-epileptic drugs at approximately 18 months of corrected age.

RESULTS

The study involved 42 infants with CCMVI (median gestational age 38 weeks, birthweight 2,516 g). At least one abnormal finding was detected in 28 (67%) infants. Abnormal findings consisted of 3 cerebellar hypoplasia (7%), 7 migration disorders (17%), 26 white matter abnormalities (62%), 12 periventricular cysts (28%), 1 hippocampal dysplasia (2%), and 20 ventriculomegaly (48%). Abnormal findings were significantly more prevalent in infants with clinical symptoms (21/24, 91%) than in those without (7/19, 37%, p < 0.01). For NDI prediction, having ≥2 of ventriculomegaly, periventricular cysts, and white matter abnormality produced the highest Youden index values (0.78).

CONCLUSION

Infants with CCMVI with at least 2 of the abovementioned specific brain image abnormalities may be at high risk of developing NDI.

Real-time PCR versus shell vial culture on urine of patients with suspected congenital cytomegalovirus infection

Aims: Cytomegalovirus (CMV) is the most common cause of congenital infection. Aim of this study is to support quantitative real-time polymerase chain reaction (PCR) versus shell vials culture for CMV screening in urine samples. Patients & methods: A retrospective study was conducted on 255 urine samples belonging to patients admitted to Bambino Gesù Pediatric Hospital, Rome, Italy, with suspected congenital CMV infection. Results & conclusion: Quantitative real-time PCR resulted more standardized, faster, less operator-dependent, less laborious and most of all cost saving and more sensitive than shell vial culture. Since a negative result for CMV in urine means no congenital infection, a more sensitive tool for detection of CMV DNA is essential to improve patient management and to reduce healthcare costs associated to a late diagnosis.