Prognostic markers of symptomatic congenital human cytomegalovirus infection in fetal blood

Diagnosis and counseling of fetal and neonatal HCMV infection

Fetal HCMV infection is investigated by amniocentesis when a maternal primary infection is diagnosed or ultrasound (US/MRI) abnormalities are observed. In fetal blood, prognostic markers of symptomatic congenital infection may be evaluated for parental counseling. At birth, viral load measurement in body fluids may correlate with long-term sequelae, but the prognostic accuracy of symptomatic infection increases when maternal, fetal, and neonatal parameters are combined.

Quantification of cytomegalovirus viral load

Cytomegalovirus (CMV), a member of the Herpesviridae family, is worldwide distributed. After the primary infection, CMV induces a latent infection with possible reactivation(s). It is responsible for severe to life-threatening diseases in immunocompromised patients and in foetuses and newborns of infected mothers. For monitoring CMV load, classical techniques based on rapid culture or pp65 antigenemia are progressively replaced by quantitative nuclear acid tests (QNAT), easier to implement and standardize. A large variety of QNAT are available from laboratory-developed assays to fully-automated commercial tests. The indications of CMV quantification include CMV infection during pregnancy and in newborns, and viral surveillance of grafted and non-grafted immunocompromised patients, patients with bowel inflammatory diseases and those hospitalised in intensive care unit. A close cooperation between virologists and clinicians is essential for optimizing the benefit of CMV DNA monitoring.

Clinical, biochemical, and neuroimaging findings predict long-term neurodevelopmental outcome in symptomatic congenital cytomegalovirus infection

OBJECTIVE

To evaluate clinical, biochemical, and neuroimaging findings as predictors of neurodevelopmental outcome in patients with symptomatic congenital cytomegalovirus (CMV).

STUDY DESIGN

The study cohort comprised 26 patients with symptomatic congenital CMV born between 1993 and 2009 in a single center. Absolute and weight deficit-adjusted head circumference were considered. Cerebrospinal fluid (CSF) investigations included standard cytochemical analysis, determination of beta2-microglobulin (β2-m), neuron-specific enolase, and CMV DNA detection. Neuroimaging was classified according to a validated scoring system comprising calcifications, ventriculomegaly, and atrophy, with findings graded from 0 to 3. Systematic long-term neurodevelopmental assessment included motor function, cognition, behavior, hearing, vision, and epilepsy. Sequelae were graded as mild/absent, moderate, or severe; adverse outcome was defined as death or moderate to severe disability.

RESULTS

Three children died. The mean age at follow-up of the survivors was 8.7 ± 5.3 years (range, 19 months to 18.0 years). Neonatal findings showing a significant association with adverse outcome were relative microcephaly, CSF β2-m concentrations, and grade 2-3 neuroimaging abnormalities (P < .05). Receiver operator characteristic curve analysis indicated that the most accurate single factor for predicting unfavorable outcome was CSF β2-m >7.9 mg/L (area under the curve, 0.84 ± 0.08; sensitivity, 69%; specificity, 100%). The combination of CSF β2-m >7.9 mg/L and moderate-severe neuroimaging alterations improved predictive ability (area under the curve, 0.92 ± 0.06; sensitivity, 87%; specificity, 100%).

CONCLUSION

Adjusted head circumference, CSF β2-m level, and neuroimaging studies have prognostic significance for neurodevelopmental outcome in newborns with congenital CMV. A combination of early findings improves the predictive value.

A series of 238 cytomegalovirus primary infections during pregnancy: description and outcome

OBJECTIVE

To analyze the outcome of maternal primary cytomegalovirus (CMV) infection.

METHODS

Retrospective analysis of a cohort of 238 patients with maternal primary CMV infection detected at routine screening. The cases were managed with serial ultrasound (US) scans, and amniocentesis was performed in 36.1% of cases. All prenatal results were confirmed at birth.

RESULTS

The average age was 31.9 (18-44) years. Patients were symptomatic in 21% of cases. The rate of intrauterine transmission was 24.9%, and it was 8.8%, 19%, 30.6%, 34.1% and 40% in the preconceptional period, the periconceptional period, and the first, second and third trimesters of pregnancy, respectively (p = 0.025). There was a significantly higher risk of US abnormalities when maternal infection occurred during the preconceptional or periconceptional period and the first trimester compared with later (p < 0.001). Because of US abnormalities, pregnancy was terminated in 18 cases at the parents' request. Three infected newborns were symptomatic; all three cases were suspected at US before birth. We did not observe any symptomatic fetal infection when maternal infection occurred after 14 weeks of gestation. A number of clinically asymptomatic cases (5.5%) developed hearing loss.

CONCLUSION

The rate of materno fetal transmission is linearly correlated to the gestational age at infection. No severe case of congenital infection was observed if maternal infection occurred after 14 weeks of gestation.

Management of pregnancies with confirmed cytomegalovirus fetal infection

Systematic screening for cytomegalovirus (CMV) maternal infection is not recommended in most countries. Nevertheless, primary CMV infection will occur in around 1% of women. The vertical transmission rate is estimated to be around 30-50%. Newborns with congenital CMV infection remain asymptomatic in the majority of cases and around 10% will present with a wide range of abnormalities. Fetal infection can be diagnosed by amniocentesis with amplification of the viral genome in the amniotic fluid by polymerase chain reaction. This prenatal diagnosis is mainly performed when ultrasound abnormalities are observed. The purpose of this mini-review is to describe the management options when a fetus is known to be infected.

Prevalence of cytomegalovirus DNA in cord blood and voided urine obtained from pregnant women at the end of pregnancy

OBJECTIVE

This study was undertaken to determine the prevalence of congenital cytomegalovirus (CMV) infection in pregnant women at the end of pregnancy in Kuwait using cord blood and maternal urine.

SUBJECTS AND METHODS

Urine samples were collected prior to childbirth, and cord blood was collected immediately after delivery from 983 women. Anti-CMV IgG and IgM antibodies were determined using ELISA; CMV DNA was detected using nested PCR, and viral load was calculated using real-time PCR. CMV concentration in samples was categorized as low when the viral load ≤10(3) copies/µl, intermediate when the viral load = 10(3)-10(4) copies/µl, and high when the viral load >10(4) copies/µl. The cord blood serology outcome was compared to cord blood PCR, cord blood viral load, maternal urine PCR and viral load analyses.

RESULTS

Serology showed that of the 983 cord blood samples, 89 (9%) were positive for anti-CMV IgM antibodies; PCR test showed 44 (4.5%) contained CMV DNA, and there was a high viral load in all. Maternal urine PCR showed that 9 (10.11%) women had CMV DNA, and there was a high viral load in 7 (78%). The kappa test for measures of agreement showed a reasonable agreement (0.45) between cord blood PCR and urine PCR.

CONCLUSION

This study showed that CMV infection in the cord blood sera of pregnant women is common in Kuwait and highlights the need for more clinically based studies to follow up newborns with congenital CMV infection.

[Congenital cytomegalovirus infection and cortical/subcortical malformations]

INTRODUCTION

Intrauterine infection due to cytomegalovirus is the most common of the intrauterine viral/parasitic infections that affect the central nervous system and cause permanent lesions in the cortex as well as the subcortical white matter. Studies using brain magnetic resonance imaging (MRI) are limited.

MATERIAL AND METHODS

Six patients (4 females and 2 males) were studied in the first months of life in order to make a diagnosis of congenital cytomegalovirus, and identify the cortical and subcortical lesions using the necessary MRI sequences.

RESULTS

The six patients showed malformations of cortical development (MDC) (schizencephaly, polymicrogyria or lissencephaly-pachygyria) from the neonatal period, and diffuse changes of the white matter, which remained with few changes during the first two years. They then began reducing in size in the form of high signal areas in T2, restricted to certain areas, and were evident for a few years more with little change.

CONCLUSION

Intrauterine infection due to cytomegalovirus causes changes in the cortical grey matter, which consists of MDC, and in the subcortical white matter. The latter show a changing aspect as they appear as diffuse and wide areas of high signal intensity, which is usually due to delay in myelinisation, but could also be caused directly by the cytomegalovirus. These changes in the white matter are subjected to morphological changes throughout the first years of life, leading to brain atrophy. The neurological sequelae of these lesions left by these alterations are severe and chronic.