Compartmentalized dynamics of cytomegalovirus replication in treated congenital infection

Maternal and congenital human cytomegalovirus infection: laboratory testing for detection and diagnosis

Human cytomegalovirus (CMV) is the leading cause of congenital infection worldwide and the most common cause of non-genetic sensorineural hearing loss. As there is no vaccine or other specific intervention to prevent congenital CMV infection, there is a need to identify maternal and congenital infections with sensitive and specific testing as early as possible. There is no widely accepted practice for screening during pregnancy or in all newborns for identification of possible cases of congenital CMV. Currently, screening during pregnancy is limited to those identified as at risk followed by fetal and/or neonatal testing when congenital infection is suspected. This review focuses primarily on the current status of laboratory testing for diagnosis of maternal and congenital CMV infections. Primary maternal infection is best diagnosed using serologic testing, including CMV IgM, IgG, and avidity testing, while fetal infection should be assessed by nucleic acid amplification testing (NAAT) of amniotic fluid. Urine and saliva NAATs are the mainstay for diagnosis of congenital CMV in the first 3 weeks of life. Testing of dried blood spots can be useful for diagnosis of congenital CMV outside of the newborn period. The gaps in knowledge such as the prognostic value of viral loads in various sample types are addressed.

Perinatal Cytomegalovirus Infection

PURPOSE OF REVIEW

There have been recent advances in the field of congenital CMV infection (cCMV) related to antiviral treatment of pregnant women and infants, the implementation of newborn CMV screening programs, and the frequency and diagnosis of complications among infected children. In addition, postnatal CMV infection (pCMV) is increasingly recognized as a potential cause of long-term sequelae in addition to acute complications among preterm infants, raising important questions related to treatment, and prevention.

RECENT FINDINGS

High-dose valacyclovir appears to be safe and effective for the prevention of cCMV among women with first-trimester primary CMV infection. New studies reveal high rates of vestibular dysfunction and neuropsychiatric manifestations among children with cCMV. Some studies report associations between pCMV and long-term consequences, including neurodevelopmental delay and bronchopulmonary dysplasia, among very low birth weight infants, in addition to high risk of sepsis and death acutely, which has motivated efforts to eliminate the virus from breast milk by different methods.

SUMMARY

More long-term complications of cCMV are increasingly recognized among children previously thought to be asymptomatic. Although a preventive CMV vaccine may be achievable, strategies to reduce the burden of cCMV disease include maternal education about risk-reduction behaviors, antiviral treatment of pregnant women with primary infection, and newborn screening to allow timely, appropriate care. Similarly, although it remains unclear if pCMV causes long-term problems, there is growing interest in identifying and preventing disease from CMV infections among preterm infants.

Virus-specific memory T cell responses unmasked by immune checkpoint blockade cause hepatitis

Treatment of advanced melanoma with combined PD-1/CTLA-4 blockade commonly causes serious immune-mediated complications. Here, we identify a subset of patients predisposed to immune checkpoint blockade-related hepatitis who are distinguished by chronic expansion of effector memory CD4⁺ T cells (T_EM cells). Pre-therapy CD4⁺ T_EM cell expansion occurs primarily during autumn or winter in patients with metastatic disease and high cytomegalovirus (CMV)-specific serum antibody titres. These clinical features implicate metastasis-dependent, compartmentalised CMV reactivation as the cause of CD4⁺ T_EM expansion. Pre-therapy CD4⁺ T_EM expansion predicts hepatitis in CMV-seropositive patients, opening possibilities for avoidance or prevention. 3 of 4 patients with pre-treatment CD4⁺ T_EM expansion who received αPD-1 monotherapy instead of αPD-1/αCTLA-4 therapy remained hepatitis-free. 4 of 4 patients with baseline CD4⁺ T_EM expansion given prophylactic valganciclovir and αPD-1/αCTLA-4 therapy remained hepatitis-free. Our findings exemplify how pathogen exposure can shape clinical reactions after cancer therapy and how this insight leads to therapeutic innovations.

Congenital Cytomegalovirus Infection: Update on Diagnosis and Treatment

Congenital cytomegalovirus (cCMV) infection is the most common congenital viral infection and is the leading non-genetic cause of sensorineural hearing loss (SNLH) and an important cause of neurodevelopmental disabilities. The risk of intrauterine transmission is highest when primary infection occurs during pregnancy, with a higher rate of vertical transmission in mothers with older gestational age at infection, while the risk of adverse fetal effects significantly increases if fetal infection occurs during the first half of pregnancy. Despite its prevalence and morbidity among the neonatal population, there is not yet a standardized diagnostic test and therapeutic approach for cCMV infection. This narrative review aims to explore the latest developments in the diagnosis and treatment of cCMV infection. Literature analysis shows that preventive interventions other than behavioral measures during pregnancy are still lacking, although many clinical trials are currently ongoing to formulate a vaccination for women before pregnancy. Currently, we recommend using a PCR assay in blood, urine, and saliva in neonates with suspected cCMV infection. At present, there is no evidence of the benefit of antiviral therapy in asymptomatic infants. In the case of symptomatic cCMV, we actually recommend treatment with oral valganciclovir for a duration of 12 months. The effectiveness and tolerability of this therapy option have proven effective for hearing and neurodevelopmental long-term outcomes. Valganciclovir is reserved for congenitally-infected neonates with the symptomatic disease at birth, such as microcephaly, intracranial calcifications, abnormal cerebrospinal fluid index, chorioretinitis, or sensorineural hearing loss. Treatment with antiviral drugs is not routinely recommended for neonates with the mildly symptomatic disease at birth, for neonates under 32 weeks of gestational age, or for infants more than 30 days old because of insufficient evidence from studies. However, since these populations represent the vast majority of neonates and infants with cCMV infection and they are at risk of developing late-onset sequelae, a biomarker able to predict long-term sequelae should also be found to justify starting treatment and reducing the burden of CMV-related complications.

Blood Viral Load in Symptomatic Congenital Cytomegalovirus Infection

BACKGROUND

Viral loads (VLs) frequently are followed during treatment of symptomatic congenital cytomegalovirus disease, but their predictive value is unclear.

METHODS

Post hoc analysis of 2 antiviral studies was performed. Seventy-three subjects were treated for 6 weeks and 47 subjects were treated for 6 months. Whole blood VL was determined by real-time polymerase chain reaction before and during therapy.

RESULTS

Higher baseline VL was associated with central nervous system involvement (3.82 log, range 1-5.65 vs 3.32 log, range 1-5.36; P = .001), thrombocytopenia (3.68 log, range 1-5.65 vs 3.43 log, range 1-5.36; P = .03), and transaminitis at presentation (3.73 log, range 1-5.60 vs 3.39 log, range 1-5.65; P = .009), but with overlap in the amount of virus detected between groups. In subjects treated for 6 months, lower VL at presentation correlated with better hearing outcomes at 12 months, but VL breakpoints predictive of hearing loss were not identified. Sustained viral suppression during 6 months of therapy correlated with better hearing outcomes at 6, 12, and 24 months (P = .01, P = .0007, P = .04), but a majority without viral suppression still had improved hearing.

CONCLUSIONS

In infants with symptomatic congenital cytomegalovirus disease, higher whole blood VL before initiation of antiviral therapy has no clinically meaningful predictive value for long-term outcomes.

Congenital Cytomegalovirus Infection: A Narrative Review of the Issues in Screening and Management From a Panel of European Experts

Maternal primary and non-primary cytomegalovirus (CMV) infection during pregnancy can result in in utero transmission to the developing fetus. Congenital CMV (cCMV) can result in significant morbidity, mortality or long-term sequelae, including sensorineural hearing loss, the most common sequela. As a leading cause of congenital infections worldwide, cCMV infection meets many of the criteria for screening. However, currently there are no universal programs that offer maternal or neonatal screening to identify infected mothers and infants, no vaccines to prevent infection, and no efficacious and safe therapies available for the treatment of maternal or fetal CMV infection. Data has shown that there are several maternal and neonatal screening strategies, and diagnostic methodologies, that allow the identification of those at risk of developing sequelae and adequately detect cCMV. Nevertheless, many questions remain unanswered in this field. Well-designed clinical trials to address several facets of CMV treatment (in pregnant women, CMV-infected fetuses and both symptomatic and asymptomatic neonates and children) are required. Prevention (vaccines), biology and transmission factors associated with non-primary CMV, and the cost-effectiveness of universal screening, all demand further exploration to fully realize the ultimate goal of preventing cCMV. In the meantime, prevention of primary infection during pregnancy should be championed to all by means of hygiene education.

Viral Loads in Congenital Cytomegalovirus Infection From a Highly Immune Population

Among newborns with congenital cytomegalovirus (CMV) infection from China, there was no difference in CMV viral load in saliva specimens dried and stored at room temperature compared with those kept wet and stored cold, even after longer storage time for the former than the later (74 vs 58 days, P = .02).