Congenital Cytomegalovirus Infection in Children with Autism Spectrum Disorder: Systematic Review and Meta-Analysis

Well controlled maternal inflammatory bowel disease does not increase the risk of abnormal neurocognitive outcome screening in offspring

Background

Exposure to maternal inflammation is associated with an increased risk of neurocognitive and developmental disorders in offspring. Early diagnosis and intervention improves childhood motor and cognitive functioning. Neonatal cerebral MRI and remote app-based generalised movement assessments (GMAs) are both predictive of adverse neurocognitive outcomes but have only been used in infants at significantly increased risk for these outcomes, rather than following in utero exposure to maternal inflammatory disorders.

Methods

Pregnant women with inflammatory bowel disease were assessed clinically and biochemically in each trimester of pregnancy in this single centre prospective study. Neonatal cerebral MRIs were performed at 6-12 weeks post-corrected term. Two GMA videos were filmed using the 'BabyMoves' app from 12 to 16 weeks of age. MRIs and GMAs were assessed by a blinded highly qualified practitioner using validated scoring systems.

Results

40/53 of invited maternal-infant dyads were recruited. C-reactive protein was elevated antenatally in less than 13%. 5/37 neonatal MRIs had incidental or obstetric trauma related gross anatomical abnormalities, with none abnormal on validated gross abnormality scoring. 3/35 GMAs were abnormal, with one GMA abnormality being clinically significant. Of those with abnormal GMAs, 2/3 were in exposed to severely active IBD in-utero.

Conclusion

Neonatal cerebral MRI and GMA for neurocognitive screening is feasible in the setting of maternal inflammatory bowel disease, where the risk of cerebral palsy is poorly defined and thus burdensome screening interventions are less appealing to parents. Larger studies are required to stratify adverse neurocognitive outcome risk in infants born to women with maternal inflammatory disorders, but these data are reassuring for women with IBD in remission antenatally.

Genetic causal relationship between placental weight and autism spectrum disorder: A two-sample Mendelian randomization study

OBJECT

Previous research has suggested an association between placental tissue abnormalities and the diagnosis of autism spectrum disorder. This study aims to explore the causal relationship between placental weight and autism spectrum disorder.

METHODS

This study employed Mendelian randomization analysis to investigate the potential causal relationship between placental weight and autism spectrum disorder. The study design involved two sample populations, with data for the exposed population sourced from previous studies focusing on PW, and data for the outcome population obtained from the Integrative Psychiatric Research and the Psychiatric Genomics Consortium study. To ensure the robustness of the results, three sensitivity analyses were performed, including heterogeneity testing, pleiotropy testing, and a leave-one-out analysis. The inverse variance weighted method served as the gold standard for the Mendelian randomization analysis.

RESULTS

The results of the first analysis revealed a significant correlation between an increase in placental weight and an elevated risk of autism spectrum disorder (p = 0.02). Sensitivity analysis detected heterogeneity and outliers. After removing two outlier SNPs in the second round of analysis, the results still supported a genetic causal relationship between placental weight and autism spectrum disorder (p = 0.01). The second-round sensitivity analysis did not reveal any heterogeneity or outliers.

CONCLUSION

Our study provides compelling evidence supporting a causal relationship between elevated placental weight and increased risk of autism spectrum disorder. These findings underscore the significance of placental development in the etiology of autism spectrum disorder and propose a potential early predictive indicator for autism spectrum disorder.

Autism Spectrum Disorder Diagnoses and Congenital Cytomegalovirus

OBJECTIVE

To examine the association between congenital cytomegalovirus (cCMV) and autism spectrum disorder (ASD) administrative diagnoses in US children.

METHODS

Cohort study using 2014 to 2020 Medicaid claims data. We used diagnosis codes to identify cCMV (exposure), ASD (outcome), and covariates among children enrolled from birth through ≥4 to <7 years. Covariates include central nervous system (CNS) anomaly or injury diagnosis codes, including brain anomaly, microcephaly within 45 days of birth, cerebral palsy, epilepsy, or chorioretinitis. We used Cox proportional hazards regression models to estimate hazard ratios and 95% confidence intervals, overall and stratified by sex, birth weight and gestational age outcome (low birth weight or preterm birth), and presence of CNS anomaly or injury.

RESULTS

Among 2 989 659 children, we identified 1044 (3.5 per 10 000) children with cCMV and 74 872 (25.0 per 1000) children with ASD. Of those with cCMV, 49% also had CNS anomaly or injury diagnosis codes. Children with cCMV were more likely to have ASD diagnoses (hazard ratio: 2.5; 95% confidence interval: 2.0-3.2, adjusting for birth year, sex, and region). This association differed by sex and absence of CNS anomaly or injury but not birth outcome.

CONCLUSIONS

Children with (versus without) cCMV diagnoses in Medicaid claims data, most of whom likely had symptomatic cCMV, were more likely to have ASD diagnoses. Future research investigating ASD risk among cohorts identified through universal cCMV screening may help elucidate these observed associations.

Neurobehavioral outcomes of neonatal asymptomatic congenital cytomegalovirus infection at 12-months

BACKGROUND

Congenital cytomegalovirus (cCMV) is the most common congenital viral infection in the United States. Symptomatic infections can cause severe hearing loss and neurological disability, although ~ 90% of cCMV infections are asymptomatic at birth. Despite its prevalence, the long-term neurobehavioral risks of asymptomatic cCMV infections are not fully understood. The objective of this work was to evaluate for potential long-term neurobehavioral sequelae in infants with asymptomatic cCMV.

METHODS

Infants with cCMV were identified from a universal newborn cCMV screening study in a metropolitan area in the midwestern United States. Asymptomatic infants with cCMV were enrolled in a longitudinal neurodevelopmental study (N = 29). Age- and sex-matched healthy control infants (N = 193) were identified from the Baby Connectome Project (BCP), a longitudinal study of brain and behavioral development. The BCP sample supplemented an additional group of healthy control infants (N = 30), recruited from the same participant registry as the BCP specifically for comparison with infants with asymptomatic cCMV. Neurobehavioral assessments and parent questionnaires, including the Mullen Scales of Early Learning, the Repetitive Behavior Scales for Early Childhood (RBS-EC), and the Infant Toddler Social Emotional Assessment (ITSEA) were administered at 12 months of age. Neurobehavioral scores were compared between infants with asymptomatic cCMV and all identified healthy control infants.

RESULTS

Infants with asymptomatic cCMV performed equivalently compared to healthy control infants on the neurobehavioral measures tested at 12 months of age.

CONCLUSIONS

These results indicate that at 12 months of age, infants with asymptomatic cCMV are not statistically different from controls in a number of neurobehavioral domains. Although follow-up is ongoing, these observations provide reassurance about neurobehavioral outcomes for infants with asymptomatic cCMV and inform the ongoing discussion around universal screening. Additional follow-up will be necessary to understand the longer-term outcomes of these children.

Neurodevelopmental outcomes of children with congenital cytomegalovirus: a systematic scoping review

BACKGROUND

With the emergence of newborn congenital cytomegalovirus (cCMV) screening programs, more infants are being diagnosed and require long-term follow-up. The objective of the study was to summarize the literature to date on neurodevelopmental outcomes in children with cCMV with attention to study-specific definitions of disease severity (symptomatic vs. asymptomatic).

METHODS

This systematic scoping review included studies of children with cCMV (≤18 years-old) measuring neurodevelopment in ≥1 domain: global, gross motor, fine motor, speech/language, and intellectual/cognitive. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. PubMed, PsychInfo, and Embase databases were searched.

RESULTS

33 studies met inclusion criteria. Global development most frequently measured (n = 21), followed by cognitive/intellectual (n = 16) and speech/language (n = 8). Most (31/33) studies differentiated children by cCMV severity (symptomatic vs. asymptomatic), definitions of which ranged broadly. 15/21 studies described global development categorically (e.g., normal vs. abnormal). Across studies and domains, children with cCMV generally had equivalent or lower scores (vs. controls or normed measures).

CONCLUSIONS

Variation in definitions of cCMV severity and blunt categorical outcomes may limit the generalizability of findings. Future studies should utilize standardized definitions of disease severity and in-depth measurement and reporting of neurodevelopmental outcomes in children with cCMV.

IMPACT

Neurodevelopmental delays are common among children with cCMV, although gaps in the literature to have made quantification of such delays challenging. Variation in definitions of asymptomatic and symptomatic cCMV as well as the use of categorical outcomes of neurodevelopment (e.g., normal vs. abnormal) limits the generalizability and clinical utility of findings.

The early life exposome and autism risk: a role for the maternal microbiome?

Autism spectrum disorders (ASD) are highly heritable, heterogeneous neurodevelopmental disorders characterized by clinical presentation of atypical social, communicative, and repetitive behaviors. Over the past 25 years, hundreds of ASD risk genes have been identified. Many converge on key molecular pathways, from translational control to those regulating synaptic structure and function. Despite these advances, therapeutic approaches remain elusive. Emerging data unearthing the relationship between genetics, microbes, and immunity in ASD suggest an integrative physiology approach could be paramount to delivering therapeutic breakthroughs. Indeed, the advent of large-scale multi-OMIC data acquisition, analysis, and interpretation is yielding an increasingly mechanistic understanding of ASD and underlying risk factors, revealing how genetic susceptibility interacts with microbial genetics, metabolism, epigenetic (re)programming, and immunity to influence neurodevelopment and behavioral outcomes. It is now possible to foresee exciting advancements in the treatment of some forms of ASD that could markedly improve quality of life and productivity for autistic individuals. Here, we highlight recent work revealing how gene X maternal exposome interactions influence risk for ASD, with emphasis on the intrauterine environment and fetal neurodevelopment, host-microbe interactions, and the evolving therapeutic landscape for ASD.

Association between Autism Spectrum Disorder (ASD) and vision problems. A systematic review and meta-analysis

AIM

To conduct a systematic review and meta-analysis assessing whether vision and/or eye disorders are associated with Autism Spectrum Disorder (ASD).

METHOD

Based on a pre-registered protocol (PROSPERO: CRD42022328485), we searched PubMed, Web of Knowledge/Science, Ovid Medline, Embase and APA PsycINFO up to 5th February 2022, with no language/type of document restrictions. We included observational studies 1) reporting at least one measure of vision in people of any age with a diagnosis of ASD based on DSM or ICD criteria, or ADOS; or 2) reporting the prevalence of ASD in people with and without vision disorders. Study quality was assessed with the Appraisal tool for Cross-Sectional Studies (AXIS). Random-effects meta-analyses were used for data synthesis.

RESULTS

We included 49 studies in the narrative synthesis and 46 studies in the meta-analyses (15,629,159 individuals distributed across multiple different measures). We found meta-analytic evidence of increased prevalence of strabismus (OR = 4.72 [95% CI: 4.60, 4.85]) in people with versus those without ASD (non-significant heterogeneity: Q = 1.0545, p = 0.7881). We also found evidence of increased accommodation deficits (Hedge's g = 0.68 [CI: 0.28, 1.08]) (non-significant heterogeneity: Q = 6.9331, p = 0.0741), reduced peripheral vision (-0.82 [CI: -1.32, -0.33]) (non-significant heterogeneity: Q = 4.8075, p = 0.4398), reduced stereoacuity (0.73 [CI: -1.14, -0.31]) (non-significant heterogeneity: Q = 0.8974, p = 0.3435), increased color discrimination difficulties (0.69 [CI: 0.27,1.10]) (non-significant heterogeneity: Q = 9.9928, p = 0.1890), reduced contrast sensitivity (0.45 [CI: -0.60, -0.30]) (non-significant heterogeneity: Q = 9.9928, p = 0.1890) and increased retinal thickness (=0.29 [CI: 0.07, 0.51]) (non-significant heterogeneity: Q = 0.8113, p = 0.9918) in ASD.

DISCUSSION

ASD is associated with some self-reported and objectively measured functional vision problems, and structural alterations of the eye, even though we observed several methodological limitations in the individual studies included in our meta-analyses. Further research should clarify the causal relationship, if any, between ASD and problems of vision during early life.

PROSPERO REGISTRATION

CRD42022328485.

Congenital cytomegalovirus infection: the state of the art and future perspectives

Congenital cytomegalovirus (cCMV) infection is the most common congenital infection, with an estimated incidence of approximately one in 200 infants in high-income settings. Approximately one in four children may experience life-long consequences, including sensorineural hearing loss and neurodisability. Knowledge regarding prevention, diagnosis, and treatment increased in the recent years, but some challenges remain. In this review, we tried to summarize the current knowledge on both the obstetrical and pediatric areas, while also highlighting controversial aspects and future perspectives. There is a need to enhance awareness among the general population and pregnant women through specific information programs. Further research is needed to better define the classification of individuals at birth and to have a deeper understanding of the long-term outcomes for so defined children. Finally, the availability of valaciclovir medication throughout pregnancy, where appropriate, has prompted the assessment of a universal serological antenatal screening. It is recommended to establish a dedicated unit for better evaluation and management of both mothers and children.

Two-sample Mendelian randomization study does not reveal a significant relationship between cytomegalovirus (CMV) infection and autism spectrum disorder

BACKGROUND

Autism spectrum disorder (ASD) is a neurodevelopmental disorder affecting ~ 2% of children worldwide and is characterized by repetitive, stereotypical behaviours and impaired expressive communication. Cytomegalovirus (CMV) is considered a risk factor for ASD; however, published studies are usually limited by covering too few events and have different conclusions, indicating that the relationship between CMV infection and ASD remains elusive.

METHODS

To investigate the association between CMV infection and ASD, we conducted this 2-sample Mendelian randomization (MR) study using genome-wide association studies (GWAS) summary data from FinnGen and the IEU Open GWAS project.

RESULTS

Our results showed no significant relationship between all 3 CMV infections (unspecified cytomegaloviral diseases, anti-CMV IgG levels, and maternal CMV) and ASD.

CONCLUSIONS

Our results indicate that CMV infection does not significantly increase ASD risk. These results show that the relationship between CMV infection and ASD remains elusive and needs to be further clarified.

Neurodevelopmental outcome in children with congenital cytomegalovirus infection: A prospective multicenter cohort study

BACKGROUND

Congenital cytomegalovirus infection (cCMV) is the most common congenital infection worldwide and is a major cause of neurodevelopmental impairment in children. At this point there are insufficient data on neurodevelopmental outcome of children with cCMV, both symptomatic and asymptomatic.

AIM

This study aimed to describe the neurodevelopmental outcome in a large prospective cohort of children with cCMV.

METHODS

All children with cCMV, included in the Flemish cCMV register, were eligible for this study. Data on neurodevelopmental outcome was available in 753 children. Data on neuromotor, cognitive, behavioral, audiological and ophthalmological outcome were analyzed.

RESULTS

Neurodevelopmental outcome was normal in 530/753 (70,4 %) at any age of last follow-up. Mild, moderate and severe neurodevelopmental impairment was found in 128/753 (16,9 %), 56/753 (7,4 %) and 39/753 (5,2 %), respectively. Adverse outcome is found both in the symptomatic and asymptomatic children (53,5 % versus 17,8 %). Autism spectrum disorder (ASD) was diagnosed more often than in the general population in Flanders (2,5 % versus 0,7 %). Speech and language impairment was found in 2 %, even in absence of hearing loss.

CONCLUSION

Both symptomatic and asymptomatic cCMV children are at risk of sequelae, with higher risk in case of first trimester infection. During follow-up of this population, special attention should be given to the audiological follow-up, the presence of hypotonia at young age, the possible higher risk of ASD and the risk of speech and language impairment even in absence of hearing loss. Our results emphasize the need for multidisciplinary neurodevelopmental follow-up of all cCMV infected children.

Toxoplasmosis and cytomegalovirus infection and their role in Egyptian autistic children

Autism is a neurodevelopmental disorder with a significantly increased incidence rate across the world over the past few years. Toxoplasmosis and cytomegalovirus (CMV) infection are globally prevalent and have been associated with diverse neurological and psychiatric disorders. A few studies have demonstrated the role of toxoplasmosis and CMV as potential etiological factors for autism. Accordingly, this study was performed to estimate the relationship between toxoplasmosis and CMV infection in children with autism as well as to assess their impact on the Childhood Autism Rating Scale (CARS) score. A total of 45 autistic children (6 girls, 39 boys) and 45 (21 girls, 24 boys) healthy control children were enrolled in our study. Their blood samples were collected and tested for the presence of Toxoplasma and CMV (IgG and IgM) antibodies and DNA by ELISA and real-time PCR (RT-PCR), respectively. Toxoplasmosis was detected in 11 (24.4%) autistic children through the ELISA [10 (22.2%) IgG + /IgM - and 1 (2.2%) IgG + /IgM +]; however, RT-PCR assay recorded only 1 positive case (2.2%), while it was detected in 10 (22.2%) control children through ELISA [9 (20%) IgG + /IgM - and 1 (2.2%) IgG + /IgM +] and 1 (2.2%) by RT-PCR. On the other hand, CMV infection was detected in all autistic children with 44 (97.8%) testing positive by ELISA [24 (53.3%) IgG + /IgM - , 18 (40%) IgG + /IgM + and 2 (4.4%) IgG - /IgM +] and 25 (55.6%) testing positive by RT-PCR assay. In addition, ELISA assay recorded 43 (95.6%) [19 (42.2%) IgG + /IgM + and 22 (48.9%) IgG + /IgM - and 2 (4.4%) IgG-/IgM +] and RT-PCR recorded 21 (46.7%) positive samples in control children with CMV. No significant difference was noted between autistic and control children for the overall prevalence of Toxoplasma or/and CMV infection. Similarly, the CARS score indicated a non-significant difference with Toxoplasma or/and CMV infection. Our data does not show an association between autism and toxoplasmosis or/and CMV infection. Nevertheless, considering that autistic children are at a high risk of contracting these infections, further studies with a larger sample size are recommended.

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.

The myth of vaccination and autism spectrum

BACKGROUND

Among all of the studied potential causes of autism, vaccines have received some of the most scrutiny and have been the topic of many evidence-based studies. These efforts have led the great majority of scientists, physicians, and public health researchers to refute causation between vaccines and autism.

RATIONALE

This presumed association and concern has been a major contributor to parents' refusal to immunize their children and has become a major threat to public health in secluded populations over the last two decades, even prior to the COVID-19 pandemic. With the emergence of COVID-19 immunizations, sentiments towards this topic were addressed as a public health concern that may influence the ability to overcome the Corona virus worldwide.

SCIENTIFIC REVIEW OF DATA

Despite the overwhelming data demonstrating that there is no link between vaccines and autism, many parents are hesitant to immunize their children because of the alleged association. Other contributing factors to the myths and conspiracy theories surrounding the association between vaccines and autism include the fact that the diagnosis of autism is typically made after the age of receiving the main childhood immunizations, as well as the occasional occurrence of regression after the age of first year vaccinations. In spite of vast evidence that the main contribution to the increase in incidence is from improvement of the diagnostic process, this rapid and publicized rise in autism diagnoses feeds parental concerns regarding any medical intervention that may be associated with the health of their children.

RECOMMENDATIONS

It is plausible that with more evidence-based studies linking autism to specific etiologies the myth will diminish and disappear eventually. In an era where conspiracy theories are prevalent on social media, it is critical that evidence-based studies relating autism to specific etiologies be made public, and that information concerning autism diagnosis and causes be made more readily available through social media and parental organizations.

Cytomegalovirus Infection in Infancy May Increase the Risk of Subsequent Epilepsy and Autism Spectrum Disorder in Childhood

Cytomegalovirus (CMV) is a ubiquitous virus, and CMV-associated diseases range from mild illness in immunologically normal hosts to life-threatening diseases in newborns and immunocompromised children. This study investigated the association between childhood CMV infection and subsequent epilepsy or neurodevelopmental disorders, attention deficit hyperactivity disorder (ADHD), and autism spectrum disorder (ASD). A retrospective analysis was performed on data for 69 children with confirmed CMV infections (CMV infection group) and 292 patients with other infections (control group) between 1 January 2006 to 31 December 2012. The results indicated that the CMV infection group had a higher risk of epilepsy in comparison to the control (odds ratio (OR), 16.4; 95% CI (confidence interval), 3.32–80.7; p = 0.001). Epilepsy risk increased in younger children (age 0–2) with CMV infection when compared to the control group (OR, 32.6; 95% CI, 3.84–276; p = 0.001). The ASD risk was also determined to be higher in the CMV infection group (OR, 17.9; 95% CI, 1.96–162; p = 0.01). The ADHD risk between the groups was not significant. This study suggests that CMV infection in infancy may increase the risk of subsequent epilepsy and ASD, especially in infants younger than 2 years, but is not associated with ADHD.

The Association Between Serum Vitamin D3 Levels and Autism Among Jordanian Boys

This study assesses the correlation between vitamin-D deficiency and autism spectrum disorder (ASD) in Jordan. We performed a case-controlled cross-sectional analysis to assess vitamin D levels in 83 children with ASD aged less than 8 years old compared to 106 healthy controls. In addition, the association between vitamin D deficiencies and gastrointestinal (GI) complains and electroencephalogram (EEG) abnormalities commonly found in children with ASD was investigated. Vitamin D levels in ASD patients were significantly lower. Also, Vitamin D levels in ASD patients had significant correlation with GI complains, but no correlation between vitamin D levels and Ca²⁺or EEG abnormalities was detected. These data suggest a possible role for vitamin D deficiency in the pathophysiology of ASD.

Autism spectrum disorders and natural killer cells: a review on pathogenesis and treatment

Introduction: Autism spectrum disorder (ASD), as a wide spectrum of neurodevelopmental disorders, is characterized by early-onset impairments in social-communication, repetitive behaviors, and restrictive interests.Areas covered: Although still unknown, there are some pieces of evidence suggesting altered immune function in the etiology of ASD. This review aims to summarize studies linking Natural Killer (NK) cells to ASD by searching through databases like MEDLINE and Scopus up to October 2020. NK cells play important roles in the innate immune system and immune regulation. As parts of the immune system, they interact with the neural system as well. Immune dysregulations such as autoimmunity and improper immune responses to both internal and external stimulations, especially in early developmental stages of the brain, may induce neurodevelopmental disorders. NK cells' dysfunction in children with ASD as well as their parents have been highlighted in many studies.Expert opinion: Changes in the frequency, gene expressions, cytotoxicity features, and receptors of NK cells are reported in children with ASD. Immune therapy for children with ASD with immune abnormality has shown promising results. However, further studies are needed to elucidate the exact role of NK cells in the pathogenesis of ASD providing future treatment options for these children.

Cytomegalovirus infection during pregnancy: state of the science

Cytomegalovirus is the most common congenital infection, affecting 0.5-2% of all live births and the main nongenetic cause of congenital sensorineural hearing loss and neurological damage. Congenital cytomegalovirus can follow maternal primary infection or nonprimary infection. Sensorineurological morbidity is confined to the first trimester with up to 40-50% of infected neonates developing sequelae after first-trimester primary infection. Serological testing before 14 weeks is critical to identify primary infection within 3 months around conception but is not informative in women already immune before pregnancy. In Europe and the United States, primary infection in the first trimester are mainly seen in young parous women with a previous child younger than 3 years. Congenital cytomegalovirus should be evoked on prenatal ultrasound when the fetus is small for gestation and shows echogenic bowel, effusions, or any cerebral anomaly. Although the sensitivity of routine ultrasound in predicting neonatal symptoms is around 25%, serial targeted ultrasound and magnetic resonance imaging of known infected fetuses show greater than 95% sensitivity for brain anomalies. Fetal diagnosis is done by amniocentesis from 17 weeks. Prevention consists of both parents avoiding contact with body fluids from infected individuals, especially toddlers, from before conception until 14 weeks. Candidate vaccines failed to provide more than 75% protection for >2 years in preventing cytomegalovirus infection. Medical therapies such as cytomegalovirus hyperimmune globulins aim to reduce the risk of vertical transmission but 2 randomized controlled trials have not found any benefit. Valaciclovir given from the diagnosis of primary infection up to amniocentesis decreased vertical transmission rates from 29.8% to 11.1% in the treatment group in a randomized controlled trial of 90 pregnant women. In a phase II open-label trial, oral valaciclovir (8 g/d) given to pregnant women with a mildly symptomatic fetus was associated with a higher chance of delivering an asymptomatic neonate (82%), compared with an untreated historical cohort (43%). Valganciclovir given to symptomatic neonates is likely to improve hearing and neurological symptoms, the extent of which and the duration of treatment are still debated. In conclusion, congenital cytomegalovirus infection is a public health challenge. In view of recent knowledge on diagnosis and pre- and postnatal management, health care providers should reevaluate screening programs in early pregnancy and at birth.

[Immunopsychiatry and SARS-CoV-2 pandemic: Links and possible consequences]

OBJECTIVE

The SARS-CoV-2 (or COVID-19) pandemic has been propagating since December 2019, inducing a drastic increase in the prevalence of anxious and depressive disorders in the general population. Psychological trauma can partly explain these disorders. However, since psychiatric disorders also have an immuno-inflammatory component, the direct effects of the virus on the host's immune system, with a marked inflammatory response, but also the secondary inflammation to these psychosocial stressors, may cause the apparition or the worsening of psychiatric disorders. We describe here the probable immunopsychiatric consequences of the SARS-CoV-2 pandemic, to delineate possible screening actions and care that could be planned.

METHOD

Data from previous pandemics, and existing data on the psychopathological consequences of the SARS-CoV-2 pandemic, allowed us to review the possible immunopsychiatric consequences of the SARS-CoV-2 pandemic, on the gestational environment, with the risk of consecutive neurodevelopmental disorders for the fetus on one hand, on the children and adults directly infected being at increased risks of psychiatric disorders on the other hand.

RESULTS

As in previous pandemics, the activation of the immune system due to psychological stress and/or to infection during pregnancy, might lead to an increased risk of neurodevelopmental disorders for the fetus (schizophrenia and autism spectrum disorders). Furthermore, in individuals exposed to psychological trauma and/or infected by the virus, the risk of psychiatric disorders, especially mood disorders, is probably increased.

CONCLUSION

In this context, preventive measures and specialized care are necessary. Thus, it is important to propose a close follow-up to the individuals who have been infected by the virus, in order to set up the earliest care possible. Likewise, in pregnant women, screening of mood disorders during the pregnancy or the postpartum period must be facilitated. The follow-up of the babies born during the pandemic must be strengthened to screen and care for possible neurodevelopmental disorders.

Bridging the Gap Between Physical Health and Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a highly complex and heterogeneous developmental disorder that affects how individuals communicate with other people and relate to the world around them. Research and clinical focus on the behavioural and cognitive manifestations of ASD, whilst important, have obscured the recognition that ASD is also commonly associated with a range of physical and mental health conditions. Many physical conditions appear with greater frequency in individuals with ASD compared to non-ASD populations. These can contribute to a worsening of social communication and behaviour, lower quality of life, higher morbidity and premature mortality. We highlight some of the key physical comorbidities affecting the immune and the gastrointestinal systems, metabolism and brain function in ASD. We discuss how healthcare professionals working with individuals with ASD and parents/carers have a duty to recognise their needs in order to improve their overall health and wellbeing, deliver equality in their healthcare experiences and reduce the likelihood of morbidity and early mortality associated with the condition.

Transcriptome signatures from discordant sibling pairs reveal changes in peripheral blood immune cell composition in Autism Spectrum Disorder

Notwithstanding several research efforts in the past years, robust and replicable molecular signatures for autism spectrum disorders from peripheral blood remain elusive. The available literature on blood transcriptome in ASD suggests that through accurate experimental design it is possible to extract important information on the disease pathophysiology at the peripheral level. Here we exploit the availability of a resource for molecular biomarkers in ASD, the Italian Autism Network (ITAN) collection, for the investigation of transcriptomic signatures in ASD based on a discordant sibling pair design. Whole blood samples from 75 discordant sibling pairs selected from the ITAN network where submitted to RNASeq analysis and data analyzed by complementary approaches. Overall, differences in gene expression between affected and unaffected siblings were small. In order to assess the contribution of differences in the relative proportion of blood cells between discordant siblings, we have applied two different cell deconvolution algorithms, showing that the observed molecular signatures mainly reflect changes in peripheral blood immune cell composition, in particular NK cells. The results obtained by the cell deconvolution approach are supported by the analysis performed by WGCNA. Our report describes the largest differential gene expression profiling in peripheral blood of ASD subjects and controls conducted by RNASeq. The observed signatures are consistent with the hypothesis of immune alterations in autism and an increased risk of developing autism in subjects exposed to prenatal infections or stress. Our study also points to a potential role of NMUR1, HMGB3, and PTPRN2 in ASD.

Outcome and management of newborns with congenital cytomegalovirus infection

Congenital cytomegalovirus (CMV) infection is the most common non-genetic cause of hearing loss and neurological disorder in children. Its overall prevalence is approximately 0.5% in Europe. In France, systematic screening during pregnancy is not recommended; screening is performed only if there are maternal or fetal symptoms suggestive of this infection. Approximately 90% of infected newborns are asymptomatic at birth, and among them the risk of neurosensory sequelae is 5-15%. By contrast, the prevalence of neurosensory impairment in symptomatic newborns at birth varies from 17% to 60%. Congenital CMV infection must be confirmed at birth before the 21st day of life by polymerase chain reaction (PCR) on saliva or urine samples. A complete clinical examination, blood tests (blood count, liver function test, CMV PCR), hearing tests, brain ultrasound and eye fundus examination should be performed. Neurological and auditory follow-up must be extended well beyond the neonatal period because the occurrence of neurosensory sequelae may be delayed. Oral valganciclovir is the recommended treatment in moderate or severe congenital CMV infections for a period of 6 weeks to 6 months; such treatment requires regular monitoring because of its possible side effects.

Congenital human cytomegalovirus infection and neurologic diseases in newborns

Objective:

This review aimed to summarize research progress regarding congenital cytomegalovirus (cCMV) infection-related nervous system diseases and their mechanisms.

Data sources:

All literature quoted in this review was retrieved from PubMed and Web of Science using the keywords “Cytomegalovirus” and “Neurologic disease” in English. To identify more important information, we did not set time limits.

Study selection:

Relevant articles were selected by carefully reading the titles and abstracts. Then, different diagnosis and clinical treatment methods for human CMV infection-related neurologic diseases were compared, and the main mechanism and pathogenesis of neurologic damage caused by CMV were summarized from the selected published articles.

Results:

cCMV infection is a major cause of neonatal malformation. cCMV can infect the fetal encephalon during early gestation and compromise neurodevelopment, resulting in varying degrees of neurologic damage, mainly including hearing impairment, central nervous system (CNS) infection, neurodevelopmental disorders, ophthalmic complications, cerebral neoplasms, infantile autism, epilepsy, and other neurologic abnormalities.

Conclusions:

cCMV infection-induced neurodevelopmental abnormalities, which were directly caused by fetal encephalon infection, thus inducing neuroimmune responses to damage nerve cells. Such abnormalities were also caused by suppression of the proliferation and differentiation of neural progenitor cells by CMV's gene products. cCMV infection in the fetal encephalon can also inhibit neuronal migration and synapse formation and indirectly trigger placental inflammation and thus disrupt the oxygen supply to the fetus.

Overview and Introduction to Autism Spectrum Disorder (ASD)

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder generally manifesting in the first few years of life and tending to persist into adolescence and adulthood. It is characterized by deficits in communication and social interaction and restricted, repetitive patterns of behavior, interests, and activities. It is a disorder with multifactorial etiology. In this chapter, we will focus on the most important and common epidemiological studies, pathogenesis, screening, and diagnostic tools along with an explication of genetic testing in ASD.

Endogenous Retroviruses Activity as a Molecular Signature of Neurodevelopmental Disorders

Human endogenous retroviruses (HERVs) are genetic elements resulting from relics of ancestral infection of germline cells, now recognized as cofactors in the etiology of several complex diseases. Here we present a review of findings supporting the role of the abnormal HERVs activity in neurodevelopmental disorders. The derailment of brain development underlies numerous neuropsychiatric conditions, likely starting during prenatal life and carrying on during subsequent maturation of the brain. Autism spectrum disorders, attention deficit hyperactivity disorders, and schizophrenia are neurodevelopmental disorders that arise clinically during early childhood or adolescence, currently attributed to the interplay among genetic vulnerability, environmental risk factors, and maternal immune activation. The role of HERVs in human embryogenesis, their intrinsic responsiveness to external stimuli, and the interaction with the immune system support the involvement of HERVs in the derailed neurodevelopmental process. Although definitive proofs that HERVs are involved in neurobehavioral alterations are still lacking, both preclinical models and human studies indicate that the abnormal expression of ERVs could represent a neurodevelopmental disorders-associated biological trait in affected individuals and their parents.

Environmental risk factors and biomarkers for autism spectrum disorder: an umbrella review of the evidence

BACKGROUND

Numerous studies have identified potential risk factors and biomarkers for autism spectrum disorder. We aimed to study the strength and validity of the suggested environmental risk factors or biomarkers of autism spectrum disorder.

METHODS

We did an umbrella review and systematically appraised the relevant meta-analyses of observational studies. We searched PubMed, Embase, and the Cochrane Database of Systematic Reviews for papers published between database inception and Oct 17, 2018, and screened the reference list of relevant articles. We obtained the summary effect, 95% CI, heterogeneity, and 95% prediction intervals. We examined small study effects and excess significance. We did analyses under credibility ceilings. This review is registered with PROSPERO, number CRD42018091704.

FINDINGS

46 eligible articles yielded data on 67 environmental risk factors (544 212 cases, 81 708 787 individuals) and 52 biomarkers (15 614 cases, 15 433 controls). Evidence of association was convincing for maternal age of 35 years or over (relative risk [RR] 1·31, 95% CI 1·18-1·45), maternal chronic hypertension (odds ratio [OR] 1·48, 1·29-1·70), maternal gestational hypertension (OR 1·37, 1·21-1·54), maternal overweight before or during pregnancy (RR 1·28, 1·19-1·36), pre-eclampsia (RR 1·32, 1·20-1·45), prepregnancy maternal antidepressant use (RR 1·48, 1·29-1·71), and maternal selective serotonin reuptake inhibitor (SSRI) use during pregnancy (OR 1·84, 1·60-2·11). Only two associations, maternal overweight before or during pregnancy and SSRI use during pregnancy, retained their high level of evidence under subset sensitivity analyses. Evidence from biomarkers was scarce, being supported by p values close to the significance threshold and too few cases.

INTERPRETATION

Convincing evidence suggests that maternal factors, such as age and features of metabolic syndrome, are associated with risk of autism spectrum disorder. Although SSRI use during pregnancy was also associated with such risk when exposed and non-exposed groups were compared, this association could be affected by other confounding factors, considering that prepregnancy maternal antidepressant use was also convincingly associated with higher risk of autism spectrum disorder. Findings from previous studies suggest that one possible confounding factor is underlying maternal psychiatric disorders.

FUNDING

None.

The contribution of environmental exposure to the etiology of autism spectrum disorder

Autism spectrum disorder (ASD) is a neurodevelopmental condition of heterogeneous etiology. While it is widely recognized that genetic and environmental factors and their interactions contribute to autism phenotypes, their precise causal mechanisms remain poorly understood. This article reviews our current understanding of environmental risk factors of ASD and their presumed adverse physiological mechanisms. It comprehensively maps the significance of parental age, teratogenic compounds, perinatal risks, medication, smoking and alcohol use, nutrition, vaccination, toxic exposures, as well as the role of extreme psychosocial factors. Further, we consider the role of potential protective factors such as folate and fatty acid intake. Evidence indicates an increased offspring vulnerability to ASD through advanced maternal and paternal age, valproate intake, toxic chemical exposure, maternal diabetes, enhanced steroidogenic activity, immune activation, and possibly altered zinc-copper cycles and treatment with selective serotonin reuptake inhibitors. Epidemiological studies demonstrate no evidence for vaccination posing an autism risk. It is concluded that future research needs to consider categorical autism, broader autism phenotypes, as well as autistic traits, and examine more homogenous autism variants by subgroup stratification. Our understanding of autism etiology could be advanced by research aimed at disentangling the causal and non-causal environmental effects, both founding and moderating, and gene-environment interplay using twin studies, longitudinal and experimental designs. The specificity of many environmental risks for ASD remains unknown and control of multiple confounders has been limited. Further understanding of the critical windows of neurodevelopmental vulnerability and investigating the fit of multiple hit and cumulative risk models are likely promising approaches in enhancing the understanding of role of environmental factors in the etiology of ASD.

Autism-like phenotype and risk gene mRNA deadenylation by CPEB4 mis-splicing

Common genetic contributions to autism spectrum disorder (ASD) reside in risk gene variants that individually have minimal effect sizes. As environmental factors that perturb neurodevelopment also underlie idiopathic ASD, it is crucial to identify altered regulators that can orchestrate multiple ASD risk genes during neurodevelopment. Cytoplasmic polyadenylation element binding proteins 1-4 (CPEB1-4) regulate the translation of specific mRNAs by modulating their poly(A)-tails and thereby participate in embryonic development and synaptic plasticity. Here we find that CPEB4 binds transcripts of most high-confidence ASD risk genes. The brains of individuals with idiopathic ASD show imbalances in CPEB4 transcript isoforms that result from decreased inclusion of a neuron-specific microexon. In addition, 9% of the transcriptome shows reduced poly(A)-tail length. Notably, this percentage is much higher for high-confidence ASD risk genes, correlating with reduced expression of the protein products of ASD risk genes. An equivalent imbalance in CPEB4 transcript isoforms in mice mimics the changes in mRNA polyadenylation and protein expression of ASD risk genes and induces ASD-like neuroanatomical, electrophysiological and behavioural phenotypes. Together, these data identify CPEB4 as a regulator of ASD risk genes.

Zika Virus as a Possible Risk Factor for Autism Spectrum Disorder: Neuroimmunological Aspects

The recent outbreak of the Zika virus (ZIKV) and the discovery that perinatal Zika exposure can lead to the Congenital Zika Syndrome has promoted a call for prevention measures. Due to the increased number of babies born with microcephaly, structural brain abnormalities, and neurological alterations in regions affected by ZIKV, investigations were carried out in order to better understand this process. The maternal immune system directly influences the fetal central nervous system, and complications during pregnancy have been associated with neurodevelopmental disorders. Autism spectrum disorder (ASD), a neurodevelopmental disorder commonly manifested in the first years of life, is a disease with multifactorial etiology and is manifested typically by social and communication impairments, as well as stereotyped behaviors. Brain abnormalities, including both anatomically and functionally, can be observed in this disorder, suggesting delays in neuronal maturation and altered brain connectivity. It is known that some viral congenital infections, such as rubella, and cytomegalovirus can interfere with brain development, being associated with brain calcification, microcephaly, and ASD. Here, we reviewed a range of studies evaluating the aspects concerning brain development, immunological status during pregnancy, and neuroimmunomodulation in congenital viral infections, and we discuss if the fetal brain infection caused by ZIKV could predispose to ASD. Finally, we suggest a mechanism encompassing neurological and immunological pathways that could play a role in the development of ASD in infants after ZIKV infection in pregnancy.