Measurement of serum hepatitis B surface antibody levels in Iranian autistic children and evaluation of immunological memory after booster dose injection in comparison with controls.

BACKGROUND: Responsiveness to hepatitis B vaccine among patients with autism spectrum disorders (ASD) has not been evaluated worldwide. We aimed to determine the anti-HBs antibody duration in autistic and healthy children few years after primary vaccination and evaluate their immunological memory against hepatitis B virus (HBV) vaccine with booster dose administration. METHODS: One hundred seven and 147 HBsAg-negative children from ASD and normal population were recruited, respectively. HBV seromarkers (HBc-Ab, HBsAg, and HBs-Ab) were assessed and subsequently, molecular tests were used on all the subjects. A booster dose of vaccine was injected for those who showed low levels (<10 mIU/mL) of anti-HBs and their antibody levels was measured 4 weeks later. RESULTS: The mean ages of ASD and control groups were 7.14 ± 2.42 and 8.68 ± 1.96, respectively. Seven (6.5%) of the ASD group were positive for anti-HBc and one child was positive for occult hepatitis B infection (HBsAg negative, HBV DNA positive). In ASD, 54 (50.4%) and 53 (49.6%) had adequate (>10 mIU/mL) and low anti-HBs levels, respectively. Among control group, 74 (50.4%) and 73 (49.6%) had sufficient and low antibody levels, respectively. After injection of a booster dose for all children with low antibody, 100% of ASD and 92% (59 of 64) of control pupils contained >10 mIU/mL of antibody, respectively. In both the groups, the HBs-Ab titer increased similarly in response to the booster injection (P < 0.05). CONCLUSION: Despite previous investigations regarding immune impairment in individuals with autism, the immune system of these individuals was able to manage the hepatitis B vaccine challenge.

Maternal cytomegalovirus sero-positivity and autism symptoms in children.

PROBLEM: Autism spectrum disorder (ASD) is one of the most commonly diagnosed neurodevelopmental disorders in the United States. While ASD can be significantly influenced by genetics, prenatal exposure to maternal infections has also been implicated in conferring risk. Despite this, the effects of several important maternal pathogens, such as cytomegalovirus (CMV) and herpes simplex virus 2 (HSV2), remain unknown. METHOD OF STUDY: We tested whether maternal CMV and/or HSV2 sero-positivity was associated with ASD symptoms in children. ELISA was used to assay for CMV IgG and HSV2 IgG in serum from the mothers of 82 children whose ASD symptoms were assessed at 3-6 years of age using the Social Responsiveness Scale version 2 (SRS-2). RESULTS: Associations between maternal viral serostatus and SRS-2 scores were estimated using linear regression with covariate adjustments. The children of mothers sero-positive for CMV, but not for HSV2, had SRS-2 scores 3.6-4.2 points higher, depending on the adjustment model, than sero-negative women, a significant finding, robust to several statistical adjustments. CONCLUSION: Our results suggest that maternal CMV infections may influence ASD symptoms. These findings are being further evaluated in ongoing prospective studies with larger population samples.

Evaluation of antibodies to cytomegalovirus and Epstein-Barr virus in patients with autism spectrum disorder.

Autism is a neurodevelopmental disease that manifested by a wide range of behavioral disorders. Although the etiology of autism is remained unknown but it is suggested that ASD have a complex etiology, including genetic and environmental factors, which may explain the observed different behavioral disorders in these patients. One of the proposed reasons for autism is viral infection in the early stages of development. The mechanism by which viral infection could lead to autism is still unclear.Previous studiesemphasized on the role of family membersof Herpesviruses in autism susceptibility. In this study, anti-Cytomegalovirus (CMV) and anti-Epstein-Barr virus (EBV) antibodies in the serum of 45 children with autism and 45 healthy individuals were evaluated. Serum samples were isolated from 5 ml blood of the patients and controls. Sandwich ELISA was used to quantitatively measure antibodies against the mentioned viruses. Results analyzed by SPSS software showed an increased amount of anti-CMV IgG and IgM antibodies in the blood of patients with Autism but not statistically significant (P< 0.05). The anti-EBV IgM antibody in the blood of patients with Autism was not only increased but also statistically significant (P< 0.05), however, the IgG level against EBV in the serum of ASD patients showed no significant difference in comparison to healthy controls. So it can be said that although the mechanisms of viral infection in autism is unknown, but probably EBV infection is associated with an increased risk of autism.

The role of parvovirus in the etiology of somatic pathology.

The scope of the present research was to study parvovirus circulation in Tbilisi population and its role in etiology of somatic pathologies. Parvovirus circulation in persons with autism and disorder of the nervous system was examined. Blood of 110 patients was examined. Among them 35 were children (up to 15 years old) and 75 adults, mainly with different somatic pathologies such as mineral metabolism disorder, allergic reactions, cystic fibrosis, cerebral palsy and autism. Almost all the children came from the so called frequently ill category and suffered from disbacteriosis. Among adults, 16 were parents of the ill children, while the rest came with hepatitis, mineral metabolism disorder of different type and psoriasis. Blood serum of 30 adults was taken as an adult control group. Their age varied from 18 to 25 years. 10 children aged 2-15 constituted a children control group. Preventive examination was made and there were practically, absolutely healthy persons. A total of 150 persons were involved in the research. Frequency of parvoviral antibody detection in the ill children and adults is much higher than in healthy individuals. Consequently, positive results for the presence of M and G immunoglobulins in children equals to 54% and 85% respectively. In adults these indicator stand at 24% and 60% respectively. At the same time in 25% and 70% of parents of positive children were found to be positive for M immunoglobulin and G immunoglobulin respectively. Thus our investigation made it clear that parvoviral infection actively circulates in Georgia. The present research did not study manifested parvoviral infection, i.e. 5th disease. If it had than the number of positive results probably would have been much higher. In autistic children presence of parvoviral infection is consistent with the literature data.

Differential transmission and postnatal outcomes in triplets with intrauterine cytomegalovirus infection.

We present a case of triplets with intrauterine cytomegalovirus (CMV) infection, each of whom showed differential transmission, placental pathology, and postnatal outcome. The first- and second-born infants were both vigorous and asymptomatic at birth, although the first-, but not the second-born, triplet had a high copy number of CMV DNA in the peripheral blood (1.2 × 10³ copy/mL). The third-born triplet suffered from symptomatic CMV infection with a high viral load (6.0 × 106 copy/mL). The triamniotic-trichorionic placentas were not fused to each other. The histopathologic analysis showed that CMV-positive cells were frequently found in the decidua, villi, and amnion of the third-born triplet's placenta but were limited and scattered in the decidua or villi but not amnion of the other 2 placentas. The third-born triplet underwent ganciclovir therapy. None of the infants had physical or auditory problems at 4 years of age, whereas the third-born triplet had been diagnosed with an autistic disorder. This observation exemplifies the preventive roles of the individual placentas of triplets with regard to virus infection, thus suggesting that developing CMV disease largely depends on the placental function.

Induction of Toll-like receptor 3-mediated immunity during gestation inhibits cortical neurogenesis and causes behavioral disturbances.

Maternal infection during pregnancy with a wide range of RNA and DNA viruses is associated with increased risk for schizophrenia and autism in their offspring. A common feature in these exposures is that virus replication induces innate immunity through interaction with Toll-like receptors (TLRs). We employed a mouse model wherein pregnant mice were exposed to polyinosinic-polycytidylic acid [poly(I ⋅ C)], a synthetic, double-stranded RNA molecular mimic of replicating virus. Poly(I ⋅ C) inhibited embryonic neuronal stem cell replication and population of the superficial layers of the neocortex by neurons. Poly(I ⋅ C) also led to impaired neonatal locomotor development and abnormal sensorimotor gating responses in adult offspring. Using Toll-like receptor 3 (TLR3)-deficient mice, we established that these effects were dependent on TLR3. Inhibition of stem cell proliferation was also abrogated by pretreatment with the nonsteroidal anti-inflammatory drug (NSAID) carprofen, a cyclooxygenase (COX) inhibitor. Our findings provide insights into mechanisms by which maternal infection can induce subtle neuropathology and behavioral dysfunction, and they may suggest strategies for reducing the risk of neuropsychiatric disorders subsequent to prenatal exposures to pathogens and other triggers of innate immunity.

Association of autism with polyomavirus infection in postmortem brains.

Autism is a highly heritable behavioral disorder. Yet, two decades of genetic investigation have unveiled extremely few cases that can be solely explained on the basis of de novo mutations or cytogenetic abnormalities. Vertical viral transmission represents a nongenetic mechanism of disease compatible with high parent-to-offspring transmission and with low rates of disease-specific genetic abnormalities. Vertically transmitted viruses should be found more frequently in the affected tissues of autistic individuals compared to controls. Our initial step was thus to assess by nested polymerase chain reaction (PCR) and DNA sequence analysis the presence of cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes simplex virus type 1 (HSV1), herpes simplex virus type 2 (HSV2), human herpes virus 6 (HHV6), BK virus (BKV), JC virus (JCV), and simian virus 40 (SV40) in genomic DNA extracted from postmortem temporocortical tissue (Brodmann areas 41/42) belonging to 15 autistic patients and 13 controls. BKV, JCV, and SV40 combined are significantly more frequent among autistic patients compared to controls (67% versus 23%, respectively; P < .05). The majority of positives yielded archetypal sequences, whereas six patients and two controls unveiled single-base pair changes in two or more sequenced clones. No association is present with the remaining viruses, which are found in relatively few individuals (N

Prenatal viral infection of mice at E16 causes changes in gene expression in hippocampi of the offspring.

The hippocampus governs memory formation and emotional regulation, and there is widespread evidence of hippocampal dysfunction in psychiatric disorders, including schizophrenia and autism. There is abundant evidence that prenatal viral infection may play a role in the development of these two disorders. In the current study, we have examined gene expression and structural changes of the hippocampi of exposed neonates following maternal infection at embryonic day (E) 16 (middle second trimester). We observed significant changes in gene expression in the offspring at postnatal day (P) 0 (birth), P14 (childhood), and P56 (adulthood), including a number of candidate genes for autism and schizophrenia. qRT-PCR verified the direction and magnitude of change for 5 of the genes from the microarray data set and revealed mRNA changes for additional genes associated with schizophrenia and autism. MRI revealed a decrease in hippocampal volume at P35 (adolescence). Our results demonstrate altered gene expression and reduced hippocampal volume in the offspring following prenatal viral infection at E16.

Measles vaccination and antibody response in autism spectrum disorders.

OBJECTIVE: To test the hypothesis that measles vaccination was involved in the pathogenesis of autism spectrum disorders (ASD) as evidenced by signs of a persistent measles infection or abnormally persistent immune response shown by circulating measles virus or raised antibody titres in children with ASD who had been vaccinated against measles, mumps and rubella (MMR) compared with controls. DESIGN: Case-control study, community based. METHODS: A community sample of vaccinated children aged 10-12 years in the UK with ASD (n = 98) and two control groups of similar age, one with special educational needs but no ASD (n = 52) and one typically developing group (n = 90), were tested for measles virus and antibody response to measles in the serum. RESULTS: No difference was found between cases and controls for measles antibody response. There was no dose-response relationship between autism symptoms and antibody concentrations. Measles virus nucleic acid was amplified by reverse transcriptase-PCR in peripheral blood mononuclear cells from one patient with autism and two typically developing children. There was no evidence of a differential response to measles virus or the measles component of the MMR in children with ASD, with or without regression, and controls who had either one or two doses of MMR. Only one child from the control group had clinical symptoms of possible enterocolitis. CONCLUSION: No association between measles vaccination and ASD was shown.

Are there altered antibody responses to measles, mumps, or rubella viruses in autism?

The role that virus infections play in autism is not known. Others have reported that antibodies against measles virus are higher in the sera/plasma of children with autism versus controls. The authors investigated antibody titers to measles, mumps, and rubella viruses and diphtheria toxoid in children with autism, both classic onset (33) and regressive onset (26) forms, controls (25, healthy age- and gender-matched) and individuals with Tourette's syndrome (24) via enzyme-linked immunosorbent assays. No significant differences in antibody titers to measles, mumps, and rubella viruses and diphtheria toxoid were found among the four groups. Additionally, there were no significant differences between the four groups for total immunoglobulin (Ig)G or IgM. Interestingly, the authors did find a significant number (15/59) of autism subjects (classic and regressive onset combined) who had a very low or no antibody titer against rubella virus, compared to a combine control/Tourette's group (2/49).

Evidence for Mycoplasma ssp., Chlamydia pneunomiae, and human herpes virus-6 coinfections in the blood of patients with autistic spectrum disorders.

We examined the blood of 48 patients from central and southern California diagnosed with autistic spectrum disorders (ASD) by using forensic polymerase chain reaction and found that a large subset (28/48 or 58.3%) of patients showed evidence of Mycoplasma spp. infections compared with two of 45 (4.7%) age-matched control subjects (odds ratio = 13.8, P < 0.001). Because ASD patients have a high prevalence of one or more Mycoplasma spp. and sometimes show evidence of infections with Chlamydia pneumoniae, we examined ASD patients for other infections. Also, the presence of one or more systemic infections may predispose ASD patients to other infections, so we examined the prevalence of C. pneumoniae (4/48 or 8.3% positive, odds ratio = 5.6, P < 0.01) and human herpes virus-6 (HHV-6, 14/48 or 29.2%, odds ratio = 4.5, P < 0.01) coinfections in ASD patients. We found that Mycoplasma-positive and -negative ASD patients had similar percentages of C. pneumoniae and HHV-6 infections, suggesting that such infections occur independently in ASD patients. Control subjects also had low rates of C. pneumoniae (1/48 or 2.1%) and HHV-6 (4/48 or 8.3%) infections, and there were no coinfections in control subjects. The results indicate that a large subset of ASD patients shows evidence of bacterial and/or viral infections (odds ratio = 16.5, P < 0.001). The significance of these infections in ASD is discussed in terms of appropriate treatment.

Abnormal social behaviors in young and adult rats neonatally infected with Borna disease virus.

Autism spectrum disorders (ASD) have been the focus of a great deal of research and clinical speculation. This intense interest relates to both the perplexing pathogenesis and devastating consequences of these disorders. One of the obstacles to understanding the pathogenesis of autism and to developing efficient treatment has been the paucity of animal models that could be used for hypotheses-driven mechanistic studies of abnormal brain and behavior development and for the pre-clinical testing novel pharmacological treatments. In this report, we briefly review our animal model of ASD based on neonatal Borna disease virus (BDV) infection and present new data about abnormal social interaction in adult BDV-infected rats. We found that neonatal BDV infection profoundly affected social behaviors in adult rats. Compared to the control rats, both 90- and 180-day-old infected rats spent less time in active social interaction and more time in following their partners. In the intruder-resident test, the BDV-infected resident rats exhibited less aggression towards the intruders and showed more the following-the-intruder behavior. The following-the-partner behavior may be an example of "stereotypic" activity due to BDV-induced abnormal social communication between rats. The previously published results and present findings indicate that neonatal BDV infection significantly altered the normal pattern of social interaction in rats. Co-localization of activated microglia and dying Purkinje cells in BDV-infected rats suggests that the BDV model could be used to study a pathogenic link of Purkinje cell dropout and neuroinflammation to abnormal social behaviors.

No evidence of persisting measles virus in peripheral blood mononuclear cells from children with autism spectrum disorder.

OBJECTIVES: Despite epidemiologic evidence to the contrary, claims of an association between measles-mumps-rubella vaccination and the development of autism have persisted. Such claims are based primarily on the identification of measles virus nucleic acids in tissues and body fluids by polymerase chain reaction. We sought to determine whether measles virus nucleic acids persist in children with autism spectrum disorder compared with control children. PATIENTS AND METHODS: Peripheral blood mononuclear cells were isolated from 54 children with autism spectrum disorder and 34 developmentally normal children, and up to 4 real-time polymerase chain reaction assays and 2 nested polymerase chain reaction assays were performed. These assays targeted the nucleoprotein, fusion, and hemagglutinin genes of measles virus using previously published primer pairs with detection by SYBR green I. Our own real-time assay targeted the fusion gene using novel primers and an internal fluorescent probe. Positive reactions were evaluated rigorously, and amplicons were sequenced. Finally, anti-measles antibody titers were measured by enzyme immunoassay. RESULTS: The real-time assays based on previously published primers gave rise to a large number of positive reactions in both autism spectrum disorder and control samples. Almost all of the positive reactions in these assays were eliminated by evaluation of melting curves and amplicon band size. The amplicons for the remaining positive reactions were cloned and sequenced. No sample from either autism spectrum disorder or control groups was found to contain nucleic acids from any measles virus gene. In the nested polymerase chain reaction and in-house assays, none of the samples yielded positive results. Furthermore, there was no difference in anti-measles antibody titers between the autism and control groups. INTERPRETATION: There is no evidence of measles virus persistence in the peripheral blood mononuclear cells of children with autism spectrum disorder.

Morbilliviruses and human disease.

Morbilliviruses are a group of viruses that belong to the family Paramyxoviridae. The most instantly recognizable member is measles virus (MV) and individuals acutely infected with the virus exhibit a wide range of clinical symptoms ranging from a characteristic mild self-limiting infection to death. Canine distemper virus (CDV) and rinderpest virus (RPV) cause a similar but distinctive pathology in dogs and cattle, respectively, and these, alongside experimental MV infection of primates, have been useful models for MV pathogenesis. Traditionally, viruses were identified because a distinctive disease was observed in man or animals; an infectious agent was subsequently isolated, cultured, and this could be used to recapitulate the disease in an experimentally infected host. Thus, satisfying Koch's postulates has been the norm. More recently, particularly due to the advent of exceedingly sensitive molecular biological assays, many researchers have looked for infectious agents in disease conditions for which a viral aetiology has not been previously established. For these cases, the modified Koch's postulates of Bradford Hill have been developed as criteria to link a virus to a specific disease. Only in a few cases have these conditions been fulfilled. Therefore, many viruses have over the years been definitely and tentatively linked to human diseases and in this respect the morbilliviruses are no different. In this review, human diseases associated with morbillivirus infection have been grouped into three broad categories: (1) those which are definitely caused by the infection; (2) those which may be exacerbated or facilitated by an infection; and (3) those which currently have limited, weak, unsubstantiated or no credible scientific evidence to support any link to a morbillivirus. Thus, an attempt has been made to clarify the published data and separate human diseases actually linked to morbilliviruses from those that are merely anecdotally associated.

Prenatal viral infection in mouse causes differential expression of genes in brains of mouse progeny: a potential animal model for schizophrenia and autism.

Schizophrenia and autism are neurodevelopmental disorders with genetic and environmental etiologies. Prenatal viral infection has been associated with both disorders. We investigated the effects of prenatal viral infection on gene regulation in offspring of Balb-c mice using microarray technology. The results showed significant upregulation of 21 genes and downregulation of 18 genes in the affected neonatal brain homogenates spanning gene families affecting cell structure and function, namely, cytosolic chaperone system, HSC70, Bicaudal D, aquaporin 4, carbonic anhydrase 3, glycine receptor, norepinephrine transporter, and myelin basic protein. We also verified the results using QPCR measurements of selected mRNA species. These results show for the first time that prenatal human influenza viral infection on day 9 of pregnancy leads to alterations in a subset of genes in brains of exposed offspring, potentially leading to permanent changes in brain structure and function.