Intracellular Pathogen Infections and Immune Response in Autism

Abstract

Background/Aims: Perinatal exposure to infections during critical developmental periods is a promising area of study in autism spectrum disorder (ASD). Epidemiological data has highlighted this relationship, pointing out significant correlations between perinatal exposure to pathogens and the occurrence of ASD. The aim of this review is to critically examine the present state of the art on intracellular pathogenic infection during pregnancy and postnatally, pointing out possible correlations with the development of ASD. Methods: We reviewed and collected studies concerning potential associations between intracellular pathogens like viral, bacterial, and parasite infection and the risk of ASD. Results: We included 14 publications, considering bacterial and/or viral infection that demonstrated the potential to trigger ASD. Nine case-control studies were included and 5 of them reported an association between infections and ASD. One of the 2 cohorts investigated demonstrated that maternal infection increased the risk of ASD in the offspring. Three cross-sectional studies demonstrated that ASD patients presented with chronic infections and active neuroinflammatory processes. Most of the reports suggest inflammatory response as a common factor, and interleukin 6 appears to be a key-player in this process. Conclusion: The immune responses generated by organisms that cause perinatal maternal infection, i.e., bacteria, viruses, or parasites, have been associated with the development of autism in offspring. Physiological changes transmitted from the mother during chronic or acute inflammation should be further investigated so that modulatory preventive measures can be developed.

Impact of Zinc Transport Mechanisms on Embryonic and Brain Development

“…This is for example the case for schizophrenia, which has a genetic component with risk variants and risk loci associated with higher incidence of the pathology [93], but also fetal origins, including in utero infections [94] gestational starvation [95,96], and smoking [97]. Similar evidence also exists for autism spectrum disorder (ASD) [98][99][100], as well as anxiety and depression-related behaviors [101][102][103][104]. Concerning Zn, a recent study showed that gestational Zn deficiency produced disturbances in microbiota composition that caused neuroinflammation in the hippocampus, increasing the risk for depression later in adult life [105].…”

Rubella Virus Infection, the Congenital Rubella Syndrome, and the Link to Autism

“…These data suggested a strong causal association between congenital rubella viral infection and autism. Later studies suggested links between other systemic viral infections and neurodegenerative conditions such as Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis, multiple sclerosis, and autism spectrum disorders [24,25,26].…”

The Use of Optical Coherence Tomography and Electrophysiological Tests in the Early Diagnosis of Inflammatory Changes in the CNS in children with ASD—A Review of Contemporary Literature

“…Some theories point to viral intrauterine (such as rubella, measles, mumps, cytomegalovirus (CMV), polyomavirus, and influenza), bacterial ( Mycoplasma ssp. , Chlamydia pneumoniae , and Borrelia burgdorferi ), and parasitic infections, especially those of the TORCH group, as the ones playing a notable part in the development of ASD [ 14 , 15 , 16 ]. Other factors of the perinatal period begging concern are birth complications, prolonged labor, the oxidative stress in the child’s body that accompanies it, birth asphyxia, and prematurity [ 17 ].…”