Study links autistic children back to mothers who had chronic respiratory ailments, inflammation during pregnancy

Clinical trials have shown an association between the autism spectrum disorder (ASD) and maternal immune activation (MIA), an active immune response after an infectious exposure during pregnancy, but this study is the first one to examine its link to an increase in behavioral abnormalities in children. The connection between ASD and MIA is still largely unknown but research suggests than an immune system-mediated subtype of ASD is triggered by changes in the cellular activity such as antibody levels in the mother and/or child. Animal models have revealed that MIA is a risk factor in developmental abnormalities in the offspring.

ASD is a neurological and developmental disorder that manifests in early childhood and lasts through a person’s adult life. It can have a range of symptoms but mainly affects interaction and communication skills. A person with ASD may have difficulty expressing themselves and talking with others. They also show repetitive behaviors and limited interests.

The study recruited children from the Autism Diagnostic Observation Schedule-Generic (ADOS-G) and used simple activities and questions that prompted interaction and communication and other behaviors stereotypical to the diagnosis of ASD.

A primary caregiver had completed a rating scale called Social Responsiveness Scale (SRS) which measured social interaction, language, repetitive behaviors and restricted interests in the child. The primary caregiver also completed a family history questionnaire which included medical history such as diagnosed illnesses and chronic conditions. The tests provide scores on awareness, cognition, mannerisms, communication and motivation.

Results of the study showed evidence of immune system-mediated subtype of autism that could have diagnostic and treatment implications.

“Our results build on existing research by showing an association between maternal immune activation caused by asthma and allergies and ASD symptom severity in children with ASD,” PhD candidate and study author Shrujna Patel from the University of Sydney said. She led the study with her colleagues at the Brain and Mind Centre, Children’s Hospital Westmead, Macquarie University and the Telethon Kids Institute.

Natalie Pollard, an academic from the University of Sydney and mother to Ethan who has autism, thinks that the findings are a positive step toward understanding the intricacies of the disorder and its factors better.

“I knew something wasn’t quite right early on, and his development was slower and he would scream for hours,” she said. “As a mum, I think the findings are great, because we need more information out there and it could potentially help solve the puzzle of autism, which is multi-factorial.” (Related: Autism in girls linked to grandmothers who SMOKED during pregnancy reveals new research.)

The results reveal that children whose mothers reported a history of immune activation caused by asthma and allergies exhibit higher scores in the SRS, particularly in cognition and mannerisms, displaying more restricted social behaviors. This suggests a clear association between MIA and ASD.

The identification of an immune system-mediated subtype in ASD driven by MIA would enable more streamlined diagnosis, and present potential new targets for immune-modulating drug therapies, according to the researchers.

Sources include:

ScienceDaily.com

NCBI.NLM.NIH.gov