Brief ReportPilot Study of Maternal Autoantibody–Related AutismAngkustsiri, Kathleen MD, MAS*,†; Fussell, Jill J. MD‡; Bennett, Amanda MD, MPH§; Schauer, Joseph BS‖; Ramirez-Celis, Alexandra PhD‖; Hansen, Robin L. MD*,†; Van de Water, Judy PhD†,‖ Author Information *Developmental Behavioral Pediatrics, Department of Pediatrics, University of California Davis Health, Sacramento, CA; †UC Davis MIND Institute, Sacramento, CA; ‡Developmental-Behavioral Pediatrics and Rehabilitative Medicine, Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR; §Developmental and Behavioral Pediatrics, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA; ‖Rheumatology, Allergy, and Clinical Immunology, Department of Internal Medicine, University of California, Davis, CA. Address for reprints: Kathleen Angkustsiri, MD, Developmental Behavioral Pediatrics, Department of Pediatrics, University of California Davis Health, 2825 50th St, Sacramento, CA 95817; e-mail: [email protected]. DBPNet is supported by cooperative agreement UT5MC42432 from the Maternal and Child Health Bureau, Health Resources and Services Administration (HRSA), US Department of Health and Human Services (HHS). This information or content and conclusions are those of the author and should not be construed as the social position or policy of, nor should any endorsements be inferred by the HRSA, HHS, or the US Government. Disclosure: The authors declare no conflict of interest. The data used for this study were collected as part of the DBPNet. Data were contributed by the following DBPNet member sites: UC Davis MIND Institute (Angkustsiri), University of Arkansas for Medical Sciences (Fussell), and Children's Hospital of Philadelphia (Bennett). The following individuals contributed as members of the DBPNet Steering Committee, by institution: Albert Einstein College of Medicine/Children's Hospital at Montefiore Medical Center: Ruth Stein; Baylor College of Medicine: Robert Voigt; Boston Children's Hospital, Harvard School of Medicine: William Barbaresi; Boston Medical Center: Marilyn Augustyn; Children's Hospital Colorado: Sandra Friedman; Children's Hospital Los Angeles: Douglas Vanderbilt; Children's Hospital of Philadelphia: Nathan Blum; Cincinnati Children's Hospital Medical Center/University of Cincinnati: Susan Wiley; Hasbro Children's Hospital/Brown Medical School: Pamela High; Kansas City Developmental Behavioral Pediatrics (KC-DBP) Consortium: Cy Nadler; Lucile Packard Children's Hospital: Heidi M. Feldman; NYU Grossman School of Medicine: Alan Mendelsohn; Rainbow Babies and Children's Hospital: Nancy Roizen; and University of Oklahoma Health Sciences Center: Ami Bax. NIEHS Center for Children's Environmental Health (2P01ES011269-11) and EPA grants (83543201), NIEHS-CHARGE study (R01ES015359), and NICHD IDDRC 054 (U54HD079125). The Center for Excellence in Developmental Disabilities at the UC Davis MIND Institute is funded by the Administration on Intellectual and Developmental Disabilities (AIDD) of the US Department of HHS under grant number 90DD0823. MIND Institute Intellectual and Developmental Disabilities Research Center (P50 HD103526). Journal of Developmental & Behavioral Pediatrics: June 1, 2022 - Volume - Issue - 10.1097/DBP.0000000000001100 doi: 10.1097/DBP.0000000000001100 Buy PAP Metrics Abstract Objective: The objective of this study was to investigate the presence of maternal autoantibody–related autism spectrum disorder (MAR-ASD) in 2 geographically distinct DBPNet clinical sites (Pennsylvania and Arkansas). MAR-ASD is a biologically defined subtype of ASD that is defined by the presence of autoantibodies specific to proteins in the fetal brain and present in approximately 20% of a Northern California sample but has not been studied in other states. Methods: Sixty-eight mothers of children with ASD were recruited from 2 DBPNet clinics and provided blood samples. Mothers also completed behavioral questionnaires about their children, and data from the child's clinical diagnostic assessment were abstracted. Results: The mean age of mothers was 38.5 ± 6.1 years, and the mean age of children was 8.3 ± 2.7 years. MAR-ASD was present in 24% of the sample and similar across sites. Children of +MAR mothers had more severe autism symptoms as measured by Autism Diagnostic Observation Schedule comparison scores (W = 3604; p < 0.001) and the Social Communication Questionnaire (W = 4556; p < 0.001). There were no differences in IQ, adaptive function, or aberrant behavior. Conclusion: MAR-ASD is a subtype of autism that is present in similar frequencies across 3 states and related to autism severity. Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.