Keely Cheslack-Postava, MSPH, Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, Craig Newschaffer, PhD, Department of Epidemiology and Biostatistics, Drexel University School of Public Health, Philadelphia, PA 19102, and Judith K. Grether, PhD, California Department of Public Health, 850 Marina Bay Parkway, Richmond, CA 94814.
Background: Previous studies have suggested that CNS-reactive antibodies may be more prevalent among both subjects with autism and their mothers than controls. Fetal or neonatal exposure to such antibodies may affect the developing nervous system. Because it is likely that prenatal factors affect the development of autism, antibody status during gestation may be more relevant to autism risk than that during later life.
Objectives: To determine whether neonatal levels of antigen-specific antibodies are associated with autism risk.
Methods: The authors conducted a population-based case-control study comparing autism cases (n=424) identified through the California Department of Developmental Services (DDS) to birth certificate controls (N=644). A group with idiopathic mental retardation (n= 434) identified through DDS was also included to allow assessment of the specificity of any differences to autism. Serum samples from each subject were obtained in the form of punches removed from neonatal heel-stick cards archived by the Genetic Disease Branch newborn screening program of the California Department of Public Health. IgM and IgG antibodies, including those to nervous system, thyroid, and infectious antigens, were measured using microbead suspension arrays. The effect of each antibody on risk for ASD will be assessed using non-parametric rank-sum scores and multiple logistic regression, adjusting for potential effect modification and confounding by demographic, birth and diagnostic characteristics.
Results: Laboratory assays have been completed for antigen specific antibodies. Crude and adjusted data will be presented for the following analytes: thyroid peroxidase, thyroglobulin, MBP, GFAP, neurofilament proteins, BDNF, polysialic acid, gangliosides, fetal mouse brain extracts, toxoplasmosis, CMV, HSV1, HSV2, and pneumococcal polysaccharides.
Conclusions: There may be differences in maternal antibody levels between autism cases and controls at birth. The results of this study will help to elucidate the nature of any such differences.