摘要:Introduction: The etiology of Autism Spectrum Disorder (ASD) is still unknown. New evidence is increasing for the involvement of altered immune responses in the pathogenesis of ASD. This study aimed to compare the serum immunoglobulin levels in children with ASD and a group of healthy children. Methods: This case-control study was performed on 42 patients referred to the Psychiatric clinics of Taleghani Hospital, Gorgan, Iran in 2019-2020 (Referral center). Children were divided into two subgroups with and without autism according to the standard autism diagnosis questionnaire (MChat). After obtaining informed written consent, 5 ml of the blood sample was taken from each patient for laboratory evaluation of serum Immunoglobulins (IgM,IgG,IgA) levels; then the patients' information (Demographic, laboratory) was recorded in a checklist. Finally, the data analyzed using SPSS software version 18.0. Results: The results of the study showed that among 42 children participating, 21 were healthy (57.15% male) and 21 had autism (61.90% male). There was no significant difference in the levels of immunoglobulins M and G between the autism and control groups. The serum level IgA in male in the control and autism groups was different (p = 0.001), showing low IgA levels in male children with autism. Conclusion: This study showed the serum level of immunoglobulin A in patients with autism and in males was lower than in healthy children, which may be due to autoimmune disorders, immune system defects.