Fig. 6. Case examples of responders to intravenous immunoglobulin (IVIG) treatment. Case #1 is a child with autism spectrum disorder (ASD) and mitochondrial dysfunction that had a sudden worsening in behavior at 8 years of age.

a Initiating IVIG significantly improved behavior as measured by the Aberrant Behavior Checklist (ABC) and social function as measured by the Social Responsiveness Scale (SRS). b The writing sample on the left shows the patient’s handwriting a few months before IVIG treatment, and the sample on the right shows the patient’s handwriting 2 days after his first IVIG treatment. Case #2 is a boy with sudden regression found to have an N-Type Voltage-Gated Calcium-Channel autoantibody. c IVIG treatment significantly improved autoantibody titers. Case #3 is a girl with multiple regressions and severe ASD and related symptoms. d IVIG normalized CamKinase II activity but CamKinase II activity increased to abnormal levels and behavior, as measured by the ABC and SRS, worsened with increasing the IVIG treatment interval to every 6 weeks. Behavior improved after reinstating the original every 4 weeks dosing interval