Repeated infections are common is ASD patients. Children with ASD are more prone to infections in first 2 years of life. It is due to the fact that they have low levels of immunoglobulins. Some children suffering from ASD have decreased levels of serum IgA making them extremely vulnerable to respiratory and GI infections. Several studies have reported that some ASD children also have low IgG and IgM immunoglobulins, low T cell numbers and abnormal NK cells. This leads to dysregulation in immunity of the child with autism. Contact your doctor immediately if you observe any sign of infection in your child especially if he is already diagnosed with ASD.