This article discusses issues related to the hypotheses regarding the existence of immune mechanisms underlying the pathophysiology of a subgroup of patients with obsessive-compulsive disorder and/or Tourette's syndrome. Though developed from the studies on Sydenham's chorea, other concepts about the immune system regulation hypotheses still need further investigation. The proposition of PANDAS, the pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection, combined with the results obtained with plasma exchange procedure, which showed a remarkable improvement of the symptoms in children with obsessive-compulsive disorder and/or Tourette's syndrome, have given additional support to this model.
Obsessive-compulsive disorder; Tourette syndrome; Chorea, Sydenham; Autoimmune diseases; Receptors, cytokine
