Obsessive-Compulsive Disorder, PANDAS, and Tourette Syndrome: Immuno-inflammatory Disorders

In the last years, much focus has been given to the possible role of inflammatory and immunologic alterations in the pathophysiology of obsessive-compulsive disorder (OCD) and some related conditions, such as pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection (PANDAS) and Tourette syndrome (TS). Although the matter is intriguing, the available data are still controversial and/or limited. Therefore, the aim of this chapter was at reviewing and commenting on the literature on possible dysfunctions of inflammatory and immune system processes in OCD, PANDAS, and TS.This narrative review was carried out through searching PubMed and Google Scholar for English language papers from January 1985 to December 31, 2021.The data gathered up to now would suggest that the mechanisms involved might be heterogeneous according to the age of the patients and the disorder examined. Indeed, PANDAS seem more related to infections triggering autoimmunity not necessarily following group A beta-hemolytic streptococcal (GABHS) infection, as supposed in the past. Autoimmunity seems also important in TS, if coupled with an individual vulnerability that can be genetic and/or environmental. The data in adult OCD, albeit scattered and sometimes obtained in small samples of patients, would indicate that immune system and inflammatory processes are involved in the pathophysiology of the disorder. However, it is still unclear to conclude whether they are primary or secondary phenomena.In conclusion, taken together, the current findings pave that way towards novel and promising domains to explore the pathophysiology of OCD and related disorders, as well towards the development of innovative therapeutic strategy beyond current pharmacological paradigms.

Paediatric Acute-onset Neuropsychiatric Syndrome (PANS) and intravenous immunoglobulin (IVIG): comprehensive open-label trial in ten children

BACKGROUND

Treatment with intravenous immunoglobulin (IVIG) in children with Paediatric Acute-onset Neuropsychiatric Syndrome (PANS) has for many years been used on clinical indications, but the research evidence for its efficacy is insufficient.

METHODS

Open-label prospective in-depth trial including ten children (median age 10.3 years) with PANS, who received IVIG treatment 2 g/kg monthly for three months. Primary outcomes were changes in symptom severity and impairment from baseline to first and second follow-up visits one month after first and one month after third treatment, using three investigator-rated scales: Paediatric Acute Neuropsychiatric Symptom (PANS) scale, Clinical Global Impression - Severity and Improvement (CGI-S and CGI-I) scales. Secondary outcomes reported here were changes in Children's Yale-Brown Obsessive Compulsive Scale (CY-BOCS) scores, and side effects.

RESULTS

All ten children received three treatments at one-month intervals according to study plan. From baseline to second follow-up marked reductions were seen in mean total PANS scale scores (p = .005), and CGI-S scores (p = .004). CGI-I ratings showed much to very much global improvement (mean CGI-I 1.8). Nine children had clinical response defined as > 30% reduction in PANS Scale scores. Improvements were also noted for CY-BOCS scores (p = .005), and in school attendance. Three children suffered moderate to severe temporary side effects after the first treatment, and the remaining seven had mild to moderate side effects. Side effects were much less severe after second and third treatments.

CONCLUSIONS

Considerable and pervasive improvements in symptoms and clinical impairments were seen in these ten children after three monthly IVIG treatments. Moderate to severe transient side effects occurred in three cases.

TRIAL REGISTRATION

EudraCT no. 2019-004758-27, Clinicaltrials.gov no. NCT04609761, 05/10/2020.