A total-population multigenerational family clustering study of autoimmune diseases in obsessive-compulsive disorder and Tourette’s/chronic tic disorders

• DOI: 10.17615/1f8s-vt45
• Publication Date: 2017-11-14
• Authors: Kayoko Isomura; Kayoko Isomura; David Mataix-Cols; David Mataix-Cols; Emma M. Frans; L. Fernández de l...; Christian Rück; Christian Rück; Henrik Larsson; Henrik Larsson; Ralf Kuja-Halkola; Ana Pérez-Vigil; James F. Leckman; Catarina Almqvist; Catarina Almqvist; Caroline Gromark; Caroline Gromark; James J. Crowley; James J. Crowley; Eva Serlachius; Eva Serlachius; Paul Lichtenstein
• Keywords: Adult; Male; Sweden; Obsessive-Compulsive Disorder; Adolescent; Siblings; Comorbidity; Autoimmune Diseases; Pedigree; 3. Good health; 03 medical and health sciences; 0302 clinical medicine; Risk Factors; Case-Control Studies; Tic Disorders; 616; Cluster Analysis; Humans; Family; Female; Child; Aged; Tourette Syndrome

The association between obsessive–compulsive disorder (OCD) and Tourette’s/chronic tic disorders (TD/CTD) with autoimmune diseases (ADs) is uncertain. In this nationwide study, we sought to clarify the patterns of comorbidity and familial clustering of a broad range of ADs in individuals with OCD, individuals with TD/CTD and their biological relatives. From a birth cohort of 7 465 455 individuals born in Sweden between 1940 and 2007, we identified 30 082 OCD and 7279 TD/CTD cases in the National Patient Register and followed them up to 31 December 2013. The risk of 40 ADs was evaluated in individuals with OCD, individuals with TD/CTD and their first- (siblings, mothers, fathers), second- (half siblings) and third-degree (cousins) relatives, compared with population controls. Individuals with OCD and TD/CTD had increased comorbidity with any AD (43% and 36%, respectively) and many individual ADs. The risk of any AD and several individual ADs was consistently higher among first-degree relatives than among second- and third-degree relatives of OCD and TD/CTD probands. The risk of ADs was very similar in mothers, fathers and siblings of OCD probands, whereas it tended to be higher in mothers and fathers of TD/CTD probands (compared with siblings). The results suggest a familial link between ADs in general (that is, not limited to Streptococcus-related conditions) and both OCD and TD/CTD. Additional mother-specific factors, such as the placental transmission of antibodies, cannot be fully ruled out, particularly in TD/CTD.