Potential mechanisms for the association among immune-related comorbidities and OCD include shared genetic and environmental susceptibility, given associations between autoimmune disease in adults with OCD and their first-degree relatives (Mataix-Cols et al. 2017); maternal antibody transfer during pregnancy given increased frequency among mothers with autoimmune disorders compared with other first-degree relatives (Vincent et al. 2003), although this appears more relevant in tic disorders (Mataix-Cols et al. 2017); or exposure to dysregulated plasma cytokines (Golan et al. 2005) leading to altered brain development. For example, previous work has also suggested a familial relationship between obsessive compulsive spectrum disorders and RF (Seixas et al. 2008), an autoimmune disease thought to arise from humoral and cellular autoreactivity following group A streptococcal (GAS) pharyngitis (Bright et al. 2016).
