(PS2-80) Investigating the Prevalence of Familial Autoimmune Disease in Youth with Infection-triggered Neuropsychiatric Symptoms

Introduction: Pediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcal infections (PANDAS) and Pediatric Acute-onset Neuropsychiatric Syndrome (PANS) are characterized by the sudden and acute-onset of neuropsychiatric symptoms in youth following an infection. The presentation of PANDAS/PANS may closely resemble other psychiatric conditions including obsessive-compulsive disorder (OCD) or tic disorders (TD). Past research suggests that compared to the general population, there may be an increased rate of autoimmune disease (AD) in relatives of those diagnosed with OCD or TD (Mataix-Cols, 2017) and in relatives of those with a suspected diagnosis or diagnosis of PANDAS/PANS (e.g. Leonardi et al., 2024). This study explored the familial rates of AD in a sample of youth who presented to a PANDAS/PANS specialty clinic and compared familial rates of AD in youth who received versus did not receive a PANDAS or PANS diagnosis.

Methods: One-hundred and forty-four patients (mean age=12.11 years; 55.1% male) were evaluated by a psychiatrist at Massachusetts General Hospital’s Pediatric Neuropsychiatry and Immunology Program for a suspected diagnosis of PANDAS or PANS. Sixty-two patients were diagnosed with PANDAS, 30 were diagnosed with PANS, and 52 did not meet criteria for either diagnosis. Patients’ familial histories of AD and immune deficiencies were indicated on a caregiver-report questionnaire and analyzed using SPSS. Differences in prevalence rates between groups were examined using Fisher’s exact test.

Results: Elevated rates of autoimmune disease in first-degree relatives of youth diagnosed with PANDAS/PANS were primarily driven by maternal prevalence. Any history of AD was reported in 23.9% of mothers, with psoriasis (9.9%), Hashimoto’s disease (7.6%) and Celiac disease (7.6%) being most common. This demonstrates an elevated prevalence rate compared to the 5% general prevalence rate of AD in women in the United States (Cooper & Stroehla, 2003). While rates of AD were slightly higher in mothers of diagnosed children than those who were not diagnosed (21.6%), these differences did not reach statistical significance. There were no significant differences in overall family rates of AD in the diagnosed versus non-diagnosed subgroups.

Conclusion: Youth with PANDAS/PANS may have a higher rate of family autoimmune disease and immune deficiencies relative to the general population. Youth diagnosed with PANDAS/PANS did not demonstrate significantly higher rates of family AD than youth who did not meet criteria for PANDAS/PANS, but this may be due to the study’s relatively small sample size, low AD base rates, and/or elevated rates of these conditions in both the diagnosed and non-diagnosed subgroups. Family susceptibility to AD may contribute to the development of other neuropsychiatric disorders including OCD and TD in addition to PANDAS/PANS. Providers should carefully assess family autoimmune histories when evaluating youth presenting with potential PANDAS/PANS, OCD, and TD (Murphy et al., 2010). Future research should further explore the genetic risk factors that may contribute to the development of neuropsychiatric symptoms in youth.