Cognitive inflexibility and immunome biomarkers in children with autism spectrum disorder

Cognitive inflexibility is a transdiagnostic endophenotype that presents across a range of disorders, including autism spectrum disorder (ASD), which is maintained through adulthood, and encompasses both cognitive and behavioral rigidity. There is evidence for immune dysfunction in a subgroup of ASD, including systemic inflammation, cytokine dysregulation and anti-brain autoantibodies. Although immunome pathways are involved in ASD pathophysiology, there is little known about how they relate to symptom domains or symptom severity, and whether such biomarkers may be useful in optimizing future clinical trials. We correlated baseline clinical measures of cognitive inflexibility and resultant irritability with immunome biomarker levels in children with ASD, aged 5-18 years with ABC-I scores ≥18, CGI-S scores ≥4 and SRS-2 scores ≥66T, at Albert Einstein College of Medicine (AECOM). Non-parametric Spearman correlations and estimated multivariable regression analyses adjusting for potential confounders, including other clinical variables, race, sex, and age were completed. Strong positive correlations (r_s > .70) were found between the Montefiore Einstein Rigidity Scale - Revised (MERS-R) Total Score and the pro-inflammatory cytokines IL-6 (r_s=.80), granulocyte-colony stimulating factor (GCSF; r_s =.72), macrophage inflammatory protein-1 alpha (MIP-1a; r_s =.71). The MERS-R subscales also had moderate and strong correlations with the immunome biomarkers. The MERS-R Total Rigidity Subscale Score had a strong positive relationship with IL-6 (r_s = 0.7856). Using multivariable regression analyses significant relationships were found between the MERS-R Total Rigidity Subscale Score and proinflammatory cytokine IL-18 (p = 0.02), and a nonsignificant trend was found between it and IFN-alpha2 (β = -4.982, p = 0.058). The ABC-I was significantly correlated with pro-inflammatory cytokine IL-18 (p = .013), IFN-alpha2 (p = 0.039), the anti-inflammatory cytokine IL-10 (p = 0.02), and adaptive immunity cytokine IL-2 (p = 0.041). This preliminary data is the first to examine the relationship of clinical measures of cognitive inflexibility and immunome biomarkers in children with ASD, and may provide a framework for better understanding the relationship between immunome mechanisms, cognitive inflexibility, and ASD symptomatology. Clinicaltrials.gov: NCT03202303.