Sensory, behavioral, and basic immunological profiles: are their associations specific for Autism in adults with moderate-to-profound Intellectual Disability?

Autism Spectrum Disorder (ASD) has a high probability to co-occur with Intellectual Disability (ID). When ID is particularly severe, it becomes harder to clearly differentiate ID with and without ASD. This is often due to the presence of features that are common to both conditions, such as altered immune activity, atypical sensory processing and rigidity in behaviors. The present observational, cross-sectional study aimed at exploring the immunity, sensory and behavioral profiles of 20 adults with moderate-to-profound ID and 53 adults with ID and ASD (ASD+ID). Associations between leucocytes blood counts and scores of sensory/behavioral questionnaires compiled by professional caregivers were explored as primary aim both in the whole sample and within-groups. As secondary aims, associations between sensory and behavioral profiles were measured, and between-group differences of immunity, sensory, behavioral, and medications parameters were computed. Trends of mild, positive correlations were present between leucocytes blood counts and auditory, body position and sensory sensitivity alterations in the whole sample, and similar patterns were found after considering ASD+ID and ID groups separately. No associations emerged between immunity and behavioral profiles. No between-groups differences in sensory or behavioral scores were found. Olanzapine and leucocytes blood counts were higher in the ASD+ID group (p = 0.017 and p = 0.007), although only leucocytes blood counts fairly discriminated between ASD+ID and ID subjects (AUC = 0.717). Although sensory and behavioral profiles were similar across diagnostic categories, this study suggests that basic immunity profiles may be informative to characterize ASD+ID and ID groups in real-world clinical practice. The presence of associations between immune and sensory profiles might indicate that immune systems mediate sensory sensitivity, especially for auditory and body perception channels. Immune and sensory profiles have similar associations in ASD+ID and ID. To understand the possible mechanisms of such interactions (inflammation, immune activation) may allow the development of tailored therapeutic strategies and to better differentiate ASD- from ID-related features when severe cognitive impairments are present.