Predictive factors of comorbid attention-deficit/hyperactivity disorder in early systemic autoimmune and auto-inflammatory disorders.

BACKGROUND

The immune system is physiologically involved in brain development and homeostasis. Consequently, early immune-mediated events are known risk factors for neurodevelopmental disorders (NDD). We recently found that early systemic autoimmune and autoinflammatory disorders (ESAID) are associated with an increased risk of neurodevelopmental disorders due to the direct impact of inflammation on brain development. However not all ESAID patient will develop NDD. In this study, we aimed to better characterized the natural history of the NDD comorbidity and investigate the influence of others NDD risk factors in ESAID patients with ADHD (ESAID+/ADHD+; n = 14) compared to patient with ESAID without ADHD (ESAID+/ADHD-; n = 14) and patient with ADHD without ESAID (ESAID-/ADHD + = 35).

FINDINGS

We did a case control study using a cohort of ESAID patients (ARTEMIS) and an ADHD cohort (Robert Debre) and found that the onset of ADHD in patients with ESAID is associated with global cognitive brain impairment that does not appear to be due to shared genetic risk factors, reinforcing the hypothesis of an immune-mediated mechanism. Regarding the etiopathogenesis of this comorbidity, we found that low birth weight, a known risk factor for NDD, contributes to the development of ADHD in ESAID patients.

CONCLUSIONS

Pediatricians, and in particular pediatric rheumatologists, need to be aware of the frequency of ADHD-related comorbidities in ESAID patients. They should therefore systematically look for NDD in ESAID patients, particularly in cases of low birth weight. Early detection and management of NDD is the only way to limit its impact on morbidity and life trajectory.