THU0507 ASSOCIATION BETWEEN JUVENILE IDIOPATHIC ARTHRITIS AND AUTISM
Authors: R. Beesley
Journal: Annals of the Rheumatic Diseases (2020)

Background: Juvenile Idiopathic Arthritis (JIA) is a heterogenous group of autoimmune disorders characterised by chronic joint inflammation, diagnosed in around 1 in 1,000 children and young people (CYP) under the age of 16. Autistic Spectrum Condition (ASC) is a neurodevelopmental condition characterised by differences in social communication and sensory perception, as well as restricted interests and repetitive behaviours. Recent estimates from the Centers for Disease Control and Prevention (CDC) suggest that 1.68% of CYP are diagnosed with ASC, with males being more likely to be diagnosed (sex ratio of 4:1) [1]. The causes of both JIA and ASC are complex interactions between genetic and environmental factors. There appears to be some evidence that ASC may be associated with certain parental autoimmune conditions [2], although research into any association between JIA and ASC is sparse with the exception of a review of clinical database information [3]. Objectives: In this parent-led study, the association between JIA and ASC was explored in order to determine if children with JIA, or children who do not themselves have JIA but have at least one first-degree relative with JIA (FDR), are more likely to be diagnosed with ASC. Methods: Parents of CYP with JIA were invited to complete an online survey, giving details of each member of their family including diagnosis status for JIA and ASC, and age of diagnoses. A total of 247 responses were collated, representing 558 CYP. Overall, 202 CYP were diagnosed with JIA from 197 families. The eldest child with JIA from each family was selected (total 197; 66 male and 131 female) and the rate of ASC was compared against the general population using Fisher’s exact tests. Results: Children with JIA themselves and FDR children were significantly more likely to be diagnosed with ASC. Group Odds Ratio (95% CI ) p-value JIA children overall 6.107 (1.760, 21.190) 0.0020 ** FDR children overall 7.009 (2.033, 24.160) 0.0006 *** Figure 1. Proportion of children diagnosed with ASC in the general population (CDC estimates), JIA group and FDR group. Error bar indicates 95% CI. Significance indicated compared to population. Conclusion: Individuals with JIA and family members of individuals with JIA are more likely to be diagnosed with ASC. The results remained unchanged in a sensitivity analysis in which JIA children who had another sibling with JIA were excluded in order to minimise the risk that these results were affected by selecting the eldest child with JIA. It is possible that we are underestimating the association between JIA and ASC in this study. The majority of children sampled were from the United Kingdom and Ireland; however, we chose to utilise the most recent CDC estimates for ASC prevalence, as the most recent estimates from the UK were from 2006 and longitudinal data suggests that ASC prevalence continues to increase, likely due to changes in diagnostic criteria and improved recognition of the condition. When using the UK prevalence estimates, JIA children and FDR children remain significantly more likely to be diagnosed with ASC than the general population as a whole. Future research should focus on confirming these findings in larger, population-based samples. References: [1]Christensen DL, Braun KV, Baio J, et al. Prevalence and Characteristics of Autism Spectrum Disorder Among Children Aged 8 Years — Autism and Developmental Disabilities Monitoring Network, 11 Sites, United States, 2012. MMWR Surveill Summ (2018); 65 (No. SS-13):1–23. [2]Hughes, H. K., Mills Ko, E., Rose, D. &amp; Ashwood, P. Immune Dysfunction and Autoimmunity as Pathological Mechanisms in Autism Spectrum Disorders. Frontiers in Cellular Neuroscience (2018); 12 [3]Haslam, K. P16 Is there an association between paediatric rheumatological disease and autism? Rheumatology 2019; 58 Disclosure of Interests: None declared