116 - FOUR GRAND-PARENTS ETHNIC ORIGIN OF KD AND MIS-C PATIENTS. THE MONTRÉAL OBSERVATION DURING THE SARS-COV-2 PANDEMIC

Background: Differences between ethnic prevalence in KD and MIS-C suggest differences in genetic disease predisposition. Direct relationship between SARS-CoV2 and MIS-C also suggests a socio-cluster exposure effects of the trigger virus. We conducted a retrospective study on ethnic origin of children diagnosed with KD or MIS-C in a tertiary children’s hospital in Montreal. We also sought to assess high-risk exposure to SARS-CoV2 on ethnic groups.

Methods: Patients with a diagnosis of KD or MIS-C at CHU Sainte-Justine, Montreal during the COVID-19 pandemic (January 2020 – June 2023) were recruited. The country of origin of the patients' four grandparents obtained via standardized questionnaire were distributed based on Statistics Canada ethnic categories. Annualized incidence rate (AIR) was calculated using the standard denominator (SD) of 100,000 iso-ethnic children under 5 years old. Eight ethno-regional conglomerate classes were used (Canadian Institute for Health Information); accordingly, French-Canadians, a genetically established Founding Father, were considered separately.  High-risk contagion for SARS-CoV2 was determined when parents worked in high-risk exposure settings, such as healthcare jobs. Family or personal auto-immune conditions were also captured for risk assessment.

Results:  From 110 KD and 68 MIS-C, 72 (66%) and 48 (71%) consented to participate. French-Canadians represented the highest ethnicity (55% of KD) (Figure-1), with the highest AIR (57/SD) (Figure-2). Other ethnicities included East-Asians (17%), Blacks/Africans (10%), Middle-Eastern (8%), Southeast-Asians (4%) and Latino (3%). The incidence of KD in non-French-Canadian Caucasians was exceptionally low (3.03/SD), further highlighting French-Canadians risk for KD. The AIR of MIS-C was also the highest among French Canadians (11.1/SD), which accounted for 39% of MIS-C cases, followed by Blacks (6.57/SD), Middle-Eastern (4.71/SD) and Latino (2.19/SD), but low in Caucasians of non-French-Canadian descents (1.1/SD). There were no cases of MIS-C of Asian origin.  Otherwise, there was no statistically significant distribution of high-risk virus exposure between ethnic classes in KD (25/72 KD (34%); p=0.455) and borderline significance in MIS-C (11/48 (23%); p=0.064). Finally, a significant clustering of personal autoimmune conditions in KD (n=25) showed statistically significant clustering in French-Canadians 13/25 (p=0.012), but not in MIS-C (n=8), (p=0.27). 

 




Conclusion:

In this methodologically determined ethnic assessment, French-Canadians are at greater risk to develop KD and MIS-C, more so for KD. High-risk parental exposure to SARS-CoV2 did not affect ethnic distribution; instead, autoimmune conditions were more prevalent in French-Canadian KD patients.  The overrepresentation of French-Canadians in the exposed population is possible bias.  Nevertheless, the observations merit consideration for multi-ethnicity factors and genetic predisposition.