Kawasaki Disease Shock Syndrome; a Different Subtype of Kawasaki Disease?

Background. Super antigen (SAg) is suspected to be responsible of Kawasaki Disease Shock Syndrome (KDSS) which is an aggressive complication of Kawasaki Disease (KD). We hypothesize that KDSS is associated with the activation of TCRVβ2 and TCRVβ8 lymphocytes through the presence of SAg from bacteria that colonize the gastrointestinal tract.

Objective. To compare the expression of TCRVβ2 and Vβ8 receptor variants in lymphocytes of the KDSS and KD groups.

Methods. A case-control study was performed in patients admitted in the National Institute of Pediatrics between January 2018 and July 2019. Case group (n=8), patients with KDSS; control group (n=56), patients with KD without shock. The percentage (%) of CD4 and CD8 T cells expressing TCRVβ2 and TCRVβ8 as well the activated lymphocytes CD25+ were determined in blood samples by flow cytofluorometry. Wilcoxon Rank-Sum Test was used to compare both groups.

Results. The expression of variants CD3+CD4+TCRVβ2+ and CD3+CD8+TCRVβ8+CD25+ was significantly higher in the KDSS group, in comparison to non-shock KD group with a median [Q1, Q3]: 27.7 [4.0, 53.2] vs. 2.2 [0.3, 9.4] (P= 0.016) and 13.7 [3.9, 56.3] vs. 2.6 [0.5, 11.2] (P=0.028), respectively.

Conclusion. These preliminary data suggests that a SAg is triggering the excessive response observed in patients with KDSS. Continuing this study with a bigger sample size will be necessary.