Impact of COVID-19 infection on Kawasaki disease and immune status in children.

Patients infected with SARS-CoV-2 may experience acute and long-term immune disorders. Immunological factors are thought to play an important role in Kawasaki disease. To analyze the impact of COVID-19 infection on Kawasaki disease, this study retrospectively analyzed 161 children with Kawasaki disease onset during the COVID-19 pandemic. The proportion of IVIG-Resistant individuals and the rate of corticosteroid use in the 1-7 weeks from COVID-19 infection to Kawasaki disease onset were higher than that of the noninfected group, even after excluding suspected cases of multiple system inflammatory syndrome. Compared to the noninfected group, the level of CD4 was lower, and the levels of CD3-CD16+CD56+, complement C4, TNF-α, and IFN-γ were higher in the 1-7 weeks after COVID-19 infection. In conclusion, the risk of IVIG resistance was significantly increased in children with Kawasaki disease onset 1-7 weeks after COVID-19 infection, which may be related to the long-term impact of COVID-19 on immunity.