Background: Rare cases of Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C) have been reported following the coronavirus disease 2019 (COVID-19) vaccination; however, the association between COVID-19 vaccination and the risk of developing KD/MIS-C has not yet been established. Methods: We conducted a self-controlled case series analysis using a large-linked database that connects the COVID-19 immunization registry with nationwide claims data. We identified individuals aged < 18 years who received their initial COVID-19 vaccination and had a KD/MIS-C diagnosis with a prescription for intravenous immunoglobulin or corticosteroids between October 18, 2021, and April 15, 2023. The observation period was set as 240 days from the date of the COVID-19 vaccination. The risk window was 60 days after vaccination, with the remaining observation period serving as the control window. The incidence rate ratios (IRRs) and 95% confidence intervals (CIs) in the risk versus control windows were estimated using the conditional Poisson regression model. We further analyzed the vaccine doses and types for secondary analysis. We also performed subgroup analyses stratified by sex, age, comorbidities, and other conditions and sensitivity analyses by varying the length of the risk window and outcome definition. Results: Among 2,369,490 individuals who received the COVID-19 vaccination, 12 cases of KD/MIS-C were identified, which included five and seven patients in the risk and control windows, respectively. There was no increased risk of KD/MIS-C within the 60-day period of vaccination (IRR, 0.53; 95% CI, 0.17–1.60). Secondary subgroup and sensitivity analyses showed no significant increase in the risk of KD/MIS-C after COVID-19 vaccination, which is consistent with the results of the main analysis. Conclusion The results of this nationwide study suggest that the risk of developing KD/MIS-C did not increase after COVID-19 vaccination. However, owing to the lack of a sufficient number of cases, future studies utilizing multinational long-term follow-up databases should be conducted. Considering the increasing incidence of KD/MIS-C and the limited understanding of its precise biological mechanisms, additional research on KD/MIS-C is warranted.

Background: Rare cases of Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C) have been reported following the coronavirus disease 2019 (COVID-19) vaccination; however, the association between COVID-19 vaccination and the risk of developing KD/MIS-C has not yet been established. Methods: We conducted a self-controlled case series analysis using a large-linked database that connects the COVID-19 immunization registry with nationwide claims data. We identified individuals aged < 18 years who received their initial COVID-19 vaccination and had a KD/MIS-C diagnosis with a prescription for intravenous immunoglobulin or corticosteroids between October 18, 2021, and April 15, 2023. The observation period was set as 240 days from the date of the COVID-19 vaccination. The risk window was 60 days after vaccination, with the remaining observation period serving as the control window. The incidence rate ratios (IRRs) and 95% confidence intervals (CIs) in the risk versus control windows were estimated using the conditional Poisson regression model. We further analyzed the vaccine doses and types for secondary analysis. We also performed subgroup analyses stratified by sex, age, comorbidities, and other conditions and sensitivity analyses by varying the length of the risk window and outcome definition. Results: Among 2,369,490 individuals who received the COVID-19 vaccination, 12 cases of KD/MIS-C were identified, which included five and seven patients in the risk and control windows, respectively. There was no increased risk of KD/MIS-C within the 60-day period of vaccination (IRR, 0.53; 95% CI, 0.17–1.60). Secondary subgroup and sensitivity analyses showed no significant increase in the risk of KD/MIS-C after COVID-19 vaccination, which is consistent with the results of the main analysis. Conclusion The results of this nationwide study suggest that the risk of developing KD/MIS-C did not increase after COVID-19 vaccination. However, owing to the lack of a sufficient number of cases, future studies utilizing multinational long-term follow-up databases should be conducted. Considering the increasing incidence of KD/MIS-C and the limited understanding of its precise biological mechanisms, additional research on KD/MIS-C is warranted.

Background: Rare cases of Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C) have been reported following the coronavirus disease 2019 (COVID-19) vaccination; however, the association between COVID-19 vaccination and the risk of developing KD/MIS-C has not yet been established. Methods: We conducted a self-controlled case series analysis using a large-linked database that connects the COVID-19 immunization registry with nationwide claims data. We identified individuals aged < 18 years who received their initial COVID-19 vaccination and had a KD/MIS-C diagnosis with a prescription for intravenous immunoglobulin or corticosteroids between October 18, 2021, and April 15, 2023. The observation period was set as 240 days from the date of the COVID-19 vaccination. The risk window was 60 days after vaccination, with the remaining observation period serving as the control window. The incidence rate ratios (IRRs) and 95% confidence intervals (CIs) in the risk versus control windows were estimated using the conditional Poisson regression model. We further analyzed the vaccine doses and types for secondary analysis. We also performed subgroup analyses stratified by sex, age, comorbidities, and other conditions and sensitivity analyses by varying the length of the risk window and outcome definition. Results: Among 2,369,490 individuals who received the COVID-19 vaccination, 12 cases of KD/MIS-C were identified, which included five and seven patients in the risk and control windows, respectively. There was no increased risk of KD/MIS-C within the 60-day period of vaccination (IRR, 0.53; 95% CI, 0.17–1.60). Secondary subgroup and sensitivity analyses showed no significant increase in the risk of KD/MIS-C after COVID-19 vaccination, which is consistent with the results of the main analysis. Conclusion The results of this nationwide study suggest that the risk of developing KD/MIS-C did not increase after COVID-19 vaccination. However, owing to the lack of a sufficient number of cases, future studies utilizing multinational long-term follow-up databases should be conducted. Considering the increasing incidence of KD/MIS-C and the limited understanding of its precise biological mechanisms, additional research on KD/MIS-C is warranted.

Background: Rare cases of Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C) have been reported following the coronavirus disease 2019 (COVID-19) vaccination; however, the association between COVID-19 vaccination and the risk of developing KD/MIS-C has not yet been established. Methods: We conducted a self-controlled case series analysis using a large-linked database that connects the COVID-19 immunization registry with nationwide claims data. We identified individuals aged < 18 years who received their initial COVID-19 vaccination and had a KD/MIS-C diagnosis with a prescription for intravenous immunoglobulin or corticosteroids between October 18, 2021, and April 15, 2023. The observation period was set as 240 days from the date of the COVID-19 vaccination. The risk window was 60 days after vaccination, with the remaining observation period serving as the control window. The incidence rate ratios (IRRs) and 95% confidence intervals (CIs) in the risk versus control windows were estimated using the conditional Poisson regression model. We further analyzed the vaccine doses and types for secondary analysis. We also performed subgroup analyses stratified by sex, age, comorbidities, and other conditions and sensitivity analyses by varying the length of the risk window and outcome definition. Results: Among 2,369,490 individuals who received the COVID-19 vaccination, 12 cases of KD/MIS-C were identified, which included five and seven patients in the risk and control windows, respectively. There was no increased risk of KD/MIS-C within the 60-day period of vaccination (IRR, 0.53; 95% CI, 0.17–1.60). Secondary subgroup and sensitivity analyses showed no significant increase in the risk of KD/MIS-C after COVID-19 vaccination, which is consistent with the results of the main analysis. Conclusion The results of this nationwide study suggest that the risk of developing KD/MIS-C did not increase after COVID-19 vaccination. However, owing to the lack of a sufficient number of cases, future studies utilizing multinational long-term follow-up databases should be conducted. Considering the increasing incidence of KD/MIS-C and the limited understanding of its precise biological mechanisms, additional research on KD/MIS-C is warranted.

Purpose: Metabolic diseases share common risk factors, requiring the development of therapeutic agents with multi-target effects. Although the ameliorating effects of Porphyra tenera ethanol extract (PTE) have been reported on some individual metabolic disorders, studies addressing various other metabolic diseases are still limited. This study investigated the ameliorating effects of PTE supplementation for 12 weeks on obesity, dyslipidemia, and hepatic lipid metabolism in high-fat diet (HFD)-induced obese mice and its molecular mechanisms. Methods: Male C57BL/6 mice (n = 12/in each group) were divided into six groups for 12 weeks: control, HFD, chow diet + 1% porphyran, chow diet + 4% porphyran, HFD + 1% porphyran (HPYP-L), and HFD + 4% porphyran (HPYP-H). To confirm the attenuation of metabolic disease in vivo, mice in the HFD, HPYP-L and HPYP-H groups were fed 60% HFD to induce obesity. PTE was prepared using ethanol and dissolved in drinking water to concentrations of 1% and 4% porphyran. After 12 weeks of free PTE intake, body weight measurement, serum analysis, histopathological analysis, real-time quantitative polymerase chain reaction, and Western blot analysis of liver tissues were performed for comparative evaluation. Results: After 12 weeks, the HPYP-L and HPYP-H groups showed a decreased body weight, improved blood lipids, and reduced hepatic lipid droplet accumulation vs. the HFD group.Liver acetyl-CoA carboxylase, was suppressed in the HPYP-L group vs. the HFD group.The B-cell lymphoma 2 (Bcl-2)-associated X protein/Bcl-2 protein and messenger RNA (mRNA) level ratio in the liver decreased after PTE intake, indicating inhibition of apoptosis.Interleukin-1 beta mRNA expression in the liver was reduced in the HPYP-L group vs. the HFD group. In the liver, lower protein carbonylation levels in the HPYP-H group indicated reduced oxidative stress, while the increased mitochondrial DNAuclear DNA ratio indicated improved mitochondrial function. Conclusion PTE protects against diet-induced metabolic disorders and could be a potential agent for the prevention and treatment of metabolic diseases.

Purpose: Metabolic diseases share common risk factors, requiring the development of therapeutic agents with multi-target effects. Although the ameliorating effects of Porphyra tenera ethanol extract (PTE) have been reported on some individual metabolic disorders, studies addressing various other metabolic diseases are still limited. This study investigated the ameliorating effects of PTE supplementation for 12 weeks on obesity, dyslipidemia, and hepatic lipid metabolism in high-fat diet (HFD)-induced obese mice and its molecular mechanisms. Methods: Male C57BL/6 mice (n = 12/in each group) were divided into six groups for 12 weeks: control, HFD, chow diet + 1% porphyran, chow diet + 4% porphyran, HFD + 1% porphyran (HPYP-L), and HFD + 4% porphyran (HPYP-H). To confirm the attenuation of metabolic disease in vivo, mice in the HFD, HPYP-L and HPYP-H groups were fed 60% HFD to induce obesity. PTE was prepared using ethanol and dissolved in drinking water to concentrations of 1% and 4% porphyran. After 12 weeks of free PTE intake, body weight measurement, serum analysis, histopathological analysis, real-time quantitative polymerase chain reaction, and Western blot analysis of liver tissues were performed for comparative evaluation. Results: After 12 weeks, the HPYP-L and HPYP-H groups showed a decreased body weight, improved blood lipids, and reduced hepatic lipid droplet accumulation vs. the HFD group.Liver acetyl-CoA carboxylase, was suppressed in the HPYP-L group vs. the HFD group.The B-cell lymphoma 2 (Bcl-2)-associated X protein/Bcl-2 protein and messenger RNA (mRNA) level ratio in the liver decreased after PTE intake, indicating inhibition of apoptosis.Interleukin-1 beta mRNA expression in the liver was reduced in the HPYP-L group vs. the HFD group. In the liver, lower protein carbonylation levels in the HPYP-H group indicated reduced oxidative stress, while the increased mitochondrial DNAuclear DNA ratio indicated improved mitochondrial function. Conclusion PTE protects against diet-induced metabolic disorders and could be a potential agent for the prevention and treatment of metabolic diseases.

Purpose: Metabolic diseases share common risk factors, requiring the development of therapeutic agents with multi-target effects. Although the ameliorating effects of Porphyra tenera ethanol extract (PTE) have been reported on some individual metabolic disorders, studies addressing various other metabolic diseases are still limited. This study investigated the ameliorating effects of PTE supplementation for 12 weeks on obesity, dyslipidemia, and hepatic lipid metabolism in high-fat diet (HFD)-induced obese mice and its molecular mechanisms. Methods: Male C57BL/6 mice (n = 12/in each group) were divided into six groups for 12 weeks: control, HFD, chow diet + 1% porphyran, chow diet + 4% porphyran, HFD + 1% porphyran (HPYP-L), and HFD + 4% porphyran (HPYP-H). To confirm the attenuation of metabolic disease in vivo, mice in the HFD, HPYP-L and HPYP-H groups were fed 60% HFD to induce obesity. PTE was prepared using ethanol and dissolved in drinking water to concentrations of 1% and 4% porphyran. After 12 weeks of free PTE intake, body weight measurement, serum analysis, histopathological analysis, real-time quantitative polymerase chain reaction, and Western blot analysis of liver tissues were performed for comparative evaluation. Results: After 12 weeks, the HPYP-L and HPYP-H groups showed a decreased body weight, improved blood lipids, and reduced hepatic lipid droplet accumulation vs. the HFD group.Liver acetyl-CoA carboxylase, was suppressed in the HPYP-L group vs. the HFD group.The B-cell lymphoma 2 (Bcl-2)-associated X protein/Bcl-2 protein and messenger RNA (mRNA) level ratio in the liver decreased after PTE intake, indicating inhibition of apoptosis.Interleukin-1 beta mRNA expression in the liver was reduced in the HPYP-L group vs. the HFD group. In the liver, lower protein carbonylation levels in the HPYP-H group indicated reduced oxidative stress, while the increased mitochondrial DNAuclear DNA ratio indicated improved mitochondrial function. Conclusion PTE protects against diet-induced metabolic disorders and could be a potential agent for the prevention and treatment of metabolic diseases.