Type I Kounis syndrome induced by COVID-19 vaccination in China: a case report.

BACKGROUND: Kounis syndrome is a rare clinical condition characterized by the occurrence of an acute coronary event induced by an acute allergic episode. The ongoing pandemic of coronavirus disease 2019 (COVID-19) has contributed to an increase in the incidence of allergic reactions to a certain extent, thereby increasing the incidence of Kounis syndrome. Timely diagnosis and effective management of this disease are important in clinical practice. CASE PRESENTATION: We report a 43-year-old woman who developed generalized pruritus, breathlessness, paroxysmal precordial crushing pain, and dyspnea after receiving the third dose of the COVID-19 vaccine. After anti-allergic treatment and therapy for acute myocardial ischemia, her symptoms resolved with improvement in cardiac function and resolution of ST-segment changes. The prognosis was satisfactory, and the final diagnosis was type I Kounis syndrome. CONCLUSION: This patient with type I Kounis syndrome rapidly developed acute coronary syndrome (ACS) after an acute allergic reaction to the COVID-19 vaccine. ​Timely diagnosis of acute allergic reaction and ACS, and targeted treatment based on the relevant guidelines are the key to successful treatment of the syndrome.​.

ApoE4 associated with severe COVID-19 outcomes via downregulation of ACE2 and imbalanced RAS pathway.

BACKGROUND: Recent numerous epidemiology and clinical association studies reported that ApoE polymorphism might be associated with the risk and severity of coronavirus disease 2019 (COVID-19), and yielded inconsistent results. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection relies on its spike protein binding to angiotensin-converting enzyme 2 (ACE2) receptor expressed on host cell membranes. METHODS: A meta-analysis was conducted to clarify the association between ApoE polymorphism and the risk and severity of COVID-19. Multiple protein interaction assays were utilized to investigate the potential molecular link between ApoE and the SARS-CoV-2 primary receptor ACE2, ApoE and spike protein. Immunoblotting and immunofluorescence staining methods were used to access the regulatory effect of different ApoE isoform on ACE2 protein expression. RESULTS: ApoE gene polymorphism (ε4 carrier genotypes VS non-ε4 carrier genotypes) is associated with the increased risk (P = 0.0003, OR = 1.44, 95% CI 1.18-1.76) and progression (P < 0.00001, OR = 1.85, 95% CI 1.50-2.28) of COVID-19. ApoE interacts with both ACE2 and the spike protein but did not show isoform-dependent binding effects. ApoE4 significantly downregulates ACE2 protein expression in vitro and in vivo and subsequently decreases the conversion of Ang II to Ang 1-7. CONCLUSIONS: ApoE4 increases SARS-CoV-2 infectivity in a manner that may not depend on differential interactions with the spike protein or ACE2. Instead, ApoE4 downregulates ACE2 protein expression and subsequently the dysregulation of renin-angiotensin system (RAS) may provide explanation by which ApoE4 exacerbates COVID-19 disease.