Immune and coagulation profiles in 3 adults with multisystem inflammatory syndrome

INTRODUCTION@#There is a paucity of information on the cytokine, complement, endothelial activation, and coagulation profiles of multisystem inflammatory syndrome in adults (MIS-A), a rare but serious complication following recovery from SARS-CoV-2 infection. We aim to examine the immune biomarker and coagulation profiles in association with the clinical presentation and course of MIS-A.@*METHOD@#The clinical features of MIS-A patients admitted to our tertiary hospital were documented. Their levels of interleukin (IL)-1β, IL-6, IL-10, IL-17, IL-18, interferon-α (IFN-α), IFN-γ, interferon gamma-induced protein 10 (IP-10), tumour necrosis factor (TNF)-α, monocyte chemoattractant protein (MCP)-1, complement activation product (complement 5a [C5a]), and endothelial biomarker intercellular adhesion molecule-1 (ICAM-1) levels were assayed. The haemostatic profile was assessed with standard coagulation testing and thromboelastography.@*RESULTS@#Three male patients were diagnosed with MIS-A at our centre from January to June 2022 with a median age of 55 years. All had tested positive for SARS-CoV-2 12-62 days prior to MIS-A presentation, with gastrointestinal and cardiovascular systems as the most commonly involved. Levels of IL-6, IL-10, IL-18, IP-10 and MCP-1 were raised whereas IL-1β, IFN-α, IFN-γ, IL-17 and TNF-α remained normal. Markedly elevated levels of C-reactive protein (CRP), ferritin and ICAM-1 were present in all. C5a was elevated in 2 patients. A hypercoagulable state was demonstrated by raised levels of D-dimer, factor VIII, von Willebrand factor antigen, and ristocetin cofactor with corresponding raised parameters in thromboelastography in the 2 patients who had their coagulation profile assessed.@*CONCLUSION@#MIS-A patients demonstrate activation of pro-inflammatory cytokines, endotheliopathy, complement hyperactivation and hypercoagulability.

ST-segment elevation myocardial infarction in post-COVID-19 patients: A case series

Coronavirus disease 2019 (COVID-19) is associated with an increased risk of thromboembolic events in the acute setting. However, the abnormal thrombotic diathesis is not known to persist into the recovery phase of COVID-19 infection. We described 3 cases of ST-segment elevation myocardial infarction in healthy male patients who recovered from COVID-19 with no prior cardiovascular risk factors. They shared features of elevated von Willebrand factor antigen, factor VIII and D-dimer level. One patient had a borderline positive lupus anticoagulant. Intravascular ultrasound of culprit vessels revealed predominantly fibrotic plaque with minimal necrotic core. Clot waveform analysis showed parameters of hypercoagulability. They were treated with dual antiplatelet therapy, angiotensin-converting-enzyme inhibitor, beta blocker and statin. These cases highlight the strong thrombogenic nature of COVID-19 that persisted among patients who recovered from infection. Several suspected mechanisms could explain the association between vascular thrombosis in the convalescent period (endothelial dysfunction, hypercoagulability, systemic inflammatory response and vasculopathy). Additional studies on "long COVID" are essential for identifying endotheliopathy and thrombotic sequalae.