Mixed storm in SARS‐CoV‐2 infection: A narrative review and new term in the Covid‐19 era

Abstract Coronavirus disease 2019 (Covid‐19) is caused by a novel severe acute respiratory syndrome coronavirus virus type 2 (SARS‐CoV‐2) leading to the global pandemic worldwide. Systemic complications in Covid‐19 are mainly related to the direct SARS‐CoV‐2 cytopathic effects, associated hyperinflammation, hypercytokinemia, and the development of cytokine storm (CS). As well, Covid‐19 complications are developed due to the propagation of oxidative and thrombotic events which may progress to a severe state called oxidative storm and thrombotic storm (TS), respectively. In addition, inflammatory and lipid storms are also developed in Covid‐19 due to the activation of inflammatory cells and the release of bioactive lipids correspondingly. Therefore, the present narrative review aimed to elucidate the interrelated relationship between different storm types in Covid‐19 and the development of the mixed storm (MS). In conclusion, SARS‐CoV‐2 infection induces various storm types including CS, inflammatory storm, lipid storm, TS and oxidative storm. These storms are not developing alone since there is a close relationship between them. Therefore, the MS seems to be more appropriate to be related to severe Covid‐19 than CS, since it develops in Covid‐19 due to the intricate interface between reactive oxygen species, proinflammatory cytokines, complement activation, coagulation disorders, and activated inflammatory signaling pathway

SARS‐CoV‐2 induced HDL dysfunction may affect the host's response to and recovery from COVID‐19

Abstract Introduction Covid‐19 is linked with the development of cardio‐metabolic disorders, including dyslipidemia, dysregulation of high‐density lipoprotein (HDL), and low‐density lipoprotein (LDL). Furthermore, SARS‐Co‐2 infection is associated with noteworthy changes in lipid profile, which is suggested as a possible biomarker to support the diagnosis and management of Covid‐19. Methods This paper adopts the literature review method to obtain information about how Covid‐19 affects high‐risk group patients and may cause severe and critical effects due to the development of acute lung injury and acute respiratory distress syndrome. A narrative and comprehensive review is presented. Results Reducing HDL in Covid‐19 is connected to the disease severity and poor clinical outcomes, suggesting that high HDL serum levels could benefit Covid‐19. SARS‐CoV‐2 binds HDL, and this complex is attached to the co‐localized receptors, facilitating viral entry. Therefore, SARS‐CoV‐2 infection may induce the development of dysfunctional HDL through different mechanisms, including induction of inflammatory and oxidative stress with activation of inflammatory signaling pathways. In turn, the induction of dysfunctional HDL induces the activation of inflammatory signaling pathways and oxidative stress, increasing Covid‐19 severity. Conclusions Covid‐19 is linked with the development of cardio‐metabolic disorders, including dyslipidemia in general and dysregulation of high‐density lipoprotein and low‐density lipoprotein. Therefore, the present study aimed to overview the causal relationship between dysfunctional high‐density lipoprotein and Covid‐19