Efficacy of Tocilizumab Therapy in Different Subtypes of COVID-19 Cytokine Storm Syndrome

Even one dose of tocilizumab could hinder bad prognosis of cytokines storm in COVID-19 patients

Severe COVID-19 pneumonia is a principal cause of death due to cascade of hyper inflammatory condition that leading to lung damage. Therefore, an effective therapy to countercurrent the surge of uncontrolled inflammation is mandatory to propose. Anti-interlukin-6 receptor antagonist monoclonal therapy, tocilizumab (TCZ) showed potential results in COVID-19 patients. This study aimed to emphasize the factors associated with mortality in COVID-19 patients that treated with tocilizumab and may influence the level of serum IL-6. A retrospective cohort study included all patients with clinical parameters that pointed to presence of cytokines storm and treated with one or more doses of TCZ beside the regular protocol of COVID-19 pneumonia. The factors that influence the mortality in addition to the level of serum IL-6 were analyzed. A total of 377 patients were included, 69.5 % of them received only one dose of TCZ which started mainly at the third day of admission. The mortality rate was 29.44 %. Regardless the time of starting TCZ, just one dose was fair enough to prevent bad consequence; OR = 0.04, P = 0.001.However, in spite of protective action of TCZ, older age and female sex were significant risk factors for mortality, P = 0.001 and 0.01 respectively, as well heart disease. Moreover, increasing the level of neutrophil, AST and IL-6 were associated with bad prognosis. In the same line, treatment with ivermectin, chloroquine and remdesivir inversely affect the level of IL-6. Early treatments of COVID-19 pneumonia with at least one dose of tocilizumab minimized the fatality rate.

Passive Immunotherapy Against SARS-CoV-2: From Plasma-Based Therapy to Single Potent Antibodies in the Race to Stay Ahead of the Variants

The COVID-19 pandemic is now approaching 2 years old, with more than 440 million people infected and nearly six million dead worldwide, making it the most significant pandemic since the 1918 influenza pandemic. The severity and significance of SARS-CoV-2 was recognized immediately upon discovery, leading to innumerable companies and institutes designing and generating vaccines and therapeutic antibodies literally as soon as recombinant SARS-CoV-2 spike protein sequence was available. Within months of the pandemic start, several antibodies had been generated, tested, and moved into clinical trials, including Eli Lilly's bamlanivimab and etesevimab, Regeneron's mixture of imdevimab and casirivimab, Vir's sotrovimab, Celltrion's regdanvimab, and Lilly's bebtelovimab. These antibodies all have now received at least Emergency Use Authorizations (EUAs) and some have received full approval in select countries. To date, more than three dozen antibodies or antibody combinations have been forwarded into clinical trials. These antibodies to SARS-CoV-2 all target the receptor-binding domain (RBD), with some blocking the ability of the RBD to bind human ACE2, while others bind core regions of the RBD to modulate spike stability or ability to fuse to host cell membranes. While these antibodies were being discovered and developed, new variants of SARS-CoV-2 have cropped up in real time, altering the antibody landscape on a moving basis. Over the past year, the search has widened to find antibodies capable of neutralizing the wide array of variants that have arisen, including Alpha, Beta, Gamma, Delta, and Omicron. The recent rise and dominance of the Omicron family of variants, including the rather disparate BA.1 and BA.2 variants, demonstrate the need to continue to find new approaches to neutralize the rapidly evolving SARS-CoV-2 virus. This review highlights both convalescent plasma- and polyclonal antibody-based approaches as well as the top approximately 50 antibodies to SARS-CoV-2, their epitopes, their ability to bind to SARS-CoV-2 variants, and how they are delivered. New approaches to antibody constructs, including single domain antibodies, bispecific antibodies, IgA- and IgM-based antibodies, and modified ACE2-Fc fusion proteins, are also described. Finally, antibodies being developed for palliative care of COVID-19 disease, including the ramifications of cytokine release syndrome (CRS) and acute respiratory distress syndrome (ARDS), are described.

Tocilizumab for COVID-19: A systematic review and meta-analysis of randomized controlled trials

The effective treatment modalities for severe coronavirus disease 2019 (COVID-19) are needed. As the primary cause of mortality is a hyperinflammatory state, the interleukin-6 antagonist tocilizumab has been used in multiple clinical studies. We conducted this systematic review and meta-analysis to estimate the effectiveness of tocilizumab in reduction of mortality due to COVID-19. A systematic search of the Pubmed and Embase databases was performed to extract randomized controlled trials (RCTs) regarding the use of tocilizumab therapy for COVID-19. An overall pooled mortality analysis was performed, and odds ratios were reported. Cochrane risk of bias assessment tool was used to assess the risk of bias. Heterogeneity was assessed using the I2 statistic. Nine RCTs, including 6489 patients, were selected for meta-analysis. Seven trials reported 28-day mortality, and one trial each reported 21-day and 30-day mortality. There were 846 deaths among 3358 participants in the steroid group while 943 deaths among 3131 patients randomized to the control group (random-effects odds ratio 0.87, 95% confidence interval 0.73-1.03, p=0.11). There was some heterogeneity among the trials as the I2 value was 15%, with a p-value of 0.31. There was a reduction in the need for ICU admission in the tocilizumab group. A higher risk of secondary infections was noted in the tocilizumab group (fixed-effects odds ratio 0.72, 95% confidence interval 0.55-0.95, p=0.02). This meta-analysis of RCTs demonstrated that the use of tocilizumab was not associated with a reduction in all-cause mortality in patients with COVID-19 and had higher odds of secondary infections.  

COVID-19 Disease, Women's Predominant Non-Heparin Vaccine-Induced Thrombotic Thrombocytopenia and Kounis Syndrome: A Passepartout Cytokine Storm Interplay

Coronavirus disease 2019 (COVID-19) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) constitute one of the deadliest pandemics in modern history demonstrating cardiovascular, gastrointestinal, hematologic, mucocutaneous, respiratory, neurological, renal and testicular manifestations and further complications. COVID-19-induced excessive immune response accompanied with uncontrolled release of cytokines culminating in cytokine storm seem to be the common pathogenetic mechanism of these complications. The aim of this narrative review is to elucidate the relation between anaphylaxis associated with profound hypotension or hypoxemia with pro-inflammatory cytokine release. COVID-19 relation with Kounis syndrome and post-COVID-19 vaccination correlation with heparin-induced thrombocytopenia with thrombosis (HITT), especially serious cerebral venous sinus thrombosis, were also reviewed. Methods: A current literature search in PubMed, Embase and Google databases was performed to reveal the pathophysiology, prevalence, clinical manifestation, correlation and treatment of COVID-19, anaphylaxis with profuse hypotension, Kounis acute coronary syndrome and thrombotic events post vaccination. Results: The same key immunological pathophysiology mechanisms and cells seem to underlie COVID-19 cardiovascular complications and the anaphylaxis-associated Kounis syndrome. The myocardial injury in patients with COVID-19 has been attributed to coronary spasm, plaque rupture and microthrombi formation, hypoxic injury or cytokine storm disposing the same pathophysiology with the three clinical variants of Kounis syndrome. COVID-19-interrelated vaccine excipients as polysorbate, polyethelene glycol (PEG) and trometamol constitute potential allergenic substances. Conclusion: Better acknowledgement of the pathophysiological mechanisms, clinical similarities, multiorgan complications of COVID-19 or other viral infections as dengue and human immunodeficiency viruses along with the action of inflammatory cells inducing the Kounis syndrome could identify better immunological approaches for prevention, treatment of the COVID-19 pandemic as well as post-COVID-19 vaccine adverse reactions.