Response to: 'Correspondence on 'Interleukin-6 blockade with subcutaneous tocilizumab in severe COVID-19 pneumonia and hyperinflammation: a case-control study' by Potere et al' by Buckley

Targeting the NLRP3 inflammasome in cardiovascular diseases

The NACHT, leucine-rich repeat (LRR), and pyrin domain (PYD)-containing protein 3 (NLRP3) inflammasome is an intracellular sensing protein complex that plays a major role in innate immunity. Following tissue injury, activation of the NLRP3 inflammasome results in cytokine production, primarily interleukin(IL)-1β and IL-18, and, eventually, inflammatory cell death - pyroptosis. While a balanced inflammatory response favors damage resolution and tissue healing, excessive NLRP3 activation causes detrimental effects. A key involvement of the NLRP3 inflammasome has been reported across a wide range of cardiovascular diseases (CVDs). Several pharmacological agents selectively targeting the NLRP3 inflammasome system have been developed and tested in animals and early phase human studies with overall promising results. While the NLRP3 inhibitors are in clinical development, multiple randomized trials have demonstrated the safety and efficacy of IL-1 blockade in atherothrombosis, heart failure and recurrent pericarditis. Furthermore, the non-selective NLRP3 inhibitor colchicine has been recently shown to significantly reduce cardiovascular events in patients with chronic coronary disease. In this review, we will outline the mechanisms driving NLRP3 assembly and activation, and discuss the pathogenetic role of the NLRP3 inflammasome in CVDs, providing an overview of the current and future therapeutic approaches targeting the NLRP3 inflammasome.

Combination therapy of Tocilizumab and steroid for management of COVID-19 associated cytokine release syndrome: A single center experience from Pune, Western India

ABSTRACT

Cytokine release syndrome (CRS) or cytokine storm is thought to be the cause of inflammatory lung damage, worsening pneumonia and death in patients with COVID-19. Steroids (Methylprednislone or Dexamethasone) and Tocilizumab (TCZ), an interleukin-6 receptor antagonist, are approved for treatment of CRS in India. The aim of this study was to evaluate the efficacy and safety of combination therapy of TCZ and steroid in COVID-19 associated CRS.This retrospective cohort study was conducted at Noble hospital and Research Centre (NHRC), Pune, India between April 2 and November 2, 2020. All patients administered TCZ and steroids during this period were included. The primary endpoint was incidence of all cause mortality. Secondary outcomes studied were need for mechanical ventilation and incidence of systemic and infectious complications. Baseline and time dependent risk factors significantly associated with death were identified by Relative risk estimation.Out of 2831 admitted patients, 515 (24.3% females) were administered TCZ and steroids. There were 135 deaths (26.2%), while 380 patients (73.8%) had clinical improvement. Mechanical ventilation was required in 242 (47%) patients. Of these, 44.2% (107/242) recovered and were weaned off the ventilator. Thirty seven percent patients were managed in wards and did not need intensive care unit (ICU) admission. Infectious complications like hospital acquired pneumonia, blood stream bacterial and fungal infections were observed in 2.13%, 2.13% and 0.06% patients respectively. Age ≥ 60 years (P = .014), presence of co-morbidities like hypertension (P = .011), IL-6 ≥ 100 pg/ml (P = .002), D-dimer ≥ 1000 ng/ml (P < .0001), CT severity index ≥ 18 (P < .0001) and systemic complications like lung fibrosis (P = .019), cardiac arrhythmia (P < .0001), hypotension (P < .0001) and encephalopathy (P < .0001) were associated with increased risk of death.Combination therapy of TCZ and steroids is likely to be safe and effective in management of COVID-19 associated cytokine release syndrome. Efficacy of this anti-inflammatory combination therapy needs to be validated in randomized controlled trials.

Tocilizumab treatment for COVID-19 patients: a systematic review and meta-analysis

BACKGROUND

Coronavirus disease 2019 (COVID-19) has killed over 2.5 million people worldwide, but effective care and therapy have yet to be discovered. We conducted this analysis to better understand tocilizumab treatment for COVID-19 patients.

MAIN TEXT

We searched major databases for manuscripts reporting the effects of tocilizumab on COVID-19 patients. A total of 25 publications were analyzed with Revman 5.3 and R for the meta-analysis. Significant better clinical outcomes were found in the tocilizumab treatment group when compared to the standard care group [odds ratio (OR) = 0.70, 95% confidential interval (C): 0.54-0.90, P = 0.007]. Tocilizumab treatment showed a stronger correlation with good prognosis among COVID-19 patients that needed mechanical ventilation (OR = 0.59, 95% CI, 0.37-0.93, P = 0.02). Among stratified analyses, reduction of overall mortality correlates with tocilizumab treatment in patients less than 65 years old (OR = 0.68, 95% CI: 0.60-0.77, P < 0.00001), and with intensive care unit patients (OR = 0.62, 95% CI: 0.55-0.70, P < 0.00001). Pooled estimates of hazard ratio showed that tocilizumab treatment predicts better overall survival in COVID-19 patients (HR = 0.45, 95% CI: 0.24-0.84, P = 0.01), especially in severe cases (HR = 0.58, 95% CI 0.49-0.68, P < 0.00001).

CONCLUSIONS

Our study shows that tocilizumab treatment is associated with a lower risk of mortality and mechanical ventilation requirement among COVID-19 patients. Tocilizumab may have substantial effectiveness in reducing mortality among COVID-19 patients, especially among critical cases. This systematic review provides an up-to-date evidence of potential therapeutic role of tocilizumab in COVID-19 management.

Upregulated IL-6 Indicates a Poor COVID-19 Prognosis: A Call for Tocilizumab and Convalescent Plasma Treatment

A comprehensive understanding of the dynamic changes in interleukin-6 (IL-6) levels is essential for monitoring and treating patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2). By analyzing the correlations between IL-6 levels and health conditions, underlying diseases, several key laboratory detection indices, and the prognosis of 1,473 patients with the coronavirus disease 2019 (COVID-19), the role of IL-6 during SARS-CoV-2 infection was demonstrated. Our results indicated that IL-6 levels were closely related to age, sex, body temperature, oxygen saturation (SpO2) of blood, and underlying diseases. As a stable indicator, the changes in IL-6 levels could indicate the inflammatory conditions during a viral infection. Two specific treatments, namely, tocilizumab and convalescent plasma therapy (CPT), decreased the level of IL-6 and relieved inflammation. CPT has an important role in the therapy for patients with critical COVID-19. We also found that patients with IL-6 levels, which were 30-fold higher than the normal level, had a poor prognosis compared to patients with lower levels of IL-6.

Efficacy of tocilizumab in COVID-19: A systematic review and meta-analysis

The efficacy of tocilizumab (TOC), monoclonal antibody against interleukin-6 (IL-6) receptor, in patients with coronavirus disease-2019 (COVID-19) patients has led to conflicting results. We performed a systematic review and meta-analysis to compare the efficacy of addition of TOC to standard of care (SOC) versus SOC in patients with COVID-19. We performed a comprehensive literature search of PubMed, Embase, Web of Science, WHO COVID, LitCOVID, and Cochrane databases. Pooled outcomes (overall mortality, need for mechanical ventilation, intensive care unit admission, and secondary infections) were compared using DerSimonian-Laird/Random-effects approach. Risk difference (RD), confidence interval (CI), and p values were generated. A total of 23 studies with 6279 patients (1897 in TOC and 4382 in SOC group, respectively) were included. The overall mortality was lower in TOC group compared to SOC group (RD: -0.06; CI: -0.12 to -0.01; p = .03). Subgroup analysis including studies with only severe cases revealed lower mortality (RD: -0.12; CI: -0.18 to -0.06; p < .01) and need for mechanical ventilation (RD: -0.11; CI: -0.19 to -0.02; p = .01) in TOC group compared to SOC group. The addition of TOC to SOC has the potential to reduce mortality and need for mechanical ventilation in patients with severe COVID-19. Randomized controlled trials are needed to validate this.

Low-dose subcutaneous tocilizumab to prevent disease progression in patients with moderate COVID-19 pneumonia and hyperinflammation

Aim

This study aimed to evaluate the safety and efficacy profile of low-dose tocilizumab (TCZ), to prevent disease progression, subcutaneously administered to patients with moderate COVID-19 pneumonia and hyperinflammation.

Methods

Clinical characteristics and outcomes were retrospectively analysed of patients – with laboratory-confirmed bilateral COVID-19 pneumonia, hyperinflammation (C-reactive protein (CRP) ≥20 mg/dL), no hypoxaemia (oxygen saturation >90%), and no contraindications to TCZ – who were treated with subcutaneous TCZ (324 mg) administered within 48 h from hospitalization on top of standard of care (SOC). They were compared with matched controls treated with SOC only before TCZ was available at the institution. Clinical data were available for all patients until death or until day 35 for those discharged from hospital.

Findings

Ten consecutive patients (six males, median age 55 years) treated with TCZ on top of SOC, and ten patients (six males, median age 56 years) treated with SOC only were included. TCZ was well-tolerated with no clinically relevant adverse events. TCZ was associated with a reduction in CRP at day 1 (–50%, IQR –28 to –80) and day 3 (–89%, IQR –79 to –96; p =  0.005 for within-group), whereas there was no significant change in CRP values in the SOC group (p <  0.001 for between-group comparisons at both time points). TCZ resulted in a parallel improvement in oxygenation, as assessed by the ratio of partial pressure of oxygen to fraction of inspired oxygen (P/F) ratio, which increased at day 1 (+11%, IQR +6 to +16; p =  0.005 for within-group and p =  0.006 for between-group comparisons), and day 3 (+23%, IQR +16 to +34; p =  0.005 for within-group and p = 0.003 for between-group comparisons). None of the TCZ-treated patients had disease progression, defined as requirement of oxygen therapy or mechanical ventilation, whereas progression occurred in five (50%) patients among the SOC group.

Conclusions

Low-dose subcutaneous TCZ may be a safe and promising therapeutic option administered on top of SOC to prevent disease progression in hospitalised patients with moderate COVID-19 and hyperinflammation.

Role for Anti-Cytokine Therapies in Severe Coronavirus Disease 2019

The causative agent for coronavirus disease 2019, severe acute respiratory syndrome coronavirus 2, appears exceptional in its virulence and immunopathology. In some patients, the resulting hyperinflammation resembles a cytokine release syndrome. Our knowledge of the immunopathogenesis of coronavirus disease 2019 is evolving and anti-cytokine therapies are under active investigation. This narrative review summarizes existing knowledge of the immune response to coronavirus infection and highlights the current and potential future roles of therapeutic strategies to combat the hyperinflammatory response of patients with coronavirus disease 2019.

DATA SOURCES

Relevant and up-to-date literature, media reports, and author experiences were included from Medline, national newspapers, and public clinical trial databases.

STUDY SELECTION

The authors selected studies for inclusion by consensus.

DATA EXTRACTION

The authors reviewed each study and selected approrpriate data for inclusion through consensus.

DATA SYNTHESIS

Hyperinflammation, reminiscent of cytokine release syndromes such as macrophage activation syndrome and hemophagocytic lymphohistiocytosis, appears to drive outcomes among adults with severe coronavirus disease 2019. Cytokines, particularly interleukin-1 and interleukin-6, appear to contribute importantly to such systemic hyperinflammation. Ongoing clinical trials will determine the efficacy and safety of anti-cytokine therapies in coronavirus disease 2019. In the interim, anti-cytokine therapies may provide a treatment option for adults with severe coronavirus disease 2019 unresponsive to standard critical care management, including ventilation.

CONCLUSIONS

This review provides an overview of the current understanding of the immunopathogenesis of coronavirus disease 2019 in adults and proposes treatment considerations for anti-cytokine therapy use in adults with severe disease.