Spontaneous NLRP3 inflammasome-driven IL-1-ß secretion is induced in severe COVID-19 patients and responds to anakinra treatment.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection may result in a severe pneumonia associated with elevation of blood inflammatory parameters, reminiscent of cytokine storm syndrome. Steroidal anti-inflammatory therapies have shown efficacy in reducing mortality in critically ill patients; however, the mechanisms by which SARS-CoV-2 triggers such an extensive inflammation remain unexplained. OBJECTIVES: To dissect the mechanisms underlying SARS-CoV-2-associated inflammation in patients with severe coronavirus disease 2019 (COVID-19), we studied the role of IL-1ß, a pivotal cytokine driving inflammatory phenotypes, whose maturation and secretion are regulated by inflammasomes. METHODS: We analyzed nod-like receptor protein 3 pathway activation by means of confocal microscopy, plasma cytokine measurement, cytokine secretion following in vitro stimulation of blood circulating monocytes, and whole-blood RNA sequencing. The role of open reading frame 3a SARS-CoV-2 protein was assessed by confocal microscopy analysis following nucleofection of a monocytic cell line. RESULTS: We found that circulating monocytes from patients with COVID-19 display ASC (adaptor molecule apoptotic speck like protein-containing a CARD) specks that colocalize with nod-like receptor protein 3 inflammasome and spontaneously secrete IL-1ß in vitro. This spontaneous activation reverts following patient's treatment with the IL-1 receptor antagonist anakinra. Transfection of a monocytic cell line with cDNA coding for the ORF3a SARS-CoV-2 protein resulted in ASC speck formation. CONCLUSIONS: These results provide further evidence that IL-1ß targeting could represent an effective strategy in this disease and suggest a mechanistic explanation for the strong inflammatory manifestations associated with COVID-19.

Efficacy of early anti-inflammatory treatment with high doses of intravenous anakinra with or without glucocorticoids in patients with severe COVID-19 pneumonia.

BACKGROUND: IL-1 plays a pivotal role in the inflammatory response during cytokine storm syndromes. OBJECTIVE: Our aim was to analyze the efficacy and safety of early anti-inflammatory treatment (AIT) with intravenous anakinra with or without glucocorticoids in coronavirus disease 2019 (COVID-19) pneumonia. METHODS: We performed a retrospective single-center cohort study of patients admitted for COVID-19 pneumonia from February 26 to April 29, 2020, to assess the efficacy of early AIT with intravenous anakinra (100 mg every 8 hours for 3 days, with tapering) alone or in combination with a glucocorticoid (intravenous methylprednisolone, 1-2 mg/kg daily, with tapering). The standard of care (SOC) treatment was hydroxychloroquine and/or azithromycin with or without antivirals and anticoagulants. Late rescue AIT with anakinra or tocilizumab was also evaluated. Treatment effect on overall survival was assessed by a propensity score-adjusted Cox model. RESULTS: A total of 128 patients were analyzed; 63 patients received early AIT (30 received anakinra alone and 33 received anakinra plus a glucocorticoid) at admission, and 65 patients did not receive early AIT and were used as controls; of the latter 65 patients, 44 received the SOC treatment alone and 21 received the SOC treatment plus late rescue AIT. After adjustment for all the unbalanced baseline covariates, early AIT reduced the hazard of mortality by 74% (adjusted hazard ratio [HR] = 0.26; P < .001). The effect was similar in patients receiving anakinra alone (adjusted HR = 0.28; P = .04) and anakinra plus a glucocorticoid (adjusted HR = 0.33; P = .07). Late rescue treatment did not show a significant advantage over SOC treatment alone (adjusted HR = 0.82; P = .70). CONCLUSIONS: This study suggests, on a larger series of patients with COVID-19 pneumonia, the potential efficacy and safety of the early use of high doses of intravenous anakinra with or without glucocorticoids.