ABSTRACT
IntroductionNeutrophilia and high levels of proinflammatory cytokines and other mediators of inflammation are common finds in patients with severe acute respiratory syndrome due to COVID-19. By its action on leukocytes, we propose colchicine as an intervention worthy of being tested. ObjectiveTo evaluate whether the addition of colchicine to standard treatment for COVID-19 results in better outcomes. MethodsWe present the interim analysis of a single-center randomized, double-blinded, placebo controlled clinical trial of colchicine for the treatment of moderate to severe COVID-19, with 38 patients allocated 1:1 from April 11 to July 06, 2020. Colchicine regimen was 0.5 mg thrice daily for 5 days, then 0.5 mg twice daily for 5 days. The first dose was 1.0 mg whether body weight was [≥] 80 kg. EndpointsThe primary endpoints were the need for supplemental oxygen; time of hospitalization; need for admission and length of stay in intensive care units; and death rate and causes of mortality. As secondary endpoints, we assessed: serum C-reactive protein, serum Lactate dehydrogenase and relation neutrophil to lymphocyte of peripheral blood samples from day zero to day 7; the number, type, and severity of adverse events; frequency of interruption of the study protocol due to adverse events; and frequency of QT interval above 450 ms. ResultsThirty-five patients (18 for Placebo and 17 for Colchicine) completed the study. Both groups were comparable in terms of demographic, clinical and laboratory data at baseline. Median (and interquartile range) time of need for supplemental oxygen was 3.0 (1.5-6.5) days for the Colchicine group and 7.0 (3.0-8.5) days for Placebo group (p = 0.02). Median (IQR) time of hospitalization was 6.0 (4.0-8.5) days for the Colchicine group and 8.5 (5.5-11.0) days for Placebo group (p = 0.03). At day 2, 53% vs 83% of patients maintained the need for supplemental oxygen, while at day 7 the values were 6% vs 39%, in the Colchicine and Placebo groups, respectively (log rank; p = 0.01). Hospitalization was maintained for 53% vs 78% of patients at day 5 and 6% vs 17% at day 10, for the Colchicine and Placebo groups, respectively (log rank; p = 0.01). One patient per group needed admission to ICU. No recruited patient died. At day 4, patients of Colchicine group presented significant reduction of serum C-reactive protein compared to baseline (p < 0.001). The majority of adverse events were mild and did not lead to patient withdrawal. Diarrhea was more frequent in the Colchicine group (p = 0.17). Cardiac adverse events were absent. DiscussionThe use of colchicine reduced the length of supplemental oxygen therapy and the length of hospitalization. Clinical improvement was in parallel with a reduction on serum levels of C-reactive protein. The drug was safe and well tolerated. Colchicine may be considered a beneficial and not expensive option for COVID-19 treatment. Clinical trials with larger numbers of patients should be conducted to further evaluate the efficacy and safety of colchicine as an adjunctive therapy for hospitalized patients with moderate to severe COVID-19.
ABSTRACT
Severe cases of COVID-19 are characterized by a strong inflammatory process that may ultimately lead to organ failure and patient death. The NLRP3 inflammasome is a molecular platform that promotes inflammation via cleavage and activation of key inflammatory molecules including active caspase-1 (Casp1p20), IL-1{beta} and IL-18. Although the participation of the inflammasome in COVID-19 has been highly speculated, the inflammasome activation and participation in the outcome of the disease is unknown. Here we demonstrate that the NLRP3 inflammasome is activated in response to SARS-CoV-2 infection and it is active in COVID-19, influencing the clinical outcome of the disease. Studying moderate and severe COVID-19 patients, we found active NLRP3 inflammasome in PBMCs and tissues of post-mortem patients upon autopsy. Inflammasome-derived products such as Casp1p20 and IL-18 in the sera correlated with the markers of COVID-19 severity, including IL-6 and LDH. Moreover, higher levels of IL-18 and Casp1p20 are associated with disease severity and poor clinical outcome. Our results suggest that the inflammasome is key in the pathophysiology of the disease, indicating this platform as a marker of disease severity and a potential therapeutic target for COVID-19.
