Incidence of autoantibodies related to systemic autoimmunity in patients with severe COVID-19 admitted to the intensive care unit.

OBJECTIVES: To assess the prevalence of autoantibodies (AAbs) in mechanically ventilated COVID-19 patients and to investigate whether AAbs influence the clinical outcome. METHODS: Serum samples were drawn within the first 48 hours upon admission to the intensive care unit (ICU) from 217 consecutive patients, from January 1st, 2021, to May 10th, 2021, and investigated for the presence of AAbs using conventional techniques. Serum samples (n=117) of age- and sex-matched healthy individuals collected before COVID-19 pandemic were used as controls. RESULTS: COVID-19 patients in the ICU had more commonly AAbs compared to age- and sex-matched controls (174/217, 80.2% vs. 73/117, 62.4%, p<0.001). Patients expressed more frequently ANAs (48.4% vs. 21.4%, p<0.001), anti-dsDNA (5.1% vs. 0%, p=0.01), anti-CCP (8.3% vs. 1.7%, p=0.014) and anti-CL IgM AAbs (21.7% vs. 9.4%, p=0.005) than controls, respectively. Simultaneous reactivity against at least three autoantigens, occurred in 144 out of 174 (82.8%) patients. The two groups did not differ in terms of clinicoepidemiologic characteristics or the mortality ratio within the ICU. Patients who died compared to convalescents were older, had higher ferritin, D-dimers levels, APACHE II score, lower oxygen saturation, higher prevalence of comorbidities and cognitive dysfunction. However, AAbs were not found to correlate with the clinical outcome. CONCLUSIONS: Patients with severe COVID-19 express AAbs more commonly compared to controls. No correlation was found between AAbs and disease outcome.

Down-regulation of KLF2 in lung fibroblasts is linked with COVID-19 immunofibrosis and restored by combined inhibition of NETs, JAK-1/2 and IL-6 signaling.

Kruppel-like factor 2 (KLF2) has been linked with fibrosis and neutrophil-associated thromboinflammation; however, its role in COVID-19 remains elusive. We investigated the effect of disease microenvironment on the fibrotic potential of human lung fibroblasts (LFs) and its association with KLF2 expression. LFs stimulated with plasma from severe COVID-19 patients down-regulated KLF2 expression at mRNA/protein and functional level acquiring a pre-fibrotic phenotype, as indicated by increased CCN2/collagen levels. Pre-incubation with the COMBI-treatment-agents (DNase I and JAKs/IL-6 inhibitors baricitinib/tocilizumab) restored KLF2 levels of LFs to normal abolishing their fibrotic activity. LFs stimulated with plasma from COMBI-treated patients at day-7 expressed lower CCN2 and higher KLF2 levels, compared to plasma prior-to-treatment, an effect not observed in standard-of-care treatment. In line with this, COMBI-treated patients had better outcome than standard-of-care group. These data link fibroblast KLF2 with NETosis and JAK/IL-6 signaling, suggesting the potential of combined therapeutic strategies in immunofibrotic diseases, such as COVID-19.

Complement C3 inhibition in severe COVID-19 using compstatin AMY-101.

Complement C3 activation contributes to COVID-19 pathology, and C3 targeting has emerged as a promising therapeutic strategy. We provide interim data from ITHACA, the first randomized trial evaluating a C3 inhibitor, AMY-101, in severe COVID-19 (PaO2/FiO2 ≤ 300 mmHg). Patients received AMY-101 (n = 16) or placebo (n = 15) in addition to standard of care. AMY-101 was safe and well tolerated. Compared to placebo (8 of 15, 53.3%), a higher, albeit nonsignificant, proportion of AMY-101-treated patients (13 of 16, 81.3%) were free of supplemental oxygen at day 14. Three nonresponders and two placebo-treated patients succumbed to disease-related complications. AMY-101 significantly reduced CRP and ferritin and restrained thrombin and NET generation. Complete and sustained C3 inhibition was observed in all responders. Residual C3 activity in the three nonresponders suggested the presence of a convertase-independent C3 activation pathway overriding the drug's inhibitory activity. These findings support the design of larger trials exploring the potential of C3-based inhibition in COVID-19 or other complement-mediated diseases.

Combined administration of inhaled DNase, baricitinib and tocilizumab as rescue treatment in COVID-19 patients with severe respiratory failure.

Aiming to reduce mortality in COVID-19 with severe respiratory failure we administered a combined rescue treatment (COMBI) on top of standard-of-care (SOC: dexamethasone/heparin) consisted of inhaled DNase to dissolve thrombogenic neutrophil extracellular traps, plus agents against cytokine-mediated hyperinflammation, namely anti-IL-6-receptor tocilizumab and JAK1/2 inhibitor baricitinib. Patients with PaO2/FiO2 < 100 mmHg were analysed. COMBI group (n = 22) was compared with similar groups that had received SOC alone (n = 26) or SOC plus monotherapy with either IL-1-receptor antagonist anakinra (n = 19) or tocilizumab (n = 11). COMBI was significantly associated with lower in-hospital mortality and intubation rate, shorter duration of hospitalization, and prolonged overall survival after a median follow-up of 110 days. In vitro, COVID-19 plasma induced tissue factor/thrombin pathway in primary lung fibroblasts. This effect was inhibited by the immunomodulatory agents of COMBI providing a mechanistic explanation for the clinical observations. These results support the conduct of randomized trials using combined immunomodulation in COVID-19 to target multiple interconnected pathways of immunothrombosis.