Complement lectin pathway activation is associated with COVID-19 disease severity, independent of MBL2 genotype subgroups.

Introduction: While complement is a contributor to disease severity in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections, all three complement pathways might be activated by the virus. Lectin pathway activation occurs through different pattern recognition molecules, including mannan binding lectin (MBL), a protein shown to interact with SARS-CoV-2 proteins. However, the exact role of lectin pathway activation and its key pattern recognition molecule MBL in COVID-19 is still not fully understood. Methods: We therefore investigated activation of the lectin pathway in two independent cohorts of SARS-CoV-2 infected patients, while also analysing MBL protein levels and potential effects of the six major single nucleotide polymorphisms (SNPs) found in the MBL2 gene on COVID-19 severity and outcome. Results: We show that the lectin pathway is activated in acute COVID-19, indicated by the correlation between complement activation product levels of the MASP-1/C1-INH complex (p=0.0011) and C4d (p<0.0001) and COVID-19 severity. Despite this, genetic variations in MBL2 are not associated with susceptibility to SARS-CoV-2 infection or disease outcomes such as mortality and the development of Long COVID. Conclusion: In conclusion, activation of the MBL-LP only plays a minor role in COVID-19 pathogenesis, since no clinically meaningful, consistent associations with disease outcomes were noted.

Baricitinib vs tocilizumab treatment for hospitalized adult patients with severe COVID-19 and associated cytokine storm: a prospective, investigational, real-world study.

OBJECTIVES: Our aim was to compare outcomes of hospitalized adults with severe COVID-19 and cytokine storm treated with tocilizumab or baricitinib. METHODS: A prospective, investigational, real-world study was performed from April 2020 to April 2021 at our center. COVID-19 severity was classified by World Health Organization criteria, and cytokine storm was documented along predefined criteria. Eligible patients were enrolled at diagnosis if they fulfilled a priori inclusion criteria and received standard-of-care plus tocilizumab or baricitinib for >48 hours. Patients were followed per protocol for 28 days post-diagnosis. The primary outcome was all-cause mortality; secondary outcomes were invasive mechanical ventilation and major infectious complications. RESULTS: Of 463 patients, 102/463 (22.1%) received tocilizumab, and 361/463 (77.9%) baricitinib. Baseline characteristics were balanced. At 28 days, there was no difference in all-cause mortality (22/102, 21.6% vs 64/361, 17.7%; P-value = 0.38). Requirement for invasive mechanical ventilation was more frequent after tocilizumab (52/102, 50.9% vs 96/361, 26.6%; P <0.01), rate of major infectious complications was similar (32/102, 31.4% vs 96/361, 26.6%; P-value = 0.34). In logistic regression, the immunomodulatory drug was not retained as a predictor of all-cause mortality. Kaplan-Meier analysis revealed statistically similar survival distributions. CONCLUSION: All-cause mortality was similar between adults treated with baricitinib or tocilizumab for severe COVID-19 with cytokine storm.

Baricitinib versus tocilizumab treatment for hospitalized adult patients with severe COVID-19 and associated cytokine storm: A prospective, investigational, real-world study

Objectives Our aim was to compare outcomes of hospitalized adults with severe COVID-19 and cytokine storm, treated with tocilizumab or baricitinib. Methods A prospective, investigational, real-world study was performed between April 2020–April 2021 at our centre. COVID-19 severity was classified by World Health Organization criteria, cytokine storm was documented along pre-defined criteria. Eligible patients were enrolled at diagnosis if they fulfilled a priori inclusion criteria and received standard-of-care plus tocilizumab or baricitinib for >48 hours. Patients were followed per protocol for 28 days post-diagnosis. Primary outcome was all-cause mortality, secondary outcomes were invasive mechanical ventilation and major infectious complications. Results From 463 patients, 102/463 (22.1%) received tocilizumab, 361/463 (77.9%) baricitinib. Baseline characteristics were balanced. At 28 days, there was no difference in all-cause mortality (22/102, 21.6% vs. 64/361, 17.7%;p=0.38). Requirement for invasive mechanical ventilation was more frequent after tocilizumab (52/102, 50.9% vs. 96/361, 26.6%;p<0.01), rate of major infectious complications was similar (32/102, 31.4% vs. 96/361, 26.6%;p=0.34). In logistic regression, immunomodulatory drug was not retained as a predictor of all-cause mortality. Kaplan–Meier analysis revealed statistically similar survival distributions. Conclusions All-cause mortality was similar between adults treated with baricitinib or tocilizumab for severe COVID-19 with cytokine storm.

A súlyos akut légzoszervi szindrómát okozó koronavírus-2 elleni immunválasz.

Coronavirus disease 2019 (COVID-19) displays tremendous inter-individual variability, ranging from asymptomatic infections to life-threatening illness. Although more studies are needed, a picture has begun to emerge that variability in the immune system components is a main contributor to the heterogeneous disease courses. Here, we provide a concept for the interaction of the innate and adaptive immune systems with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to link the observations that have been made during the first two years of the pandemic. Inborn errors of, and autoantibodies directed against, type I interferons, dysregulated myeloid response, hyperinflammation, lymphopenia, lymphocyte impairment, and heterogeneous adaptive immunity to SARS-CoV-2 are discussed, as well as their impact in the course of COVID-19. In addition, we will also review part of the key findings that have helped define and delineate some of the essential attributes of SARS-CoV-2-specific humoral and cell-mediated immune memory. Orv Hetil. 2022; 163(20): 774-787.

Complement Levels at Admission Reflecting Progression to Severe Acute Kidney Injury (AKI) in Coronavirus Disease 2019 (COVID-19): A Multicenter Prospective Cohort Study.

Background: Dysregulation of complement system is thought to be a major player in development of multi-organ damage and adverse outcomes in patients with coronavirus disease 2019 (COVID-19). This study aimed to examine associations between complement system activity and development of severe acute kidney injury (AKI) among hospitalized COVID-19 patients. Materials and Methods: In this multicenter, international study, complement as well as inflammatory and thrombotic parameters were analyzed in COVID-19 patients requiring hospitalization at one US and two Hungarian centers. The primary endpoint was development of severe AKI defined by KDIGO stage 2+3 criteria, while the secondary endpoint was need for renal replacement therapy (RRT). Complement markers with significant associations with endpoints were then correlated with a panel of inflammatory and thrombotic biomarkers and assessed for independent association with outcome measures using logistic regression. Results: A total of 131 hospitalized COVID-19 patients (median age 66 [IQR, 54-75] years; 54.2% males) were enrolled, 33 from the US, and 98 from Hungary. There was a greater prevalence of complement over-activation and consumption in those who developed severe AKI and need for RRT during hospitalization. C3a/C3 ratio was increased in groups developing severe AKI (3.29 vs. 1.71; p < 0.001) and requiring RRT (3.42 vs. 1.79; p < 0.001) in each cohort. Decrease in alternative and classical pathway activity, and consumption of C4 below reference range, as well as elevation of complement activation marker C3a above the normal was more common in patients progressing to severe AKI. In the Hungarian cohort, each standard deviation increase in C3a (SD = 210.1) was independently associated with 89.7% increased odds of developing severe AKI (95% CI, 7.6-234.5%). Complement was extensively correlated with an array of inflammatory biomarkers and a prothrombotic state. Conclusion: Consumption and dysregulation of complement system is associated with development of severe AKI in COVID-19 patients and could represent a promising therapeutic target for reducing thrombotic microangiopathy in SARS-CoV-2 infection.

Associations between the von Willebrand Factor-ADAMTS13 Axis, Complement Activation, and COVID-19 Severity and Mortality.

BACKGROUND: Endothelial and complement activation were both associated with immunothrombosis, a key determinant of COVID-19 severity, but their interrelation has not yet been investigated. OBJECTIVES: We aimed to determine von Willebrand factor (VWF) antigen (VWF:Ag) concentration, VWF collagen binding activity (VWF:CBA), a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13) activity (ADAMTS13:Ac), and their ratios in hospitalized COVID-19 patients, and to investigate how these parameters and their constellation with complement activation relate to disease severity and in-hospital mortality in COVID-19. METHODS: Samples of 102 hospitalized patients with polymerase chain reaction-confirmed severe acute respiratory syndrome coronavirus 2 positivity were included in our observational cohort study. Patients were stratified according to the peak severity of COVID-19 disease in agreement with the World Health Organization ordinal scale. Twenty-six convalescent plasma donors with previous COVID-19 disease formed the control group. VWF:Ag concentration and VWF:CBA were determined by enzyme-linked immunosorbent assay (ELISA); ADAMTS13:Ac was determined by fluorescence resonance energy transfer. Complement C3 and C3a were measured by turbidimetry and ELISA, respectively. Clinical covariates and markers of inflammation were extracted from hospital records. RESULTS: VWF:Ag and VWF:CBA were elevated in all groups of hospitalized COVID-19 patients and increased in parallel with disease severity. ADAMTS13:Ac was decreased in patients with severe COVID-19, with the lowest values in nonsurvivors. High (> 300%) VWF:Ag concentrations or decreased (< 67%) ADAMTS13:Ac were associated with higher risk of severe COVID-19 disease or in-hospital mortality. The concomitant presence of decreased ADAMTS13:Ac and increased C3a/C3 ratio-indicating complement overactivation and consumption-was a strong independent predictor of in-hospital mortality. CONCLUSION: Our results suggest that an interaction between the VWF-ADAMTS13 axis and complement overactivation and consumption plays an important role in the pathogenesis of COVID-19.

Common points of therapeutic intervention in COVID-19 and in allogeneic hematopoietic stem cell transplantation associated severe cytokine release syndrome.

Allogeneic hematopoietic stem cell transplantation (HSCT) and coronavirus disease 2019 (COVID-19) infection can both lead to severe cytokine release syndrome (sCRS) resulting in critical illness and death. In this single institution, preliminary comparative case-series study we compared clinical and laboratory co-variates as well as response to tocilizumab (TCZ)-based therapy of 15 allogeneic-HSCT- and 17 COVID-19-associated sCRS patients. Reaction to a TCZ plus posttransplant cyclophosphamide (PTCY) consolidation therapy in the allogeneic-HSCT-associated sCRS group yielded significantly inferior long-term outcome as compared to TCZ-based therapy in the COVID-19-associated group (P = 0.003). We report that a TCZ followed by consolidation therapy with a Janus kinase/signal transducer and activator of transcription (JAK/STAT) inhibitor given to 4 out of 8 critically ill COVID-19 patients resulted in their complete recovery. Non-selective JAK/STAT inhibitors influencing the action of several cytokines exhibit a broader effect than TCZ alone in calming down sCRS. Serum levels of cytokines and chemokines show similar changes in allogeneic-HSCT- and COVID-19-associated sCRS with marked elevation of interleukin-6 (IL-6), regulated upon activation normal T-cell expressed and secreted (RANTES), monocyte chemoattractant protein-1 (MCP-1) and interferon γ-induced protein 10 kDa (IP-10) levels. In addition, levels of IL-5, IL-10, IL-15 were also elevated in allogeneic-HSCT-associated sCRS. Our multi-cytokine expression data indicate that the pathophysiology of allogeneic-HSCT and COVID-19-associated sCRS are similar therefore the same clinical grading system and TCZ-based treatment approaches can be applied. TCZ with JAK/STAT inhibitor consolidation therapy might be highly effective in COVID-19 sCRS patients.

Laboratory parameters predicting mortality of adult in-patients with COVID-19 associated cytokine release syndrome treated with high-dose tocilizumab.

Large randomized clinical trials in severe Coronavirus Disease 2019 (COVID-19) patients have proven efficacy of intravenous tocilizumab. Our aim was to describe the laboratory parameters predicting in-hospital mortality of patients with tocilizumab administration in COVID-19 associated cytokine release syndrome (CRS).We evaluated high-dose (8 mg/kg) intravenous tocilizumab administration in severe and critically ill COVID-19 adult patients fulfilling predefined strict CRS criteria. A single-centre, prospective, observational cohort study was carried out among consecutive adult (≥18 years of age) in-patients with COVID-19 between April 1 and December 31, 2020. The primary endpoint was 28-day all-cause mortality. The changes in laboratory parameters from baseline on day 7 and 14 after administration of tocilizumab were analysed.In total, 1801 patients were admitted to our centre during the study period. One hundred and six patients received tocilizumab, and among them 62 (58.5%) required intensive care unit admittance while 25 (23.6%) deceased. At day 7 after tocilizumab administration, inflammatory markers (CRP, IL-6, ferritin) and lactate dehydrogenase (LDH) values were significantly lower among survivors. Subsequently, at day 14, differences of IL-6 and LDH levels has become more pronounced between subgroups. Restoration of absolute lymphocyte count (ALC) by day 7 and 14 was insufficient among patients who died.In our cohort, administration of high-dose tocilizumab for COVID-19 patients with CRS demonstrated clinical and sustained biochemical parameter improvement in 76.4%. In this patient population high and increasing LDH, IL-6, and low ALC levels had a predictive role for mortality.

Complement Overactivation and Consumption Predicts In-Hospital Mortality in SARS-CoV-2 Infection.

Objectives: Uncontrolled thromboinflammation plays an important role in the pathogenesis of coronavirus disease (COVID-19) caused by SARS-CoV-2 virus. Complement was implicated as key contributor to this process, therefore we hypothesized that markers of the complement profile, indicative for the activation state of the system, may be related to the severity and mortality of COVID-19. Methods: In this prospective cohort study samples of 102 hospitalized and 26 outpatients with PCR-confirmed COVID-19 were analyzed. Primary outcome was in-hospital, COVID-19 related mortality, and secondary outcome was COVID-19 severity as assessed by the WHO ordinal scale. Complement activity of alternative and classical pathways, its factors, regulators, and activation products were measured by hemolytic titration, turbidimetry, or enzyme-immunoassays. Clinical covariates and markers of inflammation were extracted from hospital records. Results: Increased complement activation was characteristic for hospitalized COVID-19 patients. Complement activation was significantly associated with markers of inflammation, such as interleukin-6, C-reactive protein, and ferritin. Twenty-five patients died during hospital stay due to COVID-19 related illness. Patients with uncontrolled complement activation leading to consumption of C3 and decrease of complement activity were more likely to die, than those who had complement activation without consumption. Cox models identified anaphylatoxin C3a, and C3 overactivation and consumption (ratio of C3a/C3) as predictors of in-hospital mortality [HR of 3.63 (1.55-8.45, 95% CI) and 6.1 (2.1-17.8), respectively]. Conclusion: Increased complement activation is associated with advanced disease severity of COVID-19. Patients with SARS-CoV-2 infection are more likely to die when the disease is accompanied by overactivation and consumption of C3. These results may provide observational evidence and further support to studies on complement inhibitory drugs for the treatment of COVID-19.

Successful administration of convalescent plasma in critically ill COVID-19 patients in Hungary: the first two cases / Az elso két sikeres, convalescens friss fagyasztott plazmával történo terápia hazai alkalmazása intenzív osztályon kezelt, kritikus állapotú, COVID­19-fertozésben szenvedo betegekben: (A COVID­19-pandémia orvosszakmai kérdései)

INTRODUCTION: At present, neither specific curative treatment nor vaccines for novel coronavirus 2019 (COVID-19) are available. There is an urgent need to look for alternative strategies for COVID-19 treatment especially in the case of severe and/or critically ill patients with cytokine release syndrome (CRS). AIM: Convalescent plasma proved to increase survival rates in other severe viral infections. Therefore, convalescent plasma could be a promising treatment option for severe COVID-19 patients. METHOD: In our article, we present the first two critically ill Hungarian patients with COVID-19 infection treated with convalescent fresh frozen plasma. RESULTS: At the time of plasma therapy both patients were on mechanical ventilation and received antiviral agents and a full scale of supportive care. Each patient received 3 × 200 mL of convalescent plasma of recently recovered donors with sufficient novel anti-coronavirus IgG titers. Subsequent to convalescent plasma infusion, oxygenization improved and inflammatory markers decreased in both individuals. As compared to pretransfusion, lymphocyte counts increased and interleukin-6 level lessened. Both patients were weaned from mechanical ventilation within 2 weeks of treatment. No severe adverse effects were observed. CONCLUSIONS: Our experience indicates that convalescent plasma therapy is well tolerated and could potentially improve clinical outcomes. Optimal dose and timing as well as precise assessment of clinical benefit of convalescent plasma therapy will need further investigation in larger, well-controlled trials. This is the first report of the successful use of convalescent plasma in the treatment of critically ill patients with COVID-19 infection in Hungary. Orv Hetil. 2020; 161(27): 1111-1121.

Anti-cytokine therapy in novel coronavirus disease (COVID-19) ­ the first administration of tocilizumab in Hungary at a department of infectology / Citokinellenes terápia az új típusú koronavírus okozta megbetegedés (COVID-19) kezelésében - tocilizumab elsoként való alkalmazása egy hazai infektológiai osztályon.

During the past few months, a pandemic originating from China named new coronavirus disease (COVID-19) has shown how vulnerable the world is. To date, no medication supported by randomized clinical trials has been approved for the treatment of COVID-19. At the time of writing of this paper, severe acute respiratory syndrome caused by coronavirus-2 (SARS-CoV-2) has been responsible - according to modest estimations - for around 4 million of infections and 300 000 deaths. Unveiling details of patomechanism, in fatal cases the role of immune dysregulation, namely cytokine release syndrome (CRS) has been discovered. Based on the current knowledge, interleukin-6 (IL6) plays a pivotal role in COVID-19 associated CRS. Case reports and result of small case series suggest efficacy of an IL6 inhibitor monoclonal antibody (tocilizumab) in treating CRS. Authors describe a case and review recent knowledge on the treatment of COVID-19. To our knowledge, the first case of severe COVID-19-associated cytokine storm syndrome - treated succesfully with IL6 monoclocal antibody at a Hungarian department of infectology - is presented here. Orv Hetil. 2020; 161(26): 1070-1077.