Anti-inflammatory response of cardamom extract and prediction of therapeutic window in COVID-19 patients by assessing inflammatory markers using RT-PCR.

INTRODUCTION: Molecular diagnostics using RT-PCR has now emerged as the new diagnostic method for clinicians with the dawn of SARS-CoV-2. In India, the popularity and awareness of RT-PCR and particularly the increased availability of testing machines across hospitals has now opened up possibilities of diagnostic tests with RT-PCR. In view of the cytokine storm which is the significant reason for morbidity and mortality of COVID-19 patients, we proposed to test the usefulness of a multiplex RT-PCR test kit that simultaneously measured inflammatory markers namely, IL-6, TNF- α and IL-10 (IFM) all in one tube. The study included a group of patients who were equally allotted to two treatment arms one of which received standard of care along with a food supplement capsule as a natural anti-inflammatory (RECOVEREEZ FORTE™), and the other group received standard of care that included oral Prednisolone tablets in tapered dosage. RECOVEREEZ FORTE™ consists of potent biomolecules from cardamom extract. A natural product with substantial anti-inflammatory action when consumed early at the onset of symptoms is hereby proven by comparing gene expression profile of inflammatory markers with routinely tested inflammatory parameters such as serum IL-6, CRP and LDH. In addition to predicting worse disease outcomes beforehand, RT-PCR assay tests provides an opportunity for identifying therapeutic window aiding in practicing effective treatment strategy for COVID-19. RT-PCR analysis of IFM together being used in a single multiplex kit is being first reported and such a test as a prognosticator for disease progression does seem promising and worthy of clinicians adopting novel testing modalities in clinical practice. AIM OF THE STUDY: To study the anti-inflammatory response of RECOVEREEZ FORTE™ using RT-PCR based multiplex gene profiling of inflammatory markers in disease prognosis and show its predictability of worsening outcomes and its role in identifying therapeutic window for RECOVEREEZ FORTE™. To show the potentiality of RECOVEREEZ FORTE™ in reducing COVID-19 symptoms and SARS-CoV-2 RT-PCR Ct values of the treatment group. MATERIALS AND METHODS: This was a short study of a 10-day period where the end point was the negativity of COVID-19 on RT-PCR test or the decline in cycle threshold (Ct) values of the test performed on day 10 when compared to day 0. During the course of the study, patients were given standard treatment and an oral dose of 500 mg of RECOVEREEZ FORTE™ thrice daily, or standard of care and oral Prednisolone in tapered dosage (control group). All essential interventions were included in the standard of care as decided by the attending physician. The RT-PCR results of inflammatory markers were compared to routinely tested parameters such as IL-6, CRP and LDH. Time to clinical improvement was in terms of SARS-CoV-2 RT-PCR test negativity or recovery of COVID-19 symptoms. We enrolled 64 patients, of which 32 were allocated to RECOVEREEZ FORTE ™ group and 32 to the control group. RESULTS: The RT-PCR analysis of elevated IFM on day 0 corresponded to above normal protein levels of routinely tested parameters such as serum IL-6, CRP and LDH on day 5. Similarly, elevated IFM on day 5 corresponded to above normal protein levels on day 10. Such an association was equally prevalent in both the control group and RECOVEREEZ FORTE™ group, stipulating that RECOVEREEZ FORTE™ may be used as an alternative to steroids. The obtained results indicate that the RT-PCR assessment predicts worse outcomes 5 days earlier. But, the RT-PCR analysis of elevated IFM on day 0 did not correspond to the above normal protein levels of other parameters on day 10. Hence, indicating that the IFM RT-PCR test cannot predict worse outcomes 10 days earlier. Also, RECOVEREEZ FORTE™ when consumed for a period of 10 days normalized LDH values, compared to the control group. Moreover, IFM RT-PCR test identified a 5-day therapeutic window for RECOVEREEZ FORTE™ against inflammation experienced by patients. In addition to the above findings, the authors also observed that majority of the patients belonging to the treatment group showed recovery from symptoms such as fever, cough, sore throat and breathlessness compared to control group by day 5. 12 (37.5%) out of 32 patients and 6 (18.75%) out of 32 patients belonging to the treatment group and control group, respectively, became SARS-CoV-2 negative by day 5, indicating a probable anti-viral action of RECOVEREEZ FORTE™ against SARS-CoV-2. CONCLUSION: The IFM RT-PCR test possess 5-day early prediction ability and lacks 10-day prediction ability. Treatment with RECOVEREEZ FORTE™ indicates good anti-inflammatory action which is equivalent to steroids. Intake of RECOVEREEZ FORTE ™ for a period of 5 days depicts persistent anti-inflammatory action, recovery of COVID-19 symptoms and a probable anti-viral action. Moreover, an effective normalization of LDH may be rendered by RECOVEREEZ FORTE™ when consumed for a period of 10 days.

Secretome of Mesenchymal Bone Marrow Stem Cells: Is It Immunosuppressive or Proinflammatory?

Mesenchymal stem cells (MSC) are characterized by tolerogenic potential and therefore, are used in the treatment of autoimmune diseases such as graft-versus-host disease (GVHD) reactions after allogeneic hematopoietic cell transplantation to improve the transplant functions, as well as for the therapy and prevention of cytokine storm in COVID-19 patients and some other conditions. However, MSC can exhibit proinflammatory activity, which causes risks for their clinical use. We studied the cytokine profile of bone marrow MSC culture and demonstrate intensive production of IL-6, IL-8, and chemokine MCP-1, which participate in the pathogenesis of cytokine storm and GVHD. At the same time, no anti-inflammatory IL-4 and IL-10 were detected. To reduce the risks of MSC application in the GVHD therapeutic protocols, further studies of the conditions promoting generation of MSC with tolerogenic potential and approved clinical standards of MSC use are required.

Inhibitory effects and mechanisms of the anti-covid-19 traditional Chinese prescription, Keguan-1, on acute lung injury.

ETHNOPHARMACOLOGICAL RELEVANCE: Keguan-1, a new traditional Chinese medicine (TCM) prescription contained seven Chinese herbs, is developed to treat coronavirus disease 19 (COVID-19). The first internationally registered COVID-19 randomised clinical trial on integrated therapy demonstrated that Keguan-1 significantly reduced the incidence of ARDS and inhibited the severe progression of COVID-19. AIM OF THE STUDY: To investigate the protective mechanism of Keguan-1 on ARDS, a lipopolysaccharide (LPS)-induced acute lung injury (ALI) model was used to simulate the pathological state of ARDS in patients with COVID-19, focusing on its effect and mechanism on ALI. MATERIALS AND METHODS: Mice were challenged with LPS (2 mg/kg) by intratracheal instillation (i.t.) and were orally administered Keguan-1 (low dose, 1.25 g/kg; medium dose, 2.5 g/kg; high dose, 5 g/kg) after 2 h. Bronchoalveolar lavage fluid (BALF) and lung tissue were collected 6 h and 24 h after i.t. administration of LPS. The levels of inflammatory factors tumour necrosis factor alpha (TNF-α), interleukin (IL)-6, IL-1ß, keratinocyte-derived chemokine (KC or mCXCL1), macrophage inflammatory protein 2 (MIP2 or mCXCL2), angiotensin II (Ang II), and endothelial cell junction-associated proteins were analysed using ELISA or western blotting. RESULTS: Keguan-1 improved the survival rate, respiratory condition, and pathological lung injury; decreased the production of proinflammatory factors (TNF-α, IL-6, IL-1ß, KC, and MIP2) in BALF and the number of neutrophils in the lung tissues; and ameliorated inflammatory injury in the lung tissues of the mice with LPS-induced ALI. Keguan-1 also reduced the expression of Ang II and the adhesion molecule ICAM-1; increased tight junction proteins (JAM-1 and claudin-5) and VE-cadherin expression; and alleviated pulmonary vascular endothelial injury in LPS-induced ALI. CONCLUSION: These results demonstrate that Keguan-1 can improve LPS-induced ALI by reducing inflammation and pulmonary vascular endothelial injury, providing scientific support for the clinical treatment of patients with COVID-19. Moreover, it also provides a theoretical basis and technical support for the scientific use of TCMs in emerging infectious diseases.

PaO2/FiO2 and IL-6 are risk factors of mortality for intensive care COVID-19 patients.

To identify the risk factors of mortality for the coronavirus disease 19 (COVID-19) patients admitted to intensive care units (ICUs) through a retrospective analysis. The demographic, clinical, laboratory, and chest imaging data of patients admitted to the ICU of Huoshenshan Hospital from February 10 to April 10, 2020 were retrospectively analyzed. Student's t-test and Chi-square test were used to compare the continuous and categorical variables, respectively. The logistic regression model was employed to ascertain the risk factors of mortality. This retrospective study involved 123 patients, including 64 dead and 59 survivors. Among them, 57 people were tested for interleukin-6 (IL-6) (20 died and 37 survived). In all included patients, the oxygenation index (PaO2/FiO2) was identified as an independent risk factor (odd ratio [OR] = 0.96, 95% confidence interval [CI]: 0.928-0.994, p = 0.021). The area under the curve (AUC) was 0.895 (95% CI: 0.826-0.943, p < 0.0001). Among the patients tested for IL-6, the PaO2/FiO2 (OR = 0.955, 95%CI: 0.915-0.996, p = 0.032) and IL-6 (OR = 1.013, 95%CI: 1.001-1.025, p = 0.028) were identified as independent risk factors. The AUC was 0.9 (95% CI: 0.791-0.964, p < 0.0001) for IL-6 and 0.865 (95% CI: 0.748-0.941, p < 0.0001) for PaO2/FiO2. PaO2/FiO2 and IL-6 could potentially serve as independent risk factors for predicting death in COVID-19 patients requiring intensive care.

Beneficial effects of novel aureobasidium pullulans strains produced beta-1,3-1,6 glucans on interleukin-6 and D-dimer levels in COVID-19 patients; results of a randomized multiple-arm pilot clinical study.

OBJECTIVE: In this pilot clinical study, we report the beneficial effects of beta glucans derived from two strains AFO-202 and N-163 of a black yeast Aureobasidium pullulans on the biomarkers for cytokine storm and coagulopathy in COVID-19 patients. METHODS: A total of 24 RT-PCR positive COVID-19 patients were recruited and randomly divided into three groups (Gr): Gr. 1 control (n = 8) - Standard treatment; Gr. 2: Standard treatment + AFO-202 beta glucan (n = 8); and Gr. 3, Standard treatment + combination of AFO-202 and N-163 beta glucans (n = 8) for 30 days. RESULTS: There was no mortality or requirement of ventilation of the subjects in any of the groups. There was a decrease in D-Dimer values (751 ng/ml to 143.89 ng/ml) and IL-6 values (7.395-3.16 pg/ml) in Gr. 1 in 15 days but the levels increased to abnormal levels on day 30 (D-Dimer: 202.5 ng/ml; IL-6 55.37 pg/ml); which steadily decreased up to day 30 in groups 2 (D-dimer: 560.99 ng/dl to 79.615; IL-6: 26.18-3.41 pg/ml) and 3 (D-dimer: 1614 ng/dl to 164.25 ng/dl; IL-6: 6.25-0.5 pg/ml). The same trend was observed with ESR. LCR and LeCR increased while NLR decreased significantly in Gr. 3. CD4 + and CD8 + T cell count showed relatively higher increase in Gr.3. There was no difference in CRP within the groups. CONCLUSION: As these beta glucans are well known food supplements with a track record for safety, larger multi-centric clinical studies are recommended to validate their use as an adjunct in the management of COVID-19 and the ensuing long COVID-19 syndrome.

Biomarkers for Prognosis and Treatment Response in COVID-19 Patients.

During a severe infection such as coronavirus disease 2019 (COVID-19), the level of almost all analytes can change, presenting a correlation with disease severity and survival; however, a biomarker cannot be translated into clinical practice for treatment guidance until it is proven to have a significant impact. Several studies have documented the association between COVID-19 severity and circulating levels of C-reactive protein (CRP) and interleukin-6, and the accuracy of the CRP level in predicting treatment responses has been evaluated. Moreover, promising findings on prothrombin and D-dimer have been reported. However, the clinical usefulness of these biomarkers in COVID-19 is far from proven. The burst of data generation during this pandemic has led to the publication of numerous studies with several notable drawbacks, weakening the strength of their findings. We provide an overview of the key findings of studies on biomarkers for the prognosis and treatment response in COVID-19 patients. We also highlight the main drawbacks of these studies that have limited the clinical use of these biomarkers.

Northern pig-tailed macaques ( Macaca leonina) infected with SARS-CoV-2 show rapid viral clearance and persistent immune response.

Coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus (SARS-CoV-2), has become an unprecedented global health emergency. At present, SARS-CoV-2-infected nonhuman primates are considered the gold standard animal model for COVID-19 research. Here, we showed that northern pig-tailed macaques ( Macaca leonina, NPMs) supported SARS-CoV-2 replication. Furthermore, compared with rhesus macaques, NPMs showed rapid viral clearance in lung tissues, nose swabs, throat swabs, and rectal swabs, which may be due to higher expression of interferon (IFN)-α in lung tissue. However, the rapid viral clearance was not associated with good outcome. In the second week post infection, NPMs developed persistent or even more severe inflammation and body injury compared with rhesus macaques. These results suggest that viral clearance may have no relationship with COVID-19 progression and SARS-CoV-2-infected NPMs could be considered as a critically ill animal model in COVID-19 research.

Soluble interleukin-6 receptor in the COVID-19 cytokine storm syndrome.

Data suggest that interleukin (IL)-6 blockade could reduce mortality in severe COVID-19, yet IL-6 is only modestly elevated in most patients. Chen et al. describe the role of soluble interleukin-6 receptor (sIL-6R) in IL-6 trans-signaling and how understanding the IL-6:sIL-6R axis might help define and treat COVID-19 cytokine storm syndrome.

Interleukin­6 signalling as a valuable cornerstone for molecular medicine (Review).

The biological abilities of interleukin­6 (IL­6) have been under investigation for nearly 40 years. IL­6 works through an interaction with the complex peptide IL­6 receptor (IL­6R). IL­6 is built with four α­chain nanostructures, while two different chains, IL­6Rα (gp80) and gp130/IL6ß (gp130), are included in IL­6R. The three­dimensional shapes of the six chains composing the IL­6/IL­6R complex are the basis for the nanomolecular roles of IL­6 signalling. Genes, pseudogenes and competitive endogenous RNAs of IL­6 have been identified. In the present review, the roles played by miRNA in the post­transcriptional regulation of IL­6 expression are evaluated. mRNAs are absorbed via the 'sponge' effect to dynamically balance mRNA levels and this has been assessed with regard to IL­6 transcription efficiency. According to current knowledge on molecular and nanomolecular structures involved in active IL­6 signalling, two different IL­6 models have been proposed. IL­6 mainly has functions in inflammatory processes, as well as in cognitive activities. Furthermore, the abnormal production of IL­6 has been found in patients with severe acute respiratory syndrome coronavirus 2 (SARS­CoV­2; also known as COVID­19). In the present review, both inflammatory and cognitive IL­6 models were analysed by evaluating the cytological and histological locations of IL­6 signalling. The goal of this review was to illustrate the roles of the classic and trans­signalling IL­6 pathways in endocrine glands such as the thyroid and in the central nervous system. Specifically, autoimmune thyroid diseases, disorders of cognitive processes and SARS­CoV­2 virus infection have been examined to determine the contribution of IL­6 to these disease states.

Early risk markers for severe clinical course and fatal outcome in German patients with COVID-19.

BACKGROUND: Some patients with Corona Virus Disease 2019 (COVID-19) develop a severe clinical course with acute respiratory distress syndrome (ARDS) and fatal outcome. Clinical manifestations and biomarkers in early stages of disease with relevant predictive impact for outcomes remain largely unexplored. We aimed to identify parameters which are significantly different between subgroups. DESIGN: 125 patients with COVID-19 were analysed. Patients with ARDS (N = 59) or non-ARDS (N = 66) were compared, as well as fatal outcome versus survival in the two groups. KEY RESULTS: ARDS and non-ARDS patients did not differ with respect to comorbidities or medication on developing a fatal outcome versus survival. Body mass index was higher in patients with ARDS versus non-ARDS (p = 0.01), but not different within the groups in survivors versus non-survivors. Interleukin-6 levels on admission were higher in patients with ARDS compared to non-ARDS as well as in patients with fatal outcome versus survivors, whereas lymphocyte levels were lower in the different subgroups (all p<0.05). There was a highly significant 3.5-fold difference in fever load in non-survivors compared to survivors (p<0.0001). Extrapulmonary viral spread was detected more often in patients with fatal outcome compared to survivors (P = 0.01). Further the detection of SARS-CoV-2 in serum showed a significantly more severe course and an increased risk of death (both p<0.05). CONCLUSIONS: We have identified early risk markers for a severe clinical course, like ARDS or fatal outcome. This data might help develop a strategy to address new therapeutic options early in patients with COVID-19 and at high risk for fatal outcome.

Duplex Shiny app quantification of the sepsis biomarkers C-reactive protein and interleukin-6 in a fast quantum dot labeled lateral flow assay.

Fast point-of-care (POC) diagnostics represent an unmet medical need and include applications such as lateral flow assays (LFAs) for the diagnosis of sepsis and consequences of cytokine storms and for the treatment of COVID-19 and other systemic, inflammatory events not caused by infection. Because of the complex pathophysiology of sepsis, multiple biomarkers must be analyzed to compensate for the low sensitivity and specificity of single biomarker targets. Conventional LFAs, such as gold nanoparticle dyed assays, are limited to approximately five targets-the maximum number of test lines on an assay. To increase the information obtainable from each test line, we combined green and red emitting quantum dots (QDs) as labels for C-reactive protein (CRP) and interleukin-6 (IL-6) antibodies in an optical duplex immunoassay. CdSe-QDs with sharp and tunable emission bands were used to simultaneously quantify CRP and IL-6 in a single test line, by using a single UV-light source and two suitable emission filters for readout through a widely available BioImager device. For image and data processing, a customized software tool, the MultiFlow-Shiny app was used to accelerate and simplify the readout process. The app software provides advanced tools for image processing, including assisted extraction of line intensities, advanced background correction and an easy workflow for creation and handling of experimental data in quantitative LFAs. The results generated with our MultiFlow-Shiny app were superior to those generated with the popular software ImageJ and resulted in lower detection limits. Our assay is applicable for detecting clinically relevant ranges of both target proteins and therefore may serve as a powerful tool for POC diagnosis of inflammation and infectious events.

Clinical Characteristics and Risk Factors in Coronavirus Disease 2019 Patients with Liver Injury.

BACKGROUND Emerging studies noted that liver injury in coronavirus disease 2019 (COVID-19) patients may be induced by virus-mediated inflammation, which was confirmed by liver pathology. The aim of this study was to observe clinical characteristics and explore risk factors in COVID-19 patients with liver injury. MATERIAL AND METHODS In this retrospective study, 40 confirmed COVID-19 patients with normal alanine transaminase (ALT) on admission were divided into a group of normal ALT patients whose ALT was always less than 40 U/l during hospitalization and a group of elevated ALT patients whose ALT was at least once more than 40 U/l after admission. Clinical data, especially virus-induced inflammatory parameters, were analyzed for risk factors and predictive value. The Mann-Whitney U test and t test for comparing means and logistic regression were performed for analysis of risk factors. Area under the ROC curve was used for predictive values. RESULTS Sixteen of 40 (40.0%) patients developed elevated ALT, many of them with more severe COVID-19. The highest ALT level was 101 U/l. The risk factors for liver injury were C-reactive protein (CRP), interleukin 6 (IL6), erythrocyte sedimentation rate (ESR), CD8+T cell count, and severity of disease, and CRP (OR 1.13, 95% CI 1.045-1.222, p=0.002) was the independent risk factor. CONCLUSIONS Liver injury in COVID-19 patients was mild and associated with inflammatory markers, especially CRP, which suggests that liver injury may be induced by virus-mediated inflammation in COVID-19 patients.

Inflammatory Biomarker Trends Predict Respiratory Decline in COVID-19 Patients.

In this single-center, retrospective cohort analysis of hospitalized coronavirus disease 2019 (COVID-19) patients, we investigate whether inflammatory biomarker levels predict respiratory decline in patients who initially present with stable disease. Examination of C-reactive protein (CRP) trends reveals that a rapid rise in CRP levels precedes respiratory deterioration and intubation, although CRP levels plateau in patients who remain stable. Increasing CRP during the first 48 h of hospitalization is a better predictor (with higher sensitivity) of respiratory decline than initial CRP levels or ROX indices (a physiological score of respiratory function). CRP, the proinflammatory cytokine interleukin-6 (IL-6), and physiological measures of hypoxemic respiratory failure are correlated, which suggests a mechanistic link. Our work shows that rising CRP predicts subsequent respiratory deterioration in COVID-19 and may suggest mechanistic insight and a potential role for targeted immunomodulation in a subset of patients early during hospitalization.

Lack of tocilizumab effect on mortality in COVID19 patients.

Off-label tocilizumab use in COVID-19 patients reflects concern for cytokine release syndrome. Comparison of matched COVID-19 pneumonia patients found elevated IL-6 levels correlated with mortality that did not change with tocilizumab administration. Correlating mortality with increased IL-6 doesn't imply causality however lack of improvement by tocilizumab requires further clinical trial alterations.

Hemophagocytic lymphohistiocytosis in a patient with COVID-19 treated with tocilizumab: a case report.

BACKGROUND: The understanding of coronavirus disease 2019 (COVID-19) is rapidly evolving. Although it is primarily a respiratory illness, other manifestations, such as Guillain-Barré syndrome, immune thrombocytopenia, and immune-mediated thrombotic thrombocytopenic purpura, have been described. We present a case of a patient with hemophagocytic lymphohistiocytosis secondary to COVID-19 treated with tocilizumab with a marked biochemical improvement. CASE PRESENTATION: In this case report we present a Caucasian patient with COVID-19 who developed a marked elevation of inflammatory parameters with ferritin 36,023 µg/L, but also elevated C-reactive protein 334 mg/L and lactate dehydrogenase 1074 U/L, 1 week after admission to the intensive care unit. He met five of eight criteria for hemophagocytic lymphohistiocytosis, but he lacked the high fever and cytopenia seen in the majority of cases. He was treated with tocilizumab, a monoclonal antibody targeting the interleukin-6 receptor, and over the next days, a rapid decrease in ferritin and C-reactive protein levels was observed. However, his respiratory failure only improved gradually, and he was weaned off the respirator 11 days later. CONCLUSION: COVID-19 may induce a hyperinflammatory clinical picture and in some cases develop into hemophagocytic lymphohistiocytosis. In our patient's case, therapeutic interleukin-6 blockade abrogated signs of hyperinflammation but did not seem to improve pulmonary function. Measurement of ferritin and C-reactive protein, as well as quantification of interleukin-6 on indication, should be performed in patients with severe COVID-19. Specific treatment in such patients must also be contemplated, preferably in randomized controlled trials.

Advancement in biosensors for inflammatory biomarkers of SARS-CoV-2 during 2019-2020.

COVID-19 pandemic has affected everyone throughout the world and has resulted in the loss of lives of many souls. Due to the restless efforts of the researchers working hard day and night, some success has been gained for the detection of virus. As on date, the traditional polymerized chain reactions (PCR), lateral flow devices (LFID) and enzyme linked immunosorbent assays (ELISA) are being adapted for the detection of this deadly virus. However, a more exciting avenue is the detection of certain biomarkers associated with this viral infection which can be done by simply re-purposing our existing infrastructure. SARS-CoV-2 viral infection triggers various inflammatory, biochemical and hematological biomarkers. Because of the infection route that the virus follows, it causes significant inflammatory response. As a result, various inflammatory markers have been reported to be closely associated with this infection such as C-reactive proteins, interleukin-6, procalcitonin and ferritin. Sensing of these biomarkers can simultaneously help in understanding the illness level of the affected patient. Also, by monitoring these biomarkers, we can predict the viral infections in those patients who have low SARS-CoV-2 RNA and hence are missed by traditional tests. This can give more targets to the researchers and scientists, working in the area of drug development and provide better prognosis. In this review, we propose to highlight the conventional as well as the non-conventional methods for the detection of these inflammatory biomarkers which can act as a single platform of knowledge for the researchers and scientists working for the treatment of COVID-19.

Impact of interleukin-6 blockade with tocilizumab on SARS-CoV-2 viral kinetics and antibody responses in patients with COVID-19: A prospective cohort study.

BACKGROUND: The virological and immunological effects of the immunomodulatory drugs used for COVID-19 remain unknown. We evaluated the impact of interleukin (IL)-6 blockade with tocilizumab on SARS-CoV-2 viral kinetics and the antibody response in patients with COVID-19. METHODS: Prospective cohort study in patients admitted with COVID-19. Serial nasopharyngeal and plasma samples were measured for SARS-CoV-2 RNA and S-IgG/N-IgG titers, respectively. FINDINGS: 138 patients with confirmed infection were included; 76 (55%) underwent IL-6 blockade. Median initial SOFA (p = 0•016) and SARS-CoV-2 viral load (p<0•001, Mann-Whitney-Wilcoxon test) were significantly higher among anti-IL-6 users. Patients under IL-6 blockade showed delayed viral clearance in the Kaplan-Meier curves (HR 0•35 [95%CI] [0•15-0•81], log-rank p = 0•014), but an adjusted propensity score matching model did not demonstrate a significant relationship of IL-6 blockade with viral clearance (HR 1•63 [0•35-7•7]). Cox regression showed an inverse association between SARS-CoV-2 RNA clearance and the initial viral load (HR 0•35 [0•11-0•89]). Patients under the IL-6 blocker showed shorter median time to seropositivity, higher peak antibody titers, and higher cumulative proportion of seropositivity in the Kaplan Meier curves (HR 3•1 [1•9-5] for S-IgG; and HR 3•0 [1•9-4•9] for N-IgG; log-rank p<0•001 for both). However, no significant differences between groups were found in either S-IgG (HR 1•56 [0•41-6•0]) nor N-IgG (HR 0•96 [0•26-3•5]) responses in an adjusted propensity score analysis. INTERPRETATION: Our results suggest that in patients infected with SARS-CoV-2, IL-6 blockade does not impair the viral specific antibody responses. Although a delayed viral clearance was observed, it was driven by a higher initial viral load. The study supports the safety of this therapy in patients with COVID-19. FUNDING: Instituto de salud Carlos III (Spain).

Biosensing Cytokine IL-6: A Comparative Analysis of Natural and Synthetic Receptors.

Cytokines are a family of proteins which play a major role in the regulation of the immune system and the development of several diseases, from rheumatoid arthritis to cancer and, more recently, COVID-19. Therefore, many efforts are currently being developed to improve therapy and diagnosis, as well as to produce inhibitory drugs and biosensors for a rapid, minimally invasive, and effective detection. In this regard, even more efficient cytokine receptors are under investigation. In this paper we analyze a set of IL-6 cytokine receptors, investigating their topological features by means of a theoretical approach. Our results suggest a topological indicator that may help in the identification of those receptors having the highest complementarity with the protein, a feature expected to ensure a stable binding. Furthermore, we propose and discuss the use of these receptors in an idealized experimental setup.

Appropriate use of tocilizumab in COVID-19 infection.

OBJECTIVE: This study aimed to describe the effectiveness and optimum use of tocilizumab (TCZ) treatment by the support of clinical, laboratory and radiologic observations. METHODS: All patients were followed up in the hospital with daily interleukin-6 (IL-6), C-reactive protein (CRP), ferritin, d-dimer, full blood count, and procalcitonin. Thoracic computed tomography (CT) was performed on admission, when oxygen support was necessary, and seven days after TCZ started. Disease course of the patients was grouped as severe or critical, according to their clinical, laboratory and radiologic evaluations. RESULTS: Forty-three patients were included: 70% were male; the median age was 64 years (minimum-maximum: 27-94); and six (14%) patients died. The median duration of oxygen support before the onset of TCZ was shorter among the severe patient group than the critical patient group (1 vs. 4 days, p < 0.001). Three cases of 21 (14%) who received TCZ in the ward were transferred to ICU, and none of them died. The levels of IL-6, CRP, ferritin, d-dimer, and procalcitonin were significantly lower in the severe cases group than the critical cases group (p = 0.025, p = 0.002, p = 0.008, p = 0.002, and p = 0.001, respectively). Radiological improvement was observed in severe cases on the seventh day of TCZ. Secondary bacterial infection was detected in 41% of critical cases, but none of the severe ones. CONCLUSION: Earlier use of TCZ in COVID-19 infection was beneficial for survival, length of hospitalization and duration of oxygen support. The recommendation for administration of TCZ was based on an increase in requirement of oxygen support, progression in thoracic CT, and elevation of inflammation markers, including IL-6, CRP, ferritin, and d-dimer, and decrease in % lymphocytes.