Safety of Tocilizumab in COVID-19 Patients and Benefit of Single-Dose: The Largest Retrospective Observational Study.

Severe acute respiratory coronavirus-2 (SARS-CoV-2) still presents a public threat and puts extra strain on healthcare facilities. Without an effective antiviral drug, all available treatment options are considered supportive. Tocilizumab as a treatment option has to date shown variable results. In this retrospective study, we aimed to assess predictors of mortality of COVID-19 patients (n = 300) on tocilizumab and the clinical effectiveness of this drug. The results showed that ICU admission OR = 64.6 (95% CI: 8.2, 507.4); age of the patient OR = 1.1 (95% CI: 1.0, 1.1); and number of tocilizumab doses administered by the patient OR(two doses) = 4.0 (95% CI: 1.5, 10.9), OR(three doses) = 1.5 (95% CI: 0.5, 5.1), and OR(four doses or more) = 7.2 (95% CI: 2.0, 25.5) presented strong correlation factors that may be linked to COVID-19 mortality. Furthermore, our study showed the beneficial effects of early administration of tocilizumab OR = 1.2 (95% CI: 1.1, 1.4) and longer hospital length of stay OR = 0.974 (95% CI: 0.9, 1.0) in reducing COVID-19 mortalities. High blood D-dimer concentration OR = 1.1 (95% CI: 1.0, 1.2) and reciprocal blood phosphate concentration OR = 0.008 (95% CI: 0.0, 1.2) were correlated to high mortality under SARS-CoV-2 infection. The short-term effect of a single dose of tocilizumab was a significant increase in blood BUN and liver enzymes (ALT, AST, and LDH) above their normal ranges. Furthermore, it significantly reduced CRP blood concentration, but not to normal levels (13.90 to 1.40 mg/dL, p < 0.001). Assessing the effect of different doses of tocilizumab (in terms of the number of doses, total mg, and total mg/kg administered by the patients) indicated that administering more than one dose may lead to increases in ICU length of stay and hospital length of stay of up to 14 and 22 days after the last dose of tocilizumab (6 to 14, p = 0.06, and 10 to 22, p < 0.001), with no improvement in 28- and 90-day mortality, as confirmed by Kaplan-Meier analysis. There were also clear correlations and trends between the number of doses of tocilizumab and increased blood CO2, MCV, RDW, and D-dimer concentrations and between number of doses of tocilizumab and decreased CRP, AST, and hemoglobin concentrations. Microbiology analysis showed a significant increase in the incidence of infection after tocilizumab administration (28 to 119, p < 0.001) with a median time of incidence within 6 days of the first dose of tocilizumab. A significant correlation was also found between the number of tocilizumab doses and the number of incidences of infections after tocilizumab administration r (298) = 0.396, p = 1.028 × 10-12. Based on these results and depending on the pharmacokinetic parameters of the drug, we recommend single-dose administration of tocilizumab as the optimal dosage for COVID-19 patients who do not have active bacterial infection or liver diseases, to be administered as soon as the patient is admitted to the hospital.

Genome composition and genetic characterization of SARS-CoV-2.

SARS-CoV-2 is a type of Betacoronaviruses responsible for COVID-19 pandemic disease, with more than 1.745 million fatalities globally as of December-2020. Genetically, it is considered the second largest genome of all RNA viruses with a 5' cap and 3' poly-A tail. Phylogenetic analyses of coronaviruses reveal that SARS-CoV-2 is genetically closely related to the Bat-SARS Like-Corona virus (Bat-SL-Cov) with 96% whole-genome identity. SARS-CoV-2 genome consists of 15 ORFs coded into 29 proteins. At the 5' terminal of the genome, we have ORF1ab and ORF1a, which encode the 1ab and 1a polypeptides that are proteolytically cleaved into 16 different nonstructural proteins (NSPs). The 3' terminal of the genome represents four structural (spike, envelope, matrix, and nucleocapsid) and nine accessory (3a, 3b, 6, 7a, 7b, 8b, 9a, 9b, and orf10) proteins. As the number of COVID-19 patients increases dramatically worldwide, there is an urgent need to find a quick and sensitive diagnostic tool for controlling the outbreak of SARS-CoV-2 in the community. Today, molecular testing methods utilizing viral genetic material (e.g., PCR) represent the crucial diagnostic tool for the SARS-CoV-2 virus despite its low sensitivity in the early stage of viral infection. This review summarizes the genome composition and genetic characterization of the SARS-CoV-2.

Emerging of composition variations of SARS-CoV-2 spike protein and human ACE2 contribute to the level of infection: in silico approaches.

SARS-CoV-2 is causative of pandemic COVID-19. There is a sequence similarity between SARS-CoV-2 and SARS-CoV; however, SARS-CoV-2 RBDs (receptor-binding domain) binds 20-fold strongly with human angiotensin-converting enzyme 2 (hACE2) than SARS-CoV. The study aims to investigate protein-protein interactions (PPI) of hACE2 with SARS-CoV-2 RBD between wild and variants to detect the most influential interaction. Variants of hACE2 were retrieved from NCBI and subjected to determine the most pathogenic nsSNPs. Probability of PPIs determines the binding affinity of hACE2 genetic variants with RBD was investigated. Composition variations at the hACE2 and RBD were processed for PatchDock and refined by FireDock for the PPIs. Twelve nsSNPs were identified as the top pathogenic from SNPs (n = 7489) in hACE2 using eight bioinformatics tools. Eight RBD variants were complexed with 12 nSNPS of hACE2, and the global energy scores (Kcal/mol) were calculated and classified as very weak (-3.93 to -18.43), weak (-18.42 to -32.94), moderate (-32.94 to -47.44), strong (-47.44 to -61.95) and very strong (-61.95 to -76.46) zones. Seven composition variants in the very strong zone [G726R-G476S; R768W-V367F; Y252N-V483A; Y252N-V367F; G726R-V367F; N720D-V367F and N720D-F486L], and three in very weak [P263S-S383C; RBD-H378R; G726R-A348T] are significantly (p < 0.00001) varied for global energy score. Zonation of the five zones was established based on the scores to differentiate the effect of hACE2 and RBD variants on the binding affinity. Moreover, our findings support that the combination of hACE2 and RBD is key players for the risk of infection that should be done by further laboratory studies.Communicated by Ramaswamy H. Sarma.

State-of-the-art tools to identify druggable protein ligand of SARS-CoV-2.

INTRODUCTION: The SARS-CoV-2 (previously 2019-nCoV) outbreak in Wuhan, China and other parts of the world affects people and spreads coronavirus disease 2019 (COVID-19) through human-to-human contact, with a mortality rate of > 2%. There are no approved drugs or vaccines yet available against SARS-CoV-2. MATERIAL AND METHODS: State-of-the-art tools based on in-silico methods are a cost-effective initial approach for identifying appropriate ligands against SARS-CoV-2. The present study developed the 3D structure of the envelope and nucleocapsid phosphoprotein of SARS-CoV-2, and molecular docking analysis was done against various ligands. RESULTS: The highest log octanol/water partition coefficient, high number of hydrogen bond donors and acceptors, lowest non-bonded interaction energy between the receptor and the ligand, and high binding affinity were considered for the best ligand for the envelope (mycophenolic acid: log P = 3.00; DG = -10.2567 kcal/mol; pKi = 7.713 µM) and nucleocapsid phosphoprotein (1-[(2,4-dichlorophenyl)methyl]pyrazole-3,5-dicarboxylic acid: log P = 2.901; DG = -12.2112 kcal/mol; pKi = 7.885 µM) of SARS-CoV-2. CONCLUSIONS: The study identifies the most potent compounds against the SARS-CoV-2 envelope and nucleocapsid phosphoprotein through state-of-the-art tools based on an in-silico approach. A combination of these two ligands could be the best option to consider for further detailed studies to develop a drug for treating patients infected with SARS-CoV-2, COVID-19.

State-of-the-art tools unveil potent drug targets amongst clinically approved drugs to inhibit helicase in SARS-CoV-2.

INTRODUCTION: The extreme health and economic problems in the world due to the SARS-CoV-2 infection have led to an urgent need to identify potential drug targets for treating coronavirus disease 2019 (COVID-19). The present state-of-the-art tool-based screening was targeted to identify drug targets among clinically approved drugs by uncovering SARS-CoV-2 helicase inhibitors through molecular docking analysis. MATERIAL AND METHODS: Helicase is a vital viral replication enzyme, which unwinds nucleic acids and separates the double-stranded nucleic acids into single-stranded nucleic acids. Hence, the SARS-CoV-2 helicase protein 3D structure was predicted, validated, and used to screen the druggable targets among clinically approved drugs such as protease inhibitor, nucleoside reverse transcriptase inhibitor, and non-nucleoside reverse transcriptase inhibitors, used to treat HIV infection using molecular docking analysis. RESULTS: Interaction with SARS-CoV-2 helicase, approved drugs, vapreotide (affinity: -12.88; S score: -9.84 kcal/mol), and atazanavir (affinity: -11.28; S score: -9.32 kcal/mol), approved drugs for treating AIDS-related diarrhoea and HIV infection, respectively, are observed with significantly low binding affinity and MOE score or binding free energy. The functional binding pockets of the clinically approved drugs on SARS-CoV-2 helicase protein molecule suggest that vapreotide and atazanavir may interrupt the activities of the SARS-CoV-2 helicase. CONCLUSIONS: The study suggests that vapreotide may be a choice of drug for wet lab studies to inhibit the infection of SARS-CoV-2.