Diagnostics and analysis of SARS-CoV-2: current status, recent advances, challenges and perspectives.

The disastrous spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has induced severe public healthcare issues and weakened the global economy significantly. Although SARS-CoV-2 infection is not as fatal as the initial outbreak, many infected victims suffer from long COVID. Therefore, rapid and large-scale testing is critical in managing patients and alleviating its transmission. Herein, we review the recent advances in techniques to detect SARS-CoV-2. The sensing principles are detailed together with their application domains and analytical performances. In addition, the advantages and limits of each method are discussed and analyzed. Besides molecular diagnostics and antigen and antibody tests, we also review neutralizing antibodies and emerging SARS-CoV-2 variants. Further, the characteristics of the mutational locations in the different variants with epidemiological features are summarized. Finally, the challenges and possible strategies are prospected to develop new assays to meet different diagnostic needs. Thus, this comprehensive and systematic review of SARS-CoV-2 detection technologies may provide insightful guidance and direction for developing tools for the diagnosis and analysis of SARS-CoV-2 to support public healthcare and effective long-term pandemic management and control.

Biopanning of specific peptide for SARS-CoV-2 nucleocapsid protein and enzyme-linked immunosorbent assay-based antigen assay.

The ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread worldwide which triggered serious public health issues. The search for rapid and accurate diagnosis, effective prevention, and treatment is urgent. The nucleocapsid protein (NP) of SARS-CoV-2 is one of the main structural proteins expressed and most abundant in the virus, and is considered a diagnostic marker for the accurate and sensitive detection of SARS-CoV-2. Herein, we report the screening of specific peptides from the pIII phage library that bind to SARS-CoV-2 NP. The phage monoclone expressing cyclic peptide N1 (peptide sequence, ACGTKPTKFC, with C&C bridged by disulfide bonding) specifically recognizes SARS-CoV-2 NP. Molecular docking studies reveal that the identified peptide is bound to the "pocket" region on the SARS-CoV-2 NP N-terminal domain mainly by forming a hydrogen bonding network and through hydrophobic interaction. Peptide N1 with the C-terminal linker was synthesized as the capture probe for SARS-CoV-2 NP in ELISA. The peptide-based ELISA was capable of assaying SARS-CoV-2 NP at concentrations as low as 61 pg/mL (∼1.2 pM). Furthermore, the as-proposed method could detect the SARS-CoV-2 virus at limits as low as 50 TCID50 (median tissue culture infective dose)/mL. This study demonstrates that selected peptides are powerful biomolecular tools for SARS-CoV-2 detection, providing a new and inexpensive method of rapidly screening infections as well as rapidly diagnosing coronavirus disease 2019 patients.

Trial of Endovascular Therapy for Acute Ischemic Stroke with Large Infarct.

BACKGROUND: The role of endovascular therapy for acute stroke with a large infarction has not been extensively studied in differing populations. METHODS: We conducted a multicenter, prospective, open-label, randomized trial in China involving patients with acute large-vessel occlusion in the anterior circulation and an Alberta Stroke Program Early Computed Tomography Score of 3 to 5 (range, 0 to 10, with lower values indicating larger infarction) or an infarct-core volume of 70 to 100 ml. Patients were randomly assigned in a 1:1 ratio within 24 hours from the time they were last known to be well to undergo endovascular therapy and receive medical management or to receive medical management alone. The primary outcome was the score on the modified Rankin scale at 90 days (scores range from 0 to 6, with higher scores indicating greater disability), and the primary objective was to determine whether a shift in the distribution of the scores on the modified Rankin scale at 90 days had occurred between the two groups. Secondary outcomes included scores of 0 to 2 and 0 to 3 on the modified Rankin scale. The primary safety outcome was symptomatic intracranial hemorrhage within 48 hours after randomization. RESULTS: A total of 456 patients were enrolled; 231 were assigned to the endovascular-therapy group and 225 to the medical-management group. Approximately 28% of the patients in both groups received intravenous thrombolysis. The trial was stopped early owing to the efficacy of endovascular therapy after the second interim analysis. At 90 days, a shift in the distribution of scores on the modified Rankin scale toward better outcomes was observed in favor of endovascular therapy over medical management alone (generalized odds ratio, 1.37; 95% confidence interval, 1.11 to 1.69; P = 0.004). Symptomatic intracranial hemorrhage occurred in 14 of 230 patients (6.1%) in the endovascular-therapy group and in 6 of 225 patients (2.7%) in the medical-management group; any intracranial hemorrhage occurred in 113 (49.1%) and 39 (17.3%), respectively. Results for the secondary outcomes generally supported those of the primary analysis. CONCLUSIONS: In a trial conducted in China, patients with large cerebral infarctions had better outcomes with endovascular therapy administered within 24 hours than with medical management alone but had more intracranial hemorrhages. (Funded by Covidien Healthcare International Trading [Shanghai] and others; ANGEL-ASPECT ClinicalTrials.gov number, NCT04551664.).

An ultrasensitive ELISA to assay femtomolar level SARS-CoV-2 antigen based on specific peptide and tyramine signal amplification.

The SARS-CoV-2 spreading rapidly has aroused catastrophic public healthcare issues and economy crisis worldwide. It plays predominant role to rapidly and accurately diagnose the virus for effective prevention and treatment. As an abundant transmembrane protein, spike protein (SP) is one of the most valuable antigenic biomarkers for diagnosis of COVID-19. Herein a phage expression of WNLDLSQWLPPM peptide specific to SARS-CoV-2 SP was screened. Molecular docking revealed that the isolated peptide binds to major antigenic epitope locating at S2 subunit with hydrogen bonding. Taking the specific peptide as antigen sensing probe and tyramine signal amplification (TSA), an ultrasensitive "peptide-antigen-antibody" ELISA (p-ELISA) was explored, by which the limit of detection (LOD) was 14 fM and 2.8 fM SARS-CoV-2 SP antigen for first TSA and secondary TSA, respectively. Compared with the LOD by the p-ELISA by direct mode, the sensitivity with 2nd TSA enhanced 100 times. Further, the proposed p-ELISA method can detect SARS-CoV-2 pseudoviruses down to 10 and 3 TCID50/mL spiked in healthy nasal swab sample with 1st TSA and 2nd TSA, separately. Thus, the proposed p-ELISA method with TSA is expected to be a promising ultrasensitive tool for rapidly detecting SARS-CoV-2 antigen to help control the infectious disease.

BCG-induced trained immunity: history, mechanisms and potential applications.

The Bacillus Calmette-Guérin (BCG) vaccine was discovered a century ago and has since been clinically applicable. BCG can not only be used for the prevention of tuberculosis, but also has a non-specific protective effect on the human body called trained immunity that is mediated by innate immune cells such as monocytes, macrophages, and natural killer cells. Mechanisms of trained immunity include epigenetic reprogramming, metabolic reprogramming, and long-term protection mediated by hematopoietic stem cells. Trained immunity has so far shown beneficial effects on cancer, viral-infections, autoimmune diseases, and a variety of other diseases, especially bladder cancer, respiratory viruses, and type 1 diabetes. The modulation of the immune response by BCG has led to the development of a variety of recombinant vaccines. Although the specific mechanism of BCG prevention on diseases has not been fully clarified, the potential role of BCG deserves further exploration, which is of great significance for prevention and treatment of diseases.

Effectiveness and cost-effectiveness of a group-based intervention to improve social-emotional development of young children in poverty-stricken areas: A cluster randomized controlled trial.

Background: Social-emotional ability is key to the well-being and future success of children; however, disparities in social-emotional development during an individual's early age can last a lifetime, which is particularly evident among children living in poverty-stricken areas. We aimed to determine the effectiveness, cost-effectiveness, and feasibility of a group-based intervention called the Care Group on social-emotional development for families living in poverty-stricken counties. Methods: We conducted a cluster (township) randomized controlled trial (C-RCT) every two weeks from July 2019 to June 2020 in a poverty-stricken area located in Shanxi, China. The outbreak of the COVID-19 pandemic suspended the implementation of the intervention in January 2020. The caregiver-child pairs in the intervention group participated in 12 group-based sessions with a structured curriculum and learning materials emphasizing nurturing ability and early childhood development. We applied a difference-in-differences (DID) model to estimate the intervention's impact. The analysis follows the intention-to-treat (ITT) principle. We used standard economic costing methods to estimate the cost of implementing the Care Group over the intervention period and adopted a societal perspective in the analysis. Results: We included 322 eligible caregiver-child pairs in the baseline (intervention n = 136, control n = 186) and surveyed 258 pairs in the endline (intervention n = 117, control n = 141). Compared with the control group, children in the intervention group had significantly fewer social-emotional problems (adjusted mean difference of Z score = -0.374, 95% CI = -0.718, -0.030, P = 0.033) six months after intervention. In the first year, the annual cost of implementing Care Group was US$146.10 per child, reduced to US$47.20 per child in the second year due to the exclusion of non-recurrent costs. The incremental cost-effectiveness ratio (ICER) was US$390.60. Conclusions: Care Group is an effective approach for promoting children's social-emotional development in poverty-stricken areas at an affordable cost and with high feasibility for scale-up. Considering the planned per capita health expenditure of the Chinese government for 2022, we believe that the presented evidence makes a solid scientific and financial case for integrating the Care Group intervention into the basic public health services (BPHS) package. Registration: Chinese Clinical Trials Registry (ChiCTR): ChiCTR1900022894.

Predicting flow diverter sizing using the AneuGuideTM software: a validation study.

BACKGROUND: Stent sizing remains a challenging task for flow diverter implantation because of stent foreshortening. In this study, we aimed to quantify the change in length after implantation and assess the error in length prediction using AneuGuideTM software. METHODS: In a retrospective cohort of 101 patients with 102 aneurysms undergoing treatment with a pipeline embolization device (PED; Covidien, Irvine, California, USA), we used AneuGuideTM software to obtain measured lengths (ML) and calculated lengths (CL) after stent implantation. Stent elongation was defined as the ratio of ML-LL to the labeled length (LL). Simulation error was defined as the ratio of the absolute value of CL-ML to ML. The correlation and consistency between ML and LL and between ML and CL were analyzed using Pearson's correlation test and the Bland-Altman plot. Statistical significance was set at p<0.05. RESULTS: The mean elongation of ML was 32.6% (range 26.3-109.2%). Moderate consistency was observed between LL and ML (ρ=0.74, p<0.001). With the AneuGuideTM software, the mean simulation error was 6.6% (range 0.32-21.2%). Pearson's correlation test and the Bland-Altman plot showed a high correlation and consistency between ML and CL (ρ=0.96, p<0.001). CONCLUSION: Labeled length provides only a low reference value for predicting the actual length of the flow diverter after implantation. The high consistency between ML and CL obtained from AneuGuideTM software shows its great potential for the optimization of the flow diverter sizing process.

Tocilizumab for Severe COVID-19 Pneumonia: Experience from 5 Geriatric Chinese Patients with 6 Months Follow-up

Objective To enable physicians to understand the efficacy and safety of Tocilizumab (TCZ) in patients with severe coronavirus disease-2019 (COVID-19) Methods We respectively reviewed the clinical records, laboratory results, and chest computed tomography (CT) scans of 5 geriatric patients with severe COVID-19 treated with TCZ during their inpatient hospitalization period in Wuhan from February 08, 2020 to April 04, 2020. The survival status of the patients in the third and the sixth month after being discharged was followed up and recorded. Results On the fourteenth day after TCZ administration, periphery oxygen saturation rate (SpO2) returned to normal in 4 patients. The serum Interleukin-6 (IL-6) levels altered in five patients after TCZ infusion. One patient rapidly progressed to acute respiratory distress syndrome (ARDS) and died of multiple organ failures eventually. The other 4 patients were cured and discharged from the hospital. During the inpatient hospitalization period, two patients suffered from virus shedding periods (VSPs) delay, and one patient had mild upper respiratory tract infection. One patient died of esophageal carcinoma one month after being discharged. The other 3 patients survived despite mild cough and insomnia. Serum-specific IgG type antibody titer was decreased in one patient. Six months after being discharged, the other three patients were in good condition. Conclusion TCZ may be an efficient therapeutic option for patients with COVID-19. However, the possibility of VSPs delay, secondary infection, serum protective antibody tilter attenuation, and long-term survival status should be addressed before TCZ therapy initiation.

Therapeutic Effect of Tocilizumab on Inhibiting Cytokine Release Syndrome in Severe Coronavirus Disease 2019 Patients

Background and Objectives: Older adults are more susceptible to coronavirus disease 2019 (COVID-19). Interleukin-6 (IL-6) is an important cytokine in the cytokine release syndrome (CRS), and tocilizumab blocks the IL-6 receptor. The objective is to analyze the effect of tocilizumab on CRS in older patients with severe COVID-19. Materials and Methods: Between February 10 and March 21, 2020, a total of 19 patients aged ≥60 years with severe or critical COVID-19 met the study inclusion criteria at the Tongji Hospital in Wuhan City, Hubei Province, China. The patients were divided into two groups: the tocilizumab group, with IL-6 levels, which exceeded the upper limit of normal by >10-fold and non-tocilizumab group. Results: Patients in the tocilizumab group were older (73.20 ± 4.44 vs. 66.21 ± 5.06 years, P = 0.014), had lower lymphocyte counts (0.71 ± 0.18 vs. 1.18 ± 0.59 × 109/L, P = 0.016), and higher high-sensitivity C-reactive protein (hsCRP) levels (94.04 ± 57.24 vs. 51.65 ± 45.37 mg/L, P = 0.035). Increases in ferritin (FER) and hsCRP levels in patients in the tocilizumab group were marked. Except for one patient who died, IL-6, FER, hsCRP levels, and the neutrophil/lymphocyte ratio in the remaining four patients decreased following treatment with tocilizumab. Tocilizumab did not cause any serious adverse reactions. There were no differences in mortality, days until lung computerized tomography improvement, or renal function between the two groups. The total mortality rate was 10.53%. Conclusions: Our results support the therapeutic efficacy and safety of tocilizumab in older patients with severe COVID-19.

Lung Organoids as Model to Study SARS-CoV-2 Infection.

Coronavirus disease-2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a global pandemic and has severely affected socio-economic conditions and people's life. The lung is the major target organ infected and (seriously) damaged by SARS-CoV-2, so a comprehensive understanding of the virus and the mechanism of infection are the first choices to overcome COVID-19. Recent studies have demonstrated the enormous value of human organoids as platforms for virological research, making them an ideal tool for researching host-pathogen interactions. In this study, the various existing lung organoids and their identification biomarkers and applications are summarized. At the same time, the seven coronaviruses currently capable of infecting humans are outlined. Finally, a detailed summary of existing studies on SARS-CoV-2 using lung organoids is provided and includes pathogenesis, drug development, and precision treatment. This review highlights the value of lung organoids in studying SARS-CoV-2 infection, bringing hope that research will alleviate COVID-19-associated lung infections.

Discovery of a Phage Peptide Specifically Binding to the SARS-CoV-2 Spike S1 Protein for the Sensitive Phage-Based Enzyme-Linked Chemiluminescence Immunoassay of the SARS-CoV-2 Antigen.

The COVID-19 pandemic has led to a global crisis with devastating effects on public healthcare and the economy. Sensitive detection of SARS-CoV-2 is the key to diagnose and control its spread. The spike (S) protein is an abundant viral transmembrane protein and a suitable target protein for the selective recognition of SARS-CoV-2. Here, we report that with bovine serum albumin prescreening, a specific phage peptide targeting SARS-CoV-2 S1 protein was biopanned with the pIII phage display library. The identified phage #2 expressing the peptide (amino acid sequence: NFWISPKLAFAL) shows high affinity to the target with a dissociation constant of 3.45 ± 0.58 nM. Furthermore, the identified peptide shows good specificity with a binding site at the N-terminal domain of the S1 subunit through a hydrogen bond network and hydrophobic interaction, supported by molecular docking. Then, a sandwiched phage-based enzyme-linked chemiluminescence immunoassay (ELCLIA) was established by using phage #2 as a bifunctional probe capable of SARS-CoV-2 S1 antigen recognition and signal amplification. After optimizing the conditions, the proposed phage ELCLIA exhibited good sensitivity, and as low as 78 pg/mL SARS-CoV-2 S1 could be detected. This method can be applied to detect as low as 60 transducing units (TU)/mL SARS-CoV-2 pseudovirus in 50% saliva. Therefore, specific phage peptides have good prospects as powerful biological recognition probes for immunoassay detection and biomedical applications.

Human Brain Organoids as an In Vitro Model System of Viral Infectious Diseases

Brain organoids, or brainoids, have shown great promise in the study of central nervous system (CNS) infection. Modeling Zika virus (ZIKV) infection in brain organoids may help elucidate the relationship between ZIKV infection and microcephaly. Brain organoids have been used to study the pathogenesis of SARS-CoV-2, human immunodeficiency virus (HIV), HSV-1, and other viral infections of the CNS. In this review, we summarize the advances in the development of viral infection models in brain organoids and their potential application for exploring mechanisms of viral infections of the CNS and in new drug development. The existing limitations are further discussed and the prospects for the development and application of brain organs are prospected.

Hydroxychloroquine/chloroquine in patients with COVID-19 in Wuhan, China: a retrospective cohort study.

BACKGROUND: Since the COVID-19 pandemic, several therapeutic agents have been used in COVID-19 management. However, the results were controversial. Here, we aimed to evaluate the efficacy and safety of hydroxychloroquine (HCQ)/chloroquine (CQ) in COVID-19. METHODS: We retrospectively reviewed the medical charts of patients with COVID-19 admitted to an inpatient ward in Wuhan from 2020/Feb/08 to 2020/Mar/05. Patients with HCQ/CQ and age, gender, disease severity matched ones without HCQ/CQ were selected at a 1:2 ratio. The clinical, laboratory and imaging findings were compared between these two groups. The multivariate linear regression analysis was performed to identify the factors that might influence patients' virus shedding periods (VSPs). RESULTS: A total of 14 patients with HCQ/CQ and 21 matched ones were analyzed. The HCQ/CQ treatment lasted for an average of 10.36 ± 3.12 days. The mean VSPs were longer in the HCQ/CQ treatment group (26.57 ± 10.35 days vs. 19.10 ± 7.80 days, P = 0.020). There were 3 patients deceased during inpatient period, two patients were with HCQ/CQ treatment (P = 0.551). In the multivariate linear regression analysis, disease durations at admission (t = 3.643, P = 0.001) and HCQ/CQ treatment (t = 2.637, P = 0.013) were independent parameters for patients' VSPs. One patient with CQ had recurrent first-degree atrioventricular block (AVB) and obvious QTc elongation, another one complained about dizziness and blurred vision which disappeared after CQ discontinuation. One patient with HCQ had transient AVB. CONCLUSIONS: In summary, we identify that the HCQ/CQ administration is not related to less mortality cases at later phase of COVID-19. More studies are needed to explore whether HCQ/CQ treatment would lead to SARS-Cov-2 RNA clearance delay or not.

Lung organoids, useful tools for investigating epithelial repair after lung injury.

Organoids are derived from stem cells or organ-specific progenitors. They display structures and functions consistent with organs in vivo. Multiple types of organoids, including lung organoids, can be generated. Organoids are applied widely in development, disease modelling, regenerative medicine, and other multiple aspects. Various human pulmonary diseases caused by several factors can be induced and lead to different degrees of lung epithelial injury. Epithelial repair involves the participation of multiple cells and signalling pathways. Lung organoids provide an excellent platform to model injury to and repair of lungs. Here, we review the recent methods of cultivating lung organoids, applications of lung organoids in epithelial repair after injury, and understanding the mechanisms of epithelial repair investigated using lung organoids. By using lung organoids, we can discover the regulatory mechanisms related to the repair of lung epithelia. This strategy could provide new insights for more effective management of lung diseases and the development of new drugs.

Evaluation of lung involvement in COVID-19 pneumonia based on ultrasound images.

BACKGROUND: Lung ultrasound (LUS) can be an important imaging tool for the diagnosis and assessment of lung involvement. Ultrasound sonograms have been confirmed to illustrate damage to a person's lungs, which means that the correct classification and scoring of a patient's sonogram can be used to assess lung involvement. METHODS: The purpose of this study was to establish a lung involvement assessment model based on deep learning. A novel multimodal channel and receptive field attention network combined with ResNeXt (MCRFNet) was proposed to classify sonograms, and the network can automatically fuse shallow features and determine the importance of different channels and respective fields. Finally, sonogram classes were transformed into scores to evaluate lung involvement from the initial diagnosis to rehabilitation. RESULTS AND CONCLUSION: Using multicenter and multimodal ultrasound data from 104 patients, the diagnostic model achieved 94.39% accuracy, 82.28% precision, 76.27% sensitivity, and 96.44% specificity. The lung involvement severity and the trend of COVID-19 pneumonia were evaluated quantitatively.

TMBIM6, a potential virus target protein identified by integrated multiomics data analysis in SARS-CoV-2-infected host cells.

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this study, we collected open access data to analyze the mechanisms associated with SARS-CoV-2 infection. Gene set enrichment analysis (GSEA) revealed that apoptosis-related pathways were enriched in the cells after SARS-CoV-2 infection, and the results of differential expression analysis showed that biological functions related to endoplasmic reticulum stress (ERS) and lipid metabolism were disordered. TMBIM6 was identified as a potential target for SARS-CoV-2 in host cells through weighted gene coexpression network analysis (WGCNA) of the time course of expression of host and viral proteins. The expression and related functions of TMBIM6 were subsequently analyzed to illuminate how viral proteins interfere with the physiological function of host cells. The potential function of viral proteins was further analyzed by GEne Network Inference with Ensemble of trees (GENIE3). This study identified TMBIM6 as a target protein associated with the pathogenesis of SARS-CoV-2, which might provide a novel therapeutic approach for COVID-19 in the future.

Cardiac damage in patients with the severe type of coronavirus disease 2019 (COVID-19).

BACKGROUND: Coronavirus disease 2019 (COVID-19) has become a global pandemic. Studies showed COVID-19 affected not only the lung but also other organs. In this study, we aimed to explore the cardiac damage in patients with COVID-19. METHODS: We collected data of 100 patients diagnosed as severe type of COVID-19 from February 8 to April 10, 2020, including demographics, illness history, physical examination, laboratory test, and treatment. In-hospital mortality were observed. Cardiac damage was defined as plasma hypersensitive troponin I (hsTnI) over 34.2 pg/ml and/or N-terminal-pro brain natriuretic peptide (NTproBNP) above 450 pg/ml at the age < 50, above 900 pg/ml at the age < 75, or above 1800 pg/ml at the age ≥ 75. RESULTS: The median age of the patients was 62.0 years old. 69 (69.0%) had comorbidities, mainly presenting hypertension, diabetes, and cardiovascular disease. Fever (69 [69.0%]), cough (63 [63.0%]), chest distress (13 [13.0%]), and fatigue (12 [12.0%]) were the common initial symptoms. Cardiac damage occurred in 25 patients. In the subgroups, hsTnI was significantly higher in elder patients (≥ 60 years) than in the young (median [IQR], 5.2 [2.2-12.8] vs. 1.9 [1.9-6.2], p = 0.018) and was higher in men than in women (4.2 [1.9-12.8] vs. 2.9 [1.9-7.4], p = 0.018). The prevalence of increased NTproBNP was significantly higher in men than in women (32.1% vs. 9.1%, p = 0.006), but was similar between the elder and young patients (20.0% vs. 25.0%, p = 0.554). After multivariable analysis, male and hypertension were the risk factors of cardiac damage. The mortality was 4.0%. CONCLUSIONS: Cardiac damage exists in patients with the severe type of COVID-19, especially in male patients with hypertension. Clinicians should pay more attention to cardiac damage.

Tocilizumab May Be a Key in Therapy for Cytokine Release Syndrome in Older Patients With Severe Symptoms of COVID-19 (preprint)

Background Older adults are more susceptible to the novel coronavirus disease 2019 (hereafter, COVID-19) and more likely to develop severe illness. Cytokine release syndrome (CRS) may be an important factor in the development of severe disease in patients with COVID-19. Interleukin-6 (IL-6) is an important cytokine in CRS, and tocilizumab can block the IL-6 receptor. In this study, we analyzed the therapeutic effects and safety of tocilizumab on CRS in older patients with severe COVID-19. Methods Between February 10 and March 21, 2020, a total of 19 patients with severe or critical COVID-19 aged ≥ 60 years met the study inclusion criteria at Tongji hospital in Wuhan city, Hubei Province, China. Patients were divided into two groups: 1. The tocilizumab group, whose IL-6 levels exceeded the upper limit of normal by > 10-fold; and 2. The no tocilizumab group, with 1L-6 levels < 10-fold the upper normal limit. Results Patients in the tocilizumab group were older (73.20 ± 4.44 vs. 66.21 ± 5.06 years, P = 0.014); had lower lymphocyte counts (0.71 ± 0.18 vs. 1.18 ± 0.59 × 109/L, P = 0.016); and higher high-sensitivity C-reactive protein (hsCRP) levels (94.04 ± 57.24 vs. 51.65 ± 45.37 mg/L, P = 0.035). The increases in ferritin (FER) and hsCRP levels in patients in the tocilizumab group were marked. Except in one patient who died, IL-6, FER, and hsCRP levels, and the neutrophil/lymphocyte ratio, in the remaining four patients decreased following treatment with tocilizumab. Further, patient computerized tomography scan results improved after 3–8 days of tocilizumab treatment. Tocilizumab did not cause any serious adverse reactions. There were no differences in mortality or days until lung computerized tomography improvement between the two groups. The total mortality rate was 10.53%. Conclusions Our results support the therapeutic efficacy and safety of tocilizumab on older patients with severe COVID-19.