Clinical evaluation of anterior nasal cavity swab specimens by a rapid antigen test using a GLINE-2019-nCoV Ag Kit to diagnose COVID-19.

The promising diagnostic performance of rapid antigen tests (RATs) using non-invasive anterior nasal (AN) swab specimens to diagnose COVID-19 has been reported. A large number of RATs are commercially available; however, the careful assessment of RATs is essential prior to their implementation in clinical practice. We evaluated the clinical performance of the GLINE-2019-nCoV Ag Kit as a RAT using AN swabs in a prospective, blinded study. Adult patients who visited outpatient departments and received SARS-CoV-2 tests between August 16 and September 8, 2022, were eligible for this study. Patients who were aged under 18 years and patients without appropriate specimens were excluded. Two sets of AN and nasopharyngeal (NP) swabs were collected from all patients. Each set of specimens was tested by the RAT and quantitative reverse-transcription polymerase chain reaction (RT-qPCR). Of the 138 recruited patients, 84 were positive and 54 were negative by RT-qPCR using NP swabs. The positive agreement rate between RT-qPCR using NP swabs and RAT using AN swabs was 78.6% (95% confidence interval [CI], 68.3%-86.8%), the negative agreement rate was 98.1% (95% CI, 90.1%-99.9%), and the overall agreement rate was 86.2% (95% CI, 79.3%-91.5%), with a κ coefficient of 0.73. The positive agreement rate in the early phase (≤3 days from symptom onset) was >80%, but this fell to 50% in the late phase (≥4 days). This study demonstrates that the GLINE-2019-nCoV Ag Kit using AN swabs has good clinical performance and might be a reliable alternative method for diagnosing COVID-19.

A Case of COVID-Related MERS (Clinically Mild Encephalitis/Encephalopathy with a Reversible Splenial Lesion) with a Typical Imaging Course and Hyponatremia in Adults - A Case Report and Literature Review

Clinically mild encephalitis/encephalopathy with reversible splenial lesions (MERS) is a mild form of encephalitis/encephalopathy that appears in association with various conditions, including infection. COVID-19 is also known to cause MERS. MERS more commonly occurs in children, and adult cases are relatively rare. Typical head MRI findings include a round lesion in the mid-layer of the corpus callosum with a high signal intensity on diffusion-weighted images. Most improve within a week. Although the exact mechanism by which the cerebral corpus callosum is affected is still unknown, several hypotheses have been proposed, including the involvement of electrolyte abnormalities (e.g., hyponatremia) and inflammatory cytokines (e.g., IL-6). In this report, we describe the first case of COVID-associated MERS with a typical imaging course and hyponatremia, with a review of the relevant literature. When psychiatric symptoms and the disturbance of consciousness appear in COVID patients, MERS should be considered in addition to delirium due to fever and hypoxia.

A Retrospective Observational Cohort Study on the Efficacy and Safety of Methylprednisolone Pulse Therapy for COVID-19 Pneumonia

Coronavirus disease 2019 (COVID-19) is associated with fatal acute respiratory distress syndrome, which can be ameliorated by methylprednisolone pulse therapy, thereby reducing the risk of progression to respiratory failure and death. We aimed to determine the efficacy and safety of methylprednisolone pulse therapy for patients with COVID-19 pneumonia. In this retrospective, observational cohort study, seventy patients (age, 35–91 years) who were admitted to Saitama Medical University Hospital in Japan between March 2020 and January 2021 due to COVID-19 pneumonia were included. The difference in mortality between the methylprednisolone pulse therapy (n = 22) and dexamethasone therapy (n = 48) groups was the primary outcome. Between-group differences in the average length of intensive care unit stay, duration of invasive mechanical ventilation, and incidence of treatment-related adverse events were the secondary outcomes. The methylprednisolone pulse therapy group showed a significantly lower mortality rate (3.8% vs. 20.2%, p = 0.006) and increased survival rate compared with the dexamethasone therapy group (p = 0.044). Additionally, without statistical significance, the average length of intensive care unit stay tended to be shorter in the methylprednisolone pulse therapy group (11.5 ±6.1 days) than in the dexamethasone therapy group (22.3 ±23.1 days) (p = 0.793). The average duration of invasive mechanical ventilation also tended to be shorter in the methylprednisolone pulse therapy group (15.3 ±10.1 vs. 28.8 ±9.2 days, p = 0.120). There were no significant differences in the incidence of treatment-related serious adverse events between the two groups. In conclusion, methylprednisolone pulse therapy for patients with COVID-19 pneumonia significantly reduced mortality and increased the survival rate compared to conventional dexamethasone therapy.

HbA1c level may be a risk factor for oxygen therapy requirement in patients with coronavirus disease 2019.

INTRODUCTION: Many clinical studies have identified significant predictors or risk factors for the severity or mortality of coronavirus disease 2019 (COVID-19) cases. However, there are very limited reports on the risk factors for requiring oxygen therapy during hospitalization. In particular, we sought to investigate whether plasma glucose and HbA1c levels could be risk factors for oxygen therapy requirement. MATERIALS AND METHODS: A single-center, retrospective study was conducted of 131 COVID-19 patients hospitalized at Saitama Medical University Hospital between March 2020 and November 2020. To identify the risk factors for oxygen therapy requirement during hospitalization, a stepwise multivariate binary logistic regression analysis was performed using several clinical parameters commonly obtained on admission, including plasma glucose and HbA1c levels. RESULTS: Of the 131 patients with COVID-19, 33.6% (44/131) received oxygen therapy during hospitalization. According to the logistic regression analysis, male sex (odds ratio [OR]: 8.76, 95% confidence interval [CI]: 1.65-46.5, P < 0.05), age (OR: 1.07, 95% CI: 1.02-1.12, P < 0.01), HbA1c levels (OR: 1.94, 95% CI: 1.09-3.44, P < 0.05), and serum C-reactive protein (CRP) levels (OR: 2.22, 95% CI: 1.54-3.20, P < 0.01) emerged as independent variables associated with oxygen therapy requirement during hospitalization. CONCLUSIONS: In addition to male sex, age, and serum CRP levels, HbA1c levels on admission may serve as a risk factor for oxygen therapy requirement during the clinical course of COVID-19, irrespective of diabetes history and status. This may contribute to the efficient delegation of limited numbers of hospital beds to patients at risk for oxygen therapy requirement.

Antibody response patterns in COVID-19 patients with different levels of disease severity in Japan.

We analyzed antibody response patterns according to the level of disease severity in patients with novel coronavirus disease 2019 (COVID-19) in Japan. We analyzed 611 serum specimens from 231 patients with COVID-19 (mild, 170; severe, 31; critical, 30). Immunoglobulin M (IgM) and IgG antibodies against nucleocapsid protein (N) and spike 1 protein (S1) were detected by enzyme-linked immunosorbent assays. The peaks of fitting curves for the optical density (OD) values of IgM and IgG antibodies against N appeared simultaneously, while those against S1 were delayed compared with N. The OD values of IgM against N and IgG against both N and S1 were significantly higher in the severe and critical cases than in the mild cases at 11 days after symptom onset. The seroconversion rates of IgG were higher than those of IgM against both N and S1 during the clinical course based on the optimal cut-off values defined in this study. The seroconversion rates of IgG and IgM against N and S1 were higher in the severe and critical cases than in the mild cases. Our findings show that a stronger antibody response occurred in COVID-19 patients with greater disease severity and there were low seroconversion rates of antibodies against N and S1 in the mild cases.

Clinical evaluation of the antibody response in patients with COVID-19 using automated high-throughput immunoassays.

Several automated high-throughput immunoassays for detecting anti-SARS-CoV-2 antibodies by a semi-quantitative approach have been commercialized. In this study, we describe the timeline of the antibody response in patients with RT-PCR-confirmed COVID-19. A total of 292 sequential serum samples from 33 Japanese patients were retrospectively analyzed using four test kits for SARS-CoV-2: the Abbott SARS-CoV-2 IgG assay (Abbott), Elecsys® Anti-SARS-CoV-2 assay (Roche Diagnostic), and VITROS® Anti-SARS-CoV-2 Total and IgG assays (Ortho Clinical Diagnostics). All automated immunoassays could equivalently identify positive sera collected within 2 weeks after symptom onset (99.3%-100%). In addition, the S protein-based automated immunoassay, the VITROS® Anti-SARS-CoV-2 Total assay, may play a complementary role in evaluating passive antibody therapies or vaccines against SARS-CoV-2, although further research is required.

Evaluation of rapid diagnosis of novel coronavirus disease (COVID-19) using loop-mediated isothermal amplification.

With the rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), there is an urgent need for more rapid and simple detection technologies at the forefront of medical care worldwide. In this study, we evaluated the effectiveness of the Loopamp® 2019-SARSCoV-2 Detection Reagent Kit, which uses loop-mediated isothermal amplification (LAMP) technology. In this protocol, cDNA is synthesized from SARS-CoV-2 RNA using reverse transcriptase, followed by DNA amplification under isothermal conditions in one step. The RT-LAMP test kit amplified the targeted RNA of a SARS-CoV-2 isolate with a detection limit of 1.0 × 101 copies/µL, which was comparable to the detection sensitivity of quantitative reverse transcription PCR (RT-qPCR). Comparison with the results of RT-qPCR for 76 nasopharyngeal swab samples from patients with suspected COVID-19 showed a sensitivity of 100 % and a specificity of 97.6 %. In the 24 RNA specimens derived from febrile Japanese patients with or without influenza A, no amplification was observed using RT-LAMP. RT-LAMP could be a simple and easy-to-use diagnostic tool for the detection of SARS-CoV-2.

Clinical evaluation of an immunochromatographic IgM/IgG antibody assay and chest computed tomography for the diagnosis of COVID-19.

BACKGROUND: We evaluated the clinical performance of an immunochromatographic (IC) IgM/IgG antibody assay for severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) and chest computed tomography (CT) for the diagnosis of Coronavirus disease 2019 (COVID-19). METHODS: We examined 139 serum specimens collected from 112 patients with COVID-19 and 48 serum specimens collected from 48 non-COVID-19 patients. The presence of IgM/IgG antibody for SARS-COV2 was determined using the One Step Novel Coronavirus (COVID-19) IgM/IgG Antibody Test. Chest CT was performed in COVID-19 patients on admission. FINDINGS: Of the139 COVID-19 serum specimens, IgM was detected in 27.8 %, 48.0 %, and 95.8 % of the specimens collected within 1 week, 1-2 weeks, and >2 weeks after symptom onset and IgG was detected in 3.3 %, 8.0 %, and 62.5 %, respectively. Among the 48 non-COVID-19 serum specimens, 1 generated a false-positive result for IgM. Thirty-eight of the 112 COVID-19 patients were asymptomatic, of whom 15 were positive for IgM, and 74 were symptomatic, of whom 22 were positive for IgM and 7 were positive for IgG. The diagnostic sensitivity of CT scan alone and in combination with the IC assay was 57.9 % (22/38) and 68.4 % (26/38) for the asymptomatic patients and 74.3 % (55/74) and 82.4 % (61/74) for the symptomatic patients, respectively. CONCLUSION: The IC assay had low sensitivity during the early phase of infection, and thus IC assay alone is not recommended for initial diagnostic testing for COVID-19. If RT-qPCR is not available, the combination of chest CT and IC assay may be useful for diagnosing COVID-19.