Earliest histopathological changes in COVID-19 pneumonia with comprehensive gene expression analyses: A case series study.

AIMS: In COVID-19 pneumonia, early detection and appropriate treatment are essential to prevent severe exacerbation. Therefore, it is important to understand the initiating events of COVID-19 pneumonia. However, at present, the literature about early stage disease has been very limited. Here, we investigated the earliest histopathological changes and gene expression profiles associated with COVID-19 pneumonia. METHODS AND RESULTS: We carefully examined 25 autopsied cases with different clinical courses. Dilation of capillaries and edematous thickening of the alveolar septa were found even in areas that macroscopically looked almost normal. Pneumocytes, histocytes/macrophages, and vascular endothelial cells were immunohistochemically positive for tissue factor, which is an important early responder to tissue injuries. Comprehensive gene expression analyses revealed that those lesions presented differential profiles compared to those of control lungs and were associated with a significant upregulation of the lysosomal pathway. CONCLUSIONS: Alveolar capillary dilation and edematous thickening may be the earliest histopathological change detected in COVID-19 pneumonia. Intensive investigations of such lesions may lead to an understanding of the initiating event of not only COVID-19 pneumonia but also of general diffuse alveolar damage.

Multimodal single-cell analyses of peripheral blood mononuclear cells of COVID-19 patients in Japan.

SARS-CoV-2 continues to spread worldwide. Patients with COVID-19 show distinct clinical symptoms. Although many studies have reported various causes for the diversity of symptoms, the underlying mechanisms are not fully understood. Peripheral blood mononuclear cells from COVID-19 patients were collected longitudinally, and single-cell transcriptome and T cell receptor repertoire analysis was performed. Comparison of molecular features and patients' clinical information revealed that the proportions of cells present, and gene expression profiles differed significantly between mild and severe cases; although even among severe cases, substantial differences were observed among the patients. In one severely-infected elderly patient, an effective antibody response seemed to have failed, which may have caused prolonged viral clearance. Naïve T cell depletion, low T cell receptor repertoire diversity, and aberrant hyperactivation of most immune cell subsets were observed during the acute phase in this patient. Through this study, we provided a better understanding of the diversity of immune landscapes and responses. The information obtained from this study can help medical professionals develop personalized optimal clinical treatment strategies for COVID-19.

Comparison of the levels of neopterin, CRP, and IL-6 in patients infected with and without SARS-CoV-2.

Background: Neopterin (NP) is a biomarker for activated cellular immunity and is elevated in diseases including viral and bacterial infections, autoimmune diseases, and cancer. However, the clinical assessment of neopterin has not been used for these disorders because the physiological significance of measuring NP is obscure. It would be important to compare the NP profiles with those of other inflammation markers especially in relatively early phase of patients to reveal the significance of NP measurements in pathological states. Methods: Plasma NP, biopterin, CRP, and IL-6 levels were measured in 46 patients with Coronavirus Disease 2019 (COVID-19) and 23 patients with non-COVID-19 disorders. The correlations between these markers were analyzed in the COVID-19 and non-COVID-19 patients independently. Results: The NP levels were significantly higher in the COVID-19 patients than in the non-COVID-19 patients, while biopterin, CRP and IL-6 were not changed significantly. The NP levels were found to show a weak negative correlation against the days after onset in the COVID-19 patients (rs = -0.348, p = 0.0192), suggesting that the elevation of NP would be an early event of viral infection. Correlations between NP and CRP, or between NP and IL-6 in COVID-19 patients were weaker than that between CRP and IL-6. Conclusions: The elevation of NP levels was supposed to be distinct from those of CRP and IL-6 in relatively early and mild COVID-19 patients. Our data suggest that NP is produced at the early phase of infection by different signaling pathways and/or cells from those of CRP and IL-6. Further study on the signaling pathway to induce NP is expected.

Prevalence, characteristics, and psychological outcomes of workplace cyberbullying during the COVID-19 pandemic in Japan: a cross-sectional online survey.

BACKGROUND: The rapid introduction of teleworking due to the coronavirus disease 2019 pandemic has led to concerns about increases in cyberbullying (CB) worldwide. However, little is known about workplace CB in non-Western countries. The first objective was to clarify the prevalence and characteristics regarding workplace CB victimization in Japan. The second objective was to demonstrate the psychological outcomes of CB victimization in combination with traditional bullying (TB). METHODS: We conducted an anonymous, cross-sectional, Internet-based survey targeting regular employees in Japan (N = 1200) in January 2021. We investigated CB victimization using the Inventory of Cyberbullying Acts at Work and TB victimization by using the Short Negative Act Questionnaire. Possible explanatory factors for TB/CB victimization were sociodemographic variables, personality trait, chronic occupational stress, organizational climate, and gratitude at work. We also measured psychological distress, insomnia, and loneliness to assess adverse effects of workplace bullying. Two-step cluster analysis was used in determining the patterns combined with TB and CB victimization. Hierarchical binomial logistic regression analysis was used. RESULTS: In total, 8.0% of employees reported experiencing CB on a weekly basis. CB victimization was associated with younger age, managerial position, higher qualitative workload, and active information dissemination via the Internet, and frequency of teleworking. Three clusters based on TB and CB victimization patterns were identified: those who belong to the first cluster suffered neither from TB and CB (81.0%), the second cluster suffered only from TB (14.3%), and the third cluster suffered from both TB and CB (4.8%). The third cluster exhibited higher odds ratios (ORs) and 95% confidence intervals (CIs) for psychological distress (OR = 12.63, 95% CI = 4.20-38.03), insomnia (OR = 6.26, 95% CI = 2.80-14.01), and loneliness (OR = 3.24, 95% CI = 1.74-6.04) compared to the first cluster. CONCLUSIONS: These findings firstly clarify the prevalence and correlated factors of CB victimization among employees in Japan. Further, we showed that psychological wellbeing can be impaired by the coexistence of TB and CB. Our research could be the first step to develop the effective countermeasures against workplace CB.

Acute pancreatitis or severe increase in pancreatic enzyme levels following remdesivir administration in COVID-19 patients: an observational study.

Remdesivir has been shown to reduce recovery time and mortality among patients with coronavirus disease 2019 (COVID-19). However, data regarding the efficacy and safety of remdesivir use are limited in Japan. We conducted a single-center retrospective cohort study at Yokohama Municipal Citizen's Hospital, Kanagawa, Japan. Patients with COVID-19 pneumonia treated with remdesivir were included. The onset of acute pancreatitis and increased pancreatic enzyme levels and clinical, laboratory, treatment, and outcome data were collected and analyzed. A total of 201 patients were included. Among the 201 patients treated with remdesivir, 177 recovered from COVID-19. Increased pancreatic enzyme levels of grade 3 or higher or acute pancreatitis developed in 23 of the 201 patients. The potential etiopathogenetic effects of remdesivir on increased pancreatic enzyme levels of grade 3 or higher or acute pancreatitis were ascertained by reviewing the characteristics of patients hospitalized for COVID-19 who did not receive remdesivir treatment. Only 3 of 159 patients had increased pancreatic enzyme levels of grade 3 or higher during the treatment course. Multivariate analysis indicated remdesivir administration and severe COVID-19 infection by National Institute of Health standards as independent risk factors. Acute pancreatitis and severe increases in pancreatic enzyme levels were observed among patients with COVID-19 treated with remdesivir.

Ibaraki's Amabie-chan usage and its association with infection prevention behavior and fear of COVID-19: a cross-sectional preliminary survey of the Tsukuba Salutogenic Occupational Cohort Study.

BACKGROUND: Ibaraki's Amabie-chan is a COVID-19 infection control system unique to Ibaraki prefecture, Japan. It requires residents to register each time they visit events, commercial facilities, and restaurants. The number of registrations has been limited, and its function alerting about people positive for COVID-19 infection seems not to be working. Nevertheless, registration with the system might have some impact on the user's behavior. In the current preliminary survey, the possible impact of Ibaraki's Amabie-chan on infection prevention behavior and fear of COVID-19 was investigated. METHODS: A cross-sectional, web-based, anonymous, and self-administered survey was conducted at two workplaces in Tsukuba Science City, Ibaraki, Japan. The first survey was conducted at one of the workplaces in November 2020, and the second survey, at the other workplace in February 2021. Variables of interest were sex, age group, marital status, employment status, Ibaraki's Amabie-chan use, COVID-19 Contact-Confirming Application use, ten items of infection prevention behaviors, and fear of COVID-19. Hierarchical linear regression analysis was performed. RESULTS: In both surveys, use of Ibaraki's Amabie-chan was significantly associated with COCOA use and with "physical condition management such as body temperature measurement." No association was found with other infection prevention behaviors or with fear of COVID-19. CONCLUSIONS: Our findings did not provide sufficient evidence for the effectiveness of Ibaraki's Amabie-chan in regard to users' infection control behavior. Further detailed study is needed to investigate the effectiveness in terms of infection prevention and the cost-effectiveness of Ibaraki's Amabie-chan.

An autopsy case of COVID-19-like acute respiratory distress syndrome after mRNA-1273 SARS-CoV-2 vaccination.

We report the first case with COVID-19-like acute respiratory distress syndrome after mRNA-1273 SARS-CoV-2 vaccination. An 88-year-old woman developed dyspnea several hours after vaccination with the second dose of mRNA-1273. She was hospitalized on day nine due to worsening dyspnea. Chest computed tomography showed bilateral ground-glass opacities and consolidations, mainly in the peripheral lung areas. Repeat polymerase chain reaction tests for SARS-CoV-2 were negative, although the serum level of antibodies against spike protein was extremely elevated. Her condition did not improve with high-dose corticosteroids and high-flow nasal cannula oxygen therapy; she died on day 18. Autopsy findings revealed very early-phase diffuse alveolar damage in the whole lung without other lung diseases. The clinical and pathological findings suggested vaccine-induced acute respiratory distress syndrome. Serological and pathological tests might be useful to differentiate the disease from COVID-19.

High titer of antibody against the SARS-CoV-2 spike protein among patients receiving neutralizing antibody cocktail therapy with REGN-COV.

PURPOSE: Casirivimab/imdevimab (REGN-COV), a cocktail of neutralizing antibodies against the receptor-binding domain of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein, was shown to be an effective treatment and post-exposure prophylaxis measure for coronavirus disease 2019 (COVID-19). We assessed the antibody titers among patients who received REGN-COV with the purpose of evaluating this therapeutic and prophylactic option from the serological point of view. METHODS: We collected serological data of patients with COVID-19 who were treated with REGN-COV 1200 mg (casirivimab 600 mg/imdevimab 600 mg). Antibody titers were assessed within 24 h before and within 48 h after the administration of REGN-COV using ARCHITECT SARS-CoV-2 immunoglobulin (Ig)G (IgGNC), which is against nucleocapsid protein, and ARCHITECT SARS-CoV-2 IgG II Quant (IgGSP), which is against spike protein. RESULTS: A total of nine patients were evaluated. IgGSP was elevated after REGN-COV administration with a median of 208,370 Arbitrary Units/mL while simultaneous IgGNC remained low. With the simple linear regression model, the IgGSP after the REGN-COV administration was correlated with the reciprocal of ideal body weight. CONCLUSION: The high titer of IgGSP supports the clinical benefit of therapeutic and prophylactic use of REGN-COV from the serological point of view.

Recovery from severe persistent COVID-19 without evidence of an anti-SARS-CoV-2 antibody response in a man with mantle cell lymphoma treated with rituximab.

Lymphoma has been reported to worsen the prognosis of COVID-19 partly because it disturbs the normal production of antibodies. We treated a man with mantle cell lymphoma treated with rituximab, who developed severe COVID-19 with viral shedding that lasted for 78 days. He stayed in the intensive care unit for 28 days and did not respond to any treatment against COVID-19. His increased oxygen demand at rest eventually resolved despite the absence of anti-SARS-CoV-2-IgG. This case illustrates that recovery from COVID-19 can occur without antibody production, and that even patients with an inability to produce antibodies can recover from severe COVID-19. It also illustrates that lymphoma patients who develop severe COVID-19 while on rituximab therapy can recover from a prolonged viral shedding state if the acute lung injury can be overcome.

Antibody response after COVID-19 vaccine BNT162b2 on health care workers in Japan.

BACKGROUND: Vaccination is one of the most important tools to control the COVID-19 pandemic. However, there is little information on the antibody response in humans after the COVID-19 vaccination. METHODS: This single-center, prospective study was conducted in Yokohama, Japan. We included health care workers who had received two doses of COVID-19 vaccination (BNT162b2) 21 days apart. We measured serum immunoglobulin G (IgG) to nucleoprotein and spike protein of SARS-CoV-2 with commercially available kits before and 7, 14, and 35 days after the first dose of vaccination. RESULTS: A total of 104 workers participated in this study. Of these, 7 participants were seropositive with antibodies to spike protein at baseline and 4 of the 7 seropositive participants had COVID-19 history. The mean level of IgG to spike protein (QT) was 45.2, 1219, 2845, and 23489 AU/mL at baseline, on days 7, 14, and 35, respectively, although the values for nucleoprotein (NG) were 0.2, 0.21, 0.22, and 0.19 S/C, respectively. On day 7, QT in seropositive participants at baseline was elevated, whereas it was not elevated in seronegative participants at baseline until day 14. CONCLUSIONS: QT was elevated over the cutoff in all the participants at day 35, but NG did not change between baseline and day 35.

On-admission SARS-CoV-2 RNAemia as a single potent predictive marker of critical condition development and mortality in COVID-19.

BACKGROUND: This study aimed to clarify how SARS-CoV-2 RNAemia is related to COVID-19 critical condition development and mortality in comparison with other predictive markers and scoring systems. METHODS: This is a retrospective cohort study conducted at Yokohama Municipal Citizen's Hospital and National Institute of Infectious Diseases. We recruited adult patients with COVID-19 admitted between March 2020 and January 2021. We compared RNAemia with clinical status on admission including scoring systems such as the 4C Mortality, CURB-65, and A-DROP, as well as the Ct value of the nasopharyngeal PCR, in predicting COVID-19 mortality and critical condition development. RESULTS: Of the 92 recruited patients (median age, 58; interquartile range, 45-71 years), 14 (14.9%) had RNAemia. These patients had an older age (median, 68 years vs. 55.5 years; p = 0.011), higher values of lactated dehydrogenase (median, 381 U/L vs. 256.5 U/L, p < 0.001), C-reactive protein (median, 10.9 mg/dL vs. 3.8 mg/dL; p < 0.001), D-dimer (median, 2.07 µg/mL vs. 1.28 µg/mL; p = 0.015), lower values of lymphocyte (median, 802/µL vs. 1007/µL, p = 0.025) and Ct of the nasopharyngeal PCR assay (median, 20.59 vs. 25.54; p = 0.021) than those without RNAemia. Univariate analysis showed RNAemia was associated with mortality (odds ratio [OR], 18.75; 95% confidence interval [CI], 3.92-89.76; area under the receiver operating characteristic curve [AUC], 0.7851; p = 0.002) and critical condition (OR, 72.00; 95% CI, 12.98-399.29; AUC, 0.8198; p < 0.001). Plus, multivariate analysis also revealed the association of RNAemia with critical condition (adjusted OR, 125.71; 95% CI, 11.47-1377.32; p < 0.001). CONCLUSION: On-admission SARS-CoV-2 RNAemia is a potent predictive marker of COVID-19 critical condition and mortality. The adjusted OR for critical condition was as high as 125.71.

Association of HLA-DRB1*09:01 with severe COVID-19.

HLA-A, -C, -B, and -DRB1 genotypes were analyzed in 178 Japanese COVID-19 patients to investigate the association of HLA with severe COVID-19. Analysis of 32 common HLA alleles at four loci revealed a significant association between HLA-DRB1*09:01 and severe COVID-19 (odds ratio [OR], 3.62; 95% CI, 1.57-8.35; p = 0.00251 [permutation p value = 0.0418]) when age, sex, and other common HLA alleles at the DRB1 locus were adjusted. The DRB1*09:01 allele was more significantly associated with risk for severe COVID-19 compared to preexisting medical conditions such as hypertension, diabetes, and cardiovascular diseases. These results indicate a potential role for HLA in predisposition to severe COVID-19.

Myeloid cell dynamics correlating with clinical outcomes of severe COVID-19 in Japan.

An expanded myeloid cell compartment is a hallmark of severe coronavirus disease 2019 (COVID-19). However, data regarding myeloid cell expansion have been collected in Europe, where the mortality rate by COVID-19 is greater than those in other regions including Japan. Thus, characteristics of COVID-19-induced myeloid cell subsets remain largely unknown in the regions with low mortality rates. Here, we analyzed cellular dynamics of myeloid-derived suppressor cell (MDSC) subsets and examined whether any of them correlate with disease severity and prognosis, using blood samples from Japanese COVID-19 patients. We observed that polymorphonuclear (PMN)-MDSCs, but not other MDSC subsets, transiently expanded in severe cases but not in mild or moderate cases. Contrary to previous studies in Europe, this subset selectively expanded in survivors of severe cases and subsided before discharge, but such transient expansion was not observed in non-survivors in Japanese cohort. Analysis of plasma cytokine/chemokine levels revealed positive correlation of PMN-MDSC frequencies with IL-8 levels, indicating the involvement of IL-8 on recruitment of PMN-MDSCs to peripheral blood following the onset of severe COVID-19. Our data indicate that transient expansion of the PMN-MDSC subset results in improved clinical outcome. Thus, this myeloid cell subset may be a predictor of prognosis in cases of severe COVID-19 in Japan.

A Japanese case of COVID-19: An autopsy report.

A 93-year-old woman was admitted with a 10-day history of cough and prostration. Thoracic computed tomography revealed extensive ground-glass opacities in both the lungs. The polymerase chain reaction test of sputum for severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) was positive. She was treated with antiviral agents and steroid pulse therapy. However, her oxygen saturation gradually declined, and she died 10 days after hospitalization. The most important autopsy finding was fuzzily segmented diffuse alveolar damage (DAD) that expanded from the subpleural to the medial area. No remarkable changes were observed in organs other than the lungs. Therefore, pneumocytes were suggested as the primary target for SARS-CoV-2, which might explain why coronavirus infectious disease-19 is a serious condition. Thus, early treatment is essential to prevent viral replication from reaching a level that triggers DAD.

Clinical characteristics of the coronavirus disease 2019 (COVID-19) outbreak on a cruise ship.

BACKGROUND: A large COVID-19 outbreak occurred on the cruise ship Diamond Princess in February 2020. Little information has been reported about the clinical characteristics of the patients. METHODS: This single-center, retrospective, observational study was conducted in Yokohama, Japan. We included symptomatic patients who were infected on the ship and admitted to our hospital between 5 and 19 February 2020. All the cases were confirmed with SARS-CoV-2 infection by polymerase chain reaction (PCR). RESULTS: We confirmed 17 cases. The average age was 69 years; 10 patients were Asian and 7 were Caucasian. Eleven patients had one or more chronic diseases. The major symptoms were cough and fever. Chest computed tomography (CT) scans found bilateral ground-glass opacities predominantly in the peripheral area, which were similar to reports from cases in China. C-reactive protein (CRP) levels were higher in severe and critical cases than in mild to moderate cases. The moderate to severe cases reached symptomatic resolution; one of the three critical cases resulted in death due to multiple organ failure. SARS-CoV-2 was detected by PCR at an average of 7 days after symptomatic resolution. CONCLUSIONS: Cough and fever, increased blood CRP levels, and CT findings of bilateral ground-glass opacities predominantly in the peripheral lung were characteristic of the COVID-19 cases in this study. These findings were compatible with those of previous reports.