Smoking and severe illness in hospitalized COVID-19 patients in Japan

BACKGROUND

The aim of this study was to identify associations between smoking status and the severity of COVID-19, using a large-scale data registry of hospitalized COVID-19 patients in Japan (COVIREGI-JP), and to explore the reasons for the inconsistent results previously reported on this subject.

METHODS

The analysis included 17 666 COVID-19 inpatients aged 20-89 years (10 250 men and 7416 women). We graded the severity of COVID-19 (grades 0 to 5) according to the most intensive treatment required during hospitalization. The smoking status of severe grades 3/4/5 (invasive mechanical ventilation/extracorporeal membrane oxygenation/death) and separately of grade 5 (death) were compared with that of grade 0 (no oxygen, reference group) using multiple logistic regression. Results were expressed as odds ratios (OR) and 95% confidence intervals (CI) adjusted for age and other factors considering the potential intermediate effects of comorbidities.

RESULTS

Among men, former smoking significantly increased the risk of grade 3/4/5 and grade 5, using grade 0 as a reference group, with age- and admission-date-adjusted ORs (95% CI) of 1.51 (1.18-1.93) and 1.65 (1.22-2.24), respectively. An additional adjustment for comorbidities weakened the ORs. Similar results were seen for women. Current smoking did not significantly increase the risk of grade 3/4/5 and grade 5 in either sex.

CONCLUSIONS

The severity of COVID-19 was not associated with current or former smoking per se but with the comorbidities caused by smoking. Thus, smoking cessation is likely to be a key factor for preventing smoking-related disease and hence for reducing the risk of severe COVID-19.

Small Dense Low-Density Lipoprotein Cholesterol and Cardiovascular Risk in Statin-Treated Patients with Coronary Artery Disease

Aim: We investigated the relationship between small dense low-density cholesterol (sdLDL-C) and risk of major adverse cardiovascular events (MACE) in patients treated with high- or low-dose statin therapy.

Methods: This was a prospective case-cohort study within the Randomized Evaluation of Aggressive or Moderate Lipid-Lowering Therapy with Pitavastatin in Coronary Artery Disease (REAL-CAD) study, a randomized trial of high- or low-dose (4 or 1 mg/d pitavastatin, respectively) statin therapy, in patients with stable coronary artery disease (CAD). Serum sdLDL-C was determined using an automated homogenous assay at baseline (randomization after a rule-in period, ＞1 month with 1 mg/d pitavastatin) and 6 months after randomization, in 497 MACE cases, and 1543 participants randomly selected from the REAL-CAD study population.

Results: High-dose pitavastatin reduced sdLDL-C by 20% than low-dose pitavastatin (p for interaction ＜0.001). Among patients receiving low-dose pitavastatin, baseline sdLDL-C demonstrated higher MACE risk independent of LDL-C (hazard ratio [95% confidence interval], 4th versus 1st quartile, 1.67 [1.04–2.68];p for trend=0.034). High-dose (versus low-dose) pitavastatin reduced MACE risk by 46% in patients in the highest baseline sdLDL-C quartile (＞34.3 mg/dL; 0.54 [0.36–0.81];p=0.003), but increased relative risk by 40% in patients with 1st quartile (≤ 19.5 mg/dL; 1.40 [0.94–2.09];p=0.099) and did not alter risk in those in 2nd and 3rd quartiles (p for interaction=0.002).

Conclusions: These findings associate sdLDL-C and cardiovascular risk, independent of LDL-C, in statin-treated CAD patients. Notably, high-dose statin therapy reduces this risk in those with the highest baseline sdLDL-C.

Allogeneic islet transplantation with monitoring of islet-specific cellular autoimmunity in a Japanese patient with type 1 diabetes: a case report

Here, we report a case of allogeneic islet transplantation in Japan. A 48-year-old man received intraportal islet transplantation (5,945 islet equivalent/kg), and stabilization of blood glucose levels and suppression of hypoglycemia were achieved. In this case, we used our original assessment method to detect the responses of the recipient's T cells to islet autoantigens over time to monitor cellular autoimmunity. Other markers could not predict graft dysfunction in advance, but our method detected the activation of islet antigen-specific CD8⁺ T cell responses before the deterioration of pancreatic beta cell function, indicating the possibility of the non-invasive detection of pancreatic beta cell damage due to recurrent autoimmunity.

Effect of Early vs Delayed Surgical Treatment on Motor Recovery in Incomplete Cervical Spinal Cord Injury With Preexisting Cervical Stenosis: A Randomized Clinical Trial

IMPORTANCE

The optimal management for acute traumatic cervical spinal cord injury (SCI) is unknown.

OBJECTIVE

To determine whether early surgical decompression results in better motor recovery than delayed surgical treatment in patients with acute traumatic incomplete cervical SCI associated with preexisting canal stenosis but without bone injury.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter randomized clinical trial was conducted in 43 tertiary referral centers in Japan from December 2011 through November 2019. Patients aged 20 to 79 years with motor-incomplete cervical SCI with preexisting canal stenosis (American Spinal Injury Association [ASIA] Impairment Scale C; without fracture or dislocation) were included. Data were analyzed from September to November 2020.

INTERVENTIONS

Patients were randomized to undergo surgical treatment within 24 hours after admission or delayed surgical treatment after at least 2 weeks of conservative treatment.

MAIN OUTCOMES AND MEASURES

The primary end points were improvement in the mean ASIA motor score, total score of the spinal cord independence measure, and the proportion of patients able to walk independently at 1 year after injury.

RESULTS

Among 72 randomized patients, 70 patients (mean [SD] age, 65.1 [9.4] years; age range, 41-79 years; 5 [7%] women and 65 [93%] men) were included in the full analysis population (37 patients assigned to early surgical treatment and 33 patients assigned to delayed surgical treatment). Of these, 56 patients (80%) had data available for at least 1 primary outcome at 1 year. There was no significant difference among primary end points for the early surgical treatment group compared with the delayed surgical treatment group (mean [SD] change in ASIA motor score, 53.7 [14.7] vs 48.5 [19.1]; difference, 5.2; 95% CI, -4.2 to 14.5; P = .27; mean [SD] SCIM total score, 77.9 [22.7] vs 71.3 [27.3]; P = .34; able to walk independently, 21 of 30 patients [70.0%] vs 16 of 26 patients [61.5%]; P = .51). A mixed-design analysis of variance revealed a significant difference in the mean change in ASIA motor scores between the groups (F1,49 = 4.80; P = .03). The early surgical treatment group, compared with the delayed surgical treatment group, had greater motor scores than the delayed surgical treatment group at 2 weeks (mean [SD] score, 34.2 [18.8] vs 18.9 [20.9]), 3 months (mean [SD] score, 49.1 [15.1] vs 37.2 [20.9]), and 6 months (mean [SD] score, 51.5 [13.9] vs 41.3 [23.4]) after injury. Adverse events were common in both groups (eg, worsening of paralysis, 6 patients vs 6 patients; death, 3 patients vs 3 patients).

CONCLUSIONS AND RELEVANCE

These findings suggest that among patients with cervical SCI, early surgical treatment produced similar motor regain at 1 year after injury as delayed surgical treatment but showed accelerated recovery within the first 6 months. These exploratory results suggest that early surgical treatment leads to faster neurological recovery, which requires further validation.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01485458; umin.ac.jp/ctr Identifier: UMIN000006780.

Clinical characteristics and prognosis of immunosuppressed inpatients with COVID-19 in Japan

Introduction

We aimed to analyze the clinical characteristics and outcomes of immunosuppressed inpatients with coronavirus disease 2019 (COVID-19).

Methods

In this observational study, we utilized a large nationwide registry of hospitalized patients with COVID-19 in Japan. Patients’ baseline characteristics and outcomes were compared according to the immunosuppressed states of the patients. The impact of different therapeutic agents on the clinical courses of the patients was evaluated.

Results

Data of 14,760 patients were included, and 887 (5.9%) were immunosuppressed. The immunosuppressed state of the patient resulted from solid tumor (43.3%, n = 384), chemotherapy within 3 months (15.6%, n = 138), collagen disease (16.9%, n = 150), use of immunosuppressive agents (16.0%, n = 142), and metastatic solid tumor (13.5%, n = 120). Immunosuppressed patients were older and had a higher severity of illness at admission and during hospitalization than non-immunosuppressed patients. The mortality rates for major diseases causing immunosuppression were as follows: solid tumor, 12.5% (48/384; P < 0.001; relative risk [RR], 3.41); metastatic solid tumor, 31.7% (38/120; P < 0.001; RR, 8.43); leukemia, 23.1% (9/39; P < 0.001; RR, 5.87); lymphoma, 33.3% (20/60; P < 0.001; RR, 8.63); and collagen disease, 15.3% (23/150; P < 0.001; RR 3.97). Underlying diseases with high mortality rates were not necessarily associated with high rates of invasive supportive care.

Conclusions

The prognosis of immunosuppressed COVID-19 inpatients varied according to the different immunosuppressed states. Multiple factors, including the severity of the underlying diseases, might have affected their invasive supportive care indications.

Evaluation of the efficacy of anticoagulation therapy in reducing mortality in a nationwide cohort of hospitalized patients with coronavirus disease in Japan

Objectives

To determine whether anticoagulation therapy improves outcomes in patients with coronavirus disease 2019 (COVID-19) in Japan given their lower risk of thrombosis compared with Western cohorts.

Methods

The efficacy of anticoagulation therapy in hospitalized patients with COVID-19 was evaluated using a nationwide registry: the COVID-19 Registry Japan. The inverse probability of weight treatment method was used to adjust for baseline confounders in the anticoagulation and non-anticoagulation groups.

Results

Of the 1748 patients included, anticoagulants were used in 367 patients (treatment group). The patients in the anticoagulant group were older, predominantly male, and often presented with obesity, hyperlipidaemia, hypertension, diabetes and elevated D-dimer levels. Twenty-nine-day mortality was 7.6% in the whole cohort (treatment group, 11.2%; no treatment group, 6.6%), 6% in patients who were not treated with steroids (treatment group, 12.3%; no treatment group, 5.2%), and 11.2% in patients treated with steroids (treatment group, 10.5%; no treatment group, 11.8%). Mortality in the whole cohort was similar between the treatment and no treatment groups (P=0.99), and an insignificant decreasing trend in mortality was observed in patients treated with steroids (P=0.075).

Conclusions

Anticoagulants may be beneficial in Asians, in whom comorbidities and risk of thrombosis may differ from other ethnic groups.

Predicting respiratory failure for COVID-19 patients in Japan: a simple clinical score for evaluating the need for hospitalisation

Predicting the need for hospitalisation of patients with coronavirus disease 2019 (COVID-19) is important for preventing healthcare disruptions. This observational study aimed to use the COVID-19 Registry Japan (COVIREGI-JP) to develop a simple scoring system to predict respiratory failure due to COVID-19 using only underlying diseases and symptoms. A total of 6873 patients with COVID-19 admitted to Japanese medical institutions between 1 June 2020 and 2 December 2020 were included and divided into derivation and validation cohorts according to the date of admission. We used multivariable logistic regression analysis to create a simple risk score model, with respiratory failure as the outcome for young (18-39 years), middle-aged (40-64 years) and older (≥65 years) groups, using sex, age, body mass index, medical history and symptoms. The models selected for each age group were quite different. Areas under the receiver operating characteristic curves for the simple risk score model were 0.87, 0.79 and 0.80 for young, middle-aged and elderly derivation cohorts, and 0.81, 0.80 and 0.67 in the validation cohorts. Calibration of the model was good. The simple scoring system may be useful in the appropriate allocation of medical resources during the COVID-19 pandemic.

Epidemiology and risk of COVID-19 among travelers at airport and port quarantine stations across Japan: a nationwide descriptive analysis and an individually matched case-control study

Background

The epidemiology and risk of coronavirus disease 2019 (COVID-19) among travelers at international borders remain unclear.

Methods

We conducted descriptive and individually matched case-control studies using a nationwide register for COVID-19 testing of travelers from 3 August to 31 October 2020 at airport/port quarantine stations across Japan. Case patients, defined as travelers positive for COVID-19 on arrival, were individually matched with 4 controls for arrival date and airport or port. We assessed associations between test positivity and traveler characteristics using conditional logistic regression analysis.

Results

Overall, 157 507 travelers arriving from 146 countries/areas at 17 quarantine stations across Japan were tested for COVID-19. The percentage of test positivity during the study period was 0.35%. In the case-control study, with 536 case patients and 2144 controls, we found evidence of lower test positivity in travelers aged 3–19 years, female travelers, and travel corridor users (adjusted odds ratio [95% confidence interval], 0.36 [.22–.60], 0.71 [.56–.89], and 0.48 [.30–.77], respectively), whereas higher positivity was associated with arrival from South-East Asia (1.88 [1.33–2.65]) or lower-middle- or low-income countries (2.46 [1.69–3.58] and 7.25 [2.22–23.66], respectively), any symptom (4.08 [1.43–11.65]), and nasopharyngeal compared with saliva sampling (2.75 [1.85–4.09]). A higher 14-day average incidence in the countries of stay was also associated with higher test positivity (1.64 [1.16–2.33] and 3.13 [1.88–5.23] for those from countries and areas where the 14-day average incidence was from 10 to <100 and ≥100 cases per million, respectively).

Conclusions

These findings justify travel restrictions based on the epidemic situation in countries of stay, although underestimation of the epidemic in lower-income countries should be considered. A strict travel corridor could also reduce the risk of COVID-19 importation.

Risk factors for severity on admission and the disease progression during hospitalisation in a large cohort of patients with COVID-19 in Japan

OBJECTIVES

To investigate the risk factors contributing to severity on admission. Additionally, risk factors of worst severity and fatality were studied. Moreover, factors were compared based on three points: early severity, worst severity and fatality.

DESIGN

An observational cohort study using data entered in a Japan nationwide COVID-19 inpatient registry, COVIREGI-JP.

SETTING

As of 28 September 2020, 10480 cases from 802 facilities have been registered. Participating facilities cover a wide range of hospitals where patients with COVID-19 are admitted in Japan.

PARTICIPANTS

Participants who had a positive test result on any applicable SARS-CoV-2 diagnostic tests were admitted to participating healthcare facilities. A total of 3829 cases were identified from 16 January to 31 May 2020, of which 3376 cases were included in this study.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcome was severe or nonsevere on admission, determined by the requirement of mechanical ventilation or oxygen therapy, SpO2 or respiratory rate. Secondary outcome was the worst severity during hospitalisation, judged by the requirement of oxygen and/orinvasive mechanical ventilation/extracorporeal membrane oxygenation.

RESULTS

Risk factors for severity on admission were older age, men, cardiovascular disease, chronic respiratory disease, diabetes, obesity and hypertension. Cerebrovascular disease, liver disease, renal disease or dialysis, solid tumour and hyperlipidaemia did not influence severity on admission; however, it influenced worst severity. Fatality rates for obesity, hypertension and hyperlipidaemia were relatively lower.

CONCLUSIONS

This study segregated the comorbidities influencing severity and death. It is possible that risk factors for severity on admission, worst severity and fatality are not consistent and may be propelled by different factors. Specifically, while hypertension, hyperlipidaemia and obesity had major effect on worst severity, their impact was mild on fatality in the Japanese population. Some studies contradict our results; therefore, detailed analyses, considering in-hospital treatments, are needed for validation.

TRIAL REGISTRATION NUMBER

UMIN000039873. https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000045453.

Orexin/Hypocretin and Histamine Cross-Talk on Hypothalamic Neuron Counts in Mice

The loss of hypothalamic neurons that produce wake-promoting orexin (hypocretin) neuropeptides is responsible for narcolepsy type 1 (NT1). While the number of histamine neurons is increased in patients with NT1, results on orexin-deficient mouse models of NT1 are inconsistent. On the other hand, the effect of histamine deficiency on orexin neuron number has never been tested on mammals, even though histamine has been reported to be essential for the development of a functional orexin system in zebrafish. The aim of this study was to test whether histamine neurons are increased in number in orexin-deficient mice and whether orexin neurons are decreased in number in histamine-deficient mice. The hypothalamic neurons expressing L-histidine decarboxylase (HDC), the histamine synthesis enzyme, and those expressing orexin A were counted in four orexin knock-out mice, four histamine-deficient HDC knock-out mice, and four wild-type C57BL/6J mice. The number of HDC-positive neurons was significantly higher in orexin knock-out than in wild-type mice (2,502 ± 77 vs. 1,800 ± 213, respectively, one-tailed t-test, P = 0.011). Conversely, the number of orexin neurons was not significantly lower in HDC knock-out than in wild-type mice (2,306 ± 56 vs. 2,320 ± 120, respectively, one-tailed t-test, P = 0.459). These data support the view that orexin peptide deficiency is sufficient to increase histamine neuron number, supporting the involvement of the histamine waking system in the pathophysiology of NT1. Conversely, these data do not support a significant role of histamine in orexin neuron development in mammals.

Incidence of venous thromboembolism in advanced lung cancer and efficacy and safety of direct oral anticoagulant: A multicenter, prospective, observational study (Rising-VTE/NEJ037 Study)

12021

Background: Venous thromboembolism (VTE) is a well-known kind of cancer-associated thrombosis and a common complication of malignancy. However, little is known about the incidence of VTE and the effectiveness of direct oral anticoagulants (DOACs) associated with lung cancer chemotherapy. Methods: The Rising-VTE/NEJ037 study was a multicenter, prospective, observational study with 40 participating Japanese institutions. A total of 1,021 patients diagnosed with lung cancer that was unsuitable for radical resection or radiation were enrolled and followed up for two years. The diagnosis of VTE was confirmed through a central review by two radiologists. Patients with VTE at the time of lung cancer diagnosis started treatment with edoxaban. The primary endpoint of this trial was the rate of newly diagnosed VTE after enrollment or the recurrence rate 6 months after the start of treatment with edoxaban. Results: Of the 1,021 enrolled patients, data were available for 1,008 patients. The median age was 70 years (range: 30-94 years), and 70.8% were males. Eighty-six percent of patients had non-small cell lung cancer, and 13.6% had small cell lung cancer. Histological types included adenocarcinoma (N = 641, 63.6%), squamous cell carcinoma (N = 187, 18.6%), and others (N = 42, 4.2%). Sixty-two patients (6.2%) had VTE at the time of lung cancer diagnosis, and 42 patients (4.2%) developed VTE during two years follow-up, making a total of 104 patients (10.3%). No cases of VTE recurrence were found 6 months after the start of treatment with edoxaban. Major and minor bleeding occurred in 95 patients (9.4%) and increased to 23% in the edoxaban treatment group. The two-year survival probability was 0.43 in the non-VTE group and 0.48 in the VTE with edoxaban treatment group, showing no difference. Conclusions: This study shows a high cumulative incidence of VTE, suggesting that attention should be paid to VTE during treatment for lung cancer. Treatment with edoxaban was highly effective in preventing recurrence of VTE, and there was no difference in survival with or without VTE, but treatment should be considered more carefully because of the high bleeding rate associated with DOAC. Clinical trial information: jRCTs061180025.

External validation and update of prediction models for unfavorable outcomes in hospitalized patients with COVID-19 in Japan

Introduction

Most of the currently used prognostic models for COVID-19 are based on Western cohorts, but it is unknown whether any are applicable to patients with COVID-19 in Japan.

Methods

This retrospective cohort study included 160 patients with COVID-19 who were admitted to the National Center for Global Health and Medicine between January 26, 2020 and July 25, 2020. We searched PubMed for prognostic models for COVID-19. The predicted outcome was initiation of respiratory support or death. Performance of the candidate models was evaluated according to discrimination and calibration. We recalibrated the intercept of each model with our data. We also updated each model by adding β2-microglobulin (β2MG) to the model and recalculating the intercept and the coefficient of β2MG.

Results

Mean patient age was 49.8 years, 68% were male, 88.7% were Japanese. The study outcomes occurred in 15 patients, including two deaths. Two-hundred sixty-nine papers were screened, and four candidate prognostic models were assessed. The model of Bartoletti et al. had the highest area under receiver operating characteristic curve (AUC) (0.88; 95% confidence interval 0.81–0.96). All four models overestimated the probability of occurrence of the outcome. None of the four models showed statistically significant improvement in AUCs by adding β2MG.

Conclusions

Our results suggest that the existing prediction models for COVID-19 overestimate the probability of occurrence of unfavorable outcomes in a Japanese cohort. When applying a prediction model to a different cohort, it is desirable to evaluate its performance according to the prevalent health situation in that region.

High-Density Lipoprotein Cholesterol and Cardiovascular Events in Patients with Stable Coronary Artery Disease Treated with Statins: An Observation from the REAL-CAD Study

AIM

The association between high-density lipoprotein cholesterol (HDL-C) level after statin therapy and cardiovascular events in patients with stable coronary artery disease (CAD) remains unclear. Thus, in this study, we sought to determine how HDL-C level after statin therapy is associated with cardiovascular events in stable CAD patients.

METHODS

From the REAL-CAD study which had shown the favorable prognostic effect of high-dose pitavastatin in stable CAD patients with low-density lipoprotein cholesterol (LDL-C) ＜120 mg/dL, 9,221 patients with HDL-C data at baseline and 6 months, no occurrence of primary outcome at 6 months, and reported non-adherence for pitavastatin, were examined. The primary outcome was a composite of cardiovascular death, non-fatal myocardial infarction, non-fatal ischemic stroke, or unstable angina requiring emergent admission after 6 months of randomization. Absolute difference and ratio of HDL-C levels were defined as (those at 6 months-at baseline) and (absolute difference/baseline)×100, respectively.

RESULTS

During a median follow-up period of 4.0 (IQR 3.2-4.7) years, the primary outcome occurred in 417 (4.5%) patients. The adjusted risk of all HDL-C-related variables (baseline value, 6-month value, absolute, and relative changes) for the primary outcome was not significant (hazard ratio [HR] 0.99, 95% confidence interval [CI] 0.91-1.08, HR 1.03, 95% CI 0.94-1.12, HR 1.05, 95% CI 0.98-1.12, and HR 1.08, 95% CI 0.94-1.24, respectively). Furthermore, adjusted HRs of all HDL-C-related variables remained non-significant for the primary outcome regardless of on-treatment LDL-C level at 6 months.

CONCLUSIONS

After statin therapy with modestly controlled LDL-C, HDL-C level has little prognostic value in patients with stable CAD.

Histidine decarboxylase deficiency inhibits NBP-induced extramedullary hematopoiesis by modifying bone marrow and spleen microenvironments

Histidine decarboxylase (HDC), a histamine synthase, is expressed in various hematopoietic cells and is induced by hematopoietic cytokines such as granulocyte colony-stimulating factor (G-CSF). We previously showed that nitrogen-containing bisphosphonate (NBP)-treatment induces extramedullary hematopoiesis via G-CSF stimulation. However, the function of HDC in NBP-induced medullary and extramedullary hematopoiesis remains unclear. Here, we investigated changes in hematopoiesis in wild-type and HDC-deficient (HDC-KO) mice. NBP treatment did not induce anemia in wild-type or HDC-KO mice, but did produce a gradual increase in serum G-CSF levels in wild-type mice. NBP treatment also enhanced Hdc mRNA expression and erythropoiesis in the spleen and reduced erythropoiesis in bone marrow and the number of vascular adhesion molecule 1 (VCAM-1)-positive macrophages in wild-type mice, as well as increased the levels of hematopoietic progenitor cells and proliferating cells in the spleen and enhanced expression of bone morphogenetic protein 4 (Bmp4), CXC chemokine ligand 12 (Cxcl12), and hypoxia inducible factor 1 (Hif1) in the spleen. However, such changes were not observed in HDC-KO mice. These results suggest that histamine may affect hematopoietic microenvironments of the bone marrow and spleen by changing hematopoiesis-related factors in NBP-induced extramedullary hematopoiesis.

Tibialis anterior electromyographic bursts during sleep in histamine-deficient mice

Antihistamine medications have been suggested to elicit clinical features of restless legs syndrome. The available data are limited, particularly concerning periodic leg movements during sleep, which are common in restless legs syndrome and involve bursts of tibialis anterior electromyogram. Here, we tested whether the occurrence of tibialis anterior electromyogram bursts during non-rapid eye movement sleep is altered in histidine decarboxylase knockout mice with congenital histamine deficiency compared with that in wild-type control mice. We implanted six histidine decarboxylase knockout and nine wild-type mice to record neck muscle electromyogram, bilateral tibialis anterior electromyogram, and electroencephalogram during the rest (light) period. The histidine decarboxylase knockout and wild-type mice did not differ significantly in terms of sleep architecture. In both histidine decarboxylase knockout and wild-type mice, the distribution of intervals between tibialis anterior electromyogram bursts had a single peak for intervals < 10 s. The total occurrence rate of tibialis anterior electromyogram bursts during non-rapid eye movement sleep and the occurrence rate of the tibialis anterior electromyogram bursts separated by intervals < 10 s were significantly lower in histidine decarboxylase knockout than in wild-type mice. These data do not support the hypothesis that preventing brain histamine signalling may promote restless legs syndrome. Rather, the data suggest that limb movements during sleep, including those separated by short intervals, are a manifestation of subcortical arousal requiring the integrity of brain histamine signalling.

Changes in histidine decarboxylase expression influence extramedullary hematopoiesis in postnatal mice

Histidine decarboxylase (HDC), histamine synthase, is expressed in hematopoietic stem cells and in lineage-committed progenitors in the bone marrow (BM). However, the role of histamine in hematopoiesis is not well described. To evaluate the role of histamine in hematopoiesis, we analyzed the changes in HDC expression at hematopoietic sites, the BM, spleen, and liver of 2-, 3-, and 6-week-old wild-type mice. We also performed morphological analyses of the hematopoietic sites using HDC-deficient (HDC-KO) mice. In wild-type adults, HDC expression in the BM was higher than that in the spleen and liver and showed an age-dependent increase. Histological analysis showed no significant change in the adult BM and spleen of HDC-KO mice compared to wild-type mice. In the liver, HDC expression was temporarily increased at 3 weeks and decreased at 6 weeks of age. Morphological analysis of the liver revealed more numerous hematopoietic colonies and megakaryocytes in HDC-KO mice compared to wild-type mice at 2 and 3 weeks of age, whereas no changes were observed in adults. Most of these hematopoietic colonies consisted of B220-positive B-lymphocytes and TER119-positive erythroblasts and were positive for the cell proliferation marker PCNA. Notably, these hematopoietic colonies declined in HDC-KO mice upon N-acetyl histamine treatment. A significant increase in the expression of hematopoiesis-related cytokines, Il3, Il7, Epo, Gcsf, and Cxcl12 mRNA was observed in the liver of 3-week-old HDC-KO mice compared to wild-type mice. These results suggest that histamine-deficiency may maintain an microenvironment suitable for hematopoiesis by regulating hematopoiesis-related cytokine expression in the liver of postnatal mice.

Comparison of 18F-FDG PET/CT and 67Ga-SPECT for the diagnosis of fever of unknown origin: a multicenter prospective study in Japan

OBJECTIVE

The aim of this multicenter prospective study was to compare the sensitivity of ¹⁸F-fluorodeoxyglucose (FDG)-positron emission tomography/computed tomography (PET/CT) with that of ⁶⁷Ga single photon emission computed tomography (SPECT) for the identification of the site of greatest importance for the final diagnosis of the cause of fever of unknown origin (FUO).

METHODS

The study participants consisted of patients with an axillary temperature ≥ 38.0 °C on ≥ 2 occasions within 1 week, with repeated episodes for ≥ 2 weeks prior to providing consent, and whose final diagnosis after undergoing specific examinations, including a chest-to-abdomen CT scan, was uncertain. All the patients underwent FDG-PET/CT imaging first, followed by ⁶⁷Ga-SPECT imaging within 3 days. The results of the FDG-PET/CT and ⁶⁷Ga-SPECT examinations were reviewed by the central image interpretation committee (CIIC), which was blinded to all other clinical information. The sensitivities of FDG-PET/CT and ⁶⁷Ga-SPECT were then evaluated with regard to identifying the site of greatest importance for a final diagnosis of the cause of the fever as decided by the patient's attending physician. The clinical impacts (four grades) of FDG-PET/CT and ⁶⁷Ga-SPECT on the final diagnosis were evaluated.

RESULTS

A total of 149 subjects were enrolled in this study between October 2014 and September 2017. No adverse events were identified among the enrolled subjects. Twenty-one subjects were excluded from the study because of deviations from the study protocol. Among the 128 remaining subjects, a final diagnosis of the disease leading to the appearance of FUO was made for 92 (71.9%) subjects. The final diagnoses in these 92 cases were classified into four groups: noninfectious inflammatory disease (52 cases); infectious disease (31 cases), malignancy (six cases); and other (three cases). These 92 subjects were eligible for inclusion in the study's analysis, but one case did not meet the PET/CT image acquisition criteria; thus, PET/CT results were analyzed for 91 cases. According to the patient-based assessments, the sensitivity of FDG-PET/CT (45%, 95% CI 33.1-58.2%) was significantly higher than that for ⁶⁷Ga-SPECT (25%, 95% CI 15.5-37.5%) (P = 0.0029). The clinical impact of FDG-PET/CT (91%) was also significantly higher than that for ⁶⁷Ga-SPECT (57%, P < 0.001).

CONCLUSIONS

FDG-PET/CT showed a superior sensitivity to ⁶⁷Ga-SPECT for the identification of the site of greatest importance for the final diagnosis of the cause of FUO.

Clinical epidemiology of hospitalized patients with COVID-19 in Japan: Report of the COVID-19 REGISTRY JAPAN

Background

There is limited understanding of the characteristics of patients with coronavirus disease 2019 (COVID-19) requiring hospitalization in Japan.

Methods

This study included 2638 cases enrolled from 227 healthcare facilities that participated in the COVID-19 Registry Japan (COVIREGI-JP). The inclusion criteria for enrollment of a case in COVIREGI-JP are both (1) a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test and (2) inpatient treatment at a healthcare facility.

Results

The median age of hospitalized patients with COVID-19 was 56 years (interquartile range [IQR], 40–71 years). More than half of cases were male (58.9%, 1542/2619). Nearly 60% of the cases had close contact to confirmed or suspected cases of COVID-19. The median duration of symptoms before admission was 7 days (IQR, 4–10 days). The most common comorbidities were hypertension (15%, 396/2638) and diabetes without complications (14.2%, 374/2638). The number of nonsevere cases (68.2%, n = 1798) was twice the number of severe cases (31.8%, n = 840) at admission. The respiratory support during hospitalization includes those who received no oxygen support (61.6%, 1623/2636) followed by those who received supplemental oxygen (29.9%, 788/2636) and invasive mechanical ventilation/extracorporeal membrane oxygenation (8.5%, 225/2636). Overall, 66.9% (1762/2634) of patients were discharged home, while 7.5% (197/2634) died.

Conclusions

We identified the clinical epidemiological features of COVID-19 in hospitalized patients in Japan. When compared with existing inpatient studies in other countries, these results demonstrated fewer comorbidities and a trend towards lower mortality.

Risk Profiling of Cancer Treatment-Related Cardiovascular Disorders in Breast Cancer Patients Who Received Adjuvant Chemotherapy With Trastuzumab

Background: The prognosis of cancer survivors has dramatically improved, but effective strategies for cancer treatment-related cardiovascular disorders (CTRCD) remain to be elucidated in the emerging field of cardio-oncology. In this study, we investigated risk factors for CTRCD in breast cancer patients treated with trastuzumab. Methods and Results: We performed a retrospective analysis of 141 consecutive women who received adjuvant trastuzumab, and underwent baseline (BL) and follow-up (FU) echocardiography at Juntendo University between April 2010 and December 2016. The major concomitant treatment was anthracyclines in 94% and radiotherapy in 53%. During the median treatment period of 11 months, there were 22 (15.6%) cardiology consultations, 3 (2.1%) treatment interruptions with irreversible CTRCD, and no deaths. Left ventricular ejection fraction (LVEF) was decreased from a median 67.5% (BL) to 63.4% (FU; P<0.0001), with reduced LVEF noted in 26.2% at FU<90%BL, in 13.5% at FU Collapse

Key Words

• Breast cancer
• Cancer treatment-related cardiovascular disorder
• Cardio-oncology
• Cardiovascular risk factor
• Trastuzumab

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Analysis of bronchoalveolar lavage samples collected from 30 patients with drug-induced pneumonitis

BACKGROUND

Drug-induced pneumonitis is a disease encountered by pulmonologists in the clinical setting. The diagnosis generally considers the patient's clinical course and the results of peripheral blood tests, radiological examinations, and often bronchoscopic examinations. However, few studies have reported the association between radiological patterns such as ground-glass opacity (GGO) or consolidation, and bronchoalveolar lavage fluid (BALF) cell fractions. This study aimed to clarify this association.

METHODS

Patients with a Naranjo's score of probable or definite were enrolled, and all 30 patients were categorized under probable. Data such as patient background, blood examination results, radiological findings, and BALF cell fractions were retrospectively collected. The association between BALF cell fractions and other factors such as chest computed tomography (CT) findings was evaluated.

RESULTS

The most common radiological finding in patients with lymphocyte-dominant BALF was GGO, with only one patient exhibiting consolidation. However, patients with eosinophil-dominant BALF were more likely to have consolidation; only three cases showed crazy paving and one showed GGO. In addition, patients with a GGO-dominant pattern on CT had an increased lymphocyte fraction of 41.0%; those with a consolidation-dominant pattern showed a relatively high eosinophil fraction of 5.2%; and those with a crazy paving pattern showed elevated eosinophil and neutrophil fractions of 19.1% and 9.9%, respectively.

CONCLUSIONS

In this study, a remarkable difference in radiological findings was observed among different BALF patterns.