Dynamic diversity of SARS-CoV-2 genetic mutations in a lung transplantation patient with persistent COVID-19

Numerous SARS-CoV-2 variant strains with altered characteristics have emerged since the onset of the COVID-19 pandemic. Remdesivir (RDV), a ribonucleotide analogue inhibitor of viral RNA polymerase, has become a valuable therapeutic agent. However, immunosuppressed hosts may respond inadequately to RDV and develop chronic persistent infections. A patient with respiratory failure caused by interstitial pneumonia, who had undergone transplantation of the left lung, developed COVID-19 caused by Omicron BA.5 strain with persistent chronic viral shedding, showing viral fusogenicity. Genome-wide sequencing analyses revealed the occurrence of several viral mutations after RDV treatment, followed by dynamic changes in the viral populations. The C799F mutation in nsp12 was found to play a pivotal role in conferring RDV resistance, preventing RDV-triphosphate from entering the active site of RNA-dependent RNA polymerase. The occurrence of diverse mutations is a characteristic of SARS-CoV-2, which mutates frequently. Herein, we describe the clinical case of an immunosuppressed host in whom inadequate treatment resulted in highly diverse SARS-CoV-2 mutations that threatened the patient's health due to the development of drug-resistant variants.

Suppression of Type I Interferon Signaling in Myeloid Cells by Autoantibodies in Severe COVID-19 Patients

PURPOSE

Auto-antibodies (auto-abs) to type I interferons (IFNs) have been identified in patients with life-threatening coronavirus disease 2019 (COVID-19), suggesting that the presence of auto-abs may be a risk factor for disease severity. We therefore investigated the mechanism underlying COVID-19 exacerbation induced by auto-abs to type I IFNs.

METHODS

We evaluated plasma from 123 patients with COVID-19 to measure auto-abs to type I IFNs. We performed single-cell RNA sequencing (scRNA-seq) of peripheral blood mononuclear cells from the patients with auto-abs and conducted epitope mapping of the auto-abs.

RESULTS

Three of 19 severe and 4 of 42 critical COVID-19 patients had neutralizing auto-abs to type I IFNs. Patients with auto-abs to type I IFNs showed no characteristic clinical features. scRNA-seq from 38 patients with COVID-19 revealed that IFN signaling in conventional dendritic cells and canonical monocytes was attenuated, and SARS-CoV-2-specific BCR repertoires were decreased in patients with auto-abs. Furthermore, auto-abs to IFN-α2 from COVID-19 patients with auto-abs recognized characteristic epitopes of IFN-α2, which binds to the receptor.

CONCLUSION

Auto-abs to type I IFN found in COVID-19 patients inhibited IFN signaling in dendritic cells and monocytes by blocking the binding of type I IFN to its receptor. The failure to properly induce production of an antibody to SARS-CoV-2 may be a causative factor of COVID-19 severity.

Usefulness of Combined Measurement of Surfactant Protein D, Thrombin-Antithrombin III Complex, D-Dimer, and Plasmin-α2 Plasmin Inhibitor Complex in Acute Exacerbation of Interstitial Lung Disease: A Retrospective Cohort Study

Background/Objectives: The coagulation cascade due to tissue damage is considered to be one of the causes of poor prognostic outcomes in patients with acute exacerbations of interstitial lung disease (AE-ILD). This study aimed to confirm coagulopathy in AE-ILD by evaluating the differences in the clinical characteristics of coagulation/fibrinolysis markers between stable ILD and AE-ILD. Methods: Overall, 81 patients were enrolled in this retrospective study and categorized into the following two groups: a chronic ILD group comprising 63 outpatients and an acute ILD group comprising 18 inpatients diagnosed with AE-ILD. Serum markers, including thrombin-antithrombin III complex (TAT), D-dimer, plasmin-α2 plasmin inhibitor complex (PIC), and surfactant protein D (SP-D), were compared between the groups. Results: Among the 18 patients with acute ILD, 17 did not meet the International Society of Thrombosis and Hemostasis scoring system for disseminated intravascular coagulation. In acute ILD, the SP-D levels were statistically significantly positively correlated with TAT, D-dimer, and PIC levels, while the Krebs von den Lungen 6 (KL-6) levels showed no correlation with any of these coagulation/fibrinolytic markers. A positive correlation was observed between SP-D levels and TAT, D-dimer, and PIC levels in acute ILD. Serum TAT, D-dimer, and PIC all showed good area under the receiver operating characteristic (ROC) curve (AUC) values in ROC analysis for the diagnosis of acute ILD. Conclusions: In the clinical setting of AE-ILD, it may be important to focus not only on alveolar damage markers such as SP-D but also on coagulation/fibrinolytic markers including TAT, D-dimer, and PIC.

Artificial intelligence-based model for predicting pulmonary arterial hypertension on chest x-ray images

BACKGROUND

Pulmonary arterial hypertension is a serious medical condition. However, the condition is often misdiagnosed or a rather long delay occurs from symptom onset to diagnosis, associated with decreased 5-year survival. In this study, we developed and tested a deep-learning algorithm to detect pulmonary arterial hypertension using chest X-ray (CXR) images.

METHODS

From the image archive of Chiba University Hospital, 259 CXR images from 145 patients with pulmonary arterial hypertension and 260 CXR images from 260 control patients were identified; of which 418 were used for training and 101 were used for testing. Using the testing dataset for each image, the algorithm outputted a numerical value from 0 to 1 (the probability of the pulmonary arterial hypertension score). The training process employed a binary cross-entropy loss function with stochastic gradient descent optimization (learning rate parameter, α = 0.01). In addition, using the same testing dataset, the algorithm's ability to identify pulmonary arterial hypertension was compared with that of experienced doctors.

RESULTS

The area under the curve (AUC) of the receiver operating characteristic curve for the detection ability of the algorithm was 0.988. Using an AUC threshold of 0.69, the sensitivity and specificity of the algorithm were 0.933 and 0.982, respectively. The AUC of the algorithm's detection ability was superior to that of the doctors.

CONCLUSION

The CXR image-derived deep-learning algorithm had superior pulmonary arterial hypertension detection capability compared with that of experienced doctors.

Reduction of mycophenolate mofetil dosage to limit prolonged viral shedding in solid organ transplant recipients with COVID-19: Two case reports

Solid organ transplant (SOT) recipients with coronavirus disease-2019 (COVID-19) experience prolonged viral shedding, and they are forced to stay in the hospital because of the requirement for COVID-19 isolation. Here, we present two cases (lung and renal transplant recipients), wherein the isolation period was shortened by reducing the dosage of mycophenolate mofetil (MMF). Both patients recovered well from COVID-19 pneumonia. This case study suggests that a reduction in MMF dosage may lead to a shorter hospitalization period in SOT recipients with COVID-19.

Macitentan Administration for Pulmonary Hypertension Due to β-thalassemia with Multiple Organ Failure: A Case Report

A 51-year-old Thai woman diagnosed with β-thalassemia underwent regular blood transfusion and iron-chelating therapy. However, after voluntarily discontinuing treatment, the patient developed progressive dyspnea and was diagnosed with pulmonary hypertension following right heart catheterization. Despite resuming blood transfusions, her condition did not improve. Because the patient had a history of multiple organ failure, curative treatment for β-thalassemia was not feasible, and macitentan was administered. Despite experiencing hypotension as an adverse event, her condition remained stable during macitentan treatment. Thus, macitentan may be well tolerated in patients with pulmonary hypertension caused by β-thalassemia with multiple organ dysfunction.

Role of Fibrin Monomer Complex in Coronavirus Disease 2019 for Venous Thromboembolism and the Prognosis

Objective Venous thromboembolism (VTE) is a common complication of severe coronavirus disease 2019 (COVID-19) and is associated with its prognosis. The fibrin monomer complex (FMC), a marker of thrombin generation, is reportedly useful in diagnosing acute thrombosis. To date, there has been only one report on FMC in COVID-19, and the usefulness of FMC in COVID-19 is unknown. We therefore evaluated the frequency of VTE in non-intensive-care unit COVID-19 patients in Japan and determine the clinical utility of FMC in COVID-19. Methods This was a single-center retrospective study. Laboratory test results and outcomes (thrombosis and severe progression of COVID-19) were obtained via medical record review. We assessed the relationship between FMC and VTE incidence and evaluated the association between elevated FMC levels and severe progression of COVID-19. Patients This study included 247 patients with COVID-19 who were hospitalized between December 2020 and September 2021 and had had their levels of D-dimer and FMC measured. Results Of the 247 included patients, 3 (1.2%) developed VTE. All three had elevated FMC levels on admission; however, the D-dimer level was not elevated in one case on admission. The FMC level was significantly higher in the group with severe COVID-19 progression than in the group without severe progression. A multivariate analysis showed that severe progression was associated with elevated FMC levels (odds ratio, 7.40; 95% confidence interval, 2.63-22.98; p<0.001). Conclusion FMC can be useful for diagnosing VTE in the acute phase of COVID-19. Elevated FMC was found to be associated with severity on admission and severe progression.

A Comparison of Clinical Presentations in Coronavirus Disease 2019 Caused by Different Omicron Variants in Japan: A Retrospective Study

Objective We evaluated the clinical differences in coronavirus disease 2019 (COVID-19) patients between the sixth wave with the Omicron BA.1/BA.2 dominant variant (from January to April 2022) and seventh wave with the Omicron BA.5 dominant variant (from July to August 2022). Methods This retrospective, single-center, observational study included COVID-19 patients admitted to our institution in the sixth wave (sixth-wave group) and the seventh wave (seventh-wave group). Inter-group comparisons of clinical presentations, the prognosis, and proportion of nosocomial infections were performed. Results A total of 190 patients were included (93 and 97 patients in the sixth- and seventh-wave groups, respectively). While there were no significant differences in severity, significantly more patients developed pneumonia caused by COVID-19 in the sixth-wave group than in the seventh-wave group. Although there was no marked difference in in-hospital deaths, more patients died from COVID-19 in the sixth-wave group than in the seventh-wave group. There were significantly more COVID-19 inpatients with nosocomial infections in the seventh-wave group than in the sixth-wave group. Pneumonia from COVID-19 was significantly more severe in the sixth-wave group than in the seventh-wave group. Conclusion COVID-19 patients in the seventh wave are at a lower risk of pneumonia than those in the sixth wave. However, even in the seventh wave, patients with underlying diseases have a risk of death because of the exacerbation of underlying diseases triggered by COVID-19.

Partially hydrolyzed guar gum suppresses the progression of pulmonary arterial hypertension in a SU5416/hypoxia rat model

This study investigated the effects of partially hydrolyzed guar gum (PHGG) on the development of pulmonary arterial hypertension using a SU5416/hypoxia rat model. Our results demonstrated that PHGG treatment suppressed the development of pulmonary hypertension and vascular remodeling with an altered gut microbiota composition.

Clinical significance of lung cross-sectional area measured by computed tomography in chronic thromboembolic pulmonary hypertension: The correlation with pulmonary hemodynamics and the limitations

The percentage cross-sectional area of the lung under five (%CSA<5) is the percentage of pulmonary vessels with <5 mm2 area relative to the total lung area on computed tomography (CT). The extent that %CSA<5 is related to pulmonary hemodynamics in patients with chronic thromboembolic pulmonary hypertension (CTEPH) is unclear, as is the effect of pulmonary endarterectomy (PEA) on %CSA<5. Therefore, we aimed to evaluate the clinical significance of %CSA<5 in patients with CTEPH. We studied 98 patients (64 females, mean age 62.5 ± 11.9 years), who underwent CT with %CSA<5 measurement and right heart catheterization (RHC). Patients were classified into groups based on eligibility for PEA. We compared the %CSA<5 with pulmonary hemodynamics measured by RHC in various groups. In 38 patients who underwent PEA, the relationship between %CSA<5 and pulmonary hemodynamics was also evaluated before and after PEA. Significant correlations between %CSA<5 and pulmonary vascular resistance, and compliance, and pulmonary artery pulse pressure were observed in all patients. Pulmonary hemodynamics in the patients who underwent or were eligible for PEA showed a significant correlation with %CSA<5. Additionally, %CSA<5 was significantly lower in the postoperative than in the preoperative group. There was no correlation between changes in %CSA<5 and pulmonary hemodynamics before and after PEA. Furthermore, %CSA<5 did not correlate significantly with prognosis. %CSA<5 may reflect pulmonary hemodynamics in CTEPH with central thrombosis. Furthermore, %CSA<5 was reduced by PEA postoperatively. However, %CSA<5 is not a prognostic indicator, its clinical usefulness in CTEPH patients is limited, and further validation is required.

Impact of residual pulmonary hypertension on long-term outcomes after pulmonary endarterectomy in the modern era

Residual pulmonary hypertension (PH) negatively impacts long-term results following pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (CTEPH). We sought to reveal whether modern PH therapy with PH-targeted medicine and balloon pulmonary angioplasty (BPA) improved long-term results of residual PH after PEA. Long-term findings of 80 patients who survived PEA between 2011 and 2019 were retrospectively investigated. One month after PEA, 30 patients developed residual PH defined as mean pulmonary artery pressure (mPAP) ≥25 mmHg, of whom 23 were treated by PH-targeted medicine and 9 by BPA. Patients with residual PH acquired considerably better functional status and exercise capacity after PEA, however, exhibited significantly worse survival rates than those without. Eleven patients died during follow-up: 8 patients with residual PH and 3 controls. Among patients with residual PH, the deceased had a significantly lower %decrease in mPAP from 1 month to 1 year following PEA (7.4 [-32.6 to 8.0] % vs. 10.4 [3.7-27.8] %, p = 0.03) and higher mPAP at 1 year following PEA (39.5 [33.25-42.5] vs. 27 [26-34] mmHg, p < 0.01) despite PH-targeted medicine than the survived. No patients passed away from right heart failure, and there was no difference between the groups in CTEPH-related mortality. Modern PH therapy was used to address the majority of residual PH. Long-term survival after PEA was negatively impacted by residual PH, but it appeared that long-term mortality was also correlated with unrelieved residual PH despite PH-targeted medicine. Modern PH therapy may have enhanced functional status and excercise capacity, and averted fatal right heart failure.

Modification of pulmonary endarterectomy to prevent neurologic adverse events

PURPOSE

Neurologic adverse events (NAEs) are a major complication after pulmonary endarterectomy (PEA) performed under periods of deep hypothermic circulatory arrest (HCA) for chronic thromboembolic pulmonary hypertension. We modified the PEA strategy to prevent NAEs and evaluated the effectiveness of these modifications.

METHODS

We reviewed the surgical outcomes of 87 patients divided into the following three groups based on the surgical strategy used: group S (n = 49), periods of deep HCA with alpha-stat strategy; group M1 (n = 19), deep HCA with modifications of slower cooling and rewarming rates and the pH-stat strategy for cooling: and group M2 (n = 13), multiple short periods of moderate HCA.

RESULTS

PEA provided significant improvement of pulmonary hemodynamics in each group. Sixteen (29%) of the 49 group S patients suffered NAEs, associated with total circulatory arrest time (cutoff, 57 min) and Jamieson type I disease. The Group M1 and M2 patients did not suffer NAEs, although the group M1 patients had prolonged cardiopulmonary bypass (CPB) and more frequent respiratory failure.

CONCLUSIONS

NAEs were common after PEA performed under periods of deep HCA. The modified surgical strategy could decrease the risk of NAEs but increase the risk of respiratory failure. Multiple short periods of moderate HCA may be useful for patients at risk of NAEs.

Effects of the combination of atomoxetine and oxybutynin in Japanese patients with obstructive sleep apnoea: A randomized controlled crossover trial

BACKGROUND AND OBJECTIVE

The possibility of combination therapy with atomoxetine (ATO) and oxybutynin (OXY) has been suggested for obstructive sleep apnoea (OSA). However, the effectiveness of this treatment remains uninvestigated in Japanese OSA patients. Therefore, we performed a randomized, crossover, phase II, single-centre prospective trial to examine the effects of ATO-OXY therapy in Japanese OSA patients.

METHODS

In total, 17 OSA patients participated in this study. The effects of one night of 80-mg ATO plus 5-mg OXY administration were compared with those of no medication administered before sleep. The primary and secondary outcomes comprised the apnoea-hypopnoea index (AHI) and nadir SpO₂ , SpO₂ drop time and sleep architecture, respectively. The safety endpoints included drug side effects and adverse events.

RESULTS

The values of AHI, nadir SpO₂ , 3% oxygen desaturation index (ODI), 4% ODI, and SpO₂ drop time of <90% did not significantly differ between patients receiving ATO-OXY administration and no medication. Sleep architecture exhibited a significant change: ATO-OXY increased sleep stage N1 (p < 0.0001) and decreased stage N2 (p = 0.03), rapid eye movement (p < 0.0001) and sleep efficiency (p = 0.02). However, the subanalysis demonstrated an obvious decrease in AHI in five responder patients. Total sleep time and basal sleep efficiency tended to be lower in the responders compared with nonresponders (p = 0.065). No patients experienced severe adverse events or side effects.

CONCLUSION

Overall, ATO-OXY therapy does not reduce AHI in Japanese OSA patients, although AHI was decreased in a proportion of patients. Future studies for identifying treatment response group characteristics are warranted.

Multicenter, single-blind, randomized controlled study of the efficacy and safety of favipiravir and nafamostat mesilate in patients with COVID-19 pneumonia

OBJECTIVES

To evaluate the efficacy and safety of nafamostat combined with favipiravir for the treatment of COVID-19.

METHODS

We conducted a multicenter, randomized, single-blind, placebo-controlled, parallel assignment study in hospitalized patients with mild-to-moderate COVID-19 pneumonia. Patients were randomly assigned to receive favipiravir alone (n = 24) or nafamostat with favipiravir (n = 21). The outcomes included changes in the World Health Organization clinical progression scale score, time to improvement in body temperature, and improvement in oxygen saturation (SpO₂).

RESULTS

There was no significant difference in the changes in the clinical progression scale between nafamostat with favipiravir and favipiravir alone groups (median, -0.444 vs -0.150, respectively; least-squares mean difference, -0.294; P = 0.364). The time to improvement in body temperature was significantly shorter in the combination group (5.0 days; 95% confidence interval, 4.0-7.0) than in the favipiravir group (9.0 days; 95% confidence interval, 7.0-18.0; P =0.009). The changes in SpO₂ were greater in the combination group than in the favipiravir group (0.526% vs -1.304%, respectively; least-squares mean difference, 1.831; P = 0.022). No serious adverse events or deaths were reported, but phlebitis occurred in 57.1% of the patients in the combination group.

CONCLUSION

Although our study showed no differences in clinical progression, earlier defervescence, and recovery of SpO₂ were observed in the combination group.

Efficacy, safety, and pharmacokinetics of inhaled treprostinil in Japanese patients with pulmonary arterial hypertension

Treprostinil is a chemically stable analog of prostacyclin, and inhaled treprostinil was developed to deliver the effects directly to the pulmonary vasculature while minimizing systemic side effects. The objective of the study was to evaluate the efficacy on hemodynamics and exercise capacity, safety, and pharmacokinetics (PK) of inhaled treprostinil in Japanese patients with pulmonary arterial hypertension (PAH). Inhaled treprostinil was administered at three breaths (18 μg)/session four times daily, and the dose was gradually increased to a maximum of nine breaths (54 μg)/session. Endpoints included change in pulmonary vascular resistance index (PVRI) as primary, other efficacy parameters, safety, and PK. Seventeen PAH patients, the majority of whom (76.5%) had been receiving both an endothelin receptor antagonist (ERA) and a phosphodiesterase type-5 (PDE5) inhibitor/soluble guanylate cyclase (sGC) stimulator, received inhaled treprostinil. At Week 12, PVRI statistically decreased by -39.4 ± 25.5% (95% confidence interval: -52.6 to -26.3). The most frequently reported adverse events related to treprostinil were headache, cough, throat irritation, and hot flush. Regarding PK, there were no notable differences in the geometric mean C _max and AUC_last between Japanese and non-Japanese patients. Treatment with inhaled treprostinil using the dosing regimen approved in the United States resulted in significant improvement in hemodynamics, exercise capacity, and symptoms with a favorable tolerability and safety profile in Japanese patients. Inhaled treprostinil could be a valuable therapeutic option for Japanese patients with PAH, including those receiving a combination therapy with an ERA and a PDE5 inhibitor/sGC stimulator. Trial registration: JAPIC Clinical Trials Information [JapicCTI-194651].

Pulmonary Veno-occlusive Disease that Developed Following Hematopoietic Stem Cell Transplantation for Acute Myeloid Leukemia

We herein report a case of pulmonary veno-occlusive disease (PVOD) induced by allo-hematopoietic stem cell transplantation (HSCT) in a 48-year-old man who was diagnosed with acute myeloid leukemia. Five months after transplantation, he developed dyspnea and was diagnosed with pulmonary hypertension based on right heart catheterization. Although he received treatment with pulmonary vasodilators, diuretics, and corticosteroids, his pulmonary artery pressure did not decrease, and his pulmonary edema worsened. Based on the clinical course, hypoxemia, diffusion impairment, and computed tomography findings, the patient was diagnosed with HSCT-related PVOD. Critical attention should be paid to dyspnea after HSCT for the early diagnosis of PVOD.

Two cases of pulmonary arterial hypertension with specific vascular Мalformations and unique eosinophilic inflammation in carriers of the RNF213 p. Arg4810Lys variant: Case series

RNF213 p.Arg4810Lys is linked to various vascular diseases, including pulmonary arterial hypertension (PAH); however, its pathogenesis remains unclear. Here, we report the unique features of two cases of severe PAH with this variant: one is the first reported case with stenosis of the thoracic and abdominal aorta, femoral arteries, and subclavian veins. Coexistence of severe and continuous eosinophilic inflammation, which has been suspected to be implicated in the pathogenesis of PAH in previous fundamental studies, was also present in both cases. Further studies are needed to clarify the pathogenetic mechanisms in vascular lesions with this variant.

Chronic Expanding Haematoma Causing Stenosis of the Right Ventricular Outflow Tract and Pulmonary Hypertension

A chronic expanding haematoma (CEH) is an encapsulated mass that gradually increases in size from repeated internal bleeding and neovascularization. We herein report a 69-year-old man who was admitted with dyspnoea on exertion after undergoing thymic carcinoma resection 17 years ago. Chest computed tomography showed a heterogeneous mass in the anterior mediastinum and compression of the right ventricle, and pulmonary artery. Right cardiac catheterisation revealed pulmonary hypertension that was relieved after resection of the diagnosed CEH mass. This report highlights the mechanism underlying anterior mediastinal CEH-induced stenotic compression of the right ventricle-pulmonary artery outflow and subsequent pulmonary hypertension.

Mixed venous oxygen tension is a crucial prognostic factor in pulmonary hypertension: a retrospective cohort study

BACKGROUND

The prognostic value of mixed venous oxygen tension (PvO2) at pulmonary hypertension diagnosis treated with selective pulmonary vasodilators remains unclear. This study sought to investigate the association of PvO2 with long-term prognosis in pulmonary arterial hypertension (PAH) and medically treated chronic thromboembolic pulmonary hypertension (CTEPH) and to identify the distinct mechanisms influencing tissue hypoxia in patients with CTEPH or PAH.

METHODS

We retrospectively analyzed data from 138 (age: 50.2 ± 16.6 years, 81.9% women) and 268 (age: 57.4 ± 13.1 years, 72.8% women) patients with PAH and CTEPH, respectively, diagnosed at our institution from 1983 to 2018. We analyzed the survival rates of patients with/without tissue hypoxia (PvO2 < 35 mmHg) and identified their prognostic factors based on the pulmonary hypertension risk stratification guidelines.

RESULTS

Survival was significantly poorer in patients with tissue hypoxia than in those without it for PAH (P = 0.001) and CTEPH (P = 0.017) treated with selective pulmonary vasodilators. In patients with PAH, PvO2 more strongly correlated with prognosis than other hemodynamic prognostic factors regardless of selective pulmonary vasodilators usage. PvO2 was the only significant prognostic factor in patients with CTEPH treated with pulmonary hypertension medication. Patients with CTEPH experiencing tissue hypoxia exhibited significantly poorer survival than those in the intervention group (P < 0.001). PvO2 more strongly correlated with the cardiac index (CI) than the alveolar-arterial oxygen gradient (A-aDO2) in PAH; whereas in CTEPH, PvO2 was more strongly correlated with A-aDO2 than with CI.

CONCLUSIONS

PvO2 may represent a crucial prognostic factor for pulmonary hypertension. The prognostic impact of tissue hypoxia affects different aspects of PAH and CTEPH, thereby reflecting their distinct pathogenesis.

COVID-19 infection control education for medical students undergoing clinical clerkship: a mixed-method approach

BACKGROUND

Coronavirus disease (COVID-19) has induced an urgent need to train medical students not only in infection prevention control but also in the treatment of infectious diseases, including COVID-19. This study evaluates the impact of simulated clinical practice with peer role-plays and a lecture on clinical education for COVID-19.

METHODS

The sample for the study included 82 fourth- and fifth-year medical students undergoing clinical clerkship in respiratory medicine. They answered questionnaires and participated in semi-structured focus group interviews (FGIs) regarding the advantages of simulated clinical practice with peer role-plays and lectures on clinical education for COVID-19.

RESULTS

A total of 75 students participated in the COVID-19 education program between January and November 2021. The responses to the questionnaire revealed that the satisfaction level of students with COVID-19 education was high. No significant change was found among students concerning fear of COVID-19 before and after the program. The degree of burden of handling information on COVID-19 reduced significantly, while the degree with respect to the use of personal protective equipment (PPE), including appropriate wearing and removing of PPE, and care of patients with confirmed COVID-19 while taking steps to prevent infection, exhibited a decreasing trend. Nine FGIs were conducted (n = 74). The advantages of simulated clinical practice were segregated into five categories (infection prevention control, educational methods, burden on healthcare providers, self-reflection, and fear of COVID-19); and that of the lecture were segregated into four categories (information literacy, knowledge of COVID-19, educational methods, and self-reflection).

CONCLUSIONS

Simulated clinical practice with peer role-plays and the lecture pertaining to COVID-19 can prove to be efficient and safe methods for learning about COVID-19 infection and prevention control for medical students. They can reduce the burden of COVID-19 patients' care. Moreover, they can also provide an opportunity for self-reflection, realize the burden of medical care, and acquire relevant information.

Virological characteristics of the SARS-CoV-2 Omicron BA.2 spike

Soon after the emergence and global spread of the SARS-CoV-2 Omicron lineage BA.1, another Omicron lineage, BA.2, began outcompeting BA.1. The results of statistical analysis showed that the effective reproduction number of BA.2 is 1.4-fold higher than that of BA.1. Neutralization experiments revealed that immunity induced by COVID vaccines widely administered to human populations is not effective against BA.2, similar to BA.1, and that the antigenicity of BA.2 is notably different from that of BA.1. Cell culture experiments showed that the BA.2 spike confers higher replication efficacy in human nasal epithelial cells and is more efficient in mediating syncytia formation than the BA.1 spike. Furthermore, infection experiments using hamsters indicated that the BA.2 spike-bearing virus is more pathogenic than the BA.1 spike-bearing virus. Altogether, the results of our multiscale investigations suggest that the risk of BA.2 to global health is potentially higher than that of BA.1.

Virological characteristics of the SARS-CoV-2 Omicron BA.2 spike

Soon after the emergence and global spread of the SARS-CoV-2 Omicron lineage BA.1, another Omicron lineage, BA.2, began outcompeting BA.1. The results of statistical analysis showed that the effective reproduction number of BA.2 is 1.4-fold higher than that of BA.1. Neutralization experiments revealed that immunity induced by COVID vaccines widely administered to human populations is not effective against BA.2, similar to BA.1, and that the antigenicity of BA.2 is notably different from that of BA.1. Cell culture experiments showed that the BA.2 spike confers higher replication efficacy in human nasal epithelial cells and is more efficient in mediating syncytia formation than the BA.1 spike. Furthermore, infection experiments using hamsters indicated that the BA.2 spike-bearing virus is more pathogenic than the BA.1 spike-bearing virus. Altogether, the results of our multiscale investigations suggest that the risk of BA.2 to global health is potentially higher than that of BA.1.

Clinical Outcomes of Sotrovimab Treatment in 10 High-Risk Patients with Mild COVID-19: A Case Series

Case series

Patients:—

Final Diagnosis: COVID-19

Symptoms: Cough • fever • sore throat

Medication: —

Clinical Procedure: —

Specialty: Pulmonology

Pneumocystis pneumonia in an immunocompetent patient developing a subacute disease course with central consolidation

Pneumocystis pneumonia (PCP) typically occurs in immunocompromised individuals and rarely presents in immunocompetent individuals. A 55-year-old man was referred to our hospital with cough and anorexia that persisted for 2 months. Chest computed tomography revealed bilateral central consolidation. He was diagnosed with PCP via bronchoscopy. His symptoms and imaging findings improved with the administration of only trimethoprim and sulfamethoxazole. Although he had non-alcoholic fatty liver disease, there were no other complications that could potentially cause immunodeficiency. It should be noted that PCP in immunocompetent individuals can have a subacute disease course presenting with bilateral central consolidation.

Altered gut microbiota and its association with inflammation in patients with chronic thromboembolic pulmonary hypertension: a single-center observational study in Japan

Background

The pathogenesis of chronic thromboembolic pulmonary hypertension (CTEPH) is considered to be associated with chronic inflammation; however, the underlying mechanism remains unclear. Recently, altered gut microbiota were found in patients with pulmonary arterial hypertension (PAH) and in experimental PAH models. The aim of this study was to characterize the gut microbiota in patients with CTEPH and assess the relationship between gut dysbiosis and inflammation in CTEPH.

Methods

In this observational study, fecal samples were collected from 11 patients with CTEPH and 22 healthy participants. The abundance of gut microbiota in these fecal samples was assessed using 16S ribosomal ribonucleic acid (rRNA) gene sequencing. Inflammatory cytokine and endotoxin levels were also assessed in patients with CTEPH and control participants.

Results

The levels of serum tumor necrosis factor-α (TNF-α), interleukin (IL)-6, IL-8, and macrophage inflammatory protein (MIP)-1α were elevated in patients with CTEPH. Plasma endotoxin levels were significantly increased in patients with CTEPH (P < 0.001), and were positively correlated with TNF-α, IL-6, IL-8, and MIP-1α levels. The 16S rRNA gene sequencing and the principal coordinate analysis revealed the distinction in the gut microbiota between patients with CTEPH (P < 0.01) and control participants as well as the decreased bacterial alpha-diversity in patients with CTEPH. A random forest analysis for predicting the distinction in gut microbiota revealed an accuracy of 80.3%.

Conclusion

The composition of the gut microbiota in patients with CTEPH was distinct from that of healthy participants, which may be associated with the elevated inflammatory cytokines and endotoxins in CTEPH.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-01932-0.

Multi‑omics analysis of right ventricles in rat models of pulmonary arterial hypertension: Consideration of mitochondrial biogenesis by chrysin

In pulmonary arterial hypertension (PAH), right ventricular failure is accompanied by metabolic alterations in cardiomyocytes, which may be due to mitochondrial dysfunction and decreased energy production. Chrysin (CH) is a phytochemical with pharmacological activity that is involved in the regulation of mitochondrial biogenesis. The present study investigated the role of CH in the right ventricle (RV) by analyzing the cardiac transcriptome and metabolome of a SU5416(a vascular endothelial growth factor receptor blocker, /hypoxia (Su/Hx) rat model of PAH. RNA‑sequencing of the RV transcriptome between Su/Hx, Su/Hx with CH (Su/Hx + CH) and control groups, extracellular matrix (ECM) organization and ECM‑receptor interaction‑associated genes were upregulated in the RV of Su/Hx but not Su/Hx + CH rats. Furthermore, expression of mitochondrial function‑, energy production‑, oxidative phosphorylation‑ and tricarboxylic acid (TCA) cycle‑associated genes was decreased in the RV of Su/Hx rats; this was reverse by CH. Metabolomic profiling analysis of Su/Hx and Su/Hx + CH rats showed no significant changes in glycolysis, TCA cycle, glutathione, NADH or NADPH. By contrast, in the RV of Su/Hx rats, decreased adenylate energy charge was partially reversed by CH administration, suggesting that CH was involved in the improvement of mitochondrial biogenesis. Reverse transcription‑quantitative PCR analysis revealed that expression of peroxisome proliferator‑activated receptor γ, a master regulator of fatty acid metabolism and mitochondrial biogenesis, was increased in the RV of Su/Hx + CH rats. CH ameliorated cardiac abnormality, including cardiac fibrosis, RV hypertrophy and PH. The present study suggested that CH altered patterns of gene expression and levels of mitochondrial metabolites in cardiomyocytes, thus improving RV dysfunction in a Su/Hx PAH rat model.

The Isoquinoline-Sulfonamide Compound H-1337 Attenuates SU5416/Hypoxia-Induced Pulmonary Arterial Hypertension in Rats

Pulmonary arterial hypertension (PAH) is characterized by elevated pulmonary arterial pressure and right heart failure. Selective pulmonary vasodilators have improved the prognosis of PAH; however, they are not able to reverse pulmonary vascular remodeling. Therefore, a search for new treatment agents is required. H-1337 is an isoquinoline-sulfonamide compound that inhibits multiple serine/threonine kinases, including Rho-associated protein kinase (ROCK) and mammalian target of rapamycin (mTOR). Here, we investigated the effects of H-1337 on pulmonary hypertension and remodeling in the pulmonary vasculature and right ventricle in experimental PAH induced by SU5416 and hypoxia exposure. H-1337 and H-1337M1 exerted inhibitory effects on ROCK and Akt. H-1337 inhibited the phosphorylation of myosin light chain and mTOR and suppressed the proliferation of smooth muscle cells in vitro. H-1337 treatment also suppressed the phosphorylation of myosin light chain and mTOR in the pulmonary vasculature and decreased right ventricular systolic pressure and the extent of occlusive pulmonary vascular lesions. Furthermore, H-1337 suppressed aggravation of right ventricle hypertrophy. In conclusion, our data demonstrated that inhibition of ROCK and mTOR pathways with H-1337 suppressed the progression of pulmonary vascular remodeling, pulmonary hypertension, and right ventricular remodeling.

Vascular involvement in chronic thromboembolic pulmonary hypertension is associated with spirometry obstructive impairment

BACKGROUND

Chronic thromboembolic pulmonary hypertension (CTEPH) is a type of pulmonary hypertension caused by persistent thromboembolism of the pulmonary arteries. In clinical practice, CTEPH patients often show obstructive ventilatory impairment, even in the absence of a smoking history. Recent reports imply a tendency for CTEPH patients to have a lower FEV_1.0; however, the mechanism underlying obstructive impairment remains unknown.

METHODS

We retrospectively analyzed CTEPH patients who underwent a pulmonary function test and respiratory impedance test to evaluate their exertional dyspnea during admission for right heart catheterization from January 2000 to December 2019. We excluded patients with a smoking history to rule out the effect of smoking on obstructive impairment.

RESULTS

A total of 135 CTEPH patients were analyzed. The median FEV_1.0/FVC was 76.0%, %FEV _1.0 had a negative correlation with the mean pulmonary artery pressure and pulmonary vascular resistance and the CT Angiogram (CTA) obstruction score. A multivariate regression analysis revealed that the CTA obstruction score was an independent factor of a lower %FEV_1.0. In the 54 patients who underwent pulmonary endarterectomy, %FEV_1.0 was improved in some cases and was not in some. Mean PAP largely decreased after PEA in the better %FEV_1.0 improved cases, suggesting that vascular involvement in CTEPH could be associated with spirometry obstructive impairment.

CONCLUSION

%FEV_1.0 had a significant correlation with the CTA obstruction score. Obstructive impairment might have an etiological relationship with vascular involvement. Further investigations could shed new light on the etiology of CTEPH.

Preoperative soluble cluster of differentiation 40 ligand level is associated with outcome of pulmonary endarterectomy

Objective

Soluble CD40 ligand (sCD40L) is associated with some pathobiological states. However, whether sCD40L in patients with chronic thromboembolic pulmonary hypertension (CTEPH) who underwent pulmonary endarterectomy (PEA) is associated with perioperative pulmonary hemodynamics and surgical outcomes has not been elucidated. Here we aimed to investigate whether sCD40L is a useful serologic biomarker of poor surgical outcome of PEA in patients with CTEPH.

Methods

Ninety patients with CTEPH who underwent PEA were enrolled. Independent preoperative parameters were examined, including sCD40L related to lower cardiac index (CI), higher pulmonary vascular resistance (PVR), and poor surgical outcomes after PEA, according to the multivariate logistic regression analysis. In addition, the area under the curve (AUC) value of sCD40L to predict poor surgical outcomes was compared with the AUCs of D-dimer and C-reactive protein (CRP). The generalizability of this study model was tested by a 5-fold cross-validation analysis.

Results

Multivariate logistic regression analysis showed that high sCD40L level was related to postoperative lower CI, higher PVR, and poor surgical outcomes independent of other preoperative parameters. The AUC value of sCD40L to predict poor surgical outcomes was higher than those of D-dimer and CRP. A sCD40L cutoff value of 1.45 ng/mL predicted poor surgical outcomes with 79.3% sensitivity and 67.3% specificity. The 5-fold cross-validation analysis showed the effectiveness of our model's performance.

Conclusions

Preoperative sCD40L level could be a promising serologic biomarker associated with poor surgical outcomes in CTEPH. In addition to known preoperative parameters, the biomarker might have the potential to identify patients at high risk of PEA, thereby reducing the mortality rates.

Selexipag for the treatment of chronic thromboembolic pulmonary hypertension

Treatment options for inoperable chronic thromboembolic pulmonary hypertension (CTEPH) remain limited. Selexipag, an oral selective IP prostacyclin-receptor agonist approved for pulmonary arterial hypertension, is a potential treatment option for CTEPH.In this multicentre, randomised, double-blind, placebo-controlled study, 78 Japanese patients with inoperable CTEPH or persistent/recurrent pulmonary hypertension after pulmonary endarterectomy and/or balloon pulmonary angioplasty were randomly assigned to receive placebo or selexipag. The primary endpoint was the change in pulmonary vascular resistance (PVR) from baseline to week 20. The secondary endpoints were changes in other haemodynamic parameters, 6-min walk distance (6 WMD), Borg Dyspnoea Scale score, World Health Organisation (WHO) functional class, EuroQol 5 dimensions 5-level and N-terminal pro-brain natriuretic peptide.The change in PVR was -98.2±111.3 dyn·s·cm^-5 and -4.6±163.6 dyn·s·cm^-5 in the selexipag and placebo groups, respectively (mean difference, -93.5 dyn·s·cm^-5; 95% confidence interval, -156.8, -30.3; p=0.006). The changes in cardiac index (p<0.001) and Borg Dyspnoea Scale score (p=0.036) were also significantly improved over placebo. 6WMD and WHO functional class were not significantly improved. The common adverse events in the selexipag group were corresponded to those generally observed following a prostacyclin analogue is administered.Selexipag significantly improved PVR and other haemodynamic variables in patients with CTEPH, although exercise capacity remained unchanged. Further large-scale investigation is necessary to prove the role of selexipag in CTEPH.

Interventricular septal curvature as an additional echocardiographic parameter for evaluating chronic thromboembolic pulmonary hypertension: a single-center retrospective study

BACKGROUND

Noninvasive estimation of the actual systolic pulmonary artery pressure measured via right-sided heart catheterization (sPAP_RHC) is vital for the management of pulmonary hypertension, including chronic thromboembolic pulmonary hypertension (CTEPH). Evaluation related to the interventricular septum (IVS) is generally performed with only visual assessment and has been rarely assessed quantitatively in the field of echocardiography. Thus, this study aimed to investigate the utility of echocardiographic IVS curvature to estimate sPAP_RHC in patients with CTEPH.

METHODS

Medical records of 72 patients with CTEPH were studied retrospectively. We estimated sPAP_RHC using echocardiographic IVS curvature (esPAP_curv) and left ventricular eccentricity index (esPAP_LVEI), and compared their ability to predict sPAP_RHC with estimated sPAP_RHC using tricuspid regurgitant pressure gradient (esPAP_TRPG).

RESULTS

IVS curvature and LVEI were significantly correlated with sPAP_RHC (r = - 0.52 and r = 0.49, respectively). Moreover, the IVS curvature was effective in estimating the sPAP_RHC of patients with trivial tricuspid regurgitation (r = - 0.56) and in determining patients with sPAP_RHC ≥ 70 mmHg with higher sensitivity (77.0%) compared to those with esPAP_TRPG and esPAP_LVEI.

CONCLUSION

Our results indicate that the echocardiographic IVS curvature could be a useful additional tool for estimating sPAP_RHC in CTEPH patients for whom accurate estimation of sPAP_RHC using tricuspid regurgitant pressure gradient is challenging.

Six Cases of Hemoptysis with Angiogenesis from Non-Bronchial Systemic Arteries

BACKGROUND Although bronchial arteries are the most common cause of hemoptysis, other systemic arteries can cause hemoptysis and are potential pitfalls for successful embolization. CASE REPORT We present 6 cases of hemoptysis showing vascularization from systemic arteries other than bronchial arteries that presented to our department between 2013 and 2020. Chronic inflammatory diseases such as tuberculosis and pulmonary aspergillosis were the underlying diseases in 4 of the 6 cases. In all 6 cases, the lesions were close to the pleura. The abnormal non-bronchial systemic arteries were the internal thoracic artery in 4 cases, intercostal artery in 2 cases, lateral thoracic artery in 2 cases, and the subclavian, thyrocervical, and inferior phrenic arteries in 1 case each, all of which formed a shunt with the pulmonary artery. Additionally, depending on the location of the lesion, the non-bronchial systemic arteries near the lesion proliferated into the lung parenchyma through the adherent pleura. CONCLUSIONS When lesions are in contact with the pleura, various non-bronchial systemic arteries near the lesion can develop in the pulmonary parenchyma via the adherent pleura, which can cause hemoptysis. In patients with hemoptysis, it may be useful to evaluate chest contrast-enhanced computed tomography and angiography, while always accounting for the potential involvement of non-bronchial systemic arteries to ensure a safer and more reliable treatment.

A case of pulmonary arterial hypertension with V/Q SPECT/CT that showed localized uptake of 99mTc just below the pleura and a unique distribution

Pulmonary hypertension (PH) is a life-threatening disorder, which originates from various aetiologies. Ventilation-perfusion (V/Q) scanning is commonly used to evaluate the differential diagnosis of PH. Meanwhile, previous studies have shown that single-photon emission computed tomography (SPECT)/CT imaging can provide a more detailed analysis for the assessment of pulmonary blood flow. However, there is insufficient evidence supporting the merits of V/Q SPECT/CT image data in detecting pulmonary vascular disease. Here, we report a case of pulmonary arterial hypertension with localized accumulation and peculiar distribution just below the pleura on V/Q SPECT/CT. Our finding is unique, and it suggests that V/Q SPECT/CT image data might be useful to detect blood flow not only in cases of pulmonary embolism, but also in the more commonly encountered PH.

Possibility of deterioration of respiratory status when steroids precede antiviral drugs in patients with COVID-19 pneumonia: A retrospective study

Introduction

Coronavirus disease (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2. Although most patients with COVID-19 develop asymptomatic or mild disease, some patients develop severe disease. The effectiveness of various therapeutic agents, including antiviral drugs, steroids, and anti-inflammatories for COVID-19, have been being confirmed. The effect of administering steroids in early disease is unclear. This study therefore aimed to evaluate the effectiveness and risk of exacerbation of steroids administered preceding antiviral drugs in patients with COVID-19 pneumonia.

Methods

This retrospective, single-center, observational study included consecutive patients with COVID-19 between March 2020 and March 2021. Patients were divided into a steroids-first group and antiviral-drugs-first group. Mortality, duration of hospitalization, incidence rate and duration of intensive care unit (ICU) admission, intubation, and extracorporeal membrane oxygenation (ECMO) induction of the two groups were compared.

Results

A total of 258 patients were admitted during the study period. After excluding patients who received symptomatic treatment only, who were taking immunosuppressive drugs, or who were administered antiviral drugs only, 68 patients were included in the analysis, 16 in the steroids-first group and 52 in the antiviral-drugs-first group. The rate of intubation, ICU admission and ECMO induction were significantly higher in the steroids-first group than in the antiviral-drugs-first group (81.3% vs. 33.3, p<0.001, 75.0% vs. 29.4%, p = 0.001, and 31.3% vs. 7.8%, p = 0.017, respectively). Furthermore, patients who received steroids within ten days after starting antiviral drugs had significantly lower rates of ICU admission, intubation, and ECMO induction. (81.3% vs. 42.9% p = 0.011, 75.0% vs. 37.1% p = 0.012, and 31.3% vs. 8.6% p = 0.039, respectively).

Conclusions

Administering steroids prior to antiviral drugs soon after symptom onset can aggravate disease severity. When administration of steroids is considered soon after symptom onset, it may be safer to initiate antiviral drugs first.

Characteristics of patients meeting the new definition of pre-capillary pulmonary hypertension (Nice 2018) in a single Japanese pulmonary hypertension center

Background

The 6th World Symposium on Pulmonary Hypertension (Nice 2018) proposed a new definition of pre-capillary pulmonary hypertension (PH) as a condition with mean pulmonary artery pressure (mPAP) > 20 mmHg, pulmonary artery wedge pressure  ≤ 15 mmHg, and pulmonary vascular resistance (PVR) ≥ 3 Wood units (WU). The characteristics and prognosis of patients with pre-capillary PH, according to this new definition, is unclear. Therefore, we determined the characteristics and survival of patients with borderline pre-capillary PH.

Methods

We retrospectively enrolled 683 patients who underwent their first right heart catheterization at Chiba University, Japan. Among them, 489 patients met the pre-capillary PH requirement with mPAP ≥ 25 mmHg (conventional pre-capillary PH group), while 22 patients met the borderline pre-capillary PH criteria (borderline pre-capillary PH group). Additionally, 16 patients with a mean PAP of 20–25 and PVR of 2–3 WU were also examined.

Results

The borderline pre-capillary PH group comprised 4.3% of the total patients with pre-capillary PH, and the majority was in Group 3 (40.9%) or 4 (45.5%). The survival of the borderline pre-capillary PH group tended to be better than that of the conventional pre-capillary PH group. The prognosis of Group3 PH was the worst among the patients with borderline precapillary PH. There was no significant difference in survival between the borderline pre-capillary PH group with PVR ≥ 3 WU and that with PVR of 2–3 2WU, although none of the patients in the latter group died due to right heart failure.

Conclusions

This is the first study conducted in a PH center in an Asian country to reveal the characteristics of patients with pre-capillary PH, according to the Nice 2018 definition. They comprised 4.3% of the total population with pre-capillary PH, and the majority of the pre-capillary PH cases were in either Group3 or 4. The prognosis may be affected by the patients’ underlying diseases. Further prospective studies are needed to determine whether the new definition, including the PVR cut-off, is beneficial in clinical practice.

Yellow nail syndrome with massive chylothorax after esophagectomy: A case report

Yellow nail syndrome (YNS) is a rare condition characterized by the triad of yellow nails, lymphedema, and respiratory manifestations. Diuretics and thoracic drainage are often not effective in YNS, and the most effective treatments are pleurodesis and decortication/pleurectomy. A 66-year-old man was admitted to our hospital for YNS after esophagectomy with gastric tube reconstruction for esophageal cancer. The patient presented with yellow nails and lymphedema. Chest X-rays and computed tomography showed massive pleural effusions and ascites that were both chylous. The patient was considered to have YNS that became apparent after surgery. He recovered with diuretics and a low-fat diet without pleurodesis and decortication/pleurectomy. Thoracic surgery can exacerbate the functional impairment of lymphatic drainage in patients with asymptomatic and undiagnosed YNS, and can lead to further development of YNS-related clinical symptoms. Despite relatively massive chylothorax following thoracic surgery, chylothorax related to YNS could be successfully controlled with conservative treatment without pleurodesis and decortication/pleurectomy.

Serum anti-DIDO1, anti-CPSF2, and anti-FOXJ2 antibodies as predictive risk markers for acute ischemic stroke

BACKGROUND

Acute ischemic stroke (AIS) is a serious cause of mortality and disability. AIS is a serious cause of mortality and disability. Early diagnosis of atherosclerosis, which is the major cause of AIS, allows therapeutic intervention before the onset, leading to prevention of AIS.

METHODS

Serological identification by cDNA expression cDNA libraries and the protein array method were used for the screening of antigens recognized by serum IgG antibodies in patients with atherosclerosis. Recombinant proteins or synthetic peptides derived from candidate antigens were used as antigens to compare serum IgG levels between healthy donors (HDs) and patients with atherosclerosis-related disease using the amplified luminescent proximity homogeneous assay-linked immunosorbent assay.

RESULTS

The first screening using the protein array method identified death-inducer obliterator 1 (DIDO1), forkhead box J2 (FOXJ2), and cleavage and polyadenylation specificity factor (CPSF2) as the target antigens of serum IgG antibodies in patients with AIS. Then, we prepared various antigens including glutathione S-transferase-fused DIDO1 protein as well as peptides of the amino acids 297-311 of DIDO1, 426-440 of FOXJ2, and 607-621 of CPSF2 to examine serum antibody levels. Compared with HDs, a significant increase in antibody levels of the DIDO1 protein and peptide in patients with AIS, transient ischemic attack (TIA), and chronic kidney disease (CKD) but not in those with acute myocardial infarction and diabetes mellitus (DM). Serum anti-FOXJ2 antibody levels were elevated in most patients with atherosclerosis-related diseases, whereas serum anti-CPSF2 antibody levels were associated with AIS, TIA, and DM. Receiver operating characteristic curves showed that serum DIDO1 antibody levels were highly associated with CKD, and correlation analysis revealed that serum anti-FOXJ2 antibody levels were associated with hypertension. A prospective case-control study on ischemic stroke verified that the serum antibody levels of the DIDO1 protein and DIDO1, FOXJ2, and CPSF2 peptides showed significantly higher odds ratios with a risk of AIS in patients with the highest quartile than in those with the lowest quartile, indicating that these antibody markers are useful as risk factors for AIS.

CONCLUSIONS

Serum antibody levels of DIDO1, FOXJ2, and CPSF2 are useful in predicting the onset of atherosclerosis-related AIS caused by kidney failure, hypertension, and DM, respectively.

Drug Fever Due to Favipiravir Administration for the Treatment of a COVID-19 Patient

A 55-year-old Japanese man was hospitalized with the novel coronavirus disease 2019 (COVID-19). On the 14th day after the start of favipiravir administration, the patient developed a fever with a temperature of 38.1°C. His pulse rate also became elevated to 128 bpm, so relative bradycardia was not suspected. Since he was in good overall health and no concomitant symptoms and signs were apparent, we considered it to be drug fever due to favipiravir. After the completion of favipiravir treatment, the patient's temperature normalized within 24 hours. We herein report this case of drug fever caused by favipiravir.

The clinical characteristics, treatment, and survival of portopulmonary hypertension in Japan

Background

Portopulmonary hypertension (PoPH) refers to the simultaneous presentation of pulmonary arterial and portal hypertension. However, few reports have included the characteristics and treatments for patients with PoPH of Asian population; thus, we investigated the clinical characteristics, treatment, and survival of these patients in a Japanese cohort.

Methods

Pulmonary arterial hypertension (PAH) has been included in the National Research Project on Intractable Disease in Japan; therefore, we extracted data of patients with PoPH from the forms of newly registered cases of the project from 2012 to 2013 (for 2 years), and updated cases of the project in 2013 (Study 1, n = 36 newly registered forms, n = 46 updated forms). Additionally, for Study 2, we performed a retrospective, observational cohort study at Chiba University Hospital (n = 11). We compared the characteristics between patients with PoPH and those with idiopathic/heritable PAH (I/H-PAH).

Results

Both studies showed higher cardiac outputs (COs) and cardiac indexes (CIs), lower pulmonary vascular resistance (PVR), and less treated with combination therapy in patients with PoPH than those with I/H-PAH. In Study 2, the overall and disease-specific survival between PoPH and I/H-PAH were similar. Conversely, many patients (45%) had to change their PAH-specific medicine because of adverse effects.

Conclusion

As seen in western countries, Japanese patients with PoPH showed higher COs and CIs, better exercise tolerance, and lower PVRs than patients with I/H-PAH. Further studies are needed to improve PoPH treatments.

Alternative approaches for clinical clerkship during the COVID-19 pandemic: online simulated clinical practice for inpatients and outpatients-A mixed method

BACKGROUND

The COVID-19 pandemic has created a need for educational materials and methods that can replace clinical clerkships (CCs) for online simulated clinical practice (online-sCP). This study evaluates the impact of using simulated electronic health records (sEHR) for inpatients, and electronic problem-based learning (e-PBL) and online virtual medical interviews (online-VMI) for outpatients, for an online-sCP using a learning management system (LMS) and online meeting system facilitated by a supervising physician.

METHODS

The sEHR was reviewed by medical students and subsequently discussed with a supervising physician using an online meeting system. In the e-PBL, medical students reviewed the simulated patients and discussed on the LMS. For the online-VMI, a faculty member acted as an outpatient and a student acted as the doctor. Small groups of students discussed the clinical reasoning process using the online meeting system. A mixed-method design was implemented. Medical students self-assessed their clinical competence before and after the online-sCP. They answered questionnaires and participated in semi-structured focus group interviews (FGIs) regarding the advantages and disadvantages of the practice.

RESULTS

Forty-three students completed the online-sCP during May and June 2020. All students indicated significant improvement in all aspects of self-evaluation of clinical performance after the online-sCP. Students using sEHR reported significant improvement in writing daily medical records and medical summaries. Students using e-PBL and online-VMI reported significant improvement in medical interviews and counseling. Students also indicated CCs as more useful for learning associated with medical interviews, physical examinations, and humanistic qualities like professionalism than the online-sCP. Eight FGIs were conducted (n = 42). The advantages of online-sCP were segregated into five categories (learning environment, efficiency, accessibility, self-paced learning, and interactivity); meanwhile, the disadvantages of online-sCP were classified into seven categories (clinical practice experience, learning environment, interactivity, motivation, memory retention, accessibility, and extraneous cognitive load).

CONCLUSIONS

Online-sCP with sEHR, e-PBL, and online-VMI could be useful in learning some of the clinical skills acquired through CC. These methods can be implemented with limited preparation and resources.

Cell Tracking Suggests Pathophysiological and Therapeutic Role of Bone Marrow Cells in Sugen5416/Hypoxia Rat Model of Pulmonary Arterial Hypertension

BACKGROUND

The mechanism of vascular remodelling in pulmonary arterial hypertension (PAH) remains unclear. Hence, defining the origin of cells constituting intractable vascular lesions in PAH is expected to facilitate therapeutic progress. Herein, we aimed to evaluate the origin of intractable vascular lesions in PAH rodent models via bone marrow (BM) and orthotopic lung transplantation (LT).

METHODS

To trace BM-derived cells, we prepared chimeric rats transplanted with BM cells from green fluorescent protein (GFP) transgenic rats. Male rats were transplanted with lungs obtained from female rats and vice versa. Pulmonary hypertension was induced in the transplanted rats via Sugen5416 treatment and subsequent chronic hypoxia (Su/Hx).

RESULTS

In the chimeric Su/Hx models, GFP-positive cells were observed in the pulmonary vascular area. Moreover, the right ventricular systolic pressure was significantly lower compared with wild-type Su/Hx rats without BM transplantation (P = 0.009). PAH suppression was also observed in rats that received allograft transplanted BM transplantation. In male rats that received LT and Su/Hx, BM-derived cells carrying the Y chromosome were also detected in neointimal occlusive lesions of the transplanted lungs received from female rats.

CONCLUSIONS

BM-derived cells participate in pulmonary vascular remodelling in the Su/Hx rat model, whereas BM transplantation may contribute to suppression of development of PAH.

Heritable pulmonary arterial hypertension complicated by multiple pulmonary arteriovenous malformations

Heritable pulmonary arterial hypertension (HPAH) is a type of familial pulmonary arterial hypertension, while pulmonary arteriovenous malformations (PAVMs) are abnormal communications between pulmonary arteries and veins that occur frequently in patients with hereditary hemorrhagic telangiectasia (HHT). A 21-year-old woman on continuing medication for HPAH was hospitalized. She had been diagnosed with HPAH at age 4 years and had been receiving epoprostenol infusion from age of 9 years. Although lung perfusion scintigraphy showed a shunt fraction of 18.9% at age of 19 years, the cause of the shunt was unclear. At the time of the present hospitalization, enhanced computed tomography (CT) of the chest and four-dimensional reconstructed images revealed multiple abnormal communications between the peripheral pulmonary arteries and veins. Furthermore, right heart catheterization revealed an elevated mean pulmonary arterial pressure. Wedged angiography of the pulmonary artery of the right lower lobe revealed several PAVMs. Multiple PAVMs and suspected HHT with HPAH was diagnosed. The possibility of PAVMs should be considered even in patients with HPAH. Moreover, evaluation of the shunt fraction by lung perfusion scintigraphy and morphological examination of PAVM by contrast-enhanced CT may facilitate PAVM detection in patients with HPAH.

Metabolic remodeling in the right ventricle of rats with severe pulmonary arterial hypertension

It is generally considered that there is an increase in glycolysis in the hypertrophied right ventricle (RV) during pulmonary hypertension (PH), which leads to a decrease in glucose oxidation through the tricarboxylic acid (TCA) cycle. Although recent studies have demonstrated that fatty acid (FA) and glucose accumulated in the RV of patients with PH, the details of this remain to be elucidated. The purpose of the current study was to assess the metabolic remodeling in the RV of rats with PH using a metabolic analysis. Male rats were treated with the vascular endothelial growth factor receptor blocker SU5416 followed by 3 weeks of hypoxic conditions and 5 weeks of normoxic conditions (Su/Hx rats). Hemodynamic measurements were conducted, and the RV was harvested for the measurement of metabolites. A metabolomics analysis revealed a decreasing trend in the levels of alanine, argininosuccinic acid and downstream TCA cycle intermediates, including fumaric and malic acid and an increasing trend in branched‑chain amino acids (BCAAs) in Su/Hx rats compared with the controls; however, no trends in glycolysis were indicated. The FA metabolomics analysis also revealed a decreasing trend in the levels of long‑chain acylcarnitines, which transport FA from the cytosol to the mitochondria and are essential for beta‑oxidation. The current study demonstrated that the TCA cycle was less activated because of a decreasing trend in the expression of fumaric acid and malic acid, which might be attributable to the expression of adenylosuccinic acid and argininosuccinic acid. These results suggest that dysregulated BCAA metabolism and a decrease in FA oxidation might contribute to the reduction of the TCA cycle reactions.

Severe thrombocytopenia in patients with idiopathic pulmonary arterial hypertension provided several strategies for lung transplantation

While the prognosis of idiopathic pulmonary arterial hypertension has improved significantly due to newer medications, lung transplantation remains a critical therapeutic option for severe pulmonary arterial hypertension. Hence, it is essential for patients awaiting lung transplantation to avoid complications, including thrombocytopenia, which may affect their surgical outcomes. Herein we present the case of a 21-year-old woman diagnosed with idiopathic pulmonary arterial hypertension at the age of 15. She developed thrombocytopenia while awaiting lung transplantation. Her medication was switched from epoprostenol to treprostinil, suspecting possible drug-induced thrombocytopenia. Furthermore, she was administered thrombopoietin receptor agonists in view of the possibility of idiopathic thrombocytopenic purpura, along with maximum support for right heart failure. Subsequently, her platelet count increased to >70,000/µL, enabling her to successfully undergo bilateral lung transplantation. Post-bilateral lung transplantation, pulmonary arterial hypertension as well as thrombocytopenia appeared to have resolved. In this case, we suspected that thrombocytopenia could have resulted owing to a combination of pulmonary arterial hypertension, right heart failure, drug interactions, and idiopathic thrombocytopenic purpura. Thrombocytopenia is a very critical condition in patients with pulmonary arterial hypertension, especially those awaiting lung transplantation. Several approaches are known to improve intractable thrombocytopenia in patients with pulmonary arterial hypertension.

The extent of enlarged bronchial arteries is not correlated with the development of reperfusion pulmonary edema after pulmonary endarterectomy in patients with chronic thromboembolic pulmonary hypertension

This study investigated whether dilated bronchial arteries are associated with reperfusion pulmonary edema in patients with chronic thromboembolic pulmonary hypertension. Results showed that the extent of enlarged bronchial arteries was not associated with the development of reperfusion pulmonary edema, whereas the residual pulmonary hypertension had a significant association.

Characteristics of Japanese elderly patients with pulmonary arterial hypertension

Previous nationwide Japanese data suggested that pulmonary arterial hypertension (PAH) predominantly affects young women. However, the number of elderly patients diagnosed with PAH has been increasing in western countries. There have been no reports on elderly PAH patients in Asian countries. This study aimed to investigate the clinical characteristics of elderly PAH patients in a Japanese cohort. Idiopathic/heritable PAH (I/H-PAH) was included in the national research project on intractable diseases. The patients were required to submit a clinical research form completed by their attending physicians. We analyzed the characteristics of Japanese I/H-PAH using the newly registered forms in 2013 (Study 1, n = 148). Also, we did a retrospective, observational cohort study at Chiba University Hospital (Study 2, n = 42). We compared the characteristics of elderly PAH patients (≥65 years old) with younger patients (<65) in both studies. Study 1 revealed a predominance of males (51% male), better hemodynamics and poorer exercise capacity in the elderly group (n = 72), compared with the younger group (n = 76) in study 1. In Study 2, elderly patients showed a male predominance (63% male), a higher ratio of smokers, a lower % carbon monoxide diffusing capacity, and poorer exercise tolerance. Elderly patients in Study 2 showed less improvement in hemodynamics with therapy. There was no significant difference in disease-specific survival between elderly and younger patients. Japanese elderly patients with I/H-PAH showed poorer exercise capacity and impaired gas exchange, but better pulmonary hemodynamics than younger patients.