Recurrent and persistent fever after SARS-CoV-2 infection in patients with follicular lymphoma: A case series.

Although persistent or recurrent COVID-19 infection is well described in some immunosuppressed patient cohort, to date, there have been no reports of this phenomenon in the context of repeatedly negative SARS-CoV-2 testing in the upper respiratory tract. We reported six patients with follicular lymphoma who developed recurrent symptomatic COVID-19 infection. They tested persistently negative for SARS-CoV-2 on pharyngeal swabs and ultimately confirmed by bronchoalveolar lavage fluid metagenomics next-generation sequencing. All six patients presented with lymphopenia and B-cell depletion, and five of them received the anti-cluster of differentiation 20 treatment in the last year. Persistent fever was the most common symptom and bilateral ground-glass opacities were the primary pattern on chest computed tomography. A relatively long course of unnecessary and ineffective antibacterial and/or antifungal treatments was administered until the definitive diagnosis. Persistent fever subsided rapidly with nirmatrelvir/ritonavir treatment. Our case highlighted that recurrent COVID-19 infection should be suspected in immunocompromised patients with persistent fever despite negative pharyngeal swabs, and urgent bronchoalveolar lavage fluid testing is necessary. Treatment with nirmatrelvir/ritonavir appeared to be very effective in these patients.

Performance of the Simplified Pulmonary Embolism Severity Index in predicting 30-day mortality after acute pulmonary embolism: Validation from a large-scale cohort.

BACKGROUND: The performance of existing prognostic scores including the simplified Pulmonary Embolism Severity Index (sPESI) for short-term mortality of non-high-risk PE in Chinese population has not been widely validated. METHODS: Non-high-risk patients were included from the prospective cohort of the China pUlmonary Thromboembolism REgistry Study (CURES). The sPESI, RIETE, Geneva, modified FAST, and Bova score were validated. The discriminatory performance was measured by the area under the curve (AUC). We also compared the sensitivity, odds ratio, specificity, positive predictive value and negative predictive value of these scores. RESULTS: A total of 6,873 non-high-risk patients with acute PE were included and 241 (3.5 %) patients died within 30 days. Compared to the Geneva, modified FAST, and Bova score, the AUCs for predicting 30-day death of sPESI and RIETE score were higher at 0.712 (95 % CI, 0.680, 0.743) and 0.723 (95 % CI, 0.691, 0.755) respectively. The sPESI demonstrated the highest sensitivity at 0.809, while the RIETE score, Geneva, Modified FAST and BOVA score showed sensitivities of 0.622, 0.568, 0.477 and 0.502 respectively. A sPESI ⩾1 point was associated with a 4.7-fold increased risk of 30-day all-cause mortality (95 % CI, 3.427, 6.563, p < 0.001), while a RIETE score of ⩾1 point was associated with a 4.5-fold increased risk (95 % CI, 3.127, 6.341, p < 0.001). The Geneva score, modified FAST and Bova score showed inferior performance. CONCLUSIONS: The implementation of the fewer-parameter, easier-to-calculate sPESI in Chinese patients with PE can help to discriminate patients with extremely low risk of short-term mortality for home treatment or early discharge.

Clinical characteristics and mortality predictors among very old patients with pulmonary thromboembolism: a multicenter study report.

BACKGROUND: Clinical characteristics of patients with pulmonary thromboembolism have been described in previous studies. Although very old patients with pulmonary thromboembolism are a special group based on comorbidities and age, they do not receive special attention. OBJECTIVE: This study aims to explore the clinical characteristics and mortality predictors among very old patients with pulmonary thromboembolism in a relatively large population. DESIGN AND PARTICIPANTS: The study included a total of 7438 patients from a national, multicenter, registry study, the China pUlmonary thromboembolism REgistry Study (CURES). Consecutive patients with acute pulmonary thromboembolism were enrolled and were divided into three groups. Comparisons were performed between these three groups in terms of clinical characteristics, comorbidities and in-hospital prognosis. Mortality predictors were analyzed in very old patients with pulmonary embolism. KEY RESULTS: In 7,438 patients with acute pulmonary thromboembolism, 609 patients aged equal to or greater than 80 years (male 354 (58.1%)). There were 2743 patients aged between 65 and 79 years (male 1313 (48%)) and 4095 patients aged younger than 65 years (male 2272 (55.5%)). Patients with advanced age had significantly more comorbidities and worse condition, however, some predisposing factors were more obvious in younger patients with pulmonary thromboembolism. PaO2 < 60 mmHg, eGFR < 60 mL/min/1.73m2, malignancy, anticoagulation as first therapy were mortality predictors for all-cause death in very old patients with pulmonary thromboembolism. The analysis found that younger patients were more likely to have chest pain, hemoptysis (the difference was statistically significant) and dyspnea triad. CONCLUSION: In very old population diagnosed with pulmonary thromboembolism, worse laboratory results, atypical symptoms and physical signs were common. Mortality was very high and comorbid conditions were their features compared to younger patients. PaO2 < 60 mmHg, eGFR < 60 mL/min/1.73m2 and malignancy were positive mortality predictors for all-cause death in very old patients with pulmonary thromboembolism while anticoagulation as first therapy was negative mortality predictors.

Genome-wide association analyses identified novel susceptibility loci for pulmonary embolism among Han Chinese population.

BACKGROUND: A large proportion of pulmonary embolism (PE) heritability remains unexplained, particularly among the East Asian (EAS) population. Our study aims to expand the genetic architecture of PE and reveal more genetic determinants in Han Chinese. METHODS: We conducted the first genome-wide association study (GWAS) of PE in Han Chinese, then performed the GWAS meta-analysis based on the discovery and replication stages. To validate the effect of the risk allele, qPCR and Western blotting experiments were used to investigate possible changes in gene expression. Mendelian randomization (MR) analysis was employed to implicate pathogenic mechanisms, and a polygenic risk score (PRS) for PE risk prediction was generated. RESULTS: After meta-analysis of the discovery dataset (622 cases, 8853 controls) and replication dataset (646 cases, 8810 controls), GWAS identified 3 independent loci associated with PE, including the reported loci FGG rs2066865 (p-value = 3.81 × 10-14), ABO rs582094 (p-value = 1.16 × 10-10) and newly reported locus FABP2 rs1799883 (p-value = 7.59 × 10-17). Previously reported 10 variants were successfully replicated in our cohort. Functional experiments confirmed that FABP2-A163G(rs1799883) promoted the transcription and protein expression of FABP2. Meanwhile, MR analysis revealed that high LDL-C and TC levels were associated with an increased risk of PE. Individuals with the top 10% of PRS had over a fivefold increased risk for PE compared to the general population. CONCLUSIONS: We identified FABP2, related to the transport of long-chain fatty acids, contributing to the risk of PE and provided more evidence for the essential role of metabolic pathways in PE development.

Medications and medical costs for diabetes patients with or without chronic respiratory disease in Beijing, China: A retrospective study.

Aims: The cost of drug regimens prescribed to Chinese patients has not been evaluated. This study aims to evaluate the medical costs and hypoglycemic agents for diabetes mellitus patients with or without chronic respiratory disease in Beijing, and to investigate the changes in the costs and number of antidiabetic medications used for diabetes patients with chronic respiratory disease from 2016 to 2018. Methods: This observational, retrospective study included diabetes patients with outpatient medication records from Beijing Medical Insurance between 2016 and 2018. The medications, including hypoglycemic and nonhypoglycemic drugs, insulin dosage, comorbidities, diabetes-related complications, treatment strategies, and annual medical costs, were recorded. Results: This study included 2,853,036 diabetes patients from 2016 to 2018. About 18.95%-20.53% of patients with chronic respiratory disease were predominantly distributed among those aged 45-84 years (88.7%-89.1%). Diabetes patients with chronic respiratory disease used more medications (4.48 ± 2.41 vs. 3.76 ± 2.33) and had higher total annual drug costs (¥12,286 ± 10,385 vs. ¥9700 ± 9202) to treat more comorbidities (2.52 ± 1.53 vs. 2.05 ± 1.85) than those without chronic respiratory disease (p <.0001, respectively). From 2016 to 2018, diabetes patients with chronic respiratory disease had a 4.2% increase in medication, a 1.9% decrease in comorbidities, and a 5.4% decrease in total annual drug costs. Conclusions: In summary, diabetes patients with chronic respiratory disease had more comorbidities, required more hypoglycemic drugs, and had higher medical costs. During 2016-2018, diabetes patients with chronic respiratory disease used more medications and spent less money on medical care.

LMWHs dosage and outcomes in acute pulmonary embolism with renal insufficiency, an analysis from a large real-world study.

BACKGROUND: Renal function is associated with prognoses for acute pulmonary embolism (PE). OBJECTIVE: To investigate the application of anticoagulants and dosage of LMWH among patients with renal insufficiency (RI), and the association between LWMH dosage and the patients' in-hospital outcomes. METHODS: Adult patients diagnosed with non-high risk acute PE from 2009 to 2015, with available data of creatinine clearance (CCr) were enrolled from a multicenter registry in China. Renal insufficiency (RI) was defined as CCr < 60 ml/min. LMWH dosage was converted into IU/kg daily dose and presented as adjusted dose (≤ 100 IU/kg/day) and conventional dose (> 100 IU/kg/day). All-cause death, PE-related death and bleeding events during hospitalization were analyzed as endpoints. RESULTS: Among the enrolled 5870 patients, RI occurred in 1311 (22.3%). 30 ≤ CCr < 60 ml/min was associated with higher rate of bleeding events and CCr < 30 ml/min was associated with all-cause death, PE-related death and major bleeding. Adjusted-dose LMWH was applied in 26.1% of patients with 30 ≤ CCr < 60 ml/min and in 26.2% of CCr < 30 ml/min patients. Among patients with RI, in-hospital bleeding occurred more frequently in those who were administered conventional dose of LMWH, compared with adjusted dose (9.2% vs 5.0%, p = 0.047). Adjusted dose of LMWH presented as protective factor for in-hospital bleeding (OR 0.62, 95%CI 0.27-1.00, p = 0.0496) and the risk of bleeding increased as length of hospital stay prolonged (OR 1.03, 95%CI 1.01-1.06, p = 0.0014). CONCLUSIONS: The proportion of adjusted usage of LMWH was low. The application of adjusted-dose LMWH was associated with lower risk of in-hospital bleeding for RI patients, in real-world setting of PE treatment. Anticoagulation strategy for RI patients should be paid more attention and requires evidence of high quality. TRIAL REGISTRATION: The CURES was registered in ClinicalTrias.gov, identifier number: NCT02943343 .

Clinical Phenotypes With Prognostic Implications in Pulmonary Embolism Patients With Syncope.

OBJECTIVES: There are conflicting data concerning the prognostic significance of syncope in acute pulmonary embolism (PE). This study aimed to investigate the impact of syncope on clinical outcomes of acute PE, and determine the clinical phenotypes of PE patients with syncope and their correlation with prognosis. METHODS: In the ongoing, national, multicenter, registry study, the China pUlmonary thromboembolism REgistry Study (CURES) enrolling consecutive patients with acute PE, patients with and without syncope were investigated. Principal component analysis (PCA) was performed using nine variables relevant to syncope and PE, including age, sex, body mass index, history of cardiovascular disease, recent surgery or trauma, malignancy, pulse, systolic blood pressure, and respiratory rate. Patient classification was performed using cluster analysis based on the PCA-transformed data. The clinical presentation, disease severity and outcomes were compared among the phenotypes. RESULTS: In 7,438 patients with acute PE, 777 (10.4%) had syncope, with younger age, more females and higher body mass index. Patients with syncope had higher frequency of precordial pain, palpitation, and elevated cardiac biomarkers, as well as higher D-Dimer level. In the syncope group, more patients had right ventricular/left ventricular ratio > 0.9 in ultrasonic cardiogram and these patients had higher estimated pulmonary arterial systolic pressure compared with patients without syncope. As the initial antithrombotic treatment, more patients with syncope received systemic thrombolysis. Despite a higher prevalence of hemodynamic instability (OR 7.626, 95% CI 2.960-19.644, P < 0.001), syncope did not increase in-hospital death. Principal component analysis revealed that four independent components accounted for 60.3% of variance. PE patients with syncope were classified into four phenotypes, in which patients with high pulse and respiratory rate had markedly higher all-cause mortality during admission. CONCLUSION: Syncope was associated with hemodynamic instability and more application of thrombolysis, without increasing in-hospital deaths. Different clinical phenotypes existed in PE patients with syncope, which might be caused by various mechanisms and thus correlated with clinical outcomes.

Characteristics of peripheral white blood cells in COVID-19 patients revealed by a retrospective cohort study.

BACKGROUND: Peripheral hematological changes in severe COVID-19 patients may reflect the immune response during SARS-CoV-2 infection. Characteristics of peripheral white blood cells as early signals were needed to be investigated for clarifying its associations with the fatal outcomes in COVID-19 patients. METHODS: A retrospective cohort study was performed and the hospitalized COVID-19 patients were recruited in wards of Sino-French New City Branch of Tongji Hospital in Wuhan, Hubei province, China. Characteristics of peripheral white blood cells in survivors and non-survivors were analyzed. Comparison among patients with different level of eosinophils was performed. RESULTS: Of 198 patients included in this study, 185 were discharged and 13 died. Levels of eosinophils, lymphocytes and basophils in non-survivors were significantly lower than those in survivors. Death rate in low eosinophils group was higher and no patient died in normal eosinophils group (16.7% vs 0, P < 0.001). The proportion of patients in low eosinophils group who used glucocorticoids was higher than in normal eosinophils group, but glucocorticoids usage was not an indicator for death in subgroup analysis in low eosinophils patients. Moreover, positive correlation was found between the counts of lymphocytes and eosinophils in patients with glucocorticoids use but not in patients without the treatment. CONCLUSIONS: Hematological changes differed between survivors and non-survivors with COVID-19. Lymphopenia and eosinopenia could be predictors for poor prognosis of COVID-19 patients. Initial counts of eosinophils may guide us in usage of glucocorticoids for COVID-19 treatment.

Development of a nomogram for predicting the presence of combined pulmonary fibrosis and emphysema.

BACKGROUND: In the clinical management of patients with combined pulmonary fibrosis and emphysema (CPFE), early recognition and appropriate treatment is essential. This study was designed to develop an accurate prognostic nomogram model to predict the presence of CPFE. METHODS: We retrospectively enrolled 85 patients with CPFE and 128 patients with idiopathic pulmonary fibrosis (IPF) between January 2015 and January 2020. Clinical characteristics were compared between groups. A multivariable logistic regression analysis was performed to identify risk factors for CPFE. Then, and a nomogram to predict the presence of CPFE was constructed for clinical use. Concordance index (C-index), area under the receiver operating characteristic curve (AUC), and calibration plot was used to evaluate the efficiency of the nomogram. RESULTS: Compared to the IPF group, the proportion of patients with male, smoking and allergies were significantly higher in the CPFE group. In terms of pulmonary function tests, patients with CPFE had lower FEV1/FVC%, DLCO/VA% pred, and higher RV, RV%pred, VC, VC%pred, TLC%pred, VA, TLC, TLC%pred, FVC, FVC%pred and FEV1 with significant difference than the other group. Positive correlation was found between DLCO and VA%, RV%, TLC% in patients with IPF but not in patients with CPFE. By multivariate analysis, male, smoking, allergies, FEV1/FVC% and DLCO/VA%pred were identified as independent predictors of the presence of CPFE. The nomogram was then developed using these five variables. After 1000 internal validations of bootstrap resampling, the C-index of the nomogram was 0.863 (95% CI 0.795-0.931) and the AUC was 0.839 (95% CI 0.764-0.913). Moreover, the calibration plot showed good concordance of incidence of CPFE between nomogram prediction and actual observation (Hosmer-Lemeshow test: P = 0.307). CONCLUSIONS: Patients of CPFE have a characteristic lung function profile including relatively preserved lung volumes and ventilating function, contrasting with a disproportionate reduction of carbon monoxide transfer. By incorporating clinical risk factors, we created a nomogram to predict the presence of CPFE, which may serve as a potential tool to guide personalized treatment.

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

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

Research progress on biomarkers of pulmonary embolism.

OBJECTIVES: To present a review on the traditional and new biomarkers of pulmonary embolism (PE). DATA SOURCE: A systematic search has been carried out using keywords as PE, biomarker, diagnosis and risk stratification. RESULTS: The results of this work have been structured into three parts: first, conventional biomarkers for vascular, cardiac and inflammation, including static markers and dynamic markers for measuring the time course; next, a review of new biomarkers in recent years, such as RNAs and markers obtained through proteomics and mass spectrometry; finally, use of new detection methods to directly detect the activity of existing markers, such as the determination of coagulation factor II and plasmin activities based on the proteolytic activation of an engineered zymogen. CONCLUSIONS: This work summarized the characteristics of current traditional biomarkers for clinical diagnosis and risk stratification of PE, as well as a series of newly discovered biomarkers obtained through various clinical experimental methods.

Trends in risk stratification, in-hospital management and mortality of patients with acute pulmonary embolism: an analysis from the China pUlmonary thromboembolism REgistry Study (CURES).

Similar trends of management and in-hospital mortality of acute pulmonary embolism (PE) have been reported in European and American populations. However, these tendencies are not clear in Asian countries. We retrospectively analysed the trends of risk stratification, management and in-hospital mortality for patients with acute PE through a multicentre registry in China (CURES).Adult patients with acute symptomatic PE were included between 2009 and 2015. Trends in disease diagnosis, treatment and death in hospital were fully analysed. Risk stratification was retrospectively classified by haemodynamic status and the simplified Pulmonary Embolism Severity Index (sPESI) score according to the 2014 European Society of Cardiology/European Respiratory Society guidelines.Among 7438 patients, the proportions with high (haemodynamic instability), intermediate (sPESI≥1) and low (sPESI=0) risk were 4.2%, 67.1% and 28.7%, respectively. Computed tomographic pulmonary angiography was the most widely used diagnostic approach (87.6%) and anticoagulation was the most frequently adopted initial therapy (83.7%). Between 2009 and 2015, a significant decline was observed for all-cause mortality (from 3.1% to 1.3%, adjusted pfor trend=0.0003), with a concomitant reduction in the use of initial systemic thrombolysis (from 14.8% to 5.0%, pfor trend<0.0001). The common predictors for all-cause mortality shared by haemodynamically stable and unstable patients were co-existing cancer, older age and impaired renal function.The considerable reduction of mortality over the years was accompanied by changes in initial treatment. These findings highlight the importance of risk stratification-guided management throughout the nation.

Discovery of plasma biomarkers with data-independent acquisition mass spectrometry and antibody microarray for diagnosis and risk stratification of pulmonary embolism.

BACKGROUND: Pulmonary embolism (PE) is a leading cause of cardiovascular mortality worldwide. Rapid and accurate diagnosis and risk stratification are crucial for timely treatment options, especially in high-risk PE. OBJECTIVES: The study aims to profile the comprehensive changes of plasma proteomes in PE patients and identify the potential biomarkers for both diagnosis and risk stratification. PATIENTS/METHODS: Based on the data-independent acquisition mass spectrometry and antibody array proteomic technology, we screened the plasma samples (13 and 32 proteomes, respectively) in two independent studies consisting of high-risk PE patients, non-high-risk PE patients, and healthy controls. Some significantly differentially expressed proteins were quantified by ELISA in a new study group with 50 PE patients and 26 healthy controls. RESULTS: We identified 207 and 70 differentially expressed proteins in PE and high-risk PE. These proteins were involved in multiple thrombosis-associated biological processes including blood coagulation, inflammation, injury, repair, and chemokine-mediated cellular response. It was verified that five proteins including SAA1, S100A8, TNC, GSN, and HRG had significant change in PE and/or in high-risk PE. The receiver operating characteristic curve analysis based on binary logistic regression showed that the area under the curve (AUC) of SAA1, S100A8, and TNC in PE diagnosis were 0.882, 0.788, and 0.795, and AUC of S100A8 and TNC in high-risk PE diagnosis were 0.773 and 0.720. CONCLUSION: As predictors of inflammation or injury repair, SAA1, S100A8, and TNC are potential plasma biomarkers for the diagnosis and risk stratification of PE.

Clinical characteristics and outcome of influenza virus infection among adults hospitalized with severe COVID-19: a retrospective cohort study from Wuhan, China.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is an emerging infectious disease that rapidly spreads worldwide and co-infection of COVID-19 and influenza may occur in some cases. We aimed to describe clinical features and outcomes of severe COVID-19 patients with co-infection of influenza virus. METHODS: Retrospective cohort study was performed and a total of 140 patients with severe COVID-19 were enrolled in designated wards of Sino-French New City Branch of Tongji Hospital between Feb 8th and March 15th in Wuhan city, Hubei province, China. The demographic, clinical features, laboratory indices, treatment and outcomes of these patients were collected. RESULTS: Of 140 severe COVID-19 hospitalized patients, including 73 patients (52.14%) with median age 62 years were influenza virus IgM-positive and 67 patients (47.86%) with median age 66 years were influenza virus IgM-negative. 76 (54.4%) of severe COVID-19 patients were males. Chronic comorbidities consisting mainly of hypertension (45.3%), diabetes (15.8%), chronic respiratory disease (7.2%), cardiovascular disease (5.8%), malignancy (4.3%) and chronic kidney disease (2.2%). Clinical features, including fever (≥38 °C), chill, cough, chest pain, dyspnea, diarrhea and fatigue or myalgia were collected. Fatigue or myalgia was less found in COVID-19 patients with IgM-positive (33.3% vs 50/7%, P = 0.0375). Higher proportion of prolonged activated partial thromboplastin time (APTT) > 42 s was observed in COVID-19 patients with influenza virus IgM-negative (43.8% vs 23.6%, P = 0.0127). Severe COVID-19 Patients with influenza virus IgM positive have a higher cumulative survivor rate than that of patients with influenza virus IgM negative (Log-rank P = 0.0308). Considering age is a potential confounding variable, difference in age was adjusted between different influenza virus IgM status groups, the HR was 0.29 (95% CI, 0.081-1.100). Similarly, difference in gender was adjusted as above, the HR was 0.262 (95% CI, 0.072-0.952) in the COX regression model. CONCLUSIONS: Influenza virus IgM positive may be associated with decreasing in-hospital death.

The dynamic changes of serum IgM and IgG against SARS-CoV-2 in patients with COVID-19.

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a worldwide pandemic since it emerged in December 2019. Previous studies have reported rapid antibody response to SARS-CoV-2 in the first 2 to 3 weeks after symptom onset. Here, we retrospectively described the dynamic changes of serum immunoglobulin M (IgM) and IgG specifically against SARS-CoV-2 in later weeks (mainly 4-10 weeks) in 97 hospitalized patients with COVID-19. We observed that serum IgM and IgG, especially in patients with moderate-to-high levels, declined significantly between week 4 to 10 after illness onset. Notably, IgG levels in high percentage of patients (77.5%, 31 of 40) rapidly declined by half, from 212.5 (range, 163.7-420.3) to 96.3 (range, 75.0-133.4) AU/mL, within 1 to 2 weeks in the second month and then sustained at around 100 AU/mL until discharge from hospital. Significant reduction of IgM was also observed as SARS-CoV-2 nucleic acid turned negative (P = .002). In the recovery stage, serum IgG declined significantly (early vs late recovery stage, n = 16, P = .003) with a median reduction of 50.0% (range, 3.7%-77.0%). Our results suggested that the decline of IgM may be an indicator of virus clearance and recovered patients may have a robust immunity against reinfection within at least 3 months after illness onset. Yet, the rapid reduction of IgG by half rises serious concerns on the robustness and sustainability of the humoral immune response in the period after discharge, which is crucial for immunity strategy and developing a vaccine.

Comparative Genome Analysis Reveals the Molecular Basis of Niche Adaptation of Staphylococcus epidermidis Strains.

Staphylococcus epidermidis is one of the most commonly isolated species from human skin and the second leading cause of bloodstream infections. Here, we performed a large-scale comparative study without any pre-assigned reference to identify genomic determinants associated with the diversity and adaptation of S. epidermidis strains to various environments. Pan-genome of S. epidermidis was open with 435 core proteins and had a pan-genome size of 8,034 proteins. Genome-wide phylogenetic tree showed high heterogeneity and suggested that routine whole genome sequencing was a powerful tool for analyzing the complex evolution of S. epidermidis and for investigating the infection sources. Comparative genome analyses demonstrated a range of antimicrobial resistance (AMR) genes, especially those within mobile genetic elements. The complicated host-bacterium and bacterium-bacterium relationships help S. epidermidis to play a vital role in balancing the epithelial microflora. The highly variable and dynamic nature of the S. epidermidis genome may contribute to its success in adapting to broad habitats. Genes related to biofilm formation and cell toxicity were significantly enriched in the blood and skin, demonstrating their potentials in identifying risk genotypes. This study gave a general landscape of S. epidermidis pan-genome and provided valuable insights into mechanisms for genome evolution and lifestyle adaptation of this ecologically flexible species.

Rational and design of the China Pulmonary Thromboembolism Registry Study (CURES): A prospective multicenter registry.

BACKGROUND: Epidemiological data on pulmonary embolism (PE) in China needs to be updated and reported. The China Pulmonary Thromboembolism Registry Study (CURES) is designed to provide the cross-sectional spectrum and chronological trends of PE in China, as well as to reveal the intrinsic etiology and pathogenesis of the disease. METHODS AND DESIGN: The CURES is an ongoing large prospective multicenter registry, which was originally initiated in January 2009 via enrolling suspected or confirmed PE or PE with DVT (deep venous thrombosis) patients and assessed their in-hospital outcomes. As of July 2011, in order to determine the PE-relevant short-term outcomes, enrolled participants were followed-up for at least three months in a longitudinal manner. Since August 2016, with the launch and development of precision medicine research scheme in China, the main principle investigators of CURES decided to collect enrolled patients' blood samples with regular follow-ups every three or six months for at least two years (for long-term outcomes). Up to 31 December 2019, the CURES has enrolled 14,937 eligible patients and collected 1500 blood samples of patients from 100 medical centers in the China PE-DVT network. The study protocol has been approved by the China-Japan Friendship Hospital ethics committee, and all collaborating centers received approvals from their local ethics committee. All patients provided written or verbal informed consent to their participation. CONCLUSIONS: Findings of the CURES will be valuable for revealing the natural history of PE, and facilitating better disease management in China. Registration Number inClinicalTrials.gov:NCT02943343.

Direct Determination of Coagulation Factor IIa and Plasmin Activities for Monitoring of Thrombotic State.

BACKGROUND: Current laboratory examinations for hypercoagulable diseases focus on the biomarker content of the activated coagulation cascade and fibrinolytic system. Direct detection of physiologically important protease activities in blood remains a challenge. This study aims to develop a general approach that enables the determination of activities of crucial coagulation factors and plasmin in blood. METHODS: This assay is based on the proteolytic activation of an engineered zymogen of l-phenylalanine oxidase (proPAO), for which the specific blood protease cleavage sites were engineered between the inhibitory and activity domains of proPAO. Specific cleavage of the recombinant proenzyme leads to the activation of proPAO, followed by oxidation and oxygenation of l-phenylalanine, resulting in an increase of chromogenic production when coupled with the Trinder reaction. RESULTS: We applied this method to determine the activities of both coagulation factor IIa and plasmin in their physiologically relevant basal state and fully activated state in sodium citrate-anticoagulated plasma respectively. Factor IIa and plasmin activities could be dynamically monitored in patients with thrombotic disease who were taking oral anticoagulants and used for assessing the hypercoagulable state in pregnant women. CONCLUSIONS: The high specificity, sensitivity, and stability of this novel assay not only makes it useful for determining clinically important protease activities in human blood and diagnosing thrombotic diseases but also provides a new way to monitor the effectiveness and safety of anticoagulant drugs.

Coagulopathy in elderly patients with coronavirus disease 2019.

BACKGROUND: Since the outbreak of coronavirus disease 2019 (COVID-19), clinical features have been analyzed in detail. However, coagulopathy in elderly COVID-19 patients has been scarcely reported. METHODS: Coagulation parameters of 189 patients with COVID-19 in Tongji hospital were retrospectively analyzed among age groups. RESULTS: Patients were divided into 2 groups: older group (≥65 years, n = 87) and younger group (<65 years, n = 102). The proportion of patients with elevated fibrinogen (79.0% vs 59.6%, p = .005) and D-dimer (78.0% vs 55.2%, p = .001) shows the significant difference between the groups. The elderly patients revealed significantly longer prothrombin time (14.0 [13.4-14.4]s vs 13.6 [13.2-14.1]s, p = .026), higher D-dimer (1.00 [0.5-1.9] µg/mL vs 0.6 [0.3-1.6] µg/mL, p = .013) and fibrinogen (5.2 [4.1-6.2] g/L vs 4.4 [3.4-5.7] g/L, p = .004) levels, compared to the younger group. A positive correlation was observed between the coagulation parameters and inflammatory markers including high-sensitivity C-reactive protein and interleukin-6 (p < .05). CONCLUSIONS: The hypercoagulable state is more common in elderly COVID-19 patients, and coagulopathy is associated with excessive systemic inflammation.

The predictive value of PaO2/FIO2 and additional parameters for in-hospital mortality in patients with acute pulmonary embolism: an 8-year prospective observational single-center cohort study.

BACKGROUND: Rapid stratification and appropriate treatment on admission are critical to saving lives of patients with acute pulmonary embolism (PE). None of the clinical prediction tools perform well when applied to all patients with acute PE. It may be important to integrate respiratory features into the 2014 European Society of Cardiology model. First, we aimed to assess the relationship between the arterial partial pressure of oxygen/fraction of inspired oxygen (PaO2/FIO2) ratio and in-hospital mortality, determine the optimal cutoff value of PaO2/FIO2, and determine if this value, which is quick and easy to obtain on admission, is a predictor of in-hospital mortality in this population. Second, we aimed to evaluate the potential additional determinants including laboratory parameters that may affect the in-hospital mortality. We hypothesized that the PaO2/FiO2 ratio would be a clinical prediction tool for in-hospital mortality in patients with acute PE. METHODS: A prospective single-center observational cohort study was conducted in Beijing Hospital from January 2010 to November 2017. Arterial blood gas analysis data captured on admission, clinical characteristics, risk factors, laboratory data, imaging findings, and in-hospital mortality were compared between survivors and non-survivors. The area under the receiver operating characteristic curve (AUC) for in-hospital mortality based on the PaO2/FiO2 value was determined, and the association between the parameters and in-hospital mortality was analyzed by using logistic regression analysis. RESULTS: Body mass index, history of cancer, PaO2/FiO2 value, pulse rate, cardiac troponin I level, lactate dehydrogenase level, white blood cell count, D-dimer level, and risk stratification measurements differed between survivors and non-survivors. The optimal cutoff value of PaO2/FiO2 for predicting mortality was 265 (AUC = 0.765, P < 0.001). Only a PaO2/FiO2 ratio < 265 (95% confidence interval [CI] 1.823-21.483, P = 0.004), history of cancer (95% CI 1.161-15.927, P = 0.029), and risk stratification (95% CI 1.047-16.957, P = 0.043) continued to be associated with an increased risk of in-hospital mortality of acute PE. CONCLUSION: A simple determination of the PaO2/FiO2 ratio at <265 may provide important information on admission about patients' in-hospital prognosis, and PaO2/FiO2 ratio < 265, history of cancer, and risk stratification are predictors of in-hospital mortality of acute PE.