Clinical validation of a multiplex droplet digital PCR for diagnosing suspected bloodstream infections in ICU practice: a promising diagnostic tool

Background

Droplet digital PCR (ddPCR) has emerged as a promising tool of pathogen detection in bloodstream infections (BSIs) in critical care medicine. However, different ddPCR platforms have variable sensitivity and specificity for diverse microorganisms at various infection sites. There is still a lack of prospective clinical studies aimed at validating and interpreting the discrepant ddPCR results for diagnosing BSI in intensive care unit (ICU) practice.

Methods

A prospective diagnostic study of multiplex ddPCR panels was conducted in a general ICU from May 21, 2021, to December 22, 2021. Paired blood cultures (BCs) and ddPCRs (2.5 h) were obtained synchronously to detect the 12 most common BSI pathogens and three antimicrobial resistance (AMR) genes. Firstly, ddPCR performance was compared to definite BSI. Secondly, clinical validation of ddPCR was compared to composite clinical diagnosis. Sensitivity, specificity, and positive and negative predictive values were calculated. Thirdly, the positive rate of AMR genes and related analysis was presented.

Results

A total of 438 episodes of suspected BSIs occurring in 150 critical patients were enrolled. BC and ddPCR were positive for targeted bacteria in 40 (9.1%) and 180 (41.1%) cases, respectively. There were 280 concordant and 158 discordant. In comparison with BCs, the sensitivity of ddPCR ranged from 58.8 to 86.7% with an aggregate of 72.5% in different species, with corresponding specificity ranging from 73.5 to 92.2% with an aggregate of 63.1%. Furthermore, the rate of ddPCR+/BC− results was 33.6% (147/438) with 87.1% (128 of 147) cases was associated with probable (n = 108) or possible (n = 20) BSIs. When clinically diagnosed BSI was used as true positive, the final sensitivity and specificity of ddPCR increased to 84.9% and 92.5%, respectively. In addition, 40 blaKPC, 3blaNDM, and 38 mecA genes were detected, among which 90.5% were definitely positive for blaKPC. Further, 65.8% specimens were predicted to be mecA-positive in Staphylococcus sp. according to all microbiological analysis.

Conclusions

The multiplexed ddPCR is a flexible and universal platform, which can be used as an add-on complementary to conventional BC. When combined with clinical infection evidence, ddPCR shows potential advantages for rapidly diagnosing suspected BSIs and AMR genes in ICU practice.

A trial of arbidol hydrochloride in adults with COVID-19

BACKGROUND

To date, there is no effective medicine to treat coronavirus disease 2019 (COVID-19), and the antiviral efficacy of arbidol in the treatment for COVID-19 remained equivocal and controversial. The purpose of this study was to evaluate the efficacy and safety of arbidol tablets in the treatment of COVID-19.

METHODS

This was a prospective, open-label, controlled and multicenter investigator-initiated trial involving adult patients with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Patients were stratified 1:2 to either standard-of-care (SOC) or SOC plus arbidol tablets (oral administration of 200 mg per time, three times a day for 14 days). The primary endpoint was negative conversion of SARS-CoV-2 within the first week. The rates and 95% confidential intervals were calculated for each variable.

RESULTS

A total of 99 patients with laboratory-confirmed SARS-CoV-2 infection were enrolled; 66 were assigned to the SOC plus arbidol tablets group, and 33 to the SOC group. The negative conversion rate of SARS-CoV-2 within the first week in patients receiving arbidol tablets was significantly higher than that of the SOC group (70.3% [45/64] vs. 42.4% [14/33]; difference of conversion rate 27.9%; 95% confidence interval [CI], 7.7%-48.1%; P  = 0.008). Compared to those in the SOC group, patients receiving arbidol tablets had a shorter duration of clinical recovery (median 7.0 days vs. 12.0 days; hazard ratio [HR]: 1.877, 95% CI: 1.151-3.060, P = 0.006), symptom of fever (median 3.0 days vs. 12.0 days; HR: 18.990, 95% CI: 5.350-67.410, P < 0.001), as well as hospitalization (median 12.5 days vs. 20.0 days; P < 0.001). Moreover, the addition of arbidol tablets to SOC led to more rapid normalization of declined blood lymphocytes (median 10.0 days vs. 14.5 days; P > 0.05). The most common adverse event in the arbidol tablets group was the elevation of transaminase (5/200, 2.5%), and no one withdrew from the study due to adverse events or disease progression.

CONCLUSIONS

SOC plus arbidol tablets significantly increase the negative conversion rate of SARS-CoV-2 within the first week anas, accelerate the recovery of COVID-19 patients. During the treatment with arbidol tablets, we find no significant serious adverse events.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, NCT04260594, www.clinicaltrials.gov/ct2/show/NCT04260594?term=NCT04260594&draw=2&rank=1.

Update March 2022: management of hospitalised adults with coronavirus disease-19 (COVID-19): a European Respiratory Society living guideline

Since the identification of SARS-CoV-2 at the end of 2019, the coronavirus disease 2019 (COVID-19) pandemic has affected more than 410 million people worldwide and killed almost 6 million [1, 2]. The predecessors of COVID-19, i.e. the SARS (severe acute respiratory syndrome) and MERS (Middle East respiratory syndrome) outbreaks, had been relatively self-limiting, preventing clinicians and researchers from establishing evidence-based specific therapeutic strategies [3]. Conversely, COVID-19 rapidly proved to be extremely fast spreading, which led stakeholders to encourage, guide, build or fund multidirectional therapeutic research strategies based on both repurposing and development of new agents [4–8]. In parallel, considerable efforts were directed at describing the disease and understanding the underlying mechanisms [9–13]. As a result, there has been a huge generation of evidence, as highlighted by the impressive number of COVID-19 publications (more than 200 000 since the end of 2019). As a consequence, it proved rapidly impossible for any clinician, researcher or decision-maker to gather and analyse all the corresponding literature to derive appropriate guidance [14]. The first step of such a process is to select the relevant high-quality research that can be used to answer the question(s) of interest [15]. Even if limiting the search to clinical trials, systematic reviews and meta-analyses, almost 4000 papers appear in the PubMed database, as of mid-February 2022. In June and July 2020, the European Respiratory Society (ERS) and the American Thoracic Society (ATS) released early guidance on several aspects of COVID-19 management (i.e. rehabilitation, palliative care and acute management); at that time, direct specific evidence was sparse or absent [16–18]. Simultaneously, the ERS launched a living guideline on the management of COVID-19. The format was that of a “short” guideline, as per ERS standards [19, 20], in that the purpose was to release the first iteration within 12 months. However, the number of PICO (Population, Intervention, Comparator, Outcomes) questions to be addressed (n=12) already exceeded markedly what the ERS considers as being feasible during such a short timeframe (i.e. n=1–2), which was a direct consequence of the high number of unanswered issues in the field of acute COVID-19 management, all corresponding to outstanding clinical needs. The first version of these guidelines was published in March 2021 and addressed the following potential therapeutic options: corticosteroids, interleukin (IL)-6 receptor antagonists, hydroxychloroquine, azithromycin and both combined, colchicine, lopinavir-ritonavir, remdesivir, interferon-β, anticoagulation and non-invasive ventilatory support [6, 21]. An update of the mortality meta-analyses for corticosteroids, hydroxychloroquine, azithromycin, remdesivir, anti-IL-6 monoclonal antibodies, colchicine, lopinavir/ritonavir and interferon-β was published in December 2021 [22].

The ERS COVID-19 guidelines make recommendations for corticosteroids, anti-IL-6 monoclonal antibodies, baricitinib, anticoagulation and non-invasive respiratory support for hospitalised patients with COVID-19 https://bit.ly/3QgHH7U

Soluble Immune-Related Proteins as New Candidate Serum Biomarkers for the Diagnosis and Progression of Lymphangioleiomyomatosis

Background

The goal of this study was to analyze serum from lymphangioleiomyomatosis (LAM) patients and healthy controls to identify novel biomarkers that could shed light on disease diagnosis and pathogenesis.

Methods

From April 2017 to October 2019, qualified serum samples were obtained to explore differences in 59 immune proteins between 67 LAM patients and 49 healthy controls by the Luminex method.

Results

We characterized 22 serum immune proteins that were differentially expressed in LAM patients compared with healthy people. Fifty-nine proteins were then classified into eight categories according to their biological function, and the results showed that LAM patients displayed significantly higher levels of growth factors (p = 0.006) and lower levels of costimulatory molecules (p = 0.008). LAG-3 was not only likely to have better predictive value than VEGF-D but also showed a significant difference between patients without elevated VEGF-D and healthy people. IL-18 was positively correlated with lung function and six-minute walk test (6MWT) distance and negatively correlated with St. George’s Respiratory Questionnaire (SGRQ) score and pulmonary artery systolic pressure (PASP), which suggested that IL-18 was related to disease severity. PD-1 was significantly different between patients with pneumothorax and/or chylothorax and those without complications.

Conclusion

We performed a large-scale serum immune factor analysis of LAM. Our study provides evidence that LAG-3 may be a novel candidate serum biomarker for the diagnosis of LAM. Future independent validation in prospective studies is warranted.

Neutralizing activity of BBIBP-CorV vaccine-elicited sera against Beta, Delta and other SARS-CoV-2 variants of concern

The global pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in the generation of variants that may diminish host immune responses to vaccine formulations. Here we show a registered observational clinical trial (NCT04795414), we assess the safety and immunogenicity of the inactivated SARS-CoV-2 vaccine BBIBP-CorV in a cohort of 1006 vaccine recipients. No serious adverse events are observed during the term of the study. Detectable virus-specific antibody is measured and determined to be neutralizing in 698/760 (91.84%) vaccine recipients on day 28 post second vaccine dose and in 220/581 (37.87%) vaccine recipients on day 180 post second vaccine dose, whereas vaccine-elicited sera show varying degrees of reduction in neutralization against a range of key SARS-CoV-2 variants, including variant Alpha, Beta, Gamma, Iota, and Delta. Our work show diminished neutralization potency against multiple variants in vaccine-elicited sera, which indicates the potential need for additional boost vaccinations.

Variants of SARS-CoV-2 present the potential for differential response and performance to delivered vaccine regimens. Here the authors characterise the neutralising antibody response to the inactivated SARS-CoV-2 vaccine BBIBP-CorV and assess functionality against a range of key SARS-CoV2 variants.

Research advances and clinical management of bronchiectasis: Chinese perspective

Bronchiectasis is a debilitating chronic suppurative airway disease that confers a substantial burden globally. Despite the notable prevalence, research on bronchiectasis in mainland China remains in its infancy. Nevertheless, there has been a significant leap in the quantity and quality of research, which has contributed to the ever-improving clinical practice. A nationwide collaborative platform has been established to foster multicentre studies, which will help increase the level of evidence further. Here, we summarise the status quo of clinical management and consider the research priorities for bronchiectasis that have been published previously. We also highlight the efforts of the Chinese medical communities to outline the core tasks that need to be addressed within the next decade.

The remarkable progress made in bronchiectasis research has revolutionised clinical practice in mainland Chinahttps://bit.ly/3K8kQYr

Development of Loop-Mediated Isothermal Amplification Rapid Diagnostic Assays for the Detection of Klebsiella pneumoniae and Carbapenemase Genes in Clinical Samples

Klebsiella pneumoniae is an important pathogenic bacterium commonly associated with human healthcare and community-acquired infections. In recent years, K. pneumoniae has become a significant threat to global public and veterinary health, because of its high rates of antimicrobial resistance (AMR). Early diagnosis of K. pneumoniae infection and detection of any associated AMR would help to accelerate directed therapy and reduce the risk of the emergence of multidrug-resistant isolates. In this study, we identified three target genes (yhaI, epsL, and xcpW) common to K. pneumoniae isolates from both China and Europe and designed loop-mediated isothermal amplification (LAMP) assays for the detection of K. pneumoniae in clinical samples. We also designed LAMP assays for the detection of five AMR genes commonly associated with K. pneumoniae. The LAMP assays were validated on a total of 319 type reference strains and clinical isolates of diverse genetic backgrounds, in addition to 40 clinical human sputum samples, and were shown to be reliable, highly specific, and sensitive. For the K. pneumoniae–specific LAMP assay, the calculated sensitivity, specificity, and positive and negative predictive values (comparison with culture and matrix-assisted laser desorption/ionization–time of flight mass spectrometry) were all 100% on clinical isolates and, respectively, of 100%, 91%, and 90%, and 100% when tested on clinical sputum samples, while being significantly faster than the reference methods. For the bla_KPC and other carbapenemases’ LAMP assays, the concordance between the LAMP results and the references methods (susceptibility tests) was 100%, on both pure cultures (n = 125) and clinical samples (n = 18). In conclusion, we developed highly sensitive and specific LAMP assays for the clinical identification of K. pneumoniae and detection of carbapenem resistance.

Etiology of Severe Community Acquired Pneumonia in Adults Identified by Combined Detection Methods: A Multi-center Prospective Study in China

Severe Community Acquired Pneumonia (SCAP) challenges public health globally. Considerable improvements in molecular pathogen testing emerged in the last few years. Our prospective study combinedly used traditional culture, antigen tests, PCR and mNGS in SCAP pathogen identification with clinical outcomes. From June 2018 to December 2019, we conducted a multi-centre prospective study in 17 hospitals of SCAP patients within 48 hours of emergency room stay or hospitalization in China. All clinical data were uploaded into an online database. Blood, urine and respiratory specimens were collected for routine culture, antigen detection, PCR and mNGS as designed appropriately. Aetiology confirmation was made by the local attending physician group and scientific committee according to microbiological results, clinical features, and response to the treatment. Two hundred seventy-five patients were included for final analysis. Combined detection methods made identification rate up to 74.2% (222/299), while 14.4% (43/299) when only using routine cultures and 40.8% (122/299) when not using mNGS. Influenza virus (23.2%, 46/198), S. pneumoniae (19.6%, 39/198), Enterobacteriaceae (14.6%, 29/198), Legionella pneumophila (12.6%, 25/198), Mycoplasma pneumoniae (11.1%, 22/198) were the top five common pathogens. The in-hospital mortality of patients with pathogen identified and unidentified was 21.7% (43/198) and 25.9% (20/77), respectively. In conclusion, early combined detection increased the pathogen identification rate and possibly benefitted survival. Influenza virus, S. pneumoniae, Enterobacteriaceae was the leading cause of SCAP in China, and there was a clear seasonal distribution pattern of influenza viruses. Physicians should be aware of the emergence of uncommon pathogens, including Chlamydia Psittaci and Leptospira.

[Update on COVID-19 in 2021]

The novel coronavirus disease 2019(COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has developed into a pandemic. SARS-CoV-2 is highly contagious, and is associated with high mortality. Some SARS-CoV-2 mutants are reported to be highly transmissible and pathogenic, and even have the potential to escape immune response. Distinct immune signatures exist between symptomatic and asymptomatic COVID-19 patients. Clinical characteristics of COVID-19 patients vary by age group. Currently, there are no proven effective therapeutics for COVID-19 and therefore controlling the spread of COVID-19 relies on the inoculation of vaccines, such as nucleic vaccines, inactivated vaccines, viral vector vaccines and protein vaccines. Here we summarized the progresses on the variants, clinical characteristics, treatments and vaccines for COVID-19.

CD69 mediates the protective role of adipose tissue-derived mesenchymal stem cells against Pseudomonas aeruginosa pulmonary infection

BACKGROUND

Our previous study shows that Adipose tissue-derived mesenchymal stem cells (ASCs) are a promising strategy for cell-based therapy against pulmonary infection with Pseudomonas aeruginosa (P. aeruginosa), but the underlying mechanisms remain unclear.

METHODS

cDNA microarray assay was performed to explore the transcriptome of ASCs primed by P. aeruginosa. Small interfering RNA (siRNA) was constructed to select the receptor candidates for P. aeruginosa recognition and granulocyte-macrophage colony-stimulating factor (GM-CSF) production in ASCs. The soluble protein chimeras containing the extracellular domain of human CD69 fused to the Fc region of human immunoglobulin IgG1 were used as a probe to validate the recognition of P. aeruginosa. The association between CD69 and extracellular regulated protein kinases 1/2 (ERK1/2) was explored via co-immunoprecipitation, siRNA, and inhibitor. The murine models of P. aeruginosa pneumonia treated with WT-ASCs, GM-CSF-/- -ASCs Cd69-/- -ASCs or Erk1-/- -ASCs were used to determine the role of GM-CSF, CD69, and ERK1 in ASCs against P. aeruginosa infection.

RESULTS

We showed that C-type lectin receptor CD69 mediated the protective effects of ASCs partly through GM-CSF. CD69 could specifically recognize P. aeruginosa and regulate GM-CSF secretion of ASCs. CD69 regulated the production of GM-CSF via ERK1 in ASCs after P. aeruginosa infection. Moreover, the Administration of ASCs with deficiency of CD69 or ERK1 completely blocked its protective effects in a murine model of P. aeruginosa pneumonia.

CONCLUSIONS

CD69 recognizes P. aeruginosa and further facilitates ERK1 activation, which plays a crucial role in ASCs-based therapy against P. aeruginosa pneumonia. CD69 may be a novel target molecule to improve ASCs-based therapy against P. aeruginosa infection.

[Venous thromboembolism risk and prophylaxis status of cancer inpatient]

Objective: To determine the risk profile of venous thromboembolism (VTE) and evaluate VTE prophylaxis implementation of the hospitalized cancer patients in the DissolVE 2 study. Methods: The data of hospitalized cancer patients in the DissolVE 2 study were analyzed. The risk distribution of VTE, preventive measures and in-hospital VTE events of hospitalized patients with tumors were described by percentage and 95% confident interval (CI). Results: A total of 1 535 cancer patients were included. According to the Padua score, 826 (53.8%) patients were at low risk of VTE, while 709 (46.2%) patients were at high VTE risk. VTE events occurred in 4 low-risk patients (0.5%; 95%CI: 0.1%, 1.2%) and 5 high-risk patients (0.7%; 95%CI: 0.2%, 1.6%). The overall incidence was 0.6% (9/1 535, 95%CI: 0.3%, 1.1%). Among patients with high VTE risk, 666 (93.9%) did not receive any VTE prophylaxis, and only 11 (1.6%) patients received appropriate VTE prophylaxis. Among patients who received VTE prevention, no VTE event was observed. Conclusions: Nearly half of the hospitalized cancer patients are at high risk of VTE, but most of them don't receive VTE prophylaxis. The results reflect the insufficient management of VTE risk for hospitalized cancer patients in China, and improvement of awareness and practice of VTE prophylaxis is urgently needed.

Surfaceome CRISPR screen identifies OLFML3 as a rhinovirus-inducible IFN antagonist

Background

Rhinoviruses (RVs) cause more than half of common colds and, in some cases, more severe diseases. Functional genomics analyses of RVs using siRNA or genome-wide CRISPR screen uncovered a limited set of host factors, few of which have proven clinical relevance.

Results

Herein, we systematically compare genome-wide CRISPR screen and surface protein-focused CRISPR screen, referred to as surfaceome CRISPR screen, for their efficiencies in identifying RV host factors. We find that surfaceome screen outperforms the genome-wide screen in the success rate of hit identification. Importantly, using the surfaceome screen, we identify olfactomedin-like 3 (OLFML3) as a novel host factor of RV serotypes A and B, including a clinical isolate. We find that OLFML3 is a RV-inducible suppressor of the innate immune response and that OLFML3 antagonizes type I interferon (IFN) signaling in a SOCS3-dependent manner.

Conclusion

Our study suggests that RV-induced OLFML3 expression is an important mechanism for RV to hijack the immune system and underscores surfaceome CRISPR screen in identifying viral host factors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13059-021-02513-w.

Distinct immune signatures discriminate between asymptomatic and presymptomatic SARS-CoV-2pos subjects

Increasing numbers of SARS-CoV-2-positive (SARS-CoV-2^pos) subjects are detected at silent SARS-CoV-2 infection stage (SSIS). Yet, SSIS represents a poorly examined time-window wherein unknown immunity patterns may contribute to the fate determination towards persistently asymptomatic or overt disease. Here, we retrieved blood samples from 19 asymptomatic and 12 presymptomatic SARS-CoV-2^pos subjects, 47 age/gender-matched patients with mild or moderate COVID-19 and 27 normal subjects, and interrogated them with combined assays of 44-plex CyTOF, RNA-seq and Olink. Notably, both asymptomatic and presymptomatic subjects exhibited numerous readily detectable immunological alterations, while certain parameters including more severely decreased frequencies of CD107a^low classical monocytes, intermediate monocytes, non-classical monocytes and CD62L^hi CD8⁺ T_naïve cells, reduced plasma STC1 level but an increased frequency of CD4⁺ NKT cells combined to distinguish the latter. Intercorrelation analyses revealed a particular presymptomatic immunotype mainly manifesting as monocytic overactivation and differentiation blockage, a likely lymphocyte exhaustion and immunosuppression, yielding mechanistic insights into SSIS fate determination, which could potentially improve SARS-CoV-2 management.

A New Prognostic Index PDPI for the Risk of Pneumonia Among Patients With Diabetes

Objective

Risk factors for the development of pneumonia among patients with diabetes mellitus are unclear. The aim of our study was to elucidate the potential risk factors and attempt to predict the probability of pneumonia based on the history of diabetes.

Methods

We performed a population-based, prospective multicenter cohort study of 1,043 adult patients with diabetes in China during 2017–2019. Demographic information, comorbidities, or laboratory examinations were collected.

Results

The study included 417 diabetic patients with pneumonia and 626 no-pneumonia-onset diabetic patients. The predictive risk factors were chosen on the basis of a multivariate logistic regression model to predict pneumonia among patients with diabetes including male sex [odds ratio (OR) = 1.72, 95% confidence interval (CI): 1.27–2.33, p < 0.001], age ≥ 75 years (OR = 2.31, 95% CI: 1.61–3.31, p < 0.001), body mass index < 25 (OR = 2.59, 95% CI: 1.92–3.50, p < 0.001), chronic obstructive pulmonary disease (OR = 6.58, 95% CI: 2.09–20.7, p = 0.001), hypertension (OR = 4.27, 95% CI: 3.12–5.85, p < 0.001), coronary heart disease (OR = 2.98, 95% CI: 1.61–5.52, p < 0.001), renal failure (OR = 1.82, 95% CI: 1.002–3.29, p = 0.049), cancer (OR = 3.57, 95% CI: 1.80–7.06, p < 0.001), use of insulin (OR = 2.28, 95% CI: 1.60–3.25, p < 0.001), and hemoglobin A1c ≥ 9% (OR = 2.70, 95% CI: 1.89–3.85, p < 0.001). A predictive nomogram was established. This model showed c-statistics of 0.811, and sensitivity and specificity were 0.717 and 0.780, respectively, under cut-off of 125 score.

Conclusion

We designed a clinically predictive tool for assessing the risk of pneumonia among adult patients with diabetes. This tool stratifies patients into relevant risk categories and may provide a basis for individually tailored intervention for the purpose of early prevention.

Inactivated SARS-CoV-2 vaccine does not influence the profile of prothrombotic antibody nor increase the risk of thrombosis in a prospective Chinese cohort

The presence of antiphospholipid antibodies was shown to be associated with thrombosis in coronavirus disease 2019 (COVID-19) patients. Recently, according to reports from several studies, the vaccine-induced immune thrombotic thrombocytopenia is mediated by anti-platelet factor 4 (PF4)-polyanion complex in adenovirus-vectored COVID-19 vaccine recipients. It is impendent to explore whether inactivated COVID-19 vaccine widely used in China influences prothrombotic autoantibody production and induces thrombosis. In this prospective study, we recruited 406 healthcare workers who received two doses, 21 days apart, of inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine (BBIBP-CorV, Sinopharm). Paired blood samples taken before vaccination and four weeks after the second vaccination were used in detecting prothrombotic autoantibodies, including anticardiolipin (aCL), anti-β2 glycoprotein I (aβ2GP1), anti-phosphatidylserine/prothrombin (aPS/PT), and anti-PF4-heparin. The seroconversion rate of SARS-CoV-2 specific antibodies was 95.81% (389/406) four weeks after vaccination. None of the subjects had spontaneous thrombosis or thrombocytopenia over a minimum follow-up period of eight weeks. There was no significant difference in the presence of all ten autoantibodies between samples collected before and after vaccination: for aCL, IgG (7 vs. 8, P = 0.76), IgM (41 vs. 44, P = 0.73), IgA (4 vs. 4, P = 1.00); anti-β2GP1, IgG (7 vs. 6, P = 0.78), IgM (6 vs. 5, P = 0.76), IgA (3 vs. 5, P = 0.72); aPS/PT IgG (0 vs. 0, P = 1.00), IgM (6 vs. 5, P = 0.76); aPF4-heparin (2 vs. 7, P = 0.18), and antinuclear antibody (ANA) (18 vs. 21, P = 0.62). Notably, seven cases presented with anti-PF4-heparin antibodies (range: 1.18–1.79 U/mL) after vaccination, and none of them exhibited any sign of thrombotic disorder. In conclusion, inactivated SARS-CoV-2 vaccine does not influence the profile of antiphospholipid antibody and anti-PF4-heparin antibody nor increase the risk of thrombosis.

Mobilization of the nonconjugative virulence plasmid from hypervirulent Klebsiella pneumoniae

Background

Klebsiella pneumoniae, as a global priority pathogen, is well known for its capability of acquiring mobile genetic elements that carry resistance and/or virulence genes. Its virulence plasmid, previously deemed nonconjugative and restricted within hypervirulent K. pneumoniae (hvKP), has disseminated into classic K. pneumoniae (cKP), particularly carbapenem-resistant K. pneumoniae (CRKP), which poses alarming challenges to public health. However, the mechanism underlying its transfer from hvKP to CRKP is unclear.

Methods

A total of 28 sequence type (ST) 11 bloodstream infection-causing CRKP strains were collected from Ruijin Hospital in Shanghai, China, and used as recipients in conjugation assays. Transconjugants obtained from conjugation assays were confirmed by XbaI and S1 nuclease pulsed-field gel electrophoresis, PCR detection and/or whole-genome sequencing. The plasmid stability of the transconjugants was evaluated by serial culture. Genetically modified strains and constructed mimic virulence plasmids were employed to investigate the mechanisms underlying mobilization. The level of extracellular polysaccharides was measured by mucoviscosity assays and uronic acid quantification. An in silico analysis of 2608 plasmids derived from 814 completely sequenced K. pneumoniae strains available in GenBank was performed to investigate the distribution of putative helper plasmids and mobilizable virulence plasmids.

Results

A nonconjugative virulence plasmid was mobilized by the conjugative plasmid belonging to incompatibility group F (IncF) from the hvKP strain into ST11 CRKP strains under low extracellular polysaccharide-producing conditions or by employing intermediate E. coli strains. The virulence plasmid was mobilized via four modes: transfer alone, cotransfer with the conjugative IncF plasmid, hybrid plasmid formation due to two rounds of single-strand exchanges at specific 28-bp fusion sites or homologous recombination. According to the in silico analysis, 31.8% (242) of the putative helper plasmids and 98.8% (84/85) of the virulence plasmids carry the 28-bp fusion site. All virulence plasmids carry the origin of the transfer site.

Conclusions

The nonconjugative virulence plasmid in ST11 CRKP strains is putatively mobilized from hvKP or E. coli intermediates with the help of conjugative IncF plasmids. Our findings emphasize the importance of raising public awareness of the rapid dissemination of virulence plasmids and the consistent emergence of hypervirulent carbapenem-resistant K. pneumoniae (hv-CRKP) strains.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13073-021-00936-5.

Psychological Impact During the First Outbreak of COVID-19 on Frontline Health Care Workers in Shanghai

Background: The COVID-19 pandemic is a significant health threat. Health care worker (HCWs) are at a significant risk of infection which may cause high levels of psychological distress. The aim of this study was to investigate the psychological impact of the COVID-19 on HCWs and factors which were associated with these stresses during the first outbreak in Shanghai. Methods: Between February 9 and 21, 2020, a total of 3,114 frontline HCWs from 26 hospitals in Shanghai completed an online survey. The questionnaire included questions on their sociodemographic characteristics, 15 stress-related questions, and General Health Questionnaire-12 (GHQ-12). Exploratory factor analysis was applied to the 15 stress-related questions which produced four distinct factors for evaluation. Multiple linear regression models were performed to explore the association of personal characteristics with each score of the four factors. Binary logistic analysis was used to explain the association of personal characteristics and these four factors with the GHQ-12. Results: There were 2,691 valid surveys received. The prevalence of emotional distress (defined as GHQ-12 ≥ 12) was noted in 47.7% (95%CI:45.7-49.6%) HCWs. Females (OR = 1.43, 95%CI:1.09-1.86) were more likely to have a psychological distress than males. However, HCWs who work in secondary hospitals (OR = 0.71, 95% CI:0.58-0.87) or had a no contact history (OR = 0.45, 95%CI: 0.35-0.58) were less likely to suffer psychological distress. HCWs who were nurses, married, and had a known contact history were highly likely to have anxiety. HCWs working at tertiary hospitals felt an elevated anxiety regarding the infection, a lack of knowledge, and less protected compared to those who worked at secondary hospitals. Conclusions: Our study shows that the frontline HCWs had a significant psychosocial distress during the COVID-19 outbreak in Shanghai. HCWs felt a lack of knowledge and had feelings of being not protected. It is necessary for hospitals and governments to provide additional trainings and psychological counseling to support the first-line HCWs.

The effect of physician educational intervention on venous thromboembolism pharmacological prophylaxis in medical inpatients from the respiratory department: a retrospective cohort study

BACKGROUND

Venous thromboembolism (VTE) is a serious health problem for which pharmacological prophylaxis has been proven to be effective. However, there are significant gaps between the guidelines and clinical practice. This study is to evaluate the effect of physician educational intervention (PEI) on VTE pharmacological prophylaxis in medical inpatients from the respiratory department.

METHODS

Medical inpatients from the respiratory department between February 2014 and December 2016 were recruited in this retrospective cohort study. They were assigned to the PEI group or the control group according to whether their physicians undertook a quality improvement (QI) project carried out in hospital to raise physician awareness of pharmacological thromboprophylaxis by educational intervention. Any and appropriate pharmacological VTE prophylaxis rates, the use of appropriate anticoagulants, and the occurrence of VTE events in the two groups were calculated and compared using a chi-square test and continuity correction. Poisson regression analysis was used to evaluate the relative risk (RR) of PEI on the occurrence of VTE events.

RESULTS

The any pharmacological VTE prophylaxis rate (11.3% vs. 5.9%, P=0.048) and appropriate pharmacological VTE prophylaxis rate (9.3% vs. 5.5%, P=0.036) in high-risk patients without high major bleeding risk were both significantly higher than the control group. Compared with the control group, appropriate anticoagulants in the PEI group took up a larger proportion of all used anticoagulants (90.3% vs. 78.7%, P=0.007). In anticoagulants used for high-risk patients without high major bleeding, appropriate anticoagulants show no statistical difference between the two groups (93.8% vs. 77.8%, P=0.153). There was no difference in the occurrence of VTE events between the two study groups in overall patients (0.5% vs. 0.6%, P=0.913), and among those with high VTE risk (1.7% vs. 1.0%, P=0.554). PEI had no association with the probability of VTE event occurrence (RR, 1.246; 95% CI, 0.478-2.188, P=0.954).

CONCLUSIONS

Educational intervention effectively increased physician awareness of VTE prophylaxis in the respiratory department. Further interventions are still necessary since the guidelines were implemented to a relatively low degree.

[Development of multiple organ dysfunction syndrome in patients with Coronavirus Disease 2019: clinical characteristics and risk factors]

Objective: To explore the clinical characteristics and risk factors of patients with Coronavirus Disease 2019 (COVID-19) when developing multiple organ dysfunction syndrome (MODS). Methods: Data from 458 inpatients of confirmed COVID-19 in Wuhan, Shanghai and Tongling from December 29, 2019 to March 24, 2020 were retrospectively collected. COVID-19 was confirmed by real-time RT-PCR of throat swab samples. Data of demographics, clinical presentation, laboratory tests, imaging findings, treatment and prognosis were obtained from medical record and compared between COVID-19 patients with and without MODS. Risk factors for the development of MODS were analyzed by univariate and multivariate logistic regression analysis. Results: Of the 458 COVID-19 patients (266 from Wuhan, 208 from Shanghai, and 24 from Tongling), 103 developed transient or persistent MODS in the course. More male patients were found in those with MODS (72.8% vs 54.6%, P=0.001). And MODS patients were of older age (72.8% vs 54.6%, P=0.001), more chronic comorbidities (68.0% vs 43.4%, P<0.001), and longer onset-to-admission interval (9.0 vs 7.0 d, P<0.001). In addition, patients with MODS had more expectoration (45.6% vs 29.9%, P=0.003) and shortness of breath (52.4% vs 19.4%, P<0.001), dysfunction of various systems, decreased cellular immunity and elevated IL-6 (9.6 vs 7.6 g/L, P=0.015) in laboratory tests, isolation of other pathogens (18.4% vs 5.6%, P<0.001), and infiltration of all five lobes (75.3% vs 57.6%, P=0.003). During hospitalization, patients with MODS needed a higher proportion of comprehensive treatment and reached a mortality rate of 66.0%. Independents risk factors for development of MODS in COVID-19 patients were: onset-to-admission interval>7 days (OR=2.17, 95%CI: 1.11-4.22, P=0.023), shortness of breath (OR=3.19, 95%CI: 1.60-6.37, P=0.001), lymphocyte count<1×10⁹/L (OR=2.67, 95%CI: 1.31-5.46, P=0.007), blood urea nitrogen>7mol/L (OR=6.27, 95%CI: 2.80-14.08, P<0.001), procalcitonin>0.1 ng/mL (OR=2.48, 95%CI: 1.20-5.13, P=0.014), and C-reactive protein>10 mg/L (OR=3.92, 95%CI: 1.41-10.89, P=0.009). Conclusions: COVID-19 patients with MODS were of higher severity and mortality. Early identification of high-risk groups with MODS according to risk factors may be helpful for early treatment.

Intrapulmonary distal airway stem cell transplantation repairs lung injury in chronic obstructive pulmonary disease

Objectives

Chronic obstructive pulmonary disease (COPD) is characterized by irreversible lung tissue damage including chronic bronchitis and emphysema, which could further develop into respiratory failure. Many studies have revealed a potential regenerative function of the distal airway stem/progenitor cells (DASCs) after lung injury.

Materials and Methods

Mouse and human DASCs were expanded, analysed, and engrafted into injured mouse lungs. Single‐cell analyses were performed to reveal the differentiation path of the engrafted cells. Finally, human DASCs were transplanted into COPD mice induced by porcine pancreatic elastase (PPE) and lipopolysaccharide (LPS) administration.

Results

We showed that isolated mouse and human DASCs could be indefinitely expanded and were able to further differentiate into mature alveolar structures in vitro. Single‐cell analysis indicated that the engrafted cells expressed typical cellular markers of type I alveolar cells as well as the specific secreted proteins. Interestingly, transplantation of human DASCs derived from COPD patients into the lungs of NOD‐SCID mice with COPD injury repaired the tissue damage and improved the pulmonary function.

Conclusions

The findings demonstrated that functional lung structure could be reconstituted by intrapulmonary transplantation of DASCs, suggesting a potential therapeutic role of DASCs transplantation in treatment for chronic obstructive pulmonary disease.

Risk factors for secondary hemophagocytic lymphohistiocytosis in severe coronavirus disease 2019 adult patients

BACKGROUND

Secondary hemophagocytic lymphohistiocytosis (sHLH) is a life-threatening hyperinflammatory event and a fatal complication of viral infections. Whether sHLH may also be observed in patients with a cytokine storm induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is still uncertain. We aimed to determine the incidence of sHLH in severe COVID-19 patients and evaluate the underlying risk factors.

METHOD

Four hundred fifteen severe COVID-19 adult patients were retrospectively assessed for hemophagocytosis score (HScore). A subset of 7 patients were unable to be conclusively scored due to insufficient patient data.

RESULTS

In 408 patients, 41 (10.04%) had an HScore ≥169 and were characterized as "suspected sHLH positive". Compared with patients below a HScore threshold of 98, the suspected sHLH positive group had higher D-dimer, total bilirubin, alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen, serum creatinine, triglycerides, ferritin, interleukin-6, C-reactive protein, procalcitonin, lactate dehydrogenase, creatine kinase isoenzyme, troponin, Sequential Organ Failure Assessment (SOFA) score, while leukocyte, hemoglobin, platelets, lymphocyte, fibrinogen, pre-albumin, albumin levels were significantly lower (all P < 0.05). Multivariable logistic regression revealed that high ferritin (>1922.58 ng/mL), low platelets (<101 × 10⁹/L) and high triglycerides (>2.28 mmol/L) were independent risk factors for suspected sHLH in COVID-19 patients. Importantly, COVID-19 patients that were suspected sHLH positive had significantly more multi-organ failure. Additionally, a high HScore (>98) was an independent predictor for mortality in COVID-19.

CONCLUSIONS

HScore should be measured as a prognostic biomarker in COVID-19 patients. In particular, it is important that HScore is assessed in patients with high ferritin, triglycerides and low platelets to improve the detection of suspected sHLH.

Evidence-based Guideline for Therapeutic Drug Monitoring of Vancomycin: 2020 Update by the Division of Therapeutic Drug Monitoring, Chinese Pharmacological Society

BACKGROUND

Clinical practice guidelines or recommendations often require timely and regular updating as new evidence emerges, because this can alter the risk-benefit trade-off. The scientific process of developing and updating guidelines accompanied by adequate implementation can improve outcomes. To promote better management of patients receiving vancomycin therapy, we updated the guideline for the therapeutic drug monitoring (TDM) of vancomycin published in 2015.

METHODS

Our updated recommendations complied with standards for developing trustworthy guidelines, including timeliness and rigor of the updating process, as well as the use of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. We also followed the methodology handbook published by the National Institute for Health and Clinical Excellence and the Spanish National Health System.

RESULTS

We partially updated the 2015 guideline. Apart from adults, the updated guideline also focuses on pediatric patients and neonates requiring intravenous vancomycin therapy. The guideline recommendations involve a broadened range of patients requiring TDM, modified index of TDM (both 24-hour area under the curve and trough concentration), addition regarding the necessity and timing of repeated TDM, and initial dose for specific subpopulations. Overall, 1 recommendation was deleted and 3 recommendations were modified. Eleven new recommendations were added, and no recommendation was made for 2 clinical questions.

CONCLUSIONS

We updated an evidence-based guideline regarding the TDM of vancomycin using a rigorous and multidisciplinary approach. The updated guideline provides more comprehensive recommendations to inform rational and optimized vancomycin use and is thus of greater applicability.

High Dose Intravenous Vitamin C for Preventing The Disease Aggravation of Moderate COVID-19 Pneumonia. A Retrospective Propensity Matched Before-After Study

Background: Coronavirus disease 2019 (COVID-19) pandemic is continuing to impact multiple countries worldwide and effective treatment options are still being developed. In this study, we investigate the potential of high-dose intravenous vitamin C (HDIVC) in the prevention of moderate COVID-19 disease aggravation.

Methods: In this retrospective before-after case-matched clinical study, we compare the outcome and clinical courses of patients with moderate COVID-19 patients who were treated with an HDIVC protocol (intravenous injection of vitamin C, 100 mg/kg/day, 1 g/h, for 7 days from admission) during a one-month period (between March 18 and april 18, 2020, HDIVC group) with a control group treated without the HDIVC protocol during the preceding two months (January 18 to March 18, 2020). Patients in the two groups were matched in a 1:1 ratio according to age and gender.

Results: The HDIVC and control groups each comprised 55 patients. For the primary outcomes, there was a significant difference in the number of patients that evolved from moderate to severe type between the two groups (HDIVC: 4/55 vs. control: 12/55, relative risk [RR] = 0.28 [0.08, 0.93], P = 0.03). Compared to the control group, there was a shorter duration of systemic inflammatory response syndrome (SIRS) (P = 0.0004) during the first week and lower SIRS occurrence (2/21 vs 10/22, P = 0.0086) on Day 7 (6–7 days after admission). In addition, HDIVC group had lower C-reactive protein levels (P = 0.005) and higher number of CD4⁺ T cells from Day 0 (on admission) to Day 7 (P = 0.04).” The levels of coagulation indicators, including activated partial thromboplastin time and D-dimer were also improved in the HDIVC compared to the control group on Day 7.

Conclusion: HDIVC may be beneficial in limiting disease aggravation in the early stage of COVID-19 pneumonia, which may be related to its improvements on the inflammatory response, immune function and coagulation function. Further randomized controlled trials are required to augment these findings.