Erdafitinib versus pembrolizumab in pretreated patients with advanced or metastatic urothelial cancer with select FGFR alterations: cohort 2 of the randomized phase III THOR trial

BACKGROUND

Erdafitinib is an oral pan-fibroblast growth factor receptor (FGFR) tyrosine kinase inhibitor approved to treat locally advanced/metastatic urothelial carcinoma (mUC) in patients with susceptible FGFR3/2 alterations (FGFRalt) who progressed after platinum-containing chemotherapy. FGFR-altered tumours are enriched in luminal 1 subtype and may have limited clinical benefit from anti-programmed death-(ligand) 1 [PD-(L)1] treatment. This cohort in the randomized, open-label phase III THOR study assessed erdafitinib versus pembrolizumab in anti-PD-(L)1-naive patients with mUC.

PATIENTS AND METHODS

Patients ≥18 years with unresectable advanced/mUC, with select FGFRalt, disease progression on one prior treatment, and who were anti-PD-(L)1-naive were randomized 1 : 1 to receive erdafitinib 8 mg once daily with pharmacodynamically guided uptitration to 9 mg or pembrolizumab 200 mg every 3 weeks. The primary endpoint was overall survival (OS). Secondary endpoints included progression-free survival (PFS), objective response rate (ORR), and safety.

RESULTS

The intent-to-treat population (median follow-up 33 months) comprised 175 and 176 patients in the erdafitinib and pembrolizumab arms, respectively. There was no statistically significant difference in OS between erdafitinib and pembrolizumab [median 10.9 versus 11.1 months, respectively; hazard ratio (HR) 1.18; 95% confidence interval (CI) 0.92-1.51; P = 0.18]. Median PFS for erdafitinib and pembrolizumab was 4.4 and 2.7 months, respectively (HR 0.88; 95% CI 0.70-1.10). ORR was 40.0% and 21.6% (relative risk 1.85; 95% CI 1.32-2.59) and median duration of response was 4.3 and 14.4 months for erdafitinib and pembrolizumab, respectively. 64.7% and 50.9% of patients in the erdafitinib and pembrolizumab arms had ≥1 grade 3-4 adverse events (AEs); 5 (2.9%) and 12 (6.9%) patients, respectively, had AEs that led to death.

CONCLUSIONS

Erdafitinib and pembrolizumab had similar median OS in this anti-PD-(L)1-naive, FGFR-altered mUC population. Outcomes with pembrolizumab were better than assumed and aligned with previous reports in non- FGFR-altered populations. Safety results were consistent with the known profiles for erdafitinib and pembrolizumab in this patient population.

Evaluation of pain related behaviors and disease related outcomes in an immunocompetent mouse model of prostate cancer induced bone pain

Cancer-induced bone pain (CIBP) is the most common and devastating symptom of bone metastatic cancer that substantially disrupts patients' quality of life. Currently, there are few effective analgesic treatments for CIBP other than opioids which come with severe side effects. In order to better understand the factors and mechanisms responsible for CIBP it is essential to have clinically relevant animal models that mirror pain-related symptoms and disease progression observed in patients with bone metastatic cancer. In the current study, we characterize a syngeneic mouse model of prostate cancer induced bone pain. We transfected a prostate cancer cell line (RM1) with green fluorescent protein (GFP) and luciferase reporters in order to visualize tumor growth longitudinally in vivo and to assess the relationship between sensory neurons and tumor cells within the bone microenvironment. Following intra-femoral injection of the RM1 prostate cancer cell line into male C57BL/6 mice, we observed a progressive increase in spontaneous guarding of the inoculated limb between 12 and 21 days post inoculation in tumor bearing compared to sham operated mice. Daily running wheel performance was evaluated as a measure of functional impairment and potentially movement evoked pain. We observed a progressive reduction in the distance traveled and percentage of time at optimal velocity between 12 and 21 days post inoculation in tumor bearing compared to sham operated mice. We utilized histological, radiographic and μCT analysis to examine tumor induced bone remodeling and observed osteolytic lesions as well as extra-periosteal aberrant bone formation in the tumor bearing femur, similar to clinical findings in patients with bone metastatic prostate cancer. Within the tumor bearing femur, we observed reorganization of blood vessels, macrophage and nerve fibers within the intramedullary space and periosteum adjacent to tumor cells. Tumor bearing mice displayed significant increases in the injury marker ATF3 and upregulation of the neuropeptides SP and CGRP in the ipsilateral DRG as well as increased measures of central sensitization and glial activation in the ipsilateral spinal cord. This immunocompetent mouse model will be useful when combined with cell type selective transgenic mice to examine tumor, immune cell and sensory neuron interactions in the bone microenvironment and their role in pain and disease progression associated with bone metastatic prostate cancer.

Deep Learning vs. Handcrafted Radiomics to Predict Chemoradiotherapy Response for Locally Advanced Cervical Cancer

PURPOSE/OBJECTIVE(S)

To predict CRT response in locally advanced cervical cancer (LACC) with handcrafted radiomics (HCR) and deep learning radiomics (DLR) using pretreatment MRI. Furthermore, we investigate whether the incorporation of clinical factors improves prediction performance.

MATERIALS/METHODS

Two hundred and fifty-two patients with LACC are enrolled. All patients are treated with external beam radiotherapy, followed by high-dose-rate intracavitary brachytherapy with concurrent cisplatin. The patients are randomly divided into two independent groups for the training (167 patients) and test datasets (85 patients). Contrast-enhanced T1- and T2-weighted MR scans are obtained. Patients in the training and test sets have similar characteristics in terms of age, tumor size, FIGO stage, HPV infection status, or CRT response. For HCR analysis, 1890 imaging features are extracted and a support vector machine classifier with a five-fold cross-validation is trained using training dataset to predict CRT response and validated using test dataset. For DLR analysis, a 3-dimensional convolutional neural network was trained and validated using test dataset.

RESULTS

A comparison of the DLR and HCR models reveals that the DLR model exhibits better prediction performance than the HCR model for the test dataset (AUC = 0.721 vs. 0.597, p = 0.097). The incorporation of clinical factors could improve performance in both DLR and HCR models.

CONCLUSION

The DLR models outperform the HCR models in predicting CRT responses in patients with LACC. Combining clinical factors and MRI may improve the prediction performance in both HCR and DLR analyses.

Appropriateness of antibiotic use for patients with asymptomatic bacteriuria or urinary tract infection with positive urine culture: a retrospective observational multi-centre study in Korea

BACKGROUND

Antibiotic resistance threatens public health worldwide, and inappropriate use of antibiotics is one of the main causes.

AIM

To evaluate qualitative use of antibiotics in asymptomatic bacteriuria (ABU) and urinary tract infection (UTI).

METHODS

Cases of positive urine culture (≥105 colony-forning units/mL) performed in inpatient, outpatient and emergency departments in April 2021 were screened in 26 hospitals in the Republic of Korea. The cases were classified as ABU, lower UTI and upper UTI. The appropriateness of antibiotic use was evaluated retrospectively by infectious disease specialists using quality indicators based on clinical guidelines for ABU and UTI.

RESULTS

This study included a total of 2697 patients with ABU or UTI. The appropriateness of antibiotic use was assessed in 1157 patients with ABU, and in 677 and 863 patients with lower and upper UTI, respectively. Among the 1157 patients with ABU, 251 (22%) were prescribed antibiotics without appropriate indications. In 66 patients with ABU in which antibiotics were prescribed with appropriate indications, the duration was adequate in only 23 (34.8%) patients. The appropriateness of empirical and definite antibiotics was noted in 527 (77.8%) and 353 (68.0%) patients with lower UTI, and 745 (86.3%) and 583 (78.2%) patients with upper UTI, respectively. The duration of antibiotics was adequate in 321 (61.8%) patients with lower UTI and 576 (78.7%) patients with upper UTI.

CONCLUSIONS

This nationwide qualitative assessment of antibiotic use in ABU and UTI revealed that antibiotics were often prescribed inappropriately, and the duration of antibiotics was unnecessarily prolonged.

Research Note: Preliminary assessment of the impact of dietary yeast products on egg production and cecal microbial profiles of laying hens

The objective of the current study was to conduct an initial comparison of commercial yeast products in layer hen diets on egg production parameters and the corresponding impact on the cecal microbiota. A short-term feeding study was conducted with 35 laying hens receiving either a control, or 1 of 4 different yeast fermentation products, Immunowall, Hilyses (both from ICC, São Paulo, Brazil), Citristim (ADM, Decatur, IL), and Maxi-Gen Plus (CBS Bio Platforms, Calgary, Canada) with 7 hens per treatment from 40 to 46 wk of age. At the end of the trial, hens were euthanized, the ceca removed and prepared for denatured gradient gel electrophoresis (DGGE) microbial compositional analyses. Although initial shell weight and shell thickness were similar among the treatment groups, hens fed Hilyses had lower shell weight and thickness at the end of the experiment. The most predominant DGGE bands with the strongest intensity were identified as Lactobacillus species and excised double bands were identified as Bacillus, Clostridium, or Lachnospiraceae. In this short-term feeding trial, the commercial yeast products tested had little effect on egg production and shell quality, and only moderately impacted the composition of mature layer hen cecal microbiota.

Association of body mass index and bloodstream infections in patients on extracorporeal membrane oxygenation: a single-centre, retrospective, cohort study

BACKGROUND

Obesity is associated with poor clinical outcomes in critically ill patients. However, under some clinical conditions, obesity has protective effects. Bloodstream infections (BSI) are among the most common nosocomial infections associated with extracorporeal membrane oxygenation (ECMO). BSI during ECMO is associated with higher mortality rates and poorer clinical outcomes.

AIM

To analyse whether body mass index (BMI) is associated with BSI during ECMO or with in-hospital mortality.

METHODS

All adult patients who had received ECMO support for >48 h were included in the analysis. The analysis of total duration of ECMO support, in-hospital mortality and BSI was stratified by BMI category. The Cox proportional hazards model was used to compare the risk of BSI among BMI categories.

FINDINGS

In total, 473 patients were enrolled in the study. The average age was 56.5 years and 65.3% were men. The total duration of ECMO was approximately 11.8 days, with a mortality rate of 47.1%. The incidence rates of BSI and candidaemia were 20.5% and 5.5%, respectively. The underweight group required ECMO for respiratory support, whereas the overweight and obese groups required ECMO for cardiogenic support (P<0.0001). No significant difference in BSI rate was found (P=0.784). However, after adjusting for clinical factors, patients in Group 4 (BMI 25.0-<30.0 kg/m2) exhibited lower mortality compared with patients in Group 2 (normal BMI) (P=0.004).

CONCLUSION

BMI was not associated with risk of BSI, but patients with higher BMI showed lower in-hospital mortality associated with ECMO support.

Coinfection With Severe Fever With Thrombocytopenia Syndrome and Scrub Typhus in Korea

Background

Scrub typhus and severe fever with thrombocytopenia syndrome (SFTS) are the 2 most common tick-borne infectious diseases in Korea. Every year, an increasing number of cases are reported, which is a public health concern. Therefore, we aimed to investigate the prevalence of SFTS-scrub typhus coinfection in patients with SFTS.

Methods

Clinical samples were collected from 129 patients with SFTS. One-step reverse-transcription polymerase chain reaction (PCR) was performed to identify the SFTS virus (SFTSV), and real-time PCR followed by nested PCR was performed to detect the Orientia tsutsugamushi gene for scrub typhus. Phylogenetic analysis was conducted to confirm the evolutionary relationships among different species.

Results

Among 129 SFTS cases, 2 patients with SFTSV were positive for O. tsutsugamushi with a prevalence of coinfection of 1.6% (95% confidence interval, .001-.06). Phylogenetic analysis confirmed these as O. tsutsugamushi strain Boryong.

Conclusions

Our study found that 1.6% of patients were coinfected with SFTS and scrub typhus infection. We believe that this information will add a new dimension to clinical diagnosis, which should be considered for better public health management. Further research is needed to better understand the ecological transmission dynamics and geographical distribution of SFTSV and O. tsutsugamushi in endemic countries.

The impact of enhanced screening for carbapenemase-producing Enterobacterales in an acute care hospital in South Korea

BACKGROUND

Carbapenemase-producing Enterobacterales (CPE) poses a significant challenge to infection control in healthcare settings. Active screening is recommended to prevent intra-hospital CPE transmission.

METHODS

CPE screening was initiated at a 660-bed hospital in South Korea in September 2018, targeting patients previously colonized/infected or admitted to outside healthcare facilities (HCFs) within 1 month. Universal intensive care unit (ICU) screening was performed at the time of admission. After a hospital-wide CPE outbreak in July-September 2019, the screening program was enhanced by extending the indications (admission to any HCF within 6 months, receipt of hemodialysis) with weekly screening of ICU patients. The initial screening method was changed from screening cultures to the Xpert Carba-R assay. The impact was assessed by comparing the CPE incidence per 1000 admissions before (phase 1, September 2018-August 2019) and after instituting the enhanced screening program (phase 2, September 2019-December 2020).

RESULTS

A total of 13,962 (2,149 and 11,813 in each phase) were screened as indicated, among 49,490 inpatients, and monthly screening compliance increased from 18.3 to 93.5%. Compared to phase 1, the incidence of screening positive patients increased from 1.2 to 2.3 per 1,000 admissions (P = 0.005) during phase 2. The incidence of newly detected CPE patients was similar (3.1 vs. 3.4, P = 0.613) between two phases, but the incidence of hospital-onset CPE patients decreased (1.9 vs. 1.1, P = 0.018). A significant decrease was observed (0.5 to 0.1, P = 0.014) in the incidence of patients who first confirmed CPE positive through clinical cultures without a preceding positive screening. Compared to phase 1, the median exposure duration and number of CPE contacts were also markedly reduced in phase 2: 10.8 days vs. 1 day (P < 0.001) and 11 contacts vs. 1 contact (P < 0.001), respectively. During phase 2, 42 additional patients were identified by extending the admission screening indications (n = 30) and weekly in-ICU screening (n = 12).

CONCLUSIONS

The enhanced screening program enabled us to identify previously unrecognized CPE patients in a rapid manner and curtailed a hospital-wide CPE outbreak. As CPE prevalence increases, risk factors for CPE colonization can broaden, and hospital prevention strategies should be tailored to the changing local CPE epidemiology.

Clinically differential diagnosis of human granulocytic anaplasmosis and severe fever with thrombocytopenia syndrome

This study analyzed HGA and SFTS in patients with suspected tick-borne infection by focusing on key differences that clinicians can easily recognize. A retrospective analysis was performed on confirmed patients with HGA or SFTS in 21 Korean hospitals from 2013 to 2020. A scoring system was developed by multivariate regression analysis and accuracy assessment of clinically easily discriminable parameters was performed. The multivariate logistic regression analysis revealed that sex (especially male sex) (odds ratio [OR] 11.45, P = 0.012), neutropenia (< 1500) (OR 41.64, P < 0.001), prolonged activated partial thromboplastin time (OR 80.133, P < 0.001), and normal C-reactive protein concentration (≤ 1.0 mg/dL; OR 166.855, P = 0.001) were significantly associated with SFTS but not with HGA. Each factor, such as meaningful variables, was given 1 point, and a receiver-operating characteristic curve with a cutoff value (> 1) in a 5-point scoring system (0-4 points) was analyzed to evaluate the accuracy of differentiation between HGA and SFTS. The system showed 94.5% sensitivity, 92.6% specificity, and an area under the receiver-operating characteristic curve of 0.971 (0.949-0.9). Where HGA and SFTS are endemic, the scoring system based on these four parameters such as sex, neutrophil count, activated partial thromboplastin time, and C-reactive protein concentration will facilitate the differential diagnosis of HGA and SFTS in the emergency room in patients with suspected tick-borne infectious diseases.

Impact of tuberculosis on the incidence of osteoporosis and osteoporotic fractures: a nationwide population-based cohort study

OBJECTIVES

Despite the high prevalence of tuberculosis (TB) and the disease burden of osteoporosis and osteoporotic fractures, there is still a lack of well-designed, large-scale studies demonstrating associations among them. We aimed to investigate the effect of TB on the incidence of osteoporosis and osteoporotic fractures.

STUDY DESIGN

This was a nationwide population-based cohort study.

METHODS

This study was conducted using the National Health Insurance Service Database of South Korea. We included patients with newly diagnosed TB aged >40 years from January 2006 to December 2017. An uninfected control for each TB patient was randomly extracted by frequency matching for sex, age, income level, residence, and registration date at a 2:1 ratio. The primary outcome was the incidence of osteoporosis and osteoporotic fractures between the two groups, adjusted for sex, age, income level, residence, comorbidities, body mass index, blood pressure, laboratory tests, alcohol drinking, and smoking. The risk factors associated with osteoporosis or osteoporotic fractures were also investigated.

RESULTS

A total of 164,389 patients with TB and 328,778 matched controls were included (71.9% males). The mean duration of follow-up was 7.00 ± 3.49 years. The incidence of osteoporosis in patients with TB was 6.1 cases per 1000 person-years, which was significantly higher than that in matched controls (adjusted hazard ratio [aHR] 1.349, 95% confidence interval [CI] 1.302-1.398, P < 0.001). The incidence of osteoporotic fractures was also higher in patients with TB than in controls (aHR 1.392, 95% CI 1.357-1.428, P < 0.001). Among fractures, the risk of hip fracture was the highest (aHR 1.703, 95% CI 1.612-1.798, P < 0.001).

CONCLUSIONS

TB independently contributes to the incidence of osteoporosis and osteoporotic fractures, particularly hip fractures.

Sex difference in neurological outcome and post-cardiac arrest care in out-of-hospital cardiac arrest patients treated with targeted temperature management

Funding Acknowledgements

Type of funding sources: None.

Objectives

Conflicting results regarding sex-based differences in the outcomes of out-of-hospital cardiac arrest (OHCA) patients have been reported. Furthermore, no study has examined whether differences in in-hospital interventions and courses are driven by sex differences. This study evaluated the effect of sex on the in-hospital course of these patients as well as the survival rates and long-term neurological outcomes of comatose OHCA patients treated with targeted temperature management (TTM).

Methods

We retrospectively analyzed the Korean Hypothermia Network prospective registry composed of data collected from 22 hospitals in Korea between October 2015 and December 2018. To evaluate the effect of sex on patient outcomes, we created various multivariate logistic regression models including baseline characteristics, resuscitation, and in-hospital care variables with an interaction term (age × sex). We also performed a stratified analysis of different age groups (less than 50 years of age and older). Regarding the difference in in-hospital courses, we compared daily total and SOFA sub-scores between the sexes and analyzed whether the decision regarding early cardiac interventions and limitations in in-hospital care were associated with sex.

Results

Among 1339 patients included in the study, 952 were men and 387 were women. There were no differences in age or modified comorbidity index values between the gender groups. Women were more likely to experience cardiac arrest at home and unwitnessed arrests, whereas men were more likely to have shockable initial rhythm, cardiac cause arrest, and ST-segment elevation myocardial infarction (STEMI) on initial electrocardiography and undergo early coronary interventions. The rate of survival to discharge was similar, but men showed better 6-month neurological outcomes. After adjusting for confounders, the male sex was not associated with survival to discharge or good 6-month neurological outcomes. There was no association between sex and outcome in patients of reproductive age and no interaction between age and sex. Regarding the in-hospital course, the daily total and SOFA sub-scores were similar in both sexes. The adjusted effect of sex was not associated with the clinician’s decision to perform early cardiac interventions. The decision to discontinue life-sustaining treatment was determined by poor prognostic factors, not by sex.

Conclusions

The findings suggested that men had more favorable 6-month survivals and good neurological outcomes compared to women since they had more favorable resuscitation variables. However, after adjusting for confounders, there was no difference between the sexes. This result was consistent with the data in patients of reproductive age. The results regarding in-hospital course showed that daily patient severity scores, early cardiac interventions, resource consumption, and the rates of withdrawal/withholding of in-hospital care were similar in men and women.

Cerebral venous thrombosis after ChAdOx1 nCoV-19 vaccination: a systematic review

OBJECTIVE

To perform a systematic review of case reports or case series regarding thrombosis with thrombocytopenia syndrome (TTS) and cerebral venous thrombosis (CVT) related to ChAdOx1 nCoV-19 vaccination to address the clinical features, laboratory findings, treatment modalities, and prognosis related with CVT.

SUBJECTS AND METHODS

We included 64 TTS patients from 19 articles, 6 case series and 13 case reports, in which thrombosis occurred after the first dose of ChAdOx1 nCoV-19 vaccination published up to 30 June 2021 in Embase, ePubs, Medline/PubMed, Scopus, and Web of Science databases.

RESULTS

Of the 64 TTS patients, 38 (59.3%) had CVT. Patients with CVT were younger (median 36.5 vs. 52.5 years, p<0.001), had lower fibrinogen levels (130 vs. 245 mg/dL, p=0.008), had more frequent history of intracerebral hemorrhage (ICH), and had higher mortality rate (48.6% vs. 19.2%, p=0.020) than that of patients without CVT. In multivariable analysis, the possibility of presence of CVT was higher in younger age groups [odd ratio (OR): 0.91, 95% confidence interval (CI): (0.86-0.97, p<0.001)] and those with accompanying intracerebral hemorrhage (ICH) (OR: 13.60, 95% CI (1.28-144.12, p=0.045).

CONCLUSIONS

Our study demonstrated that CVT related to ChAdOx1 nCoV-19 vaccination was associated with younger age, low levels of fibrinogen, presence of ICH and more frequent mortality compared to those of non-CVT. If TTS occurs after ChAdOx1 nCoV-19 vaccination, the presence of CVT in patients with young age or ICH should be considered.

1806. The gap in the amount of monthly antimicrobial use according to the data source: Electronic Health Record Data vs. National Health Insurance Claim Data in Korea

Background

Korea has single health insurance system and insurance claim information on almost all medical practices in Korean hospitals is collected and processed by the Health Insurance Review and Assessment Service (HIRA). Since information about prescription of almost all hospitals is available in National Health Insurance (NHI) claim data, recently established the Korea National Antimicrobial Use Analysis System (KONAS) has been using NHI claim data as data source. The purpose of this study is to validate the accuracy of NHI claim data.

Methods

Data on all antimicrobial agents prescribed in four tertiary-care hospitals in Korea between January 2019 and December 2019 were obtained using NHI claim data extracted by HIRA and data extracted by common data model based on electronic health record (EHR) in each hospital. Antibiotics and antifungal agents according to the Anatomical Therapeutic Chemical class J01 and J02 were included while antiviral, antitubercular, antiparasitic, and topical antimicrobial agents were excluded. Antimicrobial consumption was measured as days of therapy (DOT) and standardized to per 1,000 patient-days. The ratio of monthly antimicrobial consumption calculated using the NHI claim data compared to that calculated using the common data model was demonstrated (HIRA/EHR ratio).

Results

The monthly HIRA/EHR ratio of broad-spectrum antibiotics predominantly used for hospital-onset infections was 1.08-1.12 and that of broad-spectrum antibiotics predominantly used for community-acquired infections was 1.11-1.21. The monthly HIRA/EHR ratio of other antimicrobial classes are as follows: antibacterial agents predominantly used for resistant gram-positive infections 1.15-1.31, narrow-spectrum beta-lactam agents 1.00-1.05, antifungal agents predominantly used for invasive candidiasis 1.00-1.27, and antibacterial agents predominantly used for extensive antibiotic-resistant gram-negative bacteria 0.70-1.09.

Conclusion

The monthly antimicrobial consumption calculated using NHI claim data differs from that calculated using EHR data by up to 30%. It would be desirable to establish a system that can analyze and monitor antimicrobial consumption using EHR data in each hospital in Korea in the future.

Disclosures

Hyunki Woo, BS, Evidnet Inc.: Employee changhui Kim, BS, Evidnet Inc.: Employee.

1783. Appropriateness of antibiotics use for patients with asymptomatic bacteriuria or urinary tract infection: A retrospective observational multicenter study in Korea

Background

Antibiotic resistance threatens public health worldwide, and inappropriate use of antibiotics is one of the main causes. Antibiotic use for asymptomatic bacteriuria (ABU) has been defined as “antibiotics never events”, and urinary tract infection (UTI) is one of the most common infectious diseases for which antibiotics are prescribed in Korea. To establish an effective antimicrobial stewardship strategy, a qualitative assessment of antibiotic use in actual clinical syndrome is necessary.

Methods

Cases of positive urine cultures (≥10⁵ CFU/ml), performed in inpatient, outpatient, and emergency departments in April 2021 were screened in 26 hospitals located throughout Korea. Cases were classified into ABU, lower UTI, and upper UTI. The appropriateness of antibiotic use was retrospectively evaluated by infectious disease specialists using quality indicators based on the domestic clinical guideline for ABU and UTI. Figure 1.

Development of the Korean Standardized Antimicrobial Administration Ratio as a Tool for Benchmarking Antimicrobial Use in Each Hospital

BACKGROUND

The Korea National Antimicrobial Use Analysis System (KONAS), a benchmarking system for antimicrobial use in hospitals, provides Korean Standardized Antimicrobial Administration Ratio (K-SAAR) for benchmarking. This article describes K-SAAR predictive models to enhance the understanding of K-SAAR, an important benchmarking strategy for antimicrobial usage in KONAS.

METHODS

We obtained medical insurance claims data for all hospitalized patients aged ≥ 28 days in all secondary and tertiary care hospitals in South Korea (n = 347) from January 2019 to December 2019 from the Health Insurance Review &amp; Assessment Service. Modeling was performed to derive a prediction value for antimicrobial use in each institution, which corresponded to the denominator value for calculating K-SAAR. The prediction values of antimicrobial use were modeled separately for each category, for all inpatients and adult patients (aged ≥ 15 years), using stepwise negative binomial regression.

RESULTS

The final models for each antimicrobial category were adjusted for different significant risk factors. In the K-SAAR models of all aged patients as well as adult patients, most antimicrobial categories included the number of hospital beds and the number of operations as significant factors, while some antimicrobial categories included mean age for inpatients, hospital type, and the number of patients transferred from other hospitals as significant factors.

CONCLUSION

We developed a model to predict antimicrobial use rates in Korean hospitals, and the model was used as the denominator of the K-SAAR.

Estimation of single-dose varicella vaccine effectiveness in South Korea using mathematical modeling

In South Korea, despite the implementation of a universal single-dose vaccination program for children aged 12–15 months in 2005, the varicella incidence rate remains significant. Prior case-control studies have reported that currently used varicella vaccines are extremely inefficacious. We estimated vaccine effectiveness (VE) by fitting a dynamic transmission model to age-specific varicella incidence data from 2007 to 2015 and available vaccine coverage data. The initial vaccine efficacy and primary failure rates were estimated to be 61.1% and 38.9%, respectively. The average duration of protection was 21.4 years. The mean VE [(1-relative risk) %] for the simulated data of 2004–2014 birth cohorts decreased from 59.8% to 50.7% over 9 years. This mathematical modeling study demonstrated that the single-dose vaccine exhibits moderate effectiveness, and a high proportion of primary failure could be a main cause of breakthrough infections. Therefore, a two-dose vaccination strategy should be considered.

Resolving the Mutually Exclusive Immune Responses of Chitosan with Nanomechanics and Immunological Assays

Multifaceted functions displayed by both pro- and anti-inflammatory properties of chitosan hinder its effective development as an immunomodulatory agent. Herein, the contributions of the bending stiffness of chitosan with regard to its immune regulatory properties toward inflammation are investigated. The anti-inflammatory properties of chitosan molecular weight (MW) with a shorter (≈1 kDa) or longer (≈15 kDa) than the persistent length (L_P ) are compared using immunological assays and nanomechanics-based experiments on the surface forces apparatus (SFA). Interestingly, 1 kDa chitosan significantly enhances the generation of anti-inflammatory regulatory T cells (Tregs) through the Dectin-1-dependent pattern recognition receptor (PRR) on antigen-presenting cells. SFA analyses also show a similar trend of interaction forces between chitosan and diverse PRRs depending on their MW. The results obtained in the immunological and nanomechanical experiments are consistent and imply that the binding features of PRRs vary depending on the MW of chitosan, which may alter immune activity. In accordance, in vivo administration of only 1 kDa represses inflammatory responses and suppresses the progression of experimental colitis. This study elucidates a previously unexplored bending stiffness-dependent immune regulatory property of chitosan and suggests the applicability of low MW (rod-like) chitosan as a pharmaceutical ingredient to treat diverse inflammatory disorders.

Site-Selective Antibody-Drug Conjugation by a Proximity-Driven S to N Acyl Transfer Reaction on a Therapeutic Antibody

Immunoglobulin Gs (IgGs) contain many Lys and Cys residues, which results in an unwanted complex product mixture with conventional drug conjugation methods. We selectively acylated the ε-NH₂ of K248 on trastuzumab using an IgG Fc-binding peptide (FcBP) equipped with a 5-norbornene-2-carboxylic acid thioester (AbClick-1). AbClick-1 locates its thioester close to the ε-NH₂ of K248 while binding to trastuzumab. Consequently, the thioester underwent proximity-driven selective acylation of ε-NH₂ through an S to N acyl transfer reaction. Furthermore, N-tert-butyl maleimide accelerated the cross-linking reaction with an approximately 95% yield of the desired product by scavenging the byproduct (FcBP-SH). Only K248 was modified selectively with the 5-norbornene-2-carbonyl group, which was further modified by click reaction to afford an antibody-drug conjugate (ADC) with two drugs per antibody. The resulting ADCs showed remarkable in vitro and in vivo anticancer activity. Our results demonstrate that a thioester is a promising chemical entity for proximity-driven site-selective conjugation of antibodies.

Prescriptions patterns and appropriateness of usage of antibiotics in non-teaching community hospitals in South Korea: a multicentre retrospective study

Background

Although non-teaching community hospitals form the majority of healthcare providers in South Korea, there is limited data on antibiotic usage in them. To evaluate the pattern of antibiotic usage and its appropriateness in hospitals with < 400 beds in South Korea.

Methods

A multicentre retrospective study was conducted in 10 hospitals (six long-term care hospitals, three acute care hospitals, and one orthopaedic hospital), with < 400 beds in South Korea. We analysed patterns of antibiotic prescription in 2019, and their appropriateness in the participating hospitals. For the evaluation of the appropriateness of the prescription, 25 patients under antibiotic therapy were randomly selected at each hospital, over two separate periods. Due to the heterogeneity of their characteristics, the orthopaedics hospital was excluded from the analysis.

Results

The most commonly prescribed antibiotics in long-term care hospitals was fluoroquinolone, followed by beta-lactam/beta-lactamase inhibitor (anti-pseudomonal). In acute care hospitals, these were third generation cephalosporin, followed by first generation cephalosporin, and second generation cephalosporin. The major antibiotics that were prescribed in the orthopedics hospital was first generation cephalosporin Only 2.3% of the antibiotics were administered inappropriately. In comparison, 15.3% of patients were prescribed an inappropriate dose. The proportion of inappropriate antibiotic prescriptions was 30.6% of the total antibiotic prescriptions.

Conclusions

The antibiotic usage patterns vary between non-teaching community hospitals in South Korea. The proportion of inappropriate prescriptions exceeded 30% of the total antibiotic prescriptions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13756-022-01082-2.

Validation of a Korean version of the quality-of-life profile for spine deformities (QLPSD) in patients with adolescent idiopathic scoliosis

OBJECTIVE

We aimed to evaluate the reliability and validity of the adapted Korean version of the Quality-of-Life Profile for Spine Deformities (QLPSD) questionnaire.

PATIENTS AND METHODS

English version of QLPSD was translated into Korean according to previously published guidelines. The Korean version of the QLPSD questionnaire and the Korean version of the SRS-22 was sent to 120 consecutive idiopathic scoliosis patients wearing braces recruited from the outpatient clinic. Reliability assessment and construct validity were evaluated.

RESULTS

The intraobserver reliability of all items in the questionnaire had a kappa statistic of agreement greater than 0.6. The QLPSD showed good test/re-test reliability (ICC = 0.815). The internal consistency of Cronbach's α was found to be very good (α = 0.918). The Korean version of QLPSD showed a significant correlation with the SRS-22 total score (p<0.001, r=-0.811) and single SRS-22 domains scores.

CONCLUSIONS

The adapted Korean version of the QLPSD was successfully translated and showed good measurement properties. As such, it is considered suitable for outcome assessments in Korean-speaking patients with idiopathic scoliosis.

790. Evaluation of an Enhanced CPE Screening Program in an Acute Care Hospital in South Korea

Background

Carbapenemase-producing Enterobacteriaceae (CPE) poses a great challenge in infection control in healthcare settings. A screening and contact precautions are recommended to prevent the spread of CPE among patients. However, screening strategies differ among countries and healthcare facilities.

Methods

In September 2018, we launched a CPE screening program at a 660-bed hospital in South Korea, which targeted previously colonized patients, patients with history of admission < 1 month or transferred patients or ICU-admitted patients. Once patients were identified to have CPE, they were isolated in a single room. After a CPE outbreak in July-Aug 2019, the enhanced screening program was implemented, which included patients with additional risk factors (exposure to hospitals in the past 6 months, receipt of hemodialysis or invasive procedures or rehabilitation) combined with weekly screening in ICU-admitted patients. Screening methods changed from two consecutive rectal screening swabs with chromogenic agar to initial screening with Xpert-Carba-R PCR, followed by one or two consecutive tests with chromogenic agar. We compared the CPE incidence in screening and clinical cultures before and after the enhanced screening program introduction (Sep 2018-Nov 2020).

Results

A total of 14,318 (2,178 vs. 12,140) were screened among 49,980 admitted patients and screening compliance increased from 18.6% to 94.5%. The number of CPE detection increased from 44 to 154 cases and the proportion of CPE-positive screening per 1000 admissions increased 0.6 to 2.2. However, the number of clinical CPE cultures decreased from 11 to 3 (Figure). Among screened patients, time-to-positivity was markedly reduced by 1.9 days (2.96 vs. 1.02 days) during the post-period. Additional 70 patients were detected: 36 due to serial screening in the ICUs and 34 due to enhanced on-admission screening. Factors significantly associated with positive screening were previous exposure to hospital (OR 3.5; 95% CI 1.7-7.1) and receipt of hemodialysis (OR 4.3; 95%CI 1.9-9.2). CPE isolates and carbapenemase genes were diverse (Figure). Trends in CPE detection in screening and clinical samples (upper), and bacterial species with detected carbapenemase genes (lower).

Conclusion

The study results showed that the enhanced screening program enabled us to identify the previously undetected CPE colonized patients and to decrease clinical CPE cultures.

Disclosures

All Authors: No reported disclosures

Research Note: Subzero saline chilling improved chilling efficiency and bacterial reduction of turkey carcasses

The poultry industry has attempted to improve carcass chilling efficiency, meat quality, and product safety. The purpose of this research was to investigate the effects of subzero saline chilling on carcass chilling time and microbial safety. Eviscerated tom turkeys were randomly picked from a local turkey processing plant and subjected to chilling in one of the 3 chilling solutions: 1) 0% NaCl/0.5°C (ice slurry control), 2) 4% NaCl/-2.41°C, and 3) 8% NaCl/-5.08°C. The turkey carcasses in subzero saline solutions were chilled more efficiently and reduced the chilling time over the carcasses in ice slurry solution. No significant difference was observed for carcass chilling yield and fillet cooking yield regardless of chilling method (P > 0.05). The number of mesophilic aerobic bacteria (MAB), Escherichia coli (E. coli), and total coliform cells were significantly reduced in the carcasses chilled in subzero saline solutions over the icy control, except MAB in 4% NaCl/-2.41°C (P < 0.05). Based on these results, the chilling of turkey carcass in subzero saline solution appears to improve carcass chilling efficiency and bacterial reduction, especially Gram-negative bacteria such as E. coli and total coliforms.

Net clinical benefit of direct oral anticoagulants in very elderly and high bleeding risk patients with atrial fibrillation who are often excluded from oral anticoagulation therapy: a nationwide popul

Background

In the Edoxaban Low-Dose for Elder Care Atrial Fibrillation Patients (ELDERCARE-AF) trial, low-dose edoxaban (15mg once daily) showed better efficacy for stroke prevention and positive net clinical benefit compared to placebo in very elderly and high bleeding risk patients with atrial fibrillation (AF) who often excluded from oral anticoagulation (OAC) therapy. However, there are limited data to generalize the ELDERCARE-AF results into daily practice.

Purpose

To investigate the optimal OAC strategy for the best net clinical benefit in ELDERCARE-AF-like patients.

Methods

Using the Korean nationwide claims database, we included patients with incident non-valvular AF aged 80 years or older between 2014 and 2017. Among these, patients with one or more of the following criteria were finally included in the analysis: a low creatinine clearance (15 to 30 mL/min), a history of bleeding from a critical area or organ or gastrointestinal bleeding, low body weight (≤45kg), continuous use of nonsteroidal anti-inflammatory drugs, or current use of an antiplatelet drug. The risks of ischemic stroke, major bleeding, all-cause death, and composite clinical outcome (ischemic stroke+major bleeding+all-cause death) as a measure of net clinical outcome were evaluated during follow-up. The inverse probability of treatment weighting (IPTW) method was used to balance covariates between the groups.

Results

A total of 23,858 patients were finally included (no OAC, n=16,575; warfarin, n=2390; and direct oral anticoagulants (DOACs), n=4893, respectively). Among DOAC group, 69% used low-dose including rivaroxaban 15 mg once daily, dabigatran 110 mg twice daily, apixaban 2.5 mg twice daily, and edoxaban 30 mg once daily and 9% used very low dose including rivaroxaban 10 mg once daily and edoxaban 15 mg once daily (Figure). Median follow-up duration was 2 years (interquartile ranges, 1 to 3 years). Baseline characteristics were well-balanced after IPTW. Compared to the no OAC group, the DOAC group was associated with a lower risk of ischemic stroke (hazard ratio [HR], 95% confidence interval [CI]: 0.81, 0.68–0.95) and all-cause death (0.90, 0.85–0.95), and a higher risk of major bleeding (1.43, 1.20–1.69) (Figure). Patients treated with DOAC showed a lower risk of composite clinical outcome compared to those without OAC treatment (0.93, 0.88–0.98). Warfarin treatment did not reduce the risk of ischemic stroke (1.03, 0.85–1.23) and all-cause death (1.05, 0.99–1.12), but increased the risk of major bleeding (1.60, 1.32–1.92) and the composite clinical outcome (1.08, 1.02–1.15) compared to no OAC group.

Conclusion

In very elderly patients with non-valvular AF who had one or more frail components, DOACs which were currently prescribed in usual clinical practice showed better effectiveness and positive net clinical benefit compared to no OAC treatment. Compared to the latter, warfarin did not show benefit and possible harm.

Funding Acknowledgement

Type of funding sources: None.

Sodium-glucose co-transporter 1 and 2 expression in the mammary artery of patients with bypass surgery: role of the pro-inflammatory response and contribution to oxidative stress

Background

Selective sodium-glucose cotransporter 2 (SGLT2) inhibitors have shown cardiovascular protection independently of glycemic control. Angiotensin II (Ang II) and H2O2 induced the expression of SGLT1 and 2 in cultured endothelial cells and isolated arteries to promote oxidative stress and endothelial dysfunction. However, the expression level and role of SGLT1 and 2 in human arteries remain poorly studied.

Purpose

This study examined the expression level of SGLT1 and 2 in the human internal mammary artery (IMA) obtained from bypass surgery patients, and, if so, determined the underlying mechanism and function.

Methods

IMAs were obtained from 40 bypass surgery patients (age 45 to 82). The expression level of target factors was assessed by Western blot analysis, immunofluorescence staining and RT-PCR, and the level of oxidative stress using dihydroethidium staining. Human kidney was used as a control tissue known to express SGLT1 and 2. Porcine coronary artery endothelial cells (CAEC) were cultured and studied at passage 1.

Results

Western blot analysis of 40 IMA samples indicated a high level of both SGLT1 and 2 in 16 and 17 IMAs, an intermediate level in 8 and 6 IMAs, and a low one in 16 and 17 IMAs, respectively. Immunofluorescence staining of IMA sections indicated that SGLT1 and 2 immunofluorescence signals were observed predominantly in the intima thickening and the media. The expression levels of SGLT1 and 2 were associated with p-p65 NF-kB signals but not angiotensin-converting enzyme (ACE), AT1R, MCP-1, VCAM-1. IMAs with a high expression level of SGLT1 and 2 had a high level of ROS throughout the arterial wall including the intima thickening and endothelium, which was inhibited by the antioxidant N-acetylcysteine, the ACE inhibitor perindoprilat, the AT1R antagonist losartan, and also by the dual SGLT1 and 2 inhibitor sotagliflozin and the selective SGLT2 inhibitor empagliflozin. Pro-inflammatory cytokines mRNA levels of IL-1β, TNF-α and IL-6 were detected in IMAs. Exposure of CAEC to either TNF-α, IL-1β or IL-6 caused a concentration-dependent upregulation of SGLT1 and 2.

Conclusion

The present findings indicate that SGLT1 and 2 expression is observed in some but not all IMAs of bypass surgery patients predominantly in the media, the intima thickening and the endothelium. High expression levels of SGLT1 and 2 are associated with NF-kB activation and oxidative stress that is prevented by a selective SGLT2 inhibitor and by a dual SGLT1/2 inhibitor. Since pro-inflammatory cytokines triggered SGLT1 and 2 expression in endothelial cells, the inflammatory burden of patients appears to be an important trigger regulating SGLT1/2 expression and the subsequent pro-oxidant response prompting pro-inflammatory and pro-thrombotic responses.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): This work was supported by an unrestricted research grant from Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany.

A novel index reflecting both anatomical and physiologic parameters in coronary artery disease, the FFR adjusted SYNTAX score (FaSs)

Background

Various physiology-based indices have been proposed to predict adverse clinical events in patients with coronary artery disease (CAD), such as the sum of three vessel-fractional flow reserve (3v-FFR), and the functional SYNTAX score (fSS). However, these values could not fully reflect the anatomical factors, which remains as a barrier for clinical application of these indices.

Purpose

To propose a novel index which can reflect both anatomical and physiologic features in CAD patients, and evaluate the additional predictive value for cardiovascular adverse events compared to previous indices.

Methods

For an index which can reflect both anatomical and physiologic features, we proposed the FFR adjusted SYNTAX score (FaSs). The FaSs is calculated by adding the product of the SYNTAX score and `1-FFR', for all three major coronary arteries. Among the 1136 patients who enrolled at 3V FFR-FRIENDS study, we investigated 866 patients, after excluding those who had missing variables. The 3v-FFR, fSS and FaSs were calculated, derived from the baseline FFR and SYNTAX score. Patients were divided into two groups according to the median value of each index. The primary endpoint was major adverse cardiac events (MACE, a composite of cardiac death, myocardial infarction and ischemia-driven revascularization) at 2 years follow-up.

Results

Among the total population, MACE occurred in 35 (4.04%) patients. Using the median value in a multivariable COX regression model, only FaSs was associated with an increased risk of MACE, (Hazard Ratio [HR] 5.256, 95% confidence interval [CI] 2.014–13.720), while 3v-FFR (HR 1.383, 95% CI 0.685–2.790) and fSS (HR 1.640, 95% CI 0.830–3.243) were not significantly associated with a higher risk of MACE. This was also observed in the Kaplan Meier survival curve analysis (log-rank p value: p&lt;0.001 for FaSs, 0.153 for 3v-FFR, and 0.061 for fSS; Figure 1) The sensitivity and specificity of the FaSs was 85.7% and 51.6%, which was higher compared to the 3v-FFR (62.9% and 49.3%, respectively) and fSS (57.1% and 58.5%, respectively). When these indices were combined with clinical risk factors (age, sex, hypertension, diabetes, hyperlipidemia, chronic renal failure, LVEF&lt;40%), FaSs was superior compared with 3v-FFR and fSS assessed in regards of the predictive accuracy for MACE (Figure 2).

Conclusion

The FaSs, which is a novel index calculated by a formula using the SYNTAX score and FFR, showed a superior predictive value for MACE compared to previous indices. Our results confirm the importance of considering both anatomical and physiologic parameters in evaluating the patient's risk for cardiovascular adverse outcomes.

Funding Acknowledgement

Type of funding sources: None.

Factors associated with the difference between the incidence and case-fatality ratio of coronavirus disease 2019 by country

Coronavirus disease (COVID-19) has been spreading all over the world; however, its incidence and case-fatality ratio differ greatly between countries and between continents. We investigated factors associated with international variation in COVID-19 incidence and case-fatality ratio (CFR) across 107 northern hemisphere countries, using publicly available COVID-19 outcome data as of 14 September 2020. We included country-specific geographic, demographic, socio-economic features, global health security index (GHSI), healthcare capacity, and major health behavior indexes in multivariate models to explain this variation. Multiple linear regression highlighted that incidence was associated with ethnic region (p < 0.05), global health security index 4 (GHSI4) (beta coefficient [β] 0.50, 95% Confidence Interval [CI] 0.14-0.87), population density (β 0.35, 95% CI 0.10-0.60), and water safety level (β 0.51, 95% CI 0.19-0.84). The CFR was associated with ethnic region (p < 0.05), GHSI4 (β 0.53, 95% CI 0.14-0.92), proportion of population over 65 (β 0.71, 95% CI 0.19-1.24), international tourism receipt level (β - 0.23, 95% CI - 0.43 to - 0.03), and the number of physicians (β - 0.37, 95% CI - 0.69 to - 0.06). Ethnic region was the most influential factor for both COVID-19 incidence (partial [Formula: see text] = 0.545) and CFR (partial [Formula: see text] = 0.372), even after adjusting for various confounding factors.

Comparison of RT-PCR, RT-nested PCRs, and real-time PCR for diagnosis of severe fever with thrombocytopenia syndrome: a prospective study

We designed a highly sensitive reverse transcription nested polymerase chain reaction targeting the M-segment (NPCR-M) of severe fever with thrombocytopenia syndrome (SFTS) virus. NPCR-M was performed in parallel with three other referenced PCR assays QPCR-S, PCR-M, and NPCR-S to assess their clinical usefulness as routine diagnostic techniques for SFTS. In this multi-centered prospective study, 122 blood samples from 38 laboratory-confirmed SFTS patients and 85 control samples were used. The results demonstrated that QPCR-S and NPCR-S had better sensitivity rate up to 21 days after symptom onset however, the PCR-M showed poor sensitivity after 7 days of symptom onset. Our designed NPCR-M had a higher detection rate up to 40 days from symptom onset and revealed the persistence of SFTSV RNA in the early convalescent phase. No false-positive results were seen for the control samples. Additionally, NPCR-M showed positive results for a sample that initially showed negative results from other PCRs and for many other samples collected in the convalescent phase of SFTS. Our designed nested PCR is suitable for SFTSV detection in patients’ blood collected in the acute and early convalescent phase of SFTS, and shows better sensitivity and high specificity even up to 40 days after symptom onset.

New-onset Nephrotic Syndrome after Janssen COVID-19 Vaccination: a Case Report and Literature Review

Various coronavirus disease 2019 (COVID-19) vaccines are being developed, which show practical preventive effects. Here, we report a 51-year-old healthy man with nephrotic syndrome secondary to minimal change disease (MCD) after Ad26.COV.2 (Janssen) vaccination. He had no comorbid disease and received Ad26.COV.2 on April 13, 2021. Seven days after vaccination, he developed edema and foamy urine. Edema rapidly aggravated with decreased urine volume. He was admitted to the hospital 28 days after vaccination, and his body weight increased by 21 kg after vaccination. His serum creatinine level was 1.54 mg/dL, and 24-h urinary protein excretion was 8.6 g/day. Kidney biopsy revealed no abnormality in the glomeruli and interstitium of the cortex and medulla under the light microscope. Electron microscopy revealed diffuse effacement of the podocyte foot processes, thus, he was diagnosed with MCD. High-dose steroid therapy was applied, and his kidney function improved three days after steroid therapy. Three weeks after steroid use, his serum creatinine decreased to 0.95 mg/dL, and spot urine protein-to-creatine decreased to 0.2 g/g. This case highlights the risk of new-onset nephrotic syndrome secondary to MCD after vectored COVID-19 vaccination. Although the pathogenesis is uncertain, clinicians need to be careful about adverse renal effects of COVID-19 vaccines.

Complications during repeated tracheal intubation in the Intensive Care Unit. A prospective, observational study comparing the first intubation and the reintubation

BACKGROUND AND GOAL OF THE STUDY

The goal of the study was to compare the incidence of complications, technical difficulty of intubation and physiologic pre-intubation status between the first intubation and reintubation performed on the same patient in an ICU.

MATERIALS AND METHODS

The study was approved by the ethics committee of Galicia (Santiago-Lugo, code No. 2015-012). Due to the observational, noninterventional, and noninvasive design of this study, the need for written consent was waived by the ethics committee of Galicia. Patients requiring tracheal intubation and reintubation in the ICU were included in this prospective observational study. Main endpoint was to compare the incidence of complications, physiologic pre-intubation status, and the rate of technical difficulty of intubation between the first intubation and reintubation performed on the same patient in an ICU.

RESULTS AND DISCUSSION

504 patients were intubated in our ICU during the study period, and 82 (16%) required reintubation. There was no difference between the first intubation and reintubation regarding number of total complication (35% vs 33%; P = ,86), hypotension (24% vs 24%; P = 1), hypoxia (26% vs 26%; P = 1), esophageal intubation (1% vs 1%; P = 1), and bronchoaspiration (2% vs 1%; P = ,86). Physiologic pre-intubation status and technical difficulty of intubation did not differ between the first intubation and reintubation.

CONCLUSIONS

In our ICU patients requiring tracheal reintubation, incidence of complications, physiologic pre-intubation status, and technical difficulty of intubation did not differ between the first intubation and reintubation.

Status of antimicrobial stewardship programmes in Korean hospitals including small to medium-sized hospitals and the awareness and demands of physicians: a nationwide survey in 2020

OBJECTIVES

This study aimed to identify the status of antimicrobial stewardship programmes (ASPs) in small to medium-sized Korean hospitals as well as the awareness and demands about ASPs of physicians.

METHODS

A questionnaire was designed based on a questionnaire from a previous nationwide survey in 2018 targeting large hospitals in Korea and modified to reflect the results of in-depth interviews with non-infectious diseases (IDs) physicians at secondary care hospitals. The survey targeted all hospitals with ≥150 beds in South Korea and was performed in May-June 2020. Only one ASP-associated physician per hospital participated in the survey.

RESULTS

The survey response rate was 31.9% (217/680). ID specialists comprised the majority of medical personnel participating in ASPs in tertiary care hospitals. Conversely, in secondary and primary care hospitals there was no predominant medical personnel for ASPs and the median full-time equivalent was 0 for all types of medical personnel. Tertiary care hospitals, more than secondary and primary care hospitals, tended to perform ASP activities more actively. 'Workforce for ASPs', 'Establishment of healthcare fees for ASPs' and 'Development of tools for ASPs' were the most important required support for ASP improvement.

CONCLUSION

The level of ASP establishment was more limited in primary care hospitals than in secondary and tertiary care hospitals in Korea. To improve ASPs in Korean hospitals, a supporting workforce and the establishment of a healthcare fee for ASPs appear to be necessary.

Off-label underdosed apixaban use in Asian patients with non-valvular atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Background

In Asian patients with atrial fibrillation (AF), off-label underdosed prescriptions of direct oral anticoagulants (DOACs) are common

Purpose

We aimed to compare the effectiveness and safety of off-label underdosed apixaban with on-label standard dose apixaban in Asian patients with AF.

Methods

Using the Korean nationwide claims database, we identified patients who prescribed apixaban and did not fulfill the dose reduction criteria of apixaban between January 2015 and December 2017. Multivariable Cox hazard regression model was performed and hazard ratios (HRs) for ischemic stroke, major bleeding (MB), all-cause death, and the composite clinical outcome were analyzed.

Results

Compared to patients prescribed on-label standard dose apixaban (n = 4,194), patients prescribed off-label underdosed apixaban (n = 2,890) were associated with higher risks of ischemic stroke (adjusted HR [aHR] 1.38, 95% confidence interval [CI] 1.06-1.81), all-cause death (aHR 1.19, 95% CI 1.01-1.39) and the composite clinical outcome (aHR 1.17, 95% CI 1.03-1.34), but with no significant differences in MB between the two groups (Figure). In patients without any dose reduction criteria, off-label underdosed apixaban use was associated with a significantly higher risk of ischemic stroke than on-label standard dose apixaban use (aHR 1.85, 95% 1.25-2.73); however, in patients who had single dose reduction criteria (age ≥80 years, serum creatinine ≥1.5mg/dL, or bodyweight ≤60 kg), off-label underdosed apixaban use did not show a significant overall benefit in the composite clinical outcome compared with on-label standard dose apixaban, but was associated with a higher risk of all-cause death (aHR 1.32, 95% CI 1.07-1.64).

Conclusion

Off-label underdosed apixaban use was associated with higher risks of ischemic stroke, all-cause death, and composite clinical outcome and comparable risk of MB compared with on-label standard dose apixaban use. Label-adherence of apixaban dosing should be emphasized to achieve the best clinical outcome for Asian patients with non-valvular AF, especially in those without any dose reduction criteria. Abstract Figure.

Safety and immunogenicity of a seasonal quadrivalent influenza vaccine (GC3110A) in healthy participants aged ≥ 65 years

BACKGROUND

Seasonal Influenza is still considered associated with seasonal morbidity and hospitalization in the elderly population. The World Health Organization (WHO) recommended seasonal quadrivalent influenza vaccine (QIV) to reduce burden of two currently circulating influenza B lineages. Until 2019 Korean National Immunization Program (NIP) recommended trivalent influenza vaccine (TIV) after ongoing debates on cost effectiveness of QIV for elderly population. Although influenza vaccine only showed modest effect on reducing influenza in elderly, this study aimed to evaluate the immunogenicity and safety of inactivated QIV in healthy participants ≥ 65 years of age.

METHODS

A total of 274 healthy participants aged ≥ 65 years received a QIV. Seroconversion-based vaccine efficacy of 4 strains of seasonal influenza was assessed 21 days after vaccination and adverse events were monitored until 180 days after vaccination.

RESULTS

The percentages of participants seroconverted after vaccination on HI antibody against each strain were 36.5% (99/271) to A/H1N1, 47.6% (129/271) to A/H3N2, 40.6% (110/271) to B Yamagata, and 49.1% (133/271) to B Victoria. The percentages of participants seroprotected after vaccination on HI antibody against each strain were 81.2% (220/271) to A/H1N1, 98.5% (267/271) to A/H3N2, 95.2% (258/271) to B Yamagata, and 93.7% (254/271) to B Victoria. There was no serious adverse event (SAE) related with the study vaccine.

CONCLUSION

The quadrivalent split influenza vaccine is expected to offer seroprotection against influenza A and both influenza B lineages even in the elderly population.

Estimating the basic reproductive number of varicella in South Korea incorporating social contact patterns and seroprevalence

Varicella, which is caused by the varicella zoster virus (VZV), is a common infectious disease affecting children. Varicella vaccines have been used for decades; however, vaccination policies vary across countries because of differences in VZV epidemiology. The basic reproductive number R0 _a transmissibility measure parameter, also differs from country to country. In this study R0 for varicella was estimated in South Korea using the contact rate matrix derived from averaged POLYMOD contact data, the Korean population, and proportionality factor fitted to the Korean VZV seroprevalence R0 for varicella in South Korea was estimated to be 5.67 (95% CI: 5.33, 6.33). Therefore, to reach the herd immunity threshold, the critical vaccine coverage should be greater than 82.4% with a perfect vaccine, or the primary vaccine failure proportion should be less than 17.6% with 100% coverage. Because of the relatively low seroconversion rate and rapidly waning immunity after one-dose vaccination in South Korea, the herd immunity threshold is difficult to attain with only a one-dose vaccine. Two doses of vaccination may be necessary to effectively interrupt varicella transmission and maintain herd immunity in South Korea. The study results can help guide the decision-making on an effective varicella vaccination policy in South Korea.

The impact of two-dose varicella vaccination on varicella and herpes zoster incidence in South Korea using a mathematical model with changing population demographics

BACKGROUND

In South Korea, one-dose varicella vaccination was introduced to the National Immunization Program in 2005, but varicella outbreaks have continued to occur. Therefore, a two-dose vaccination strategy is considered.

METHODS

We developed an age-structured deterministic compartment model using Korean population projection data. The impact of adding a second dose of varicella vaccine on varicella and herpes zoster (HZ) epidemiology was assessed under four different vaccine effectiveness (VE) scenarios (base, moderate, lowest, highest) and the optimal timing of the second vaccine dose (18 months, 4, 5, or 6 years of age) was examined over the period 2020-2065.

RESULTS

A two-dose vaccination schedule reduced the cumulative varicella incidence by > 90% compared to no vaccination, regardless of the VE. The additional reduction attributable to a second dose compared to a single dose was greatest (82%) with the lowest VE scenario. A second dose at 6 years of age reduced the varicella incidence at a population level, whereas a second dose at 18 months of age reduced the varicella incidence primarily in the target birth cohorts. Routine vaccination at the age of 18 months with a catch-up vaccination of 6-year-olds was the optimal strategy for birth cohort and population-level control. HZ incidence continued to increase under no vaccination scenario, which represents the effect of aging population. Under a two-dose scenario, the additional increase in HZ incidence attributable to the reduced exogenous boosting was small relative to a one-dose scenario and a further reduction in HZ cases was observed.

CONCLUSION

A two-dose varicella vaccination schedule would significantly reduce varicella and HZ incidence in the long term. A second dose at the age of 18 months with a catch-up vaccination of 6-year-olds would be optimal for controlling varicella in South Korea.

Measles seroprevalence among healthcare workers in South Korea during the post-elimination period

During the measles epidemic in 2019, in-hospital transmission of measles contributed to more than two-thirds of measles cases in South Korea, where measles is declared eliminated. This study aimed to examine measles seropositivity among healthcare workers (HCWs) in South Korea to help develop an effective measles prevention strategy for hospital settings. Measles IgG titer was tested in 1,579 HCWs working in a university-affiliated hospital and the measles-containing vaccine (MCV) immunization records of 870 HCWs were identified. The overall seropositivity was 92.0%, but the seropositivity and antibody titers were significantly low among HCWs aged 20-25 years (78.6%) and among one-dose vaccine recipients (86.7%). Among two-dose recipients, seropositivity was lower among young HCWs who received two doses during their childhood than among those who received the catch-up vaccination as part of job requirements (70.3% vs. 98.0%). Among 87 seronegative HCWs who received two-dose MMR vaccination, the seroconversion rate was 98.9%. A considerable proportion of young HCWs were potentially susceptible to measles despite receiving the two-dose vaccination during childhood because of the waning immunity against measles in a country with measles-eliminated status. Serological screening for measles of newly employed HCWs and MCV immunization of seronegative HCWs appears to be an effective prevention strategy.

Investigation of the optimal medium and application strategy for foot-and-mouth disease vaccine antigen production

AIMS

For the effective production of 146S particles, which determines foot-and-mouth disease (FMD) vaccine efficacy, we aimed to identify the optimal medium that is easy-to-use, productive and economically affordable for the large-scale production of FMD vaccine.

METHODS AND RESULTS

Nine combinations of cell growth media and replacement media were tested for virus propagation. Apart from the replacement strategy, we tested a simple addition strategy involving the addition of 30% v/v of fresh medium to the total spent medium using the Cellvento BHK-200 (Vento). Unlike other tested media that produced poor yields of 146S particles when the spent media were not eliminated, Vento exhibited high productivity with the 30% addition strategy.

CONCLUSIONS

Considering its lower price and media consumption compared to those of other media that require media replacement, the 30% addition strategy of Vento is highly effective. Furthermore, owing to its simple application strategy, it makes the scale-up process easy and helps in saving the time and labour involved in spent media removal.

SIGNIFICANCE AND IMPACT OF THE STUDY

Through the first comparative assessment of commercial media for the 146S particle recovery, this study suggests the best practical medium for the industrial-scale production of FMD vaccines.

Effects of steroid therapy in patients with severe fever with Thrombocytopenia syndrome: A multicenter clinical cohort study

BACKGROUND

Severe fever with thrombocytopenia syndrome (SFTS) is an acute, febrile, and potentially fatal tick-borne disease caused by the SFTS Phlebovirus. Here, we evaluated the effects of steroid therapy in Korean patients with SFTS.

METHODS

A retrospective study was performed in a multicenter SFTS clinical cohort from 13 Korean university hospitals between 2013 and 2017. We performed survival analysis using propensity score matching of 142 patients with SFTS diagnosed by genetic or antibody tests.

RESULTS

Overall fatality rate was 23.2%, with 39.7% among 58 patients who underwent steroid therapy. Complications were observed in 37/58 (63.8%) and 25/83 (30.1%) patients in the steroid and non-steroid groups, respectively (P < .001). Survival analysis after propensity score matching showed a significant difference in mean 30-day survival time between the non-steroid and steroid groups in patients with a mild condition [Acute Physiology and Chronic Health Evaluation II (APACHE II) score <14; 29.2 (95% CI 27.70-30.73] vs. 24.9 (95% CI 21.21-28.53], P = .022]. Survival times for the early steroid (≤5 days from the start of therapy after symptom onset), late steroid (>5 days), and non-steroid groups, were 18.4, 22.4, and 27.3 days, respectively (P = .005).

CONCLUSIONS

After steroid therapy, an increase in complications was observed among patients with SFTS. Steroid therapy should be used with caution, considering the possible negative effects of steroid therapy within 5 days of symptom onset or in patients with mild disease (APACHE II score <14).

A transdiagnostic examination of anxiety and stress on executive function outcomes in disorders with social impairment

BACKGROUND

Executive function (EF) difficulties characterise a number of psychiatric conditions and EF impairment may be a predisposing factor and/or consequence of anxiety and stress. The aim of the study was to examine EF factors in a mixed clinical cohort (Autism Spectrum Disorder and Social Anxiety Disorder) characterised by social impairment and investigate the influence of trait anxiety and state-based depression, anxiety and stress.

METHODS

In Study 1, a factor analysis identified EF and non-EF latent factor structures (N=205). In Study 2, (N=137) multiple regression analyses investigated the association between trait anxiety and state based depression, anxiety and stress, on EF and non-EF cognitive domains and on the two composite indices of the Behavioural Rating Inventory of Executive Function (BRIEF).

RESULTS

Trait anxiety was associated with better performance on neuropsychological measures of EF while state-based stress was associated with lower EF performance. A dissociation was observed between trait anxiety and state stress on the two behavioural indices of the BRIEF. Depression, anxiety and stress did not predict performance on non-EF cognitive domains.

LIMITATIONS

The cross-sectional design precludes cause-effect conclusions, further only self-report measures of affect were utilised and our performance measures of EF did not include a working memory test.

CONCLUSIONS

The results demonstrate that trait anxiety and state-based stress influence EF processes across disorders with social impairment. The transdiagnostic efficacy of this finding can facilitate remediation strategies, it may also contribute to individuals with Autism Spectrum Disorder gaining better access to mental health services.

The impact of the Xpert MTB/RIF screening among hospitalized patients with pneumonia on timely isolation of patients with pulmonary tuberculosis

In South Korea where the tuberculosis (TB) burden is intermediate, the risk of in-hospital transmission of TB remains high. We conducted a retrospective cohort study of 244 inpatients diagnosed with pulmonary TB (2015–2018) to evaluate the impact of the Xpert MTB/RIF assay (Xpert) screening on timely isolation. TB screening was performed with smear microscopy and a polymerase chain reaction test, and the Xpert was additionally used from November 2016. Among all patients with pulmonary TB, the median time-to-isolation was significantly reduced (22.6 vs. 69.7 h; p < 0.001) and segmented regression analysis adjusting for the time trend showed a reduction in time-to-isolation with the introduction of the Xpert (− 39.3 h; 95% CI − 85.6, 7.0; p = 0.096). Among 213 patients who were timely screened (≤ 72 h after admission), time-to-isolation decreased significantly (− 38.2 h; 95% CI − 70.6, − 5.8; p = 0.021) with the introduction of the Xpert, and its decreasing trend continued. The Xpert provided a shorter turnaround time (4.8 vs. 49.1 h; p < 0.001) and higher sensitivity (76.6% vs. 47.8%; p < 0.001) than smear microscopy. Thus, the Xpert can be a useful screening test for pulmonary TB in real-life hospital settings with an intermediate TB burden.

Mupirocin and Chlorhexidine Genotypic Resistance Found in Staphylococcus aureus Isolated From Young Infants Below 90 Days Old: A Genetic Basis for Eradication Failure

OBJECTIVES

To investigate the genetic characteristics associated with eradication failure of Staphylococcus aureus in infants below 90 days old.

METHODS

S. aureus isolated from clinical specimen cultures (blood, surgical tissue, or drainage, pus, etc.) and routine screening cultures in the neonatal intensive care unit (nasal and axillary skin swab) from patients below 90 days old were collected prospectively for 1 year, from August 2017 to July 2018. The isolates underwent typing and screening for genes associated with chlorhexidine (qacA/B), quaternary ammonium (smr), and mupirocin resistance (iles mutation, mupA, mupB), as well as Panton-Valentine leukocidin (PVL) toxin.

RESULTS

During the study period, 40 nonduplicate isolates were included for analyses, of which 70.0% were methicillin-resistant S. aureus (MRSA). Mupirocin resistance was found in 25% of the total isolates; 17.4% of the colonizers; and 35.3% of the pathogens (P = 0.196). Chlorhexidine resistance gene was found in 3 MRSA isolates colonized in the nares of preterm infants. All isolates harbored the disinfectant quaternary ammonium compound (QAC) resistance gene. PVL toxin gene was found in 57.5%, and the presence of PVL gene among colonizers and pathogens was similar (69.6% vs. 41.2%, P = 0.072).

CONCLUSIONS

Mupirocin, chlorhexidine, and QAC-resistant MRSAs harboring the PVL toxin gene were found in the nasal carriages of preterm infants. In this highly vulnerable patient population, one-fourth of the isolates harbored mupirocin-resistant genes, and all were resistant to QAC disinfectants. These strains are associated with persistence in both carriage and environmental reservoirs within the hospitals.

155. Development of antibiotic classification for measuring antibiotic usage in Korean hospitals using a modified Delphi method

Background

In 2019, the project about developing a system for measure and benchmark antibiotic usage in each hospital was launched. As the basic work for the project, we developed ‘antibiotic classification for measuring antibiotic usage in Korean hospitals’ using a modified Delphi method.

Consensual definition of antibiotic components according to the antibiotic classification in Korean hospitals.

Methods

The study consisted of two series of modified Delphi studies and was performed from July to August 2019. The study ‘antibiotic classification in Korean hospitals’ was performed first and followed by the study ‘antibiotic components according to the antibiotic classification in Korean hospitals’. Each Delphi study included two rounds of surveys in order to gather opinions and refine the information related to each study. We recruited a total of 12 panels including infectious diseases physicians (10), professor of preventive medicine (1), and the researcher of Health Insurance Review & Assessment Service (1). The questions for the Round 1 survey in each study were adopted from the antibiotic classification of the NHSN.

Results

As for the first study, the response rate of each round was 58.3% (7/12) and 75.0% (9/12), respectively. Most of the subjects of the NHSN’s antibiotic classification for adults were accepted except ‘antibacterial agents posing the highest risk for Clostridioides difficile infection’ (CVR = -1.000). On the contrary, all subjects for children were rejected. Finally, a total of 6 classifications were accepted. They were i) broad-spectrum antibacterial agents predominantly for hospital-onset infections, for adult (CVR = 1.000), ii) broad-spectrum antibacterial agents predominantly used for community-acquired infections, for adult (CVR = 1.000), iii) antibacterial agents predominantly used for resistant gram-positive infections, for adult (CVR =1.000), iv) narrow-spectrum beta-lactam agents, for adult (CVR = 1.000), v) antibacterial agents predominantly used for extensive antibiotic resistant gram-negative bacteria, for adult (CVR = 1.000), and vi) total antibacterial agent (CVR = 1.000).

Conclusion

this study provides antibiotic classification for measuring antibiotic usage in Korean hospitals. This classification may guide to develop a system for measuring of antibiotic usage in each Korean hospital.

Disclosures

All Authors: No reported disclosures

1080. Changing Epidemiology and Long-Term Outcome of Bloodstream Infection Due to Enterococcus for Patients with Acute Leukemia: Impacts and Limitations on Strategy of Restricting Antibiotics

Background

Gastrointestinal dysbiosis due to antibiotics and mucosal injury by intensive chemotherapy are important risk factors for Enterococcal infection in patients with acute leukemia. However, there is still disagreement about trends of incidence and outcome of bloodstream infection (BSI) due to Enterococcus species. This study aimed to identify the changes in the epidemiology of Enterococcal BSI and to estimate the long-term impact of Enterococcal BSI on outcome in an acute leukemia cohort.

Methods

All adult acute leukemia patients diagnosed with Enterococcal BSI (N = 512) between 2014 to 2018 at the Catholic Hematology Hospital were retrospectively reviewed. The incidence rate was compared with antibiotics use and multivariable models were used to estimate the impact of Enterococcal BSI on the outcome.

Results

Of 433 patients, 512 episodes of Enterococcal BSI occurred: 172 (33.6%) of 512 were vancomycin-resistant Enterococcus (VRE) and baseline characteristics were similar in comparison with vancomycin-susceptible Enterococcus (VSE) BSI. The incidence rate of VRE seemed to decrease for 6 months after a change in the strategy of restricting prophylactic use of fluoroquinolone and empirical use of carbapenem (39.2% vs 12.2%, Odds ratio [OR]=0.312, 95% confidence interval [CI], 0.116-0.843, p=0.018). However, overall Enterococcal BSI continued to increase with the rapidly increased use of unrestricted antibiotics. VRE BSI was associated with higher 100-day mortality than VSE BSI after adjusting for covariates (hazard ratio [HR]=1.477; 95% CI, 1.027-2.125, p=0.035), but there was no difference in long-term outcome at one year. In multivariable models, high-risk groups such as old age, advanced stage of disease, polymicrobial infection, high Pitt bacteremia score, and BSI complications after hematopoietic cell transplantation (HSCT) were strongly associated with worse long-term outcome (p< 0.05 for all variables).

Table 1. Baseline characteristics of Enterococcal bloodstream infection (BSI)

Figure 1. Incidence rate of Enterococcal BSI with changes of aggregated antibiotics utilization in acute leukemia cohort. Vertical black dash line is the time of new institutional strategy of restricting fluoroquinolone prophylaxis and use of carbapenem. Abbreviations: DDDs, defined daily doses; Q, quarter

Figure 2. Multivariable analysis of risk factors for overall survival at one year. Abbreviations: HR, hazard ratio; CI, confidence interval; BSI, bloodstream infection; CR, complete remission; HSCT, hematopoietic stem cell transplantation; ALL, acute lymphocytic leukemia; VRE, vancomycin-resistant Enterococcus

Conclusion

The effort to restrict the use of fluoroquinolone and carbapenem alone is insufficient to reduce Enterococcal BSI. To improve long-term outcomes, especially in high-risk patients, multidisciplinary interventions to reduce the overall use of antibiotics along with the total incidence of Enterococcal BSI are needed.

Disclosures

Sung-Yeon Cho, MD, Gilead (Grant/Research Support, Speaker’s Bureau)Merck Sharp & Dohme (Grant/Research Support, Speaker’s Bureau)Pfizer (Grant/Research Support, Speaker’s Bureau)

A randomized phase III trial comparing adjuvant single-agent S1, S-1 with oxaliplatin, and postoperative chemoradiation with S-1 and oxaliplatin in patients with node-positive gastric cancer after D2 resection: the ARTIST 2 trial☆

BACKGROUND

Adjuvant chemotherapy and chemoradiotherapy are some of the standards of care for gastric cancer (GC). The Adjuvant chemoRadioTherapy In Stomach Tumors (ARTIST) 2 trial compares two adjuvant chemotherapy regimens and chemoradiotherapy in patients with D2-resected, stage II or III, node-positive GC.

PATIENTS AND METHODS

The ARTIST 2 compared, in a 1:1:1 ratio, three adjuvant regimens: oral S-1 (40-60 mg twice daily 4 weeks on/2 weeks off) for 1 year, S-1 (2 weeks on/1 week off) plus oxaliplatin 130 mg/m² every 3 weeks (SOX) for 6 months, and SOX plus chemoradiotherapy 45 Gy (SOXRT). Randomization was stratified according to surgery type (total or subtotal gastrectomy), pathologic stage (II or III), and Lauren histologic classification (diffuse or intestinal/mixed). The primary endpoint was disease-free survival (DFS) at 3 years; a reduction of 33% in the hazard ratio (HR) for DFS with SOX or SOXRT, when compared with S-1, was considered clinically meaningful. The trial is registered at clinicaltrials.gov (NCT0176146).

RESULTS

A total of 546 patients were recruited between February 2013 and January 2018 with 182, 181, and 183 patients in the S-1, SOX, and SOXRT arms, respectively. Median follow-up period was 47 months, with 178 DFS events observed. Estimated 3-year DFS rates were 64.8%, 74.3%, and 72.8% in the S-1, SOX, and SOXRT arms, respectively. HR for DFS in the control arm (S-1) was shorter than that in the SOX and SOXRT arms: S-1 versus SOX, 0.692 (P = 0.042) and S-1 versus SOXRT, 0.724 (P = 0.074). No difference in DFS was found between SOX and SOXRT (HR 0.971; P = 0.879). Adverse events were as anticipated in each arm, and were generally well-tolerated and manageable.

CONCLUSIONS

In patients with curatively D2-resected, stage II/III, node-positive GC, adjuvant SOX or SOXRT was effective in prolonging DFS, when compared with S-1 monotherapy. The addition of radiotherapy to SOX did not significantly reduce the rate of recurrence after D2 gastrectomy.

Long-term clinical outcomes of endoscopic submucosal dissection for colorectal neoplasia with or without the hybrid technique

AIM

The main aim of this study was to compare the long-term outcome of a conventional colorectal endoscopic submucosal dissection (ESD) in which submucosal dissection was continued throughout until the completion of resection (ESD-T) to hybrid endoscopic submucosal dissection (ESD-H) in the colorectum.

METHOD

Medical records of 836 colorectal neoplasia patients treated by ESD-T or ESD-H were reviewed. ESD-H was defined as colorectal ESD with additional snaring in the final stage of the procedure. Primary outcomes were the overall and metastatic recurrence rates. Secondary outcomes were short-term outcomes such as the en bloc resection rate, procedure time and adverse events.

RESULTS

The overall recurrence rate was higher in the ESD-H than in the ESD-T group (5.7% vs 0.7%, P = 0.001). The metastatic recurrence rate showed no significant difference between these groups (1.4% vs 1.4%, P = 1.000). Multivariate analysis revealed that a failed en bloc resection (hazard ratio 24.097; 95% CI 5.446-106.237; P < 0.001) and larger tumour size (hazard ratio 1.042; 95% CI 1.014-1.070; P = 0.003) were independently associated with overall recurrence. The ESD-H group showed a lower en bloc resection rate (56.8% vs 96.5%, P < 0.001), shorter procedure time (45.6 vs 54.3 min, P < 0.001) and higher perforation rate (10.3% vs 6.0%, P = 0.029).

CONCLUSION

Although long-term outcomes in terms of overall recurrence are inferior following ESD-H, a failed en bloc resection and large tumour size are the only independent risk factors for recurrence. Further investigations are warranted to improve the long-term outcomes of ESD-H.

Low-dose CT angiography of the lower extremities: a comparison study of image quality and radiation dose

AIM

To investigate the image quality and radiation dose of ultralow-dose (ULD) and low-dose (LD) lower-extremity computed tomography (CT) angiography (LE-CTA) using the advanced modelled iterative reconstruction (ADMIRE) algorithm to detect peripheral arterial disease (PAD) in comparison with standard-dose (SD) CT.

MATERIALS AND METHODS

One hundred and seven consecutive patients were examined using LE-CTA at 70 kVp and a dual-source scanner to achieve three image sets using 30% (ULD), 70% (LD), and 100% (SD) tube loads. Qualitative analysis was conducted by examining the three image sets for overall quality. The image quality of arterial segments was analysed by two independent readers. In addition, the CT dose index (CTDI_vol) was measured in the three image sets.

RESULTS

The mean overall quality scores were 3.4±0.6 for ULD CT, 3.9±0.3 for LD CT, and 3.9±0.2 for SD CT. Both readers scored the arterial segments as 2-4 (adequate-excellent) in the three image sets. In addition, 89.4% (93/104) and 54.8% (57/104) segments of PAD with calcified plaques were scored 4 between SD and LD CT and between SD and ULD CT, respectively, and 45.2% (47/104) segments had a lower score by one point in ULD CT compared with SD CT. The mean CTDI_vol was 4.1±1.1 mGy for SD CT, 2.9±0.8 mGy for LD CT, and 1.2±0.3 mGy for ULD CT.

CONCLUSIONS

LD/ULD CT at 70 kVp using ADMIRE reconstruction enables a reduction in the radiation dose while enabling adequate evaluation or follow-up of PAD based on LE-CTA.

Photoconjugation of an Fc-Specific Peptide Enables Efficient DAR 2 Antibody-Drug Conjugate Formation

Antibody-drug conjugates (ADCs) in current clinical usage have been constructed via the nonspecific conjugation of drugs to antibodies, rendering the manufacturing processes difficult. In this study, a high-affinity IgG Fc-binding peptide equipped with a photoreactive amino acid was developed and successfully conjugated to Glu-382 of trastuzumab in a site-specific manner. The resulting conjugate was employed to generate a DAR 2 ADC product using click chemistry.

Impact of the Learning Curve on the Survival of Abdominal or Minimally Invasive Radical Hysterectomy for Early-Stage Cervical Cancer

Purpose

The objective of this study was to define the learning curve required to attain satisfactory oncologic outcomes of cervical cancer patients who were undergoing open or minimally invasive surgery for radical hysterectomy, and to analyze the correlation between the learning curve and tumor size.

Materials and Methods

Cervical cancer patients (stage IA–IIA) who underwent open radical hysterectomy (n=280) or minimal invasive radical hysterectomy (n=282) were retrospectively reviewed. The learning curve was evaluated using cumulative sum of 5-year recurrence rates. Survival outcomes were analyzed based on the operation period (“learning period,” P1 vs. “skilled period,” P2), operation mode, and tumor size.

Results

The 5-year disease-free and overall survival rates between open and minimally invasive groups were 91.8% and 89.0% (p=0.098) and 96.1% and 97.2% (p=0.944), respectively. The number of surgeries for learning period was 30 and 60 in open and minimally invasive group, respectively. P2 had better 5-year disease-free survival than P1 after adjusting for risk factors (hazard ratio, 0.392; 95% confidence interval, 0.210 to 0.734; p=0.003). All patients with tumors < 2 cm had similar 5-year disease-free survival regardless of operation mode or learning curve. Minimally invasive group presented lower survival rates than open group when tumors ≥ 2 cm in P2. Preoperative conization improved disease-free survival in patients with tumors ≥ 2 cm, especially in minimally invasive group.

Conclusion

Minimally invasive radical hysterectomy required more cases than open group to achieve acceptable 5-year disease-free survival. When tumors ≥ 2 cm, the surgeon’s proficiency affected survival outcomes in both groups.

A Novel KPC Variant KPC-55 in Klebsiella pneumoniae ST307 of Reinforced Meropenem-Hydrolyzing Activity

A novel Klebsiella pneumoniae carbapenemase (KPC) variant, KPC-55, produced by a K. pneumoniae ST307 strain was characterized. K. pneumoniae strain BS407 was recovered from an active surveillance rectal swab of a patient newly admitted to a general hospital in Busan, South Korea. Carbapenemase production was confirmed by the modified Hodge test, and the MICs of β-lactams were determined by the broth microdilution method. The whole genome was sequenced. Cloning and expression of the bla_KPC–55 gene in Escherichia coli and MIC determination were performed. The enzyme KPC-55 was used for kinetic assays against β-lactams and compared with the KPC-2 enzyme. The new allele of the bla_KPC gene had a T794A alteration compared to the bla_KPC–2 gene, resulting in the amino acid substitution Y264N in the middle of the β9-sheet. Compared to the KPC-2-producing strain, the KPC-55-producing strain exhibited a lower level of resistance to most β-lactam drugs tested, however, the KPC-55 enzyme catalyzed aztreonam and meropenem at an increased efficiency compared to the catalytic activity of KPC-2. KPC subtypes could have varied phenotypes due to alterations in amino acid sequences, and such an unexpected resistance phenotype emphasizes the importance of detailed characterizations for the carbapenemase-producing Enterobacterales.

A laboratory study to detect simulated pulpal blood flow in extracted human teeth using ultrasound Doppler flowmetry

AIM

To develop a laboratory-based tooth model of simulated blood flow in teeth and evaluate it using ultrasound Doppler flowmetry (UDF).

METHODOLOGY

A laboratory-based tooth model for UDF was created based on a microfluidic experimental model proposed by Kim & Park (2016 a,b). Twenty-one maxillary or mandibular anterior human teeth within 1 month of extraction were used. Four holes were made in each tooth to fit 1.6-mm diameter polytetrafluoroethylene (PTFE) tubes: at the apical foramen, palatal surface in the centre of the crown, palatal surface apical to the cementoenamel junction (CEJ) and the root centre. Fluid mimicking pulsating blood was pumped (pressure range: 0-200 mbar, flow rate range: 0-80 μL min^-1 ) into the apical foramen via the PTFE tubes, which exited the tooth through the palatal surface in the centre of the crown (control group), palatal surface below the CEJ (group 1) and the palatal surface at the mid-root level (group 2). An UDF transducer of 20 MHz was placed at a 60° angle to the labial surface of tooth and was used to measure the fluid flow velocity (Vs, Vas, Vm, Vam, Vd, Vad and Vakd). The flow velocity of the different groups was compared using the Wilcoxon signed-rank test, with a 95% confidence level.

RESULTS

UDF facilitated the detection of the simulated pulpal blood flow in the control group and group 1, but not in group 2. The mean and standard deviations of Vas, Vam and Vakd were 0.921 ± 0.394, 0.479 ± 0.208 and 0.396 ± 0.220 cm s^-1 , respectively, in the control group, and 0.865 ± 0.368, 0.424 ± 0.215 and 0.487 ± 0.279 cm s^-1 , respectively, in group 1. The pulpal blood flow values of the control group and group 1 were not significantly different (p > 0.05).

CONCLUSIONS

This laboratory study revealed that ultrasound Doppler flowmetry enabled the detection of simulated blood flow below the level of the CEJ but not at the mid-root level.