Clinical and Microbiologic Analysis of Klebsiella pneumoniae Infection: Hypermucoviscosity, Virulence Factor, Genotype, and Antimicrobial Susceptibility

Hypervirulent Klebsiella pneumoniae (KP) is defined according to hypermucoviscosity or various virulence factors and is clinically associated with community-acquired liver abscess (CLA). In this study, we investigated the clinical and microbiological characteristics of KP and significant factors associated with hypervirulence. The clinical characteristics, antimicrobial susceptibility, hypermucoviscosity, serotypes, hypervirulence-related genes, and biofilm formation of 414 KP isolates collected from the Keimyung University Dongsan Hospital between December 2013 and November 2015 were analyzed according to CLA. Significant risk factors for hypervirulent KP (HvKP) associated with CLA were investigated using logistic regression analysis. Notably, 155 (37.4%) isolates were hypermucoviscous, and 170 (41.1%) harbored aerobactin. CLA was present in 34 cases (8.2%). Epidemiology and treatment outcomes did not differ significantly between the CLA and non-CLA groups. The CLA group had significantly higher antibiotic susceptibility, K1/K2, rmpA, magA, allS, kfu, iutA, string test-positive result, and biofilm mass. Multivariate logistic regression revealed rmpA (OR, 5.67; 95% CI, 2.09-15.33; p = 0.001), magA (OR, 2.34; 95% CI, 1.01-5.40; p = 0.047), and biofilm mass >0.80 (OR, 2.13; 95% CI, 1.00-4.56; p = 0.050) as significant risk factors for CLA. rmpA was identified as the most significant risk factor for CLA among KP strains, implying that it is an important factor associated with HvKP.

Interferon-gamma signaling promotes cartilage regeneration after injury

Osteoarthritis is a common chronic disease and major cause of disability and chronic pain in ageing populations. In this pathology, the entire joint is involved, and the regeneration of articular cartilage still remains one of the main challenges. Here, we investigated the molecular mechanisms underlying cartilage regeneration in young mice using a full-thickness cartilage injury (FTCI) model. FTCI-induced cartilage defects were created in the femoral trochlea of young and adult C57BL/6 mice. To identify key molecules and pathways involved in the early response to cartilage injury, we performed RNA sequencing (RNA-seq) analysis of cartilage RNA at 3 days after injury. Young mice showed superior cartilage regeneration compared to adult mice after cartilage injury. RNA-seq analysis revealed significant upregulation of genes associated with the immune response, particularly in the IFN-γ signaling pathway and qRT-PCR analysis showed macrophage polarization in the early phase of cartilage regeneration (3 days) in young mice after injury, which might promote the removal of damaged or necrotic cells and initiate cartilage regeneration in response to injury. IFN-γR1- and IFN-γ-deficient mice exhibited impaired cartilage regeneration following cartilage injury. DMM-induced and spontaneous OA phenotypes were exacerbated in IFN-γR1-/- mice than in wild-type mice. Our data support the hypothesis that IFN-γ signaling is necessary for cartilage regeneration, as well as for the amelioration of post-traumatic and age-induced OA.

Clinical Characteristics of Uncomplicated Acute Pyelonephritis Caused by Escherichia coli and Klebsiella pneumoniae

INTRODUCTION

This study compared the clinical characteristics and antimicrobial susceptibility of uncomplicated acute pyelonephritis (APN) caused by Escherichia coli and Klebsiella pneumoniae.

METHODS

We retrospectively reviewed the medical records of patients with uncomplicated APNs caused by E. coli and K. pneumoniae admitted to Keimyung University Dongsan Hospital between February 2014 and December 2021.

RESULTS

We enrolled 497 patients (372 with E. coli infection, 125 with K. pneumoniae infection). Male, healthcare-associated infection, solid tumors, liver cirrhosis, chronic renal disease, solid organ transplantation, and antibiotic usage within the last 3 months were more strongly associated with K. pneumoniae uncomplicated APNs than with E. coli. Bacteremia and fever occurred more frequently in E. coli uncomplicated APNs. Antimicrobial resistance rates to piperacillin/tazobactam and carbapenem were higher in K. pneumoniae. Antimicrobial resistance rates to aztreonam and ciprofloxacin were lower in K. pneumoniae. Thirty-day mortality was more observed in K. pneumoniae group in univariate analysis, but this difference was not observed after adjustment. Male sex, ultimately fatal disease in McCabe, and prior antibiotic use within 3 months were more associated with K. pneumoniae.

CONCLUSIONS

Male, underlying diseases, and prior antibiotic use was more associated with K. pneumoniae. Further study will be needed that microbiome of each situation and the related with the distribution of the strains.

Clinical characteristics of persistent postural-perceptual dizziness and its visual subtype in Korean patients: A multicenter cross-sectional study

OBJECTIVES

Persistent postural-perceptual dizziness (PPPD) is a chronic functional vestibular disorder for which the Bárány Society has established diagnostic criteria. This nationwide multicenter study aims to investigate the clinical features of individuals with definite PPPD and clinical variant PPPD who do not fully meet the diagnostic criteria, with a particular focus on visual exaggeration.

METHODS

Between September 2020 and September 2021, a total of 76 individuals with definite PPPD and 109 individuals with clinical variant PPPD who did not meet all three exacerbating factors outlined in Criterion B were recruited from 18 medical centers in South Korea. The study gathered information on demographic factors, clinical manifestations, balance scales, and personality assessments.

RESULTS

Comparative analysis between groups with definite PPPD and clinical variant with visual exacerbation revealed no significant differences in sociodemographic characteristics, clinical course, dizziness impact, and specific precipitants. Only disease duration was significantly longer in definite PPPD compared with variant with visual exacerbation. However, the variant without visual exacerbation displayed significantly reduced rates of panic disorder, diminished space-motion discomfort, lesser impact of dizziness, and decreased prevalence of depression when compared with the definitive PPPD.

CONCLUSION

This is the first comprehensive nationwide study examining clinical features of both definite PPPD patients and its clinical variants, considering visual exacerbating factors. Differences in dizziness and personality traits emerged between definite PPPD and its potential variant without visual issues. Our results highlight the possibility of a distinct clinical variant of PPPD influenced by visual dependency.

Dietary patterns derived by reduced rank regression are associated with lipid disorders among Korean adults: a cross-sectional analysis

BACKGROUND

Lipid disorders are a potent risk factor for cardiovascular diseases. Moreover, the intake of dietary fatty acids has been closely related to blood lipid levels. Therefore, this cross-sectional study examined the associations between dietary patterns related to fatty acid intake and lipid disorders in Korean adults.

METHODS

From the 2013-2019 Korea National Health and Nutrition Examination Surveys data, 8399 men and 11404 women (aged ≥ 19 years) were selected. Reduced rank regression was employed to identify dietary patterns from 26 food groups, aiming to explain the maximum variation in the intake of saturated fatty acids (SFA), polyunsaturated fatty acids (PUFA), omega-3 fatty acids, and the PUFA/SFA ratio. Associations of quintiles (Q) of dietary pattern scores with lipid disorders were examined using multiple logistic regression stratified by sex.

RESULTS

Three dietary patterns were identified: dietary pattern 1 showed positive factor loadings for vegetable oils, seasonings, legumes, nuts, and fish; dietary pattern 2 was high in consumption of red meat, bread and snacks, and milk and dairy products; and dietary pattern 3 was rich in fish and milk and dairy products. In men, dietary pattern 3 was inversely associated with elevated triglycerides (Q5 vs. Q1: odds ratio [OR] = 0.82, 95% confidence interval [CI] = 0.69-0.97, P-trend = 0.008). In women, dietary pattern 2 was positively associated with elevated total cholesterol (OR = 1.31, 95% CI = 1.12-1.52, P-trend < 0.001) but inversely associated with low HDL-cholesterol (OR = 0.70, 95% CI = 0.59-0.83, P-trend < 0.001).

CONCLUSION

In this study, dietary patterns explaining the intake of various types of fatty acids were differentially associated with lipid disorders in Korean adults. Dietary pattern characterized by higher intakes of red meat, bread and snacks and milk and dairy products were positively associated with elevated total cholesterol, whereas dietary pattern rich in fish consumption showed an inverse association with elevated triglycerides. These findings could be instrumental in developing dietary guidelines and strategies for preventing and managing lipid disorders in this population.

Human amnion epithelial cell therapy reduces hypertension-induced vascular stiffening and cognitive impairment

Vascular inflammation and fibrosis are hallmarks of hypertension and contribute to the development of cardiovascular disease and cognitive impairment. However, current anti-hypertensive drugs do not treat the underlying tissue damage, such as inflammation-associated fibrosis. Human amnion epithelial cells have several properties amenable for treating vascular pathology. This study tested the effect of amnion epithelial cells on vascular pathology and cognitive impairment during hypertension. Male C57Bl6 mice (8-12 weeks) were administered vehicle (saline; n = 58) or angiotensin II (0.7 mg/kg/d, n = 56) subcutaneously for 14 d. After surgery, a subset of mice were injected with 106 amnion epithelial cells intravenously. Angiotensin II infusion increased systolic blood pressure, aortic pulse wave velocity, accumulation of aortic leukocytes, and aortic mRNA expression of collagen subtypes compared to vehicle-infused mice (n = 9-11, P < 0.05). Administration of amnion epithelial cells attenuated these effects of angiotensin II (P < 0.05). Angiotensin II-induced cognitive impairment was prevented by amnion epithelial cell therapy (n = 7-9, P < 0.05). In the brain, amnion epithelial cells modulated some of the inflammatory genes that angiotensin II promoted differential expression of (n = 6, p-adjusted < 0.05). These findings suggest that amnion epithelial cells could be explored as a potential therapy to inhibit vascular pathology and cognitive impairment during hypertension.

The Photothrombotic Model of Ischemic Stroke

Stroke is a major cause of morbidity worldwide; yet, there is a lack of treatment options to address post-stroke cognitive and motor impairment, thus there is an urgency for developing neuroprotective and restorative therapies. Much of our fundamental understanding of stroke pathology has been derived from animal models. The photothrombotic model of ischemic stroke is commonly used to study cellular and molecular mechanisms of neurodegeneration, test functional/cognitive outcomes, identify important biomarkers, and assess the effectiveness of novel therapies. It allows for the precise targeting of an infarct to a specific region of the brain, has a low mortality rate, low seizure rate, and is relatively easy to perform. This chapter outlines materials and methods for the photothrombotic model of ischemic stroke in mice, its limitations, and some considerations needed when using this model.

A causative role for periarticular skeletal muscle weakness in the progression of joint damage and pain in OA

Although osteoarthritis (OA) is regarded as a disease of the articular cartilage, recent research has demonstrated alterations in periarticular muscles that surround the affected joint. Here, we investigated changes in periarticular muscle during the progression of OA, as well as the cause-and-effect relationship between muscle weakness and OA, in a mouse model of OA by destabilization of the medial meniscus (DMM). Pathological phenotypes in the periarticular muscles were assessed in the early and late stages of OA by DMM. OA pathology and pain behavior in the mice after DMM induction were examined in response to periarticular muscle weakness induced by multiple rounds of barium chloride (BaCl2) injections. The examinations were also performed in myostatin knockout mice with strengthened muscle phenotypes by muscle hypertrophy. Morphological alterations in the tibialis anterior (TA) and quadriceps muscles in DMM mice included variations in muscle-fiber size, aberrant extracellular matrix (ECM) deposition, inflammatory cell infiltration, and decreased muscle mass. Periarticular muscle fibers isolated from DMM mice showed reductions in the number of satellite cells and myogenic capacity of primary myoblast, as well as proliferation. DMM + muscle injury mice also showed exacerbated joint degeneration compared to the DMM vehicles. Myostatin knockout mice were characterized by attenuated OA and the complete abrogation of pain behavior after DMM. Our results suggest an association between muscle weakness and OA progression and pain.

Korean guidelines for the management of gout

Gout is the most common form of arthritis, with the prevalence increasing worldwide. The present treatment guidelines provide recommendations for the appropriate treatment of acute gout, management during the inter-critical period, and prevention of chronic complications. The guidelines were developed based on evidence-based medicine and draft recommendations finalized after expert consensus. These guidelines are designed to provide clinicians with clinical evidence to enable efficient treatment of gout.

Corrigendum: Phase I trial outcome of amnion cell therapy in patients with ischemic stroke (I-ACT)

[This corrects the article DOI: 10.3389/fnins.2023.1153231.].

Clinical Characteristics and Risk Factors for Mortality in Critical COVID-19 Patients Aged 50 Years or Younger During Omicron Wave in Korea: Comparison With Patients Older Than 50 Years of Age

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic has caused the death of thousands of patients worldwide. Although age is known to be a risk factor for morbidity and mortality in COVID-19 patients, critical illness or death is occurring even in the younger age group as the epidemic spreads. In early 2022, omicron became the dominant variant of the COVID-19 virus in South Korea, and the epidemic proceeded on a large scale. Accordingly, this study aimed to determine whether young adults (aged ≤ 50 years) with critical COVID-19 infection during the omicron period had different characteristics from older patients and to determine the risk factors for mortality in this specific age group.

METHODS

We evaluated 213 critical adult patients (high flow nasal cannula or higher respiratory support) hospitalized for polymerase chain reaction-confirmed COVID-19 in nine hospitals in South Korea between February 1, 2022 and April 30, 2022. Demographic characteristics, including body mass index (BMI) and vaccination status; underlying diseases; clinical features and laboratory findings; clinical course; treatment received; and outcomes were collected from electronic medical records (EMRs) and analyzed according to age and mortality.

RESULTS

Overall, 71 critically ill patients aged ≤ 50 years were enrolled, and 142 critically ill patients aged over 50 years were selected through 1:2 matching based on the date of diagnosis. The most frequent underlying diseases among those aged ≤ 50 years were diabetes and hypertension, and all 14 patients who died had either a BMI ≥ 25 kg/m² or an underlying disease. The total case fatality rate among severe patients (S-CFR) was 31.0%, and the S-CFR differed according to age and was higher than that during the delta period. The S-CFR was 19.7% for those aged ≤ 50 years, 36.6% for those aged > 50 years, and 38.1% for those aged ≥ 65 years. In multivariate analysis, age (odds ratio [OR], 1.084; 95% confidence interval [CI], 1.043-1.127), initial low-density lipoprotein > 600 IU/L (OR, 4.782; 95% CI, 1.584-14.434), initial C-reactive protein > 8 mg/dL (OR, 2.940; 95% CI, 1.042-8.293), highest aspartate aminotransferase > 200 IU/L (OR, 12.931; 95% CI, 1.691-98.908), and mechanical ventilation implementation (OR, 3.671; 95% CI, 1.294-10.420) were significant independent predictors of mortality in critical COVID-19 patients during the omicron wave. A similar pattern was shown when analyzing the data by age group, but most had no statistical significance owing to the small number of deaths in the young critical group. Although the vaccination completion rate of all the patients (31.0%) was higher than that in the delta wave period (13.6%), it was still lower than that of the general population. Further, only 15 (21.1%) critically ill patients aged ≤ 50 years were fully vaccinated. Overall, the severity of hospitalized critical patients was significantly higher than that in the delta period, indicating that it was difficult to find common risk factors in the two periods only with a simple comparison.

CONCLUSION

Overall, the S-CFR of critically ill COVID-19 patients in the omicron period was higher than that in the delta period, especially in those aged ≤ 50 years. All of the patients who died had an underlying disease or obesity. In the same population, the vaccination rate was very low compared to that in the delta wave, indicating that non-vaccination significantly affected the progression to critical illness. Notably, there was a lack of prescription for Paxlovid for these patients although they satisfied the prescription criteria. Early diagnosis and active initial treatment was necessary, along with the proven methods of vaccination and personal hygiene. Further studies are needed to determine how each variant affects critically ill patients.

Korean guidelines for the management of gout

Gout is the most common form of arthritis, with the prevalence increasing worldwide. The present treatment guidelines provide recommendations for the appropriate treatment of acute gout, management during the inter-critical period, and prevention of chronic complications. The guidelines were developed based on evidence-based medicine and draft recommendations finalized after expert consensus. These guidelines are designed to provide clinicians with clinical evidence to enable efficient treatment of gout.

Protection against brain injury after ischemic stroke by intravenous human amnion epithelial cells in combination with tissue plasminogen activator

Background

Thrombolytic agents such as tissue plasminogen activator (tPA) are the only drug class approved to treat ischemic stroke and are usually administered within 4.5 h. However, only ~20% of ischemic stroke patients are eligible to receive the therapy. We previously demonstrated that early intravenous administration of human amnion epithelial cells (hAECs) can limit brain inflammation and infarct growth in experimental stroke. Here, we have tested whether hAECs exert cerebroprotective effects in combination with tPA in mice.

Methods

Male C57Bl/6 mice were subjected to middle cerebral artery occlusion for 60 min followed by reperfusion. Immediately following reperfusion, vehicle (saline, n = 31) or tPA (10 mg/kg; n = 73) was administered intravenously. After 30 min of reperfusion, tPA-treated mice were injected intravenously with either hAECs (1×10⁶; n = 32) or vehicle (2% human serum albumin; n = 41). A further 15 sham-operated mice were treated with vehicle (n = 7) or tPA + vehicle (n = 8). Mice were designated to be euthanised at 3, 6 or 24 h post-stroke (n = 21, 31, and 52, respectively), and brains were collected to assess infarct volume, blood-brain barrier (BBB) disruption, intracerebral bleeding and inflammatory cell content.

Results

There was no mortality within 6 h of stroke onset, but a high mortality occurred in tPA + saline-treated mice between 6 h and 24 h post-stroke in comparison to mice treated with tPA + hAECs (61% vs. 27%, p = 0.04). No mortality occurred within 24 h of sham surgery in mice treated with tPA + vehicle. We focused on early infarct expansion within 6 h of stroke and found that infarction was ~50% larger in tPA + saline- than in vehicle-treated mice (23 ± 3 mm³ vs. 15 ± 2 mm³, p = 0.02) but not in mice receiving tPA + hAECs (13 ± 2 mm³, p < 0.01 vs. tPA + saline) in which intracerebral hAECs were detected. Similar to the profiles of infarct expansion, BBB disruption and intracerebral bleeding in tPA + saline-treated mice at 6 h was 50-60% greater than in vehicle-treated controls (2.6 ± 0.5 vs. 1.6 ± 0.2, p = 0.05) but not after tPA + hAECs treatment (1.7 ± 0.2, p = 0.10 vs. tPA + saline). No differences in inflammatory cell content were detected between treatment groups.

Conclusion

When administered following tPA in acute stroke, hAECs improve safety and attenuate infarct growth in association with less BBB disruption and lower 24 h mortality.

Effectiveness of regdanvimab treatment for SARS-CoV-2 delta variant, which exhibited decreased in vitro activity: a nationwide real-world multicenter cohort study

Background

Immune-evading severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants are emerging continuously. The clinical effectiveness of monoclonal antibody agents that exhibit decreased in vitro activity against SARS-CoV-2 variants needs to be elucidated.

Methods

A nationwide, multicenter, retrospective cohort study was designed to evaluate the effectiveness of regdanvimab, an anti-SARS-CoV-2 monoclonal antibody agent. Regdanvimab was prescribed in South Korea before and after the emergence of the delta variant, against which the in vitro activity of regdanvimab was decreased but present. Mild to moderate coronavirus 2019 (COVID-19) patients with risk factors for disease progression who were admitted within seven days of symptom onset were screened in four designated hospitals between December 2020 and September 2021. The primary outcomes, O₂ requirements and progression to severe disease within 21 days of admission, were compared between the regdanvimab and supportive care groups, with a subgroup analysis of delta variant-confirmed patients.

Results

A total of 2,214 mild to moderate COVID-19 patients were included, of whom 1,095 (49.5%) received regdanvimab treatment. In the analysis of the total cohort, significantly fewer patients in the regdanvimab group than the supportive care group required O₂ support (18.4% vs. 27.1%, P < 0.001) and progressed to severe disease (4.0% vs. 8.0%, P < 0.001). In the multivariable analysis, regdanvimab was significantly associated with a decreased risk for O₂ support (HR 0.677, 95% CI 0.561-0.816) and progression to severe disease (HR 0.489, 95% CI 0.337-0.709). Among the 939 delta-confirmed patients, O₂ support (21.5% vs. 23.5%, P = 0.526) and progression to severe disease (4.2% vs. 7.3%, P = 0.055) did not differ significantly between the regdanvimab and supportive care groups. In the multivariable analyses, regdanvimab treatment was not significantly associated with a decreased risk for O₂ support (HR 0.963, 95% CI 0.697-1.329) or progression to severe disease (HR 0.665, 95% CI 0.349-1.268) in delta-confirmed group.

Conclusions

Regdanvimab treatment effectively reduced progression to severe disease in the overall study population, but did not show significant effectiveness in the delta-confirmed patients. The effectiveness of dose increment of monoclonal antibody agents should be evaluated for variant strains exhibiting reduced susceptibility.

Phase I trial outcome of amnion cell therapy in patients with ischemic stroke (I-ACT)

Background

We proposed a Phase I dose escalation trial to assess the safety of allogeneic human amniotic epithelial cells (hAECs) in stroke patients with a view to informing the design for a Phase II trial.

Methods

The design is based on 3 + 3 dose escalation design with additional components for measuring MR signal of efficacy as well as the effect of hAECs (2-8 × 106/kg, i.v.) on preventing immunosuppression after stroke.

Results

Eight patients (six males) were recruited within 24 h of ischemic stroke onset and were infused with hAECs. We were able to increase the dose of hAECs to 8 × 106 cells/kg (2 × 106/kg, n = 3; 4 × 106/kg, n = 3; 8 × 106/kg, n = 2). The mean age is 68.0 ± 10.9 (mean ± SD). The frequencies of hypertension and hyperlipidemia were 87.5%, diabetes was 37.5%, atrial fibrillation was 50%, ischemic heart disease was 37.5% and ever-smoker was 25%. Overall, baseline NIHSS was 7.5 ± 3.1, 7.8 ± 7.2 at 24 h, and 4.9 ± 5.4 at 1 week (n = 8). The modified Rankin scale at 90 days was 2.1 ± 1.2. Supplemental oxygen was given in five patients during hAEC infusion. Using pre-defined criteria, two serious adverse events occurred. One patient developed recurrent stroke and another developed pulmonary embolism whilst in rehabilitation. For the last four patients, infusion of hAECs was split across separate infusions on subsequent days to reduce the risk for fluid overload.

Conclusion

Our Phase I trial demonstrates that a maximal dose of 2 × 106/kg hAECs given intravenously each day over 2 days (a total of 4 × 106/kg) is safe and optimal for use in a Phase II trial.

Clinical trial registration

ClinicalTrials.gov, identifier ACTRN12618000076279P.

Impact of High-Intensity Statin on Early Neurologic Deterioration in Patients with Single Small Subcortical Infarction

BACKGROUNDS

One of the major hypotheses for early neurological deterioration (END) in single small subcortical infarction (SSSI) is the process of atherosclerosis. However, the association between statin therapy, especially high-intensity statin therapy, and its effectiveness in reducing the incidence of END during the acute phase of SSSI remains unclear. This study aimed to investigate the influence of high-intensity statin therapy compared to moderate-intensity statin therapy during the acute phase on the incidence of END in SSSI.

METHODS

The records of 492 patients with SSSI who received statin therapy within 72 h of symptom onset from a prospective stroke registry were analyzed. The association between END and statin intensity was evaluated using multivariable regression analysis for adjusted odds ratio (aOR).

RESULTS

Of the 492 patients with SSSI (mean age: 67.2 years, median NIHSS score on admission: 3), END occurred in 102 (20.7%). Older age (aOR, 1.02; 95% confidence interval (CI), 1.00-1.05; p = 0.017), and branch atheromatous lesion (aOR, 3.49; 95% CI 2.16-5.74; p < 0.001) were associated with END. Early high-intensity statin therapy was associated with a lower incidence of END than moderate-intensity statin therapy (aOR, 0.44; 95% CI, 0.25-0.77; p = 0.004). In addition, there was significantly lower incidence of END in early administration (≤24 h) of high-intensity statin group.

CONCLUSIONS

We identified an association between the intensity of early statin therapy and END in patients with SSSI. Early administration of high-intensity statin (≤24 h) is associated with a reduced incidence of END in patients with SSSI.

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.

Effects of remote ischemic postconditioning on hepatic injury in lipopolysaccharide-induced endotoxemic rats

Background

Remote ischemic postconditioning (RIPoC) is that several cycles of brief, reversible, mechanical blood flow occlusion and reperfusion of distal organ make protection to target organ. We investigate whether RIPoC ameliorates liver injury in lipopolysaccharide (LPS)-induced sepsis model.

Methods

Protocol 1) Rats were administered LPS solution and samples were collected at 0, 2, 6, 12, and 18 h after that. Protocol 2) After RIPoC at 2, 6, and 12 h (L+2R+18H, L+6R+18H, L+12R+18H), samples were analyzed at 18 h. Protocol 3) RIPoC performed at 2 h, analysis samples at 6, 12, 18 h (L+2R+6H, L+2R+12H, L+2R+18H), and RIPoC at 6 h, analysis at 12 h (L+6R+12H). Protocol 4) Rats were divided control group, which were injected with only ketamine and RIPoC group, which RIPoC was performed at 2, 6, 10, and 14 h, samples were analyzed at 18 h.

Results

In protocol 1, liver enzymes, MDA, TNF-α and NF-kB increased, and SOD decreased over time. In protocol 2, liver enzyme and MDA level were lower and SOD level was higher in L+12R+18H and L+6R+18H groups, compared with L+2R+18H group. In protocol 3, liver enzyme and MDA level were lower and SOD level was higher in L+2R+6H and L+6R+12H groups, compared with L+2R+12H and L+2R+18H groups. In protocol 4, liver enzyme, MDA, TNF-α, and NF-kB levels were lower and SOD level was higher in RIPoC group, compared with control group.

Conclusions

RIPoC attenuated liver injury in LPS-induced sepsis model by modifying inflammatory responses and oxidative stress response for a limited period.

Incidence, characteristics, and neuroanatomical substrates of vestibular symptoms in supratentorial stroke

The incidence and characteristics of acute vestibular symptoms, responsible structures, and lateralization of the causative lesions in supratentorial stroke remain unknown. This study aimed to determine the incidence, clinical features, and anatomical correlation of acute vestibular symptoms in supratentorial stroke. We performed a prospective, multicenter, observational study that had recruited patients with supratentorial stroke from the neurology clinics of referral-based four university hospitals in Korea. All patients received a constructed neuro-otological evaluations, and neuroimaging. We analyzed the incidence of acute vestibular symptoms, abnormal ocular motor and vestibular function tests, and stroke lesions. Of 1301 patients with supratentorial stroke, 48 (3.7%) presented with acute vestibular symptoms, and 13 of them (1%) had the vestibular symptoms in isolation. In patients with acute vestibular symptoms, abnormal findings included spontaneous nystagmus (5%), impaired horizontal smooth pursuit (41%), and abnormal tilt of the subjective visual vertical (SVV) (20%). Video head impulse and caloric tests were normal in all the patients. There was no clear correlation between acute vestibular symptoms and involvement of specific vestibular cortex. In patients with unilateral stroke, there was also no lateralization of the causative lesions of acute vestibular symptoms (left vs. right; 52 vs. 48%), even in patients with vertigo (left vs. right; 58 vs. 42%). This study demonstrates that the incidence of acute vestibular symptoms in supratentorial stroke is 3.7%, with being isolated in 1%. The widespread lesions responsible for acute vestibular symptoms implicate diffuse multisensory cortical-subcortical networks in the cerebral hemispheres without a lateralization.

Total Knee Replacement After Arthroscopic Meniscectomy in Knee Osteoarthritis: A Nationwide Population-Based Cohort Study

BACKGROUND

Recent studies raise concerns that arthroscopic meniscectomy (AM) for degenerative tear may be detrimental to the maintenance of the joint structure. This study was performed to examine the rate of total knee replacement (TKR) among patients with knee osteoarthritis (OA) who underwent AM for meniscal tears and compare this rate with those who did not.

METHODS

A retrospective cohort study was conducted using the National Health Insurance Database of South Korea. Among knee OA patients aged 50-79, those who were treated with AM due to meniscal damage from 2007 to 2009 were selected as the AM group while those not treated with AM despite the presence of meniscal damage were selected as control group. Both were matched based on a propensity score and followed-up until the earliest occurrence of: TKR, death, or 10 years. Cox proportional hazards models were used to compare the outcome.

RESULTS

A total of 36,974 patients were included in AM groups and non-AM group after 1:1 matching. TKR occurred in 9.62% and 7.64% in AM and non-AM groups with the average duration after meniscectomy of 5.88 ± 2.77 and 5.50 ± 2.94 years, respectively. After adjustment for baseline confounders, the TKR rate in the AM group was calculated to be 25% higher than that in the non-AM group (subdistribution hazard ratio, 1.25; 95% confidence interval, 1.16-1.34). The mortality rate was 5.20%, which did not significantly differ between groups.

CONCLUSION

OA patients who underwent AM for the meniscal injury had higher incidence of TKR up to 10 years of follow-up than the non-operated group. The greater TKR utilization observed in patients undergoing AM merits caution when treating OA patients with meniscal injury.

A study on changes in lung function, neutralizing antibodies, and symptoms of adult patients hospitalized with COVID-19

BACKGROUND/AIMS

To identify changes in symptoms and pulmonary sequelae in patients with coronavirus disease 2019 (COVID-19).

METHODS

Patients with COVID-19 hospitalized at seven university hospitals in Korea between February 2020 and February 2021 were enrolled, provided they had ≥ 1 outpatient follow-up visit. Between January 11 and March 9, 2021 (study period), residual symptom investigations, chest computed tomography (CT) scans, pulmonary function tests (PFT), and neutralizing antibody tests (NAb) were performed at the outpatient visit (cross-sectional design). Additionally, data from patients who already had follow-up outpatient visits before the study period were collected retrospectively.

RESULTS

Investigation of residual symptoms, chest CT scans, PFT, and NAb were performed in 84, 35, 31, and 27 patients, respectively. After 6 months, chest discomfort and dyspnea persisted in 26.7% (4/15) and 33.3% (5/15) patients, respectively, and 40.0% (6/15) and 26.7% (4/15) patients experienced financial loss and emotional distress, respectively. When the ratio of later CT score to previous ones was calculated for each patient between three different time intervals (1-14, 15-60, and 61-365 days), the median values were 0.65 (the second interval to the first), 0.39 (the third to the second), and 0.20 (the third to the first), indicating that CT score decreases with time. In the high-severity group, the ratio was lower than in the low-severity group.

CONCLUSION

In COVID-19 survivors, chest CT score recovers over time, but recovery is slower in severely ill patients. Subjects complained of various ongoing symptoms and socioeconomic problems for several months after recovery.

Temporal Change in the Use of Laboratory and Imaging Tests in One Week Before Death, 2006–2015

BACKGROUND

To analyze the trends in laboratory and imaging test use 1 week before death among decedents who died in Korean hospitals, tests used per decedents from 2006 to 2015 were examined by using the National Health Insurance Service-Elderly Sample Cohort (NHIS-ESC) dataset.

METHODS

The study population consisted of decedents aged ≥ 60 years old with a history of admission and death at a hospital, and tests recorded in the payment claims for laboratory and imaging tests according to the Healthcare Common Procedure Coding System codes were examined. Twenty-eight laboratory and 6 imaging tests were selected. For each year, crude rates of test use per decedents in each age and sex stratum were calculated. Regression analysis was used to examine the temporal changes in the test use.

RESULTS

During the follow-up period, 6,638 subjects included in the sample cohort died. The number of total laboratory and imaging tests performed on the deceased increased steadily throughout the study year from 10.3 tests/deceased in 2006 to 16.6 tests/deceased in 2015. The use of tests increased significantly in general hospitals, however, not in nursing hospitals. Laboratory tests showed yearly increase, from 9.46/deceased in 2006 to 15.57/deceased in 2015, an annual increase of 7.39%. On the other hand, the use of imaging increased from 0.86/deceased in 2006 to 1.01/deceased in 2015, which was not statistically significant.

CONCLUSION

The use of tests, especially laboratory tests, increased steadily over the years even among those elderly patients at imminent death. Reducing acute healthcare at the end of life would be one target not only to support the sustainability of the health care budget but also to improve the quality of dying and death.

Correlation between the ratio of physician consultation fees to hourly minimum wage and consultation length: a cross-sectional study of nine countries

OBJECTIVES

Current healthcare reimbursement system is criticised for not adequately compensating physicians' cognitive services. This study was performed to examine primary care physicians' consultation fees in nine countries, relative to the national hourly minimum wage and to examine the correlations of the physician consultation fee with consultation length and other healthcare indices.

DESIGN AND OUTCOME MEASURES

Nine reference countries for which healthcare statistics are publicly available and outpatient consultation is compensated by fee-for-service payment were selected. A representative consultation fee was chosen to calculate the ratio of the consultation fee to the hourly minimum wage. The primary outcome was the correlation between the consultation fee/hourly minimum wage ratio and consultation length. In addition, the consultation fees were compared with fees for haemoglobin A1c tests and brain imaging. Pearson's method was primarily used for correlation analysis.

RESULTS

The mean representative consultation fee/hourly minimum wage ratio was 4.02 (median, 2.7; range, 0.80-10.36). The mean consultation length was 12.9 min (median, 14.7 min; range, 5-21.1 min). A significant correlation (r=0.79) was found between consultation length and the consultation fee/hourly minimum wage ratio. The ratio of consultation fee to hourly minimum wage was moderately negatively correlated with the annual number of physician visits, number of consultations per doctor and length of hospital stay. The brain CT fee/consultation fee ratio was moderately positively correlated with the number of CT units per 1 million population. In Japan and Korea, where the brain CT/consultation fee ratio was highest, the number of CT examinations per population was also highest.

CONCLUSIONS

The relationship of consultation fees to each country's hourly minimum wage varied in nine reference countries; however, it was strongly correlated with consultation length. The imbalance in compensation for cognitive services might drive increased use of imaging tests in some countries.

The frequency and relationship with vestibular function test results of positional preference in acute vestibular neuritis

Objective

To assess the prevalence and relationship with vestibular function test results of positional preference in acute vestibular neuritis (VN).

Methods

We prospectively recruited 33 patients with VN during the acute phase. We assessed the severity of vertigo with a visual analog scale (VAS) and the degree of spontaneous nystagmus (SN) during sitting, the head rolling to the affected, and the healthy side. Patients performed other vestibular function tests, including ocular and cervical vestibular evoked myogenic potential (VEMP), on the same day or the next day of VNG testing.

Results

Twelve patients (12/33, 36%) with VN complained of more severe vertigo during lying on the affected side compared to the healthy side under visual fixation. Compared to patients without positional preference (without positional preference group), patients with positional preference (with positional preference group) showed a significantly higher VAS and maximal slow phase velocity (SPV) of SN at all positions except lying on the lesion side. However, there was no difference in the SPV gap between the two groups. 30% (10/33) of patients with VN complained of more severe vertigo while lying on the affected side compared to the healthy side without visual fixation. Maximal SPV of SN was not different between the two groups. There was no other significant difference in both canalith and otolith function test results between the two groups regardless of the visual fixation.

Conclusions

One-third of patients with acute VN had more severe vertigo while lying on the affected side than in the supine position. The positional preference was not directly related to the SN intensity or VEMP results. The positional preference might reflect the otolith damage in the setting of activation of the sustained otolith system, not the transient otolithic system.

Comparison of the Clinical and Genotypic Characteristics of Uropathogenic Escherichia coli Strains According to Sex in Korea

In this study, we compared the microbiological, genotypic, and antibiotic resistance characteristics of uropathogenic Escherichia coli (UPEC) strains in patients with pyelonephritis in Korea according to sex based on data corresponding to the February 2015 to June 2018 period. Based on Escherichia coli phylogenetic group analysis, gene virulence detection, and subgroup analyses by sex, we observed that the antibiotic resistance percentages and proportions corresponding to extended-spectrum beta-lactamase producing UPEC were higher in males than in females. In addition, phylogenetic group B2 showed predominance in both the male and female groups, which further showed similar adhesion molecule distributions. Toxin-associated factors, hlyA and cnf1, were more common in males. In clinical presentations, urinary predisposing factors, complicated urinary tract infections (UTIs), concomitant bacteremia, and persistent fever were also more common with males. Although females and males showed UPEC genotypic differences, there were no differences between them with respect to poor outcomes. Persistent fever was associated with community-acquired infection and bacteremic UTI and relapsed UTI within 3 months was associated with urinary tract stone. In future, it will be necessary to conduct multicenter studies, involving more cases on UPEC to validate our results.

Two-year clinical outcomes after discontinuation of long-term golimumab therapy in Korean patients with rheumatoid arthritis

BACKGROUND/AIMS

The aim of this study was to investigate long-term post-discontinuation outcomes in patients with rheumatoid arthritis (RA) who had been treated with tumor necrosis factor-α inhibitors (TNF-αi) which was then discontinued.

METHODS

Sixty Korean patients with RA who participated in a 5-year GO-BEFORE and GO-FORWARD extension trials were included in this retrospective study. Golimumab was deliberately discontinued after the extension study (baseline). Patients were then followed by their rheumatologists. We reviewed their medical records for 2 years (max 28 months) following golimumab discontinuation. Patients were divided into a maintained benefit (MB) group and a loss-of-benefit (LB) group based on treatment pattern after golimumab discontinuation. The LB group included patients whose conventional disease-modifying antirheumatic drug(s) were stepped-up or added/switched (SC) and those who restarted biologic therapy (RB).

RESULTS

The mean age of patients at baseline was 56.5 years and 55 (91.7%) were females. At the end of follow-up, 23 (38.3%) patients remained in the MB group. In the LB group, 75.7% and 24.3% were assigned into SC and RB subgroups, respectively. Fifty percent of patients lost MB after 23.3 months. Demographics and clinical variables at baseline were comparable between MB and LB groups except for age, C-reactive protein level, and corticosteroid use. Restarting biologic therapy was associated with swollen joint count (adjusted hazard ratio [HR], 1.90; 95% confidence interval [CI], 1.01 to 3.55) and disease duration (adjusted HR, 1.12; 95% CI, 1.02 to 1.23) at baseline.

CONCLUSION

Treatment strategies after discontinuing TNF-αi are needed to better maintain disease control and quality of life of patients with RA.

Clinical characteristics of patients with COVID-19 vaccine-related pneumonitis: a case series and literature review

BACKGROUND/AIMS

Pulmonary toxicities of coronavirus disease 2019 (COVID-19) vaccination are exceedingly rare. However, there are a few reported cases after mRNA vaccination, especially from Asian countries. The purpose of this study was to report the clinical characteristics of patients with COVID-19 vaccine-related pneumonitis (CV-P) and to review cases reported in the literature.

METHODS

We performed a prospective, observational case series analysis.

RESULTS

Eleven patients with a median age of 80 years were enrolled. Ten patients developed CV-P after BNT162b2-mRNA vaccination and one after ChAdOx1 nCoV-19 vaccination. We identified various patterns of CV-P, including transient infiltration, life-threatening acute respiratory distress syndrome, and aggravation of underlying interstitial lung disease. Most patients showed favorable outcomes with good responses to corticosteroid therapy.

CONCLUSION

Identifying the mechanism of CV-P requires further investigation; however, radiological and laboratory findings in our case series support inflammatory dysregulation in the lung parenchyma after vaccination. Clinicians should consider CV-P in patients with atypical lung infiltration, no specific etiologies, and recent COVID-19 vaccination.

Changes in the characteristics of community-onset fluoroquinolone-resistant Escherichia coli isolates causing community-acquired acute pyelonephritis in South Korea

PURPOSE

This study aimed to examine the changes in the characteristics of community-onset fluoroquinolone-resistant (FQ-R) Escherichia coli isolates causing community-acquired acute pyelonephritis (APN) in South Korea.

METHODS

Blood or urine samples were prospectively collected from patients aged ≥15 years with community-acquired APN who were admitted to one of the eight Korean hospitals included in this study between September 2017 and August 2018. Phylogenetic typing, multilocus sequence typing, and molecular characterization of β-lactamase resistance and plasmid-mediated quinolone resistance (PMQR) determinants were performed. The data were compared with those from a previous study with the same design conducted in 2010-2011.

RESULTS

A total of 300 and 346 isolates were identified in 2010-2011 and 2017-2018, respectively. Among them, 76 (22.0%) and 77 (25.7%) FQ-R isolates were identified in 2010-2011 and 2017-2018, respectively. A significantly higher antimicrobial resistance against third-to fourth-generation cephalosporins, including cefotaxime (23.9% vs. 77.9%, P < 0.001), were observed among FQ-R isolates in 2017-2018 than among those in 2010-2011. A higher proportion of ST131 isolates (27.6% vs. 66.2%, P < 0.001), as well as isolates that had extended-spectrum β-lactamase (ESBL)/plasmid-mediated AmpC β-lactamase (PABL) (23.7% vs. 79.2%, P < 0.001), was observed in 2017-2018 than in 2010-2011. Further, more PMQR determinants (11.8% vs. 40.8%, P < 0.001) were observed in 2017-2018 than in 2010-2011.

CONCLUSIONS

Among uropathogenic FQ-R E. coli isolates in South Korea, the prevalence of ST131 and the proportion of isolates containing ESBL and/or PMQR determinants have increased.

Osteoarthritis - Insights From Recent Research

Osteoarthritis (OA) is the most common form of arthritis and is a growing public health concern in the aging society. In rapidly aging societies such as in Korea, the increasing prevalence of OA may present serious new health issues. There is no treatment for OA that can either prevent or slow the progression of joint damage. For the development of effective therapeutics, precise understating of its pathogenesis is important. In this review, the current evidence of etiopathogenesis of OA is discussed. First, while epidemiologic study of OA are still dominated by reports from Western countries, findings from Korean epidemiologic studies are highlighted. Then, recent progresses in genetics, especially in the field of genome wide association study and mendelian randomization studies, are reviewed with focus on Asian population. Lastly, sex difference in pain etopathogenesis is reviewed. Studies of OA pathogenesis including epidemiology, genetics, animal model and pain signaling will aid in progress towards treatment of OA.

Clinical Characteristics and Risk Factors for Mortality in Critical Coronavirus Disease 2019 Patients 50 Years of Age or Younger During the Delta Wave: Comparison With Patients > 50 Years in Korea

BACKGROUND

Numerous patients around the globe are dying from coronavirus disease 2019 (COVID-19). While age is a known risk factor, risk analysis in the young generation is lacking. The present study aimed to evaluate the clinical features and mortality risk factors in younger patients (≤ 50 years) with a critical case of COVID-19 in comparison with those among older patients (> 50 years) in Korea.

METHODS

We analyzed the data of adult patients only in critical condition (requiring high flow nasal cannula oxygen therapy or higher respiratory support) hospitalized with PCR-confirmed COVID-19 at 11 hospitals in Korea from July 1, 2021 to November 30, 2021 when the delta variant was a dominant strain. Patients' electronic medical records were reviewed to identify clinical characteristics.

RESULTS

During the study period, 448 patients were enrolled. One hundred and forty-two were aged 50 years or younger (the younger group), while 306 were above 50 years of age (the older group). The most common pre-existing conditions in the younger group were diabetes mellitus and hypertension, and 69.7% of the patients had a body mass index (BMI) > 25 kg/m². Of 142 younger patients, 31 of 142 patients (21.8%, 19 women) did not have these pre-existing conditions. The overall case fatality rate among severity cases was 21.0%, and it differed according to age: 5.6% (n = 8/142) in the younger group, 28.1% in the older group, and 38% in the ≥ 65 years group. Age (odds ratio [OR], 7.902; 95% confidence interval [CI], 2.754-18.181), mechanical ventilation therapy (OR, 17.233; 95% CI, 8.439-35.192), highest creatinine > 1.5 mg/dL (OR, 17.631; 95% CI, 8.321-37.357), and combined blood stream infection (OR, 7.092; 95% CI, 1.061-18.181) were identified as independent predictors of mortality in total patients. Similar patterns were observed in age-specific analyses, but most results were statistically insignificant in multivariate analysis due to the low number of deaths in the younger group. The full vaccination rate was very low among study population (13.6%), and only three patients were fully vaccinated, with none of the patients who died having been fully vaccinated in the younger group. Seven of eight patients who died had a pre-existing condition or were obese (BMI > 25 kg/m²), and the one remaining patient died from a secondary infection.

CONCLUSION

About 22% of the patients in the young critical group did not have an underlying disease or obesity, but the rate of obesity (BMI > 25 kg/m²) was high, with a fatality rate of 5.6%. The full vaccination rate was extremely low compared to the general population of the same age group, showing that non-vaccination has a grave impact on the progression of COVID-19 to a critical condition. The findings of this study highlight the need for measures to prevent critical progression of COVID-19, such as vaccinations and targeting young adults especially having risk factors.

Diagnostic Value of Anti-Nuclear Antibodies: Results From Korean University-Affiliated Hospitals

BACKGROUND

Unnecessary and inappropriate laboratory testing accounts for a significant portion of waste in health care utilization. The aim of this study was to examine the diagnostic value of the anti-nuclear antibody (ANA) test by examining the rate of ANA associated rheumatic disease (AARD) diagnosis among ANA tested and ANA positive subjects and positive predictive value (PPV) of ANA test leading to AARD diagnosis in different ANA titers and different subsets of patients in 5 hospitals affiliated with a university.

METHODS

We retrospectively extracted data from all subjects who were tested for ANA from year 2010 to 2019. Those who were first evaluated at or referred to rheumatology were further evaluated with extraction of data including ANA titer and ultimate diagnosis. PPVs for ANA test were evaluated after stratification according to clinically relevant key parameters, such as patient age (younger < 65 years vs. older), sex, and requesting department.

RESULTS

From 2010 to 2019, A total of 94,153 patients were tested for ANA, of which 13,600 (14.4% of the total) were positive. AARD was diagnosed in only 0.69% among all ANA tested patients and 4.74% among ANA positive patients. The AARD diagnosis rate of ANA positive patients varied widely from 0.1% to 8.7% by requesting department. Using cutoff values above 1:320 yielded PPVs of 15.6 and 7.8% for all AARs and systemic lupus erythematosus. The PPV was significantly higher in young age (< 65 years) and in women, and when it was requested from internal medicine vs other departments.

CONCLUSION

AARD was diagnosed in less than 1% of all ANA tested patients in university-affiliated hospitals. This result shows that careful consideration before ordering the screening ANA is needed to improve the utility of the test for providers and patients and to reduce health costs spurred by unnecessary testing and its consequences.

Risk Factors for Coronavirus Disease 2019 (COVID-19)-Associated Pulmonary Aspergillosis in Critically Ill Patients: A Nationwide, Multicenter, Retrospective Cohort Study

BACKGROUND

Coronavirus disease 2019 (COVID-19) is often accompanied by secondary infections, such as invasive aspergillosis. In this study, risk factors for developing COVID-19-associated pulmonary aspergillosis (CAPA) and their clinical outcomes were evaluated.

METHODS

This multicenter retrospective cohort study included critically ill COVID-19 patients from July 2020 through March 2021. Critically ill patients were defined as patients requiring high-flow respiratory support or mechanical ventilation. CAPA was defined based on the 2020 European Confederation of Medical Mycology and the International Society for Human and Animal Mycology consensus criteria. Factors associated with CAPA were analyzed, and their clinical outcomes were adjusted by a propensity score-matched model.

RESULTS

Among 187 eligible patients, 17 (9.1%) developed CAPA, which is equal to 33.10 per 10,000 patient-days. Sixteen patients received voriconazole-based antifungal treatment. In addition, 82.4% and 53.5% of patients with CAPA and without CAPA, respectively, received early high-dose corticosteroids (P = 0.022). In multivariable analysis, initial 10-day cumulative steroid dose > 60 mg of dexamethasone or dexamethasone equivalent dose) (adjusted odds ratio [OR], 3.77; 95% confidence interval [CI], 1.03-13.79) and chronic pulmonary disease (adjusted OR, 4.20; 95% CI, 1.26-14.02) were independently associated with CAPA. Tendencies of higher 90-day overall mortality (54.3% vs. 35.2%, P = 0.346) and lower respiratory support-free rate were observed in patients with CAPA (76.3% vs. 54.9%, P = 0.089).

CONCLUSION

Our study showed that the dose of corticosteroid use might be a risk factor for CAPA development and the possibility of CAPA contributing to adverse outcomes in critically ill COVID-19 patients.

Trends in hospital visits and healthcare costs of gout and seropositive rheumatoid arthritis in Korea from 2010 to 2017 using National Healthcare Claims

BACKGROUND/AIMS

We examined temporal trends in the rate of gout and seropositive rheumatoid arthritis (RA) hospital visits and healthcare costs in Korea.

METHODS

We conducted a serial cross-sectional analysis of Korean national healthcare claims. We calculated the annual increase in hospital visits (emergency department [ED] visits, outpatient visits, and hospitalizations) and total healthcare costs per visit.

RESULTS

From 2010 to 2017, the annual rates of ED visits, outpatient visits, and hospitalizations for gout increased from 6.28 to 21, from 638.38 to 1059.55, and from 12.37 to 15.6 per 100,000 persons, respectively. Before 2013, ED visits for gout were most common in patients over 70 years old, but they were most common in those aged between 30 and 49 years after 2013. The number of patients with ED visits, outpatient visits, and hospitalizations for RA from 2010 to 2017 increased from 1.25 to 1.87, from 219.04 to 307.49 and from 8.44 to 12.32 per 100,000 persons, respectively. However, there was no increase in the prevalence of ED visits for RA in any age group except for those older than 70 years. The cost per ED visit for gout significantly decreased from 496.3 to 273.6 US dollar during the study period. There was no significant change in the cost per ED visit for RA between 2010 and 2017.

CONCLUSION

There was a large increase in ED visits for gout during the study period. Further studies are needed to analyze the reason behind increased ED visits for gout and suggest ways on how to improve gout care.

A risk scoring system to predict progression to severe pneumonia in patients with Covid-19

Rapid outbreak of coronavirus disease 2019 (Covid-19) raised major concern regarding medical resource constraints. We constructed and validated a scoring system for early prediction of progression to severe pneumonia in patients with Covid-19. A total of 561 patients from a Covid-19 designated hospital in Daegu, South Korea were randomly divided into two cohorts: development cohort (N = 421) and validation cohort (N = 140). We used multivariate logistic regression to identify four independent risk predictors for progression to severe pneumonia and constructed a risk scoring system by giving each factor a number of scores corresponding to its regression coefficient. We calculated risk scores for each patient and defined two groups: low risk (0 to 8 points) and high risk (9 to 20 points). In the development cohort, the sensitivity and specificity were 83.8% and 78.9%. In the validation cohort, the sensitivity and specificity were 70.8% and 79.3%, respectively. The C-statistics was 0.884 (95% CI 0.833–0.934) in the development cohort and 0.828 (95% CI 0.733–0.923) in the validation cohort. This risk scoring system is useful to identify high-risk group for progression to severe pneumonia in Covid-19 patients and can prevent unnecessary overuse of medical care in limited-resource settings.

Abnormal Development of Neural Stem Cell Niche in the Dentate Gyrus of Menkes Disease

Background and Objectives

Menkes disease (MNK) is a rare X-linked recessive disease, caused by mutations in the copper transporting ATP7A gene that is required for copper homeostasis. MNK patients experience various clinical symptoms including neurological defects that are closely related to the prognosis of MNK patients. Neural stem cells (NSCs) in the hippocampal dentate gyrus (DG) produce new neurons throughout life, and defects in DG neurogenesis are often correlated with cognitive and behavioral problems. However, neurodevelopmental defects in the DG during postnatal period in MNK have not been understood yet.

Methods and Results

Mottled-brindled (Mo^Br/y) mice (MNK mice) and littermate controls were used in this study. In vivo microCT imaging and immunohistochemistry results demonstrate that blood vasculatures in hippocampus are abnormally decreased in MNK mice. Furthermore, postnatal establishment of NSC population and their neurogenesis are severely compromised in the DG of MNK mice. In addition, in vitro analyses using hippocampal neurosphere culture followed by immunocytochemistry and immunoblotting suggest that neurogenesis from MNK NSCs is also significantly compromised, corresponding to defective neurogenic gene expression in MNK derived neurons.

Conclusions

Our study is the first reports demonstrating that improper expansion of the postnatal NSC population followed by significant reduction of neurogenesis may contribute to neurodevelopmental symptoms in MNK. In conclusion, our results provide new insight into early neurodevelopmental defects in MNK and emphasize the needs for early diagnosis and new therapeutic strategies in the postnatal central nerve system damage of MNK patients.

Relationship between the appropriateness of antibiotic treatment and clinical outcomes/medical costs of patients with community-acquired acute pyelonephritis: a multicenter prospective cohort study

BACKGROUND

Inappropriate use of antibiotics not only increases antibiotic resistance as collateral damage but also increases clinical failure rates and medical costs. The purpose of this study was to determine the relationship between the appropriateness of antibiotic prescription and outcomes of community-acquired acute pyelonephritis (CA-APN).

METHODS

A multicenter prospective cohort study was conducted at eight hospitals in Korea between September 2017 and August 2018. All hospitalized patients aged ≥ 19 years who were diagnosed with CA-APN on admission were recruited. The appropriateness of empirical and definitive antibiotics, as well as the appropriateness of antibiotic treatment duration and route of administration, was evaluated in accordance with the guideline and expert opinions. Clinical outcomes and medical costs were compared between patients who were administered antibiotics 'appropriately' and 'inappropriately.'

RESULTS

A total of 397 and 318 patients were eligible for the analysis of the appropriateness of empirical and definitive antibiotics, respectively. Of them, 10 (2.5%) and 18 (5.7%) were administered 'inappropriately' empirical and definitive antibiotics, respectively. Of the 119 patients whose use of both empirical and definitive antibiotics was classified as 'optimal,' 57 (47.9%) received antibiotics over a longer duration than that recommended; 67 (56.3%) did not change to oral antibiotics on day 7 of hospitalization, even after stabilization of the clinical symptoms. Patients who were administered empirical antibiotics 'appropriately' had shorter hospitalization days (8 vs. 10 days, P = 0.001) and lower medical costs (2381.9 vs. 3235.9 USD, P = 0.002) than those who were administered them 'inappropriately.' Similar findings were observed for patients administered both empirical and definitive antibiotics 'appropriately' and those administered either empirical or definitive antibiotics 'inappropriately'.

CONCLUSIONS

Appropriate use of antibiotics leads to better outcomes, including reduced hospitalization duration and medical costs.

Pathophysiology of blood brain barrier dysfunction during chronic cerebral hypoperfusion in vascular cognitive impairment

The prevalence of cerebrovascular disease increases with age, placing the elderly at a greater lifetime risk for dementia. Vascular cognitive impairment (VCI) encompasses a spectrum of cognitive deficits from mild cognitive impairment to dementia. VCI and its most severe form, vascular dementia (VaD), is becoming a major public health concern worldwide. As growing efforts are being taken to understand VCI and VaD in animal models and humans, the pathogenesis of the disease is being actively explored. It is postulated that chronic cerebral hypoperfusion (CCH) is a major cause of VCI. CCH activates a molecular and cellular injury cascade that leads to breakdown of the blood brain barrier (BBB) and neurodegeneration. The BBB tightly regulates the movement of substances between the blood and the brain, thereby regulating the microenvironment within the brain parenchyma. Here we illustrate how BBB damage is causal in the pathogenesis of VCI through the increased activation of pathways related to excitotoxicity, oxidative stress, inflammation and matrix metalloproteinases that lead to downstream perivascular damage, leukocyte infiltration and white matter changes in the brain. Thus, CCH-induced BBB damage may initiate and contribute to a vicious cycle, resulting in progressive neuropathological changes of VCI in the brain. This review outlines the molecular and cellular mechanisms that govern BBB breakdown during CCH and highlights the clinical evidence in identifying at-risk VCI patients.

Effectiveness of Regdanvimab Treatment in High-Risk COVID-19 Patients to Prevent Progression to Severe Disease

Objective

To evaluate clinical effectiveness of regdanvimab, a monoclonal antibody agent for treating coronavirus 2019 (COVID-19).

Methods

A retrospective cohort study was conducted at two general hospitals during the study period of December 2020 to May 2021. Mild COVID-19 patients with risk factors for disease progression admitted to the hospitals within seven days of symptom onset were enrolled and followed until discharge or referral. Multivariate analyses for disease progression were conducted in the total and propensity score (PS)-matched cohorts.

Results

A total of 778 mild COVID-19 patients were included and classified as the regdanvimab (n = 234) and supportive care (n = 544) groups. Significantly fewer patients required O₂ supplementation via nasal prong in the regdanvimab group (8.1%) than in the supportive care group (18.4%, P < 0.001). The decreased risk for O₂ support by regdanvimab treatment was noticed in the multivariate analysis of the total cohort (HR 0.570, 95% CI 0.343-0.946, P = 0.030), but it was not statistically significant in the PS-matched cohort (P = 0.057). Progression to severe disease was also significantly lower in the regdanvimab group (2.1%) than in the supportive care group (9.6%, P < 0.001). The significantly reduced risk for progression to severe disease by regdanvimab treatment was observed in the analysis of both the total cohort (HR 0.262, 95% CI 0.103-0.667, P = 0.005) and PS-matched cohort (HR 0.176, 95% CI 0.060-0.516, P = 0.002). Potential risk factors for progression were investigated in the supportive care group and SpO₂ < 97% and CRP elevation >1.5 mg/dL were common risk factors for O₂ support and progression to severe disease. Among the patients with any of these factors, regdanvimab treatment was associated with decreased risk for progression to severe disease with slightly lower HR (HR 0.202, 95% CI 0.062-0.657, P = 0.008) than that of the total cohort.

Conclusion

Regdanvimab treatment was associated with a decreased risk of progression to severe disease.

Metabolic obesity and the risk of knee osteoarthritis progression in elderly community residents: A 3-year longitudinal cohort study

OBJECTIVE

Metabolic syndrome is a major health problem worldwide associated with obesity, thus drawing attention to its relation to osteoarthritis (OA). However, it is still uncertain whether metabolic syndrome or body fat distribution is associated with knee OA. The aim of this longitudinal study was to elucidate the association between metabolic obesity and adverse structural changes of knee OA assessed by magnetic resonance imaging (MRI).

METHODS

Participants were recruited from the Hallym Aging Study cohort in Korea. Knee MRI scans, along with dual-energy X-ray absorptiometry, were assessed in 226 participants at baseline and after 3 years. The structural progression in the tibiofemoral joint was evaluated using the semi-quantitative Whole-Organ MRI Score (WORMS) for cartilage morphology and bone marrow lesions (BML). Logistic regression with generalized estimating equation was performed for associations of metabolic risk factors with worsening of WORMS scores at the subregional level.

RESULTS

In the medial compartment, fat mass in women was associated with cartilage loss, but the statistical significance disappeared after adjusting for body mass index. Metabolic syndrome and each of its components were not associated with cartilage loss or increase of BML. On the other hand, the interaction effects of metabolic syndrome on the association between obesity and knee OA progression were not significant.

CONCLUSION

In this cohort, metabolic effects of obesity on knee cartilage damage and BML were not demonstrated. Further large-scale studies are required to prove the causal relationship between metabolic obesity and knee OA.

1318. Clinical and Molecular Characteristics of Hypermucoviscous Klebsiella pneumoniae Causing Pneumonia in Korea

Background

Invasive Klebsiella pneumoniae (K. pneumoniae) was emerged in Asia, well-known for community-onset liver abscess. Healthcare-associated pneumonia caused by hypervirulent K. pneumoniae has been reported in recent studies. The purpose of this study was to evaluate the clinical and molecular characteristics of hypervirulent K. pneumoniae compared with classic K. pneumoniae in respiratory infection.

Methods

The study was performed on 163 K. pneumoniae isolates of respiratory infections collected from Keimyung University of Dongsan Medical Center from November 2013 to November 2015; group A, as classic K. pneumoniae and group B, as hypervirulent K. pneumoniae. Hypermucoviscous phenotype was confirmed with string test. Capsular serotypes, rmpA, magA, allS, mrkD, entB, kfu, and iutA were identified using specific primers by polymerase chain reaction. The biofilm mass was determined using the microtiter plate assay measured by optical density (OD, 570nm).

Results

A total 163 patients were analyzed, 100 (61.3%) of group A and 68 (38.7%) of group B. Community-acquired pneumonia was observed in 49.2% of group B and 18.0% of group A (p=0.001). Underlying diseases except chronic lung disease were more associated with group A. Mean age (72.6±11.7 vs. 68.8±12.5 years, p=0.051) and antimicrobial resistant rates were higher in group A. Mechanical ventilators (21.0% vs. 36.5%, p=0.030) was more associated with group B. Concordances of initial antibiotics (57.5% vs. 92.1%, p=0.001) were more observed in group B. Biofilm formation and infection related 30-day mortality showed no differences between the two groups.

Conclusion

Contrary to our expectations, hypervirulent K. pneumoniae was more associated with community-acquired pneumonia in this study. Compared to classic K. pneumoniae, hypervirulent K. pneumoniae showed more association with severe pneumonia and less association with underlying diseases. In respiratory infection, biofilm formation was not different according to hypermucoviscousity.

Disclosures

All Authors: No reported disclosures

Arthroscopic Partial Meniscectomy versus Physical Therapy for Degenerative Meniscal Tear: a Systematic Review

BACKGROUND

Meniscal tears are commonly observed in patients with knee osteoarthritis (OA), however, clinical significance of such lesions detected by magnetic resonance imaging is in many cases unclear. This study aimed to determine the clinical effectiveness of arthroscopic partial meniscectomy (APM) compared with non-operative care in patients with knee OA.

METHOD

We used existing systematic reviews with updates of latest studies. Three randomized controlled studies were selected, where two studies compared the effects of APM plus physical therapy (PT) with PT alone and one compared APM alone and PT alone. While 1 study exclusively included OA patients, 2 studies included 21.1 and 12% of patients with no radiographic OA. Patients with knee locking were unanimously excluded.

RESULTS

Upon comparison of APM plus PT and PT alone, there was no significant difference observed in knee function, physical activity, or adverse events. Knee pain was observed to be significantly lower in the APM plus PT group at 6 months, but there was no difference between the two groups at 12 and 24 months. With respect to the comparison between APM alone and PT alone, PT was non-inferior based on the criteria for knee function during 24 months; however, knee pain was significantly reduced in the APM alone group.

CONCLUSIONS

Our study showed that knee pain was significantly improved in the APM group compared to non-operative care group at 6 months and over 24 months. Our result was based on only 3 randomized controlled trials (RCTs) revealing a significant knowledge gap, hence demanding more high-quality RCTs in OA patients.

TRIAL REGISTRATION

PROSPERO Identifier: CRD42020215965.

Differences of virulence factors, and antimicrobial susceptibility according to phylogenetic group in uropathogenic Escherichia coli strains isolated from Korean patients

Background

Escherichia coli is among the most common uropathogens. Increased antibiotic resistance in Gram negative bacilli is global concern. Alternative therapeutic options including vaccines against uropathogenic E. coli (UPEC) have been developed. In this study, we compared the genotypic characteristics and antimicrobial susceptibility of UPEC according to phylogenetic groups.

Methods

We retrospectively reviewed the medical records of pyelonephritis patients with UPEC between February 2015 and June 2018. The study was conducted at a medical center in Korea. We compared the clinical and genotypic characteristics of UPEC according to phylogenetic groups. The phylogenetic groups and 29 virulence factors were identified using multiplex polymerase chain reaction.

Results

Phylogenetic group analysis revealed that most uropathogenic E. coli belonged to groups B2 and D: B2 (276, 77.7%), D (62, 17.5%), B1 (12, 3.4%), and A (5, 1.4%). Among the virulence factors, fyuA, fimH, traT, iutA, papG allele II, and papC were the most frequently observed. Phylogenetic group B2 was more closely related to virulence factors, including fimH, sfa/focED, focG, hlyA, cnf1, fyuA, and PAI, than group D. Groups B2 and D showed similar clinical presentations and complications. Group B2 had mostly healthcare-associated infections and antimicrobial resistance. Group D mostly had community-acquired infections. The K1 serotype was prevalent in group B2, and K5 was the most prevalent in group D.

Conclusions

Phylogenetic group B2 had more proportions and types of virulence factors than group D. Group B2 showed a high presentation of virulence factors related to adhesions and toxins. An increased presentation of antimicrobial resistance and healthcare-associated infections was also noted. Considering the genetic characteristics of UPEC, alternative therapeutic options targeting frequent virulence factors might be considered in addition to antibiotics.

Large-Scale Multivariate Analysis to Interrogate an Animal Model of Stroke: Novel Insights Into Poststroke Pathology

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Serum uric acid and knee osteoarthritis in community residents without gout: a longitudinal study

OBJECTIVES

Emerging evidence suggests a potential link between OA and gout; however, the association between serum uric acid (UA) itself and knee OA remains uncertain due to a lack of longitudinal studies. Here, we investigated the association between serum UA and knee OA according to cartilage status in elderly community residents without gout.

METHODS

In this longitudinal study, participants without a history of gout were recruited from among the Korean cohort of the Hallym Aging Study (n = 296 for radiography study and n = 223 for MRI study). Weight-bearing knee radiographs and 1.5-T MRI scans, along with blood collection for analysis of serum UA, were performed at baseline and after 3 years. The severity and structural progression of knee OA were evaluated using the Kellgren-Lawrence grading system and the Whole-Organ MRI Score (WORMS) cartilage scoring method. Multivariable logistic regression analysis was conducted using generalized estimating equation (GEE) models.

RESULTS

Serum UA levels were not associated with radiographic progression after adjusting for age, sex and BMI. There was no significant association between serum UA and tibiofemoral cartilage loss on MRI. However, baseline serum UA levels were negatively associated with patellofemoral cartilage loss over 3 years (adjusted odd ratio 0.70 per 1 mg/dl increase, 95% CI: 0.49, 0.98).

CONCLUSION

In this population-based cohort, serum UA was not a risk factor for knee OA progression. Further large-scale longitudinal studies in other populations are needed to validate the effects of UA on cartilage damage.

Norepinephrine modulates IL-1β-induced catabolic response of human chondrocytes

Background

The influence of the sympathetic nervous system (SNS) on metabolism of bone and cartilage expressing β-adrenergic receptors (AR) was suggested. Here, we investigated whether the SNS functions as a modulator of cartilage metabolism induced by interleukin-1beta (IL-1β).

Methods

Human articular chondrocytes and articular cartilage were collected from patients with osteoarthritis (OA). Chondrocyte monolayer and cartilage explant culture were stimulated with IL-1β. The activity of β-ARs was modulated by an agonist, norepinephrine (NE), and antagonists, including propranolol, atenolol, nebivolol, and nadolol.

Results

The levels of β₁-, β₂-, and β₃-AR in OA cartilage and IL-1β-treated chondrocytes were lower than normal cartilage and untreated cells. Treatment of chondrocytes with IL-1β and β-blockers, including propranolol, atenolol, nebivolol, and nadolol, for 6 h significantly upregulated IL-1β-induced expression of MMP-1, -3, and − 13, compared to chondrocytes treated with IL-1β alone, indicating that antagonism of β-AR confers catabolic signals. On the other hand, NE antagonized IL-1β-induced catabolic response. In addition, NE significantly inhibited IL-1β-induced release of glycosaminoglycan (GAG) from cartilage explant culture. In addition, β-AR activity significantly affected IL-1β-stimulated phosphorylation of JNK and ERK. These results indicate that β-AR signal is associated with cartilage metabolism.

Conclusions

Our findings showed that β-ARs is a regulator of cartilage catabolism induced with IL-1β.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04598-7.