Limited impact of bacterial virulence on early mortality risk factors in Acinetobacter baumannii bacteremia observed in a Galleria mellonella model.

Acinetobacter baumannii (AB) has emerged as a major pathogen in vulnerable and severely ill patients. It remains unclear whether early mortality (EM) due to AB bacteremia is because of worse clinical characteristics of the infected patients or the virulence of the pathogen. In this study, we aimed to investigate the effect of AB virulence on EM due to bacteremia.

Anti-SARS-CoV-2 Nucleocapsid Antibody Positivity Three Years after COVID-19.

The accurate identification of individuals without prior infection with severe acute respiratory syndrome coronavirus 2 is pivotal for seroepidemiological studies and vaccine trials. Owing to widespread vaccination against coronavirus disease 2019 (COVID-19), the anti-nucleocapsid antibody continues to serve as a valuable marker for individuals without a history of COVID-19. This study aimed to comprehensively assess anti-nucleocapsid antibody positivity using diverse commercial and in-house immunoassays among individuals who contracted COVID-19 more than three years earlier.

An ancestral SARS-CoV-2 vaccine induces anti-Omicron variants antibodies by hypermutation.

The immune escape of Omicron variants significantly subsides by the third dose of an mRNA vaccine. However, it is unclear how Omicron variant-neutralizing antibodies develop under repeated vaccination. We analyze blood samples from 41 BNT162b2 vaccinees following the course of three injections and analyze their B-cell receptor (BCR) repertoires at six time points in total.

Risk factors for resistant gram-positive bacteremia in febrile neutropenic patients with cancer.

Background: Gram-positive bacteria are frequently resistant to empirical beta-lactams in febrile neutropenic patients with cancer. As microbiology and antibiotic susceptibility changes, we reevaluated the risk factors for resistant Gram-positive bacteremia in febrile neutropenic patients with cancer.

Methods: Episodes of bacteremic febrile neutropenia in Seoul National University Hospital from July 2019 to June 2022 were reviewed.

Clinical outcomes and immunological features of COVID-19 patients receiving B-cell depletion therapy during the Omicron era.

The clinical outcomes and immunological features of coronavirus disease 2019 (COVID-19) patients receiving B-cell depletion therapy (BCDT), especially in Omicron variant era, have not been fully elucidated. We aimed to investigate the outcomes and immune responses of COVID-19 patients receiving BCDT during the Omicron period. We retrospectively compared clinical outcomes between COVID-19 patients treated with BCDT (the BCDT group) and those with the same underlying diseases not treated with BCDT (the non-BCDT group).

Tracking antigen-specific TCR clonotypes in SARS-CoV-2 infection reveals distinct severity trajectories.

Despite the importance of antigen-specific T cells in infectious disease, characterizing and tracking clonally amplified T cells during the progression of a patient's symptoms remain unclear. Here, we performed a longitudinal, in-depth single-cell multiomics analysis of samples from asymptomatic, mild, usual severe, and delayed severe patients of SARS-CoV-2 infection. Our in-depth analysis revealed that hyperactive or improper T-cell responses were more aggressive in delayed severe patients.

Risk Factors for the Prescription of Ineffective Antiviral Candidates for COVID-19 During the Early Pandemic Period in Korea.

Background: Although the evidence of treatment for coronavirus disease 2019 (COVID-19) changed rapidly, little is known about the patterns of potential pharmacological treatment during the early period of the COVID-19 pandemic in Korea and the risk factors for ineffective prescription.

Methods: Using claims data from the Korean National Health Insurance System, this retrospective cohort study included admission episodes for COVID-19 from February to December 2020. Ineffective antiviral prescriptions for COVID-19 were defined as lopinavir/ritonavir (LPN/r) and hydroxychloroquine (HCQ) prescribed after July 2020, according to the revised National Institute of Health COVID-19 treatment guidelines.

Possibility of Decreasing Incidence of Human Immunodeficiency Virus Infection in Korea.

Background: The number of newly diagnosed cases of human immunodeficiency virus (HIV) infection in Korea, which had increased until 2019, has markedly decreased since the coronavirus disease 2019 pandemic started. This study evaluated whether the decrease is due to a reduction in the incidence of HIV infection and/or delayed diagnosis during the pandemic.

Materials And Methods: We reviewed the medical records of 587 newly diagnosed patients with HIV infection between February 2018 and January 2022 from four general hospitals, and their characteristics were compared between the pre-pandemic and pandemic periods.

Empirical vs pre-emptive broad-spectrum antifungal therapy for acute myelogenous leukaemia in the era of antimould prophylaxis.

Introduction: This study compared clinical outcomes in patients with acute myelogenous leukaemia (AML) who developed prolonged (≥4 days) febrile neutropenia (FN) and received either empirical or pre-emptive antimould prophylaxis in order to evaluate the need for routine empirical antifungal therapy.

Methods: This retrospective study reviewed adult patients (aged ≥18 years) with AML who developed prolonged FN and received antimould prophylaxis during induction or re-induction chemotherapy at a single centre between September 2016 and December 2020. Patients were categorized into pre-emptive or empirical groups based on whether or not there was clinical evidence of invasive fungal infection (IFI) at the start of antifungal treatment, respectively.

Impact of T-Cell Engagers on COVID-19-Related Mortality in B-Cell Lymphoma Patients Receiving B-Cell Depleting Therapy.

Purpose: B-cell depleting therapies, including T-cell engager (TCE), are increasingly used for patients with hematologic malignancies, including during the coronavirus disease 2019 (COVID-19) pandemic. We aimed to evaluate the relationship between TCE therapy and COVID-19-related outcomes among patients with COVID-19 and B-cell lymphomas receiving B-cell depleting therapy.

Materials And Methods: This retrospective cohort study included patients with B-cell lymphoma, who were admitted to Seoul Natio-nal University Hospital with COVID-19 between September 2021 and February 2023, and received B-cell depleting therapy before COVID-19 diagnosis.

Impact of routine brain imaging on the prognosis of patients with left-sided valve infective endocarditis without neurological manifestations.

Background: There are limited data on the impact of routine use of brain magnetic resonance imaging (MRI) on the prognosis of neurologically asymptomatic patients with left-sided infective endocarditis (IE).

Methods: Among patients diagnosed with possible or definite IE in two tertiary referral centers between January 2005 and March 2019, we identified 527 left-sided IE patients without neurological symptoms or signs at the time of diagnosis. Patients who underwent brain MRI within 1 week after the IE diagnosis were classified as the routine brain imaging group (n = 216), and the rest were categorized as the control group (n = 311).

Effect of Wearing Personal Protective Equipment (PPE) for COVID-19 Treatment on Blood Culture Contamination: Implication for Optimal PPE Strategies.

The personal protective equipment (PPE) used to minimize exposure to hazards can hinder healthcare workers from performing sophisticated procedures. We retrospectively reviewed 77,535 blood cultures (202,012 pairs) performed in 28,502 patients from January 2020 to April 2022. The contamination rate of all blood cultures was significantly elevated in the coronavirus disease 2019 ward at 4.

Different degree of cytokinemia and T-cell activation according to serum IL-6 levels in critical COVID-19.

Introduction: Tocilizumab, a humanized anti-interleukin-6 receptor (IL-6R) antibody, is recommended for the treatment of severe to critical coronavirus diseases 2019 (COVID-19). However, there were conflicting results on the efficacy of tocilizumab. Therefore, we hypothesized that the differences in tocilizumab efficacy may stem from the different immune responses of critical COVID-19 patients.

Low humoral and cellular immune responses early after breakthrough infection may contribute to severe COVID-19.

Background: Little is known about the immune determinants for severe coronavirus disease 2019 (COVID-19) in individuals vaccinated against severe acute respiratory syndrome coronavirus 2. We therefore attempted to identify differences in humoral and cellular immune responses between patients with non-severe and severe breakthrough COVID-19.

Methods: We prospectively enrolled hospitalized patients with breakthrough COVID-19 (severe and non-severe groups) and uninfected individuals who were vaccinated at a similar time (control group).

Incidence, Severity, and Mortality of Influenza During 2010-2020 in Korea: A Nationwide Study Based on the Population-Based National Health Insurance Service Database.

Background: The epidemiology of influenza is commonly used to understand and establish relevant health policies for emerging respiratory infections, including coronavirus disease 2019 (COVID-19). However, Korea has no confirmed nationwide data on influenza incidence, severity, and mortality rate.

Methods: We conducted a cross-sectional study to obtain epidemic data on influenza at the national level using National Health Insurance claims data during 2010 to 2020.

Comparable humoral and cellular immunity against Omicron variant BA.4/5 of once-boosted BA.1/2 convalescents and twice-boosted COVID-19-naïve individuals.

The fourth vaccination dose confers additional protective immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in individuals with no prior coronavirus disease-19 (COVID-19). However, its immunological benefit against currently circulating BA.4/5 is unclear in individuals who have received a booster shot and been infected with Omicron variant BA.

How We Have Treated Severe to Critically Ill Patients With Coronavirus Disease 2019 in Korea.

Since 2019, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread worldwide, and the coronavirus disease 2019 (COVID-19) pandemic currently continues. In response to this unprecedented pandemic, several researchers and medical staff have struggled to find appropriate treatments for COVID-19. Patients with mild symptoms can recuperate with symptomatic care, however establishing treatment for severe to critically ill patients who can have a high mortality has been essential.

A Double-Blind, Randomized, Placebo-Controlled, Phase II Clinical Study To Evaluate the Efficacy and Safety of Camostat Mesylate (DWJ1248) in Adult Patients with Mild to Moderate COVID-19.

Although several antiviral agents have become available for coronavirus disease 2019 (COVID-19) treatment, oral drugs are still limited. Camostat mesylate, an orally bioavailable serine protease inhibitor, has been used to treat chronic pancreatitis in South Korea, and it has an inhibitory potential against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This study was a double-blind, randomized, placebo-controlled, multicenter, phase 2 clinical trial in mild to moderate COVID-19 patients.

Prospective longitudinal analysis of antibody response after standard and booster doses of SARS-COV2 vaccination in patients with early breast cancer.

Introduction: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its variants brought waves of pandemics with breakthrough infections in vaccinated individuals. We analyzed the antibody responses after primary and booster vaccination in healthy controls (HC) and patients with early breast cancer (BC).

Methods: In this prospective longitudinal cohort study, the binding activity of serum antibody level against spike proteins and antigens of SARS-CoV-2 variants was measured within 21 days after each vaccination in the BC group and HC group.

Accurate Diagnosis of COVID-19 from Self-Collectable Biospecimens Using Synthetic Apolipoprotein H Peptide-Coated Nanoparticle Assay.

A high-throughput, accurate screening is crucial for the prevention and control of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Current methods, which involve sampling from the nasopharyngeal (NP) area by medical staffs, constitute a fundamental bottleneck in expanding the testing capacity. To meet the scales required for population-level surveillance, self-collectable specimens can be used; however, its low viral load has hindered its clinical adoption.

Evaluation of Seropositivity After Standard Doses of Vaccination Against SARS-CoV-2 in Patients With Early Breast Cancer Receiving Adjuvant Treatment.

Background: Coronavirus disease 2019 (COVID-19) pandemic affected millions of individuals, and patients with cancer are known to be more susceptible. Vaccines against SARS-CoV-2 have been developed and used for patients with cancer, but scarce data are available on their efficacy in patients under active anti-cancer therapies.

Materials And Methods: In this study, we semi-quantitatively measured the titers of the immunoglobulin G against the anti-spike protein subunit 1 of SARS-CoV-2 after vaccination of patients with early breast cancer undergoing concurrent chemotherapy, endocrinal or targeted non-cytotoxic treatments, and no treatments.