The LEPR (leptin receptor) genotype is associated with obesity. Gut microbiome composition differs between obese and nonobese adults. However, the impact of LEPR genotype on gut microbiome composition in humans has not yet been studied. In this study, the association between LEPR single nucleotide polymorphism (rs1173100, rs1137101, and rs790419) and the gut microbiome composition in 65 non-obese Korean adults was investigated. Leptin, triglyceride, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol levels were also measured in all participants. Mean ± SD (standard deviation) of age, body mass index, and leptin hormone levels of participants was 35.2 ± 8.1 years, 21.4 ± 1.8 kg/m 2 , and 7989.1 ± 6687.4 pg/mL, respectively. Gut microbiome analysis was performed at the phylum level by 16S rRNA sequencing. Among the 11 phyla detected, only one showed significantly different relative abundances between LEPR genotypes. The relative abundance of Candidatus Saccharibacteria was higher in the G/A genotype group than in the G/G genotype group for the rs1137101 single nucleotide polymorphism (p=0.0322). Participant characteristics, including body mass index, leptin levels, and other lipid levels, were similar between the rs1137101 G/G and G/A genotypes. In addition, the relative abundances of Fusobacteria and Tenericutes showed significant positive relationship with plasma leptin concentrations (p=0.0036 and p=0.0000, respectively). In conclusion, LEPR genotype and gut microbiome may be associated even in normal-weight Korean adults. However, further studies with a greater number of obese adults are needed to confirm whether LEPR genotype is related to gut microbiome composition.

Background: This retrospective observational matched-cohort study of 2,151,216 individuals from the Korean coronavirus disease 2019 (COVID-19) vaccine effectiveness cohort aimed to evaluate the comparative effectiveness of the COVID-19 bivalent versus monovalent vaccines in providing additional protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, critical infection, and death in Korea. Methods: Among individuals, those vaccinated with COVID-19 bivalent vaccines were matched in a 1:1 ratio with those who were vaccinated with monovalent vaccines (bivalent vaccines non-recipients) during the observation period. We fitted a time-dependent Cox proportional-hazards model to estimate hazard ratios (HRs) of COVID-19 outcomes for infection, critical infection, and death, and we defined vaccine effectiveness (VE) as 1–HR. Results: Compared with the bivalent vaccination group, the incidence proportions in the monovalent vaccination group were approximately three times higher for infection, nine times higher for critical infection, and 11 times higher for death. In the early stage of bivalent vaccination, relative VE of bivalent vaccine against monovalent vaccine was 42.4% against SARS-CoV-2 infection, 81.3% against critical infection, and 85.3% against death. In addition, VE against critical infection and death according to the elapsed period after bivalent vaccination was maintained at > 70%. Conclusion The bivalent booster dose provided additional protection against SARS-CoV-2 infections, critical infections, and deaths during the omicron variant phase of the COVID-19 pandemic.

Background: Although fiberoptic-guided endotracheal intubation using a supraglottic airway device (SAD) is a good alternative for the management of difficult airways, its learning curve for residents has not been evaluated in pediatric patients. We aimed to train residents using a pediatric manikin and obtain learning curves to evaluate the efficiency of the training. Methods: We conducted a single-armed prospective study with anesthesiology residents. Plain endotracheal tube (ETT) intubation guided by a fiberoptic bronchoscope through Ambu® AuraGainTM was demonstrated in a pediatric manikin to the participants before training. The procedure was divided into four steps: SAD insertion, vocal cord identification, carina identification, and ETT insertion into the trachea. The results and elapsed procedure times of each trial were recorded. The learning curves for the participants were constructed and analyzed using the cumulative sum method. Results: All the 30 participants acquired proficiency at the end of practice between eight and 25 trials. The overall success rate for the procedure was 92.8%, and above 80% for all participants. Mean ± standard deviation procedure time was 71.3 ± 50.7 s. The 4th step accounted for 86.2% and 48.0% of the total failures and procedure time, respectively. The procedure time rapidly decreased in the 2nd trial; a modest decline was observed thereafter. Conclusions Trainees can obtain proficiency for fiberoptic-guided intubation through SAD within 25 times when using pediatric manikin. Effect of the training on performance in actual clinical situation should be studied.

Background/Aims: Chronic hepatitis C is a major risk factor for liver cirrhosis, hepatocellular carcinoma, and hepatic failure. Although traditional practices, including acupuncture, tend to increase the risk of HCV infection, the association remains controversial. Therefore, the current meta-analytical study was undertaken to evaluate the risks of acupuncture and hepatitis C transmission. Methods: Two researchers independently screened studies from the databases encompassing the period from inception to May 12, 2022. Baseline demographics, HCV transmission OR, and 95% CIs were extracted, pooled, and analyzed using random-effect models.Subgroup analyses utilizing study design and ethnicity were performed. Heterogeneity and publication bias were analyzed using the Higgins I2 test and funnel plots, respectively. Results: In all, 28 studies with 194,826 participants (178,583 controls [91.7%] vs. 16,243 acupuncture users [8.3%]) were included in the final analysis. The pooled analysis showed that acupuncture users had a significantly higher HCV transmission rate than controls with heterogeneity (OR, 1.84 [1.46–2.32]; p<0.001; I2 =80%). In the subgroup analysis, both cross-sectional case-control (n=14; OR, 1.96 [1.47–2.61]; p<0.001; I2 =88%) and cross-sectional studies (n=12; OR, 1.85 [1.32–2.61]; p<0.001; I2 =0%) showed significantly higher HCV infection rates in the acupuncture group than in the control group. Both Asian and non-Asian acupuncture users showed a higher HCV transmission risk than the controls (all Ps <0.001). No significant publication bias was observed. Conclusions Our findings indicate that acupuncture increases the risk of HCV transmission. Due to HCV's contagiousness, unsafe medical and social practices (including acupuncture) should be performed with caution.

Background: Clonal hematopoiesis of indeterminate potential (CHIP), which is defined as the presence of blood cells originating from somatically mutated hematopoietic stem cells, is common among the elderly and is associated with an increased risk of hematologic malignancies. We investigated the clinical, mutational, and transcriptomic characteristics in elderly Korean individuals with CHIP mutations. Methods: We investigated CHIP in 90 elderly individuals aged ≥60 years with normal complete blood counts at a tertiary-care hospital in Korea between June 2021 and February 2022. Clinical and laboratory data were prospectively obtained. Targeted next-generation sequencing of 49 myeloid malignancy driver genes and massively parallel RNA sequencing were performed to explore the molecular spectrum and transcriptomic characteristics of CHIP mutations. Results: We detected 51 mutations in 10 genes in 37 (41%) of the study individuals. CHIP prevalence increased with age. CHIP mutations were observed with high prevalence in DNMT3A (26 individuals) and TET2 (eight individuals) and were also found in various other genes, including KDM6A, SMC3, TP53, BRAF, PPM1D, SRSF2, STAG1, and ZRSR2. Baseline characteristics, including age, confounding diseases, and blood cell parameters, showed no significant differences. Using mRNA sequencing, we characterized the altered gene expression profile, implicating neutrophil degranulation and innate immune system dysregulation. Conclusions Somatic CHIP driver mutations are common among the elderly in Korea and are detected in various genes, including DNMT3A and TET2. Our study highlights that chronic dysregulation of innate immune signaling is associated with the pathogenesis of various diseases, including hematologic malignancies.

Background: Sustained interest is needed in the characteristics of critical incidents in pediatric anesthesia and related changes, for determining the causes and degree of potential harm; this will also improve the quality of medical care. This study aimed to analyze the incidence of critical incidents recorded in 2014–2019, and to compare them with those in 2008–2013. Methods: Critical incidents associated with pediatric anesthesia, including cardiac arrest, recorded in a voluntary departmental reporting system between January 2014 and December 2019 were compared with those reported between January 2008 and August 2013 using chi-square test. Results: We identified 295 (0.55%) critical incidents from 53,541 cases of pediatric anesthesia (3,471 cardiothoracic surgeries); this is consistent with the previously reported incidence of 0.46%. Among the critical incidents, the incidences of adverse events, sentinel event, near miss case and no-harm events were 93.9%, 1.7%, 0%, and 6.1% in 2014–2019, whereas those were 98.3%, 2.6%, 1.7%, and 0% in 2008–2013 (P = 0.023, 0.686, 0.080, and < 0.001, respectively). Cardiac arrest accounted for 25 (8.5%) cases of the 295 critical events, which significantly lower than that previously reported (18.3%; P = 0.020). Human factor-related events accounted for 61.0% of all critical incidences; this was similar to the previous data (58.5%). Conclusions Over six years, there has been no significant difference in the total incidence of critical events. Despite the decrease in the incidence of serious critical events, perioperative care in pediatric anesthesia can be further improved.

Background/Aims: The prospective Crohn’s Disease Clinical Network and Cohort Study is a nationwide multicenter cohort study of patients with Crohn’s disease (CD) in Korea, aiming to prospectively investigate the clinical features and long-term prognosis associated with CD. Methods: Patients diagnosed with CD between January 2009 and September 2019 were prospectively enrolled. They were divided into two cohorts according to the year of diagnosis: cohort 1 (diagnosed between 2009 and 2011) versus cohort 2 (between 2012 and 2019). Results: A total of 1,175 patients were included, and the median follow-up duration was 68 months (interquartile range, 39.0 to 91.0 months). The treatment-free durations for thiopurines (p<0.001) and anti-tumor necrosis factor agents (p=0.018) of cohort 2 were shorter than those of cohort 1. Among 887 patients with B1 behavior at diagnosis, 149 patients (16.8%) progressed to either B2 or B3 behavior during follow-up. Early use of thiopurine was associated with a reduced risk of behavioral progression (adjusted hazard ratio [aHR], 0.69; 95% confidence interval [CI], 0.50 to 0.90), and family history of inflammatory bowel disease was associated with an increased risk of behavioral progression (aHR, 2.29; 95% CI, 1.16 to 4.50). One hundred forty-one patients (12.0%) underwent intestinal resection, and the intestinal resection-free survival time was significantly longer in cohort 2 than in cohort 1 (p=0.003). The early use of thiopurines (aHR, 0.35;95% CI, 0.23 to 0.51) was independently associated with a reduced risk of intestinal resection. Conclusions The prognosis of CD in Korea appears to have improved over time, as evidenced by the decreasing intestinal resection rate. Early use of thiopurines was associated with an improved prognosis represented by a reduced risk of intestinal resection.

Background: To investigate the clinical findings of choroideremia patients and perform genetic analysis by whole-exome sequencing (WES). Methods: A total of 94 patients initially diagnosed with retinitis pigmentosa (RP) at another hospital, and who visited our hospital for genetic analysis by WES, were included in the study, along with 64 family members. All subjects underwent comprehensive ophthalmic evaluation, including best-corrected visual acuity, slit lamp examination, fundus photography, fundus autofluorescence (FAF), fluorescein angiography (FAG), visual field (VF), electroretinogram (ERG), and optical coherence tomography (OCT). Results: In six male patients with suspected choroideremia, extensive retinal pigment epithelium (RPE) and severe loss of choroid were observed in the fundus, but not in the macula. CHM gene mutation was confirmed in five patients. A novel single nucleotide variant at a splice site was observed in one patient. OCT showed marked thinning of the outernuclear layer and choroid, except in the macula. FAF showed a small area of hyperfluorescence in the posterior pole. In addition, characteristic interlaminar bridges were observed in four patients. On FAG, hypofluorescence was seen up to the far-peripheral retina in five patients. Conclusion Of the 94 patients initially diagnosed with RP, CHM mutation was identified in five (5.3%) by WES. Choroideremia should be considered as a differential diagnosis of RP.WES would be useful for identifying the causes of hereditary retinal disease.