Viral load and the duration of viral shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are important determinants of the transmission of coronavirus disease 2019.In this study, we examined the effects of viral doses on the lung and spleen of K18-hACE2 transgenic mice by temporal histological and transcriptional analyses. Approximately, 1×105 plaque-forming units (PFU) of SARS-CoV-2 induced strong host responses in the lungs from 2 days post inoculation (dpi) which did not recover until the mice died, whereas responses to the virus were obvious at 5 days, recovering to the basal state by 14 dpi at 1×102 PFU. Further, flow cytometry showed that number of CD8+ T cells continuously increased in 1×102 PFU-virusinfected lungs from 2 dpi, but not in 1×105 PFU-virus-infected lungs. In spleens, responses to the virus were prominent from 2 dpi, and number of B cells was significantly decreased at 1×105PFU; however, 1×102 PFU of virus induced very weak responses from 2 dpi which recovered by 10 dpi. Although the defense responses returned to normal and the mice survived, lung histology showed evidence of fibrosis, suggesting sequelae of SARS-CoV-2 infection. Our findings indicate that specific effectors of the immune response in the lung and spleen were either increased or depleted in response to doses of SARS-CoV-2. This study demonstrated that the response of local and systemic immune effectors to a viral infection varies with viral dose, which either exacerbates the severity of the infection or accelerates its elimination.

Background: Current international guidelines recommend against deep sedation as it is associated with worse outcomes in the intensive care unit (ICU). However, in Korea the prevalence of deep sedation and its impact on patients in the ICU are not well known. Methods: From April 2020 to July 2021, a multicenter, prospective, longitudinal, noninterventional cohort study was performed in 20 Korean ICUs. Sedation depth extent was divided into light and deep using a mean Richmond Agitation–Sedation Scale value within the first 48 hours. Propensity score matching was used to balance covariables; the outcomes were compared between the two groups. Results: Overall, 631 patients (418 [66.2%] and 213 [33.8%] in the deep and light sedation groups, respectively) were included. Mortality rates were 14.1% and 8.4% in the deep and light sedation groups (P = 0.039), respectively. Kaplan-Meier estimates showed that time to extubation (P < 0.001), ICU length of stay (P = 0.005), and death P = 0.041) differed between the groups. After adjusting for confounders, early deep sedation was only associated with delayed time to extubation (hazard ratio [HR], 0.66; 95% confidence inter val [CI], 0.55– 0.80; P < 0.001). In the matched cohort, deep sedation remained significantly associated with delayed time to extubation (HR, 0.68; 95% 0.56–0.83; P < 0.001) but was not associated with ICU length of stay (HR, 0.94; 95% CI, 0.79–1.13; P = 0.500) and in-hospital mortality (HR, 1.19; 95% CI, 0.65–2.17; P = 0.582). Conclusion In many Korean ICUs, early deep sedation was highly prevalent in mechanically ventilated patients and was associated with delayed extubation, but not prolonged ICU stay or in-hospital death.

Objectives: . Thyroid cancer is the most common endocrine tumor, with rapidly increasing incidence worldwide. However, its transcriptomic characteristics associated with immunological signatures, driver fusions, and recurrence markers remain unclear. We aimed to investigate the transcriptomic characteristics of advanced papillary thyroid cancer. Methods: . This study included 282 papillary thyroid cancer tumor samples and 155 normal samples from Chungnam National University Hospital and Seoul National University Hospital. Transcriptomic quantification was determined by high-throughput RNA sequencing. We investigated the associations of clinical parameters and molecular signatures using RNA sequencing. We validated predictive biomarkers using the Cancer Genome Atlas database. Results: . Through a comparison of differentially expressed genes, gene sets, and pathways in papillary thyroid cancer compared to normal tumor-adjacent tissue, we found increased immune signaling associated with cytokines or T cells and decreased thyroid hormone synthetic pathways. In addition, patients with recurrence presented increased CD8+ T-cell and Th1-cell signatures. Interestingly, we found differentially overexpressed genes related to immune-escape signaling such as CTLA4, IDO1, LAG3, and PDCD1 in advanced papillary thyroid cancer with a low thyroid differentiation score. Fusion analysis showed that the PI3K and mitogen-activated protein kinase (MAPK) signaling pathways were regulated differently according to the RET fusion partner genes (CCDC6 or NCOA4). Finally, we identified HOXD9 as a novel molecular biomarker that predicts the recurrence of thyroid cancer in addition to known risk factors (tumor size, lymph node metastasis, and extrathyroidal extension). Conclusion . We identified a high association with immune-escape signaling in the immune-hot group with aggressive clinical characteristics among Korean thyroid cancer patients. Moreover, RET fusion differentially regulated PI3K and MAPK signaling depending on the partner gene of RET, and HOXD9 was found to be a recurrence marker for advanced papillary thyroid cancer.

Background: As the number of large-scale studies involving multiple organizations producing data has steadily increased, an integrated system for a common interoperable format is needed. In response to the coronavirus disease 2019 (COVID-19) pandemic, a number of global efforts are underway to develop vaccines and therapeutics. We are therefore observing an explosion in the proliferation of COVID-19 data, and interoperability is highly requested in multiple institutions participating simultaneously in COVID-19 pandemic research. Results: In this study, a laboratory information management system (LIMS) approach has been adopted to systemically manage various COVID-19 non-clinical trial data, including mortality, clinical signs, body weight, body temperature, organ weights, viral titer (viral replication and viral RNA), and multiorgan histopathology, from multiple institutions based on a web interface. The main aim of the implemented system is to integrate, standardize, and organize data collected from laboratories in multiple institutes for COVID-19 non-clinical efficacy testings. Six animal biosafety level 3 institutions proved the feasibility of our system. Substantial benefits were shown by maximizing collaborative high-quality non-clinical research. Conclusions This LIMS platform can be used for future outbreaks, leading to accelerated medical product development through the systematic management of extensive data from non-clinical animal studies.

This study evaluated the safety and efficacy of tubeless patch pump called EOPatch in patients with well-controlled type 1 diabetes mellitus (T1DM). This 4-week, two-center, open-label, single-arm study enrolled 10 adult patients diagnosed with T1DM with glycosylated hemoglobin less than 7.5%. The co-primary end points were patch pump usage time for one attachment and number of serious adverse events related to the patch pump. The secondary end points were total amount of insulin injected per patch and changes in glycemic parameters including continuous glucose monitoring data compared to those at study entry. The median usage time per patch was 84.00 hours (interquartile range, 64.50 to 92.50). Serious adverse events did not occur during the trial. Four weeks later, time in range 70 to 180 mg/dL was significantly improved (70.71%±17.14 % vs. 82.96%±9.14%, P=0.01). The times spent below range (<54 mg/dL) and above range (>180 mg/dL) also improved (All P<0.05). Four-week treatment with a tubeless patch pump was safe and led to clinical improvement in glycemic control.

The aim of this study was to evaluate characteristics and risk of diabetic complications according to age at diagnosis among young adults with type 1 diabetes mellitus (T1DM).

Background/Aims: To analyze the incidence and risk factors of outcomes after liver transplantation (LT) in the Korean population. Methods: This study analyzed data from the liver cohort of Korean Organ Transplantation Registry (KOTRY) who had LT between May 2014 and December 2017. Study measures included the incidence of post-LT outcomes in recipients of living donor LT (LDLT) and deceased donor LT (DDLT). Cox multivariate proportional hazards model was used to determine the potential risk factors predicting the outcomes. Results: A total of 2,563 adult recipients with LT (LDLT, n=1,956; DDLT, n=607) were included, with mean±standard deviation age of 53.9±8.9 years, and 72.2% were male. The post-LT outcomes observed in each LDLT and DDLT recipients were death (4.0% and 14.7%), graft loss (5.0% and 16.1%), rejection (7.0% and 12.0%), renal failure (2.7% and 13.8%), new onset of diabetes (12.5% and 15.4%), and hepatocellular carcinoma (HCC) recurrence (both 6.7%). In both LDLT and DDLT recipients, the most common post-LT complications were renal dysfunction (33.6% and 51.4%), infection (26.7% and 48.4%), and surgical complication (22.5% and 23.9%). Incidence of these outcomes were generally higher among recipients of DDLT than LDLT. Multivariate analysis indicated recipient age and DDLT as significant risk factors associated with death and graft loss. DDLT and ABO incompatible transplant were prognostic factors for rejection, and HCC beyond Milan criteria at pre-transplant was a strong predictor of HCC recurrence. Conclusions This study is a good indicator of the post-LT prognosis in the Korean population and suggests a significant burden of post-LT complications.

Background/Aims: To analyze the incidence and risk factors of outcomes after liver transplantation (LT) in the Korean population. Methods: This study analyzed data from the liver cohort of Korean Organ Transplantation Registry (KOTRY) who had LT between May 2014 and December 2017. Study measures included the incidence of post-LT outcomes in recipients of living donor LT (LDLT) and deceased donor LT (DDLT). Cox multivariate proportional hazards model was used to determine the potential risk factors predicting the outcomes. Results: A total of 2,563 adult recipients with LT (LDLT, n=1,956; DDLT, n=607) were included, with mean±standard deviation age of 53.9±8.9 years, and 72.2% were male. The post-LT outcomes observed in each LDLT and DDLT recipients were death (4.0% and 14.7%), graft loss (5.0% and 16.1%), rejection (7.0% and 12.0%), renal failure (2.7% and 13.8%), new onset of diabetes (12.5% and 15.4%), and hepatocellular carcinoma (HCC) recurrence (both 6.7%). In both LDLT and DDLT recipients, the most common post-LT complications were renal dysfunction (33.6% and 51.4%), infection (26.7% and 48.4%), and surgical complication (22.5% and 23.9%). Incidence of these outcomes were generally higher among recipients of DDLT than LDLT. Multivariate analysis indicated recipient age and DDLT as significant risk factors associated with death and graft loss. DDLT and ABO incompatible transplant were prognostic factors for rejection, and HCC beyond Milan criteria at pre-transplant was a strong predictor of HCC recurrence. Conclusions This study is a good indicator of the post-LT prognosis in the Korean population and suggests a significant burden of post-LT complications.

Background: The aim of this study was to evaluate characteristics and risk of diabetic complications according to age at diagnosis among young adults with type 1 diabetes mellitus (T1DM). Methods: A total of 255 T1DM patients aged less than 40 years were included. Patients were categorized into three groups (<20, 20 to 29, and 30 to 40 years) according to age at diagnosis. Diabetic nephropathy (DN) was defined when spot urine-albumin creatinine ratio was 300 mg/g or more and/or estimated glomerular filtration ratio (eGFR) level was 60 mL/min/1.73 m2 or less. Results: Median age at diagnosis was 25 years and disease duration was 14 years. Individuals diagnosed with T1DM at childhood/adolescent (age <20 years) had lower stimulated C-peptide levels. They received more intensive insulin treatment with higher total daily insulin doses compared to older onset groups. The prevalence of DN was higher in the childhood/adolescentonset group than in older onset groups (25.3% vs. 15.3% vs. 9.6%, P=0.022). The eGFR was inversely associated with disease duration whilst the degree of decrease was more prominent in the childhood/adolescent-onset group than in the later onset group (aged 30 to 40 years; P<0.001). Childhood/adolescent-onset group was independently associated with the risk of DN compared to the older onset group (aged 30 to 40 years; odds ratio, 3.47; 95% confidence interval, 1.45 to 8.33; P=0.005). Conclusion In individuals with childhood/adolescent-onset T1DM, the reduction in renal function is more prominent with disease duration. Early age-onset T1DM is an independent risk of DN.

BACKGROUND: Prophylaxis for hepatitis B virus (HBV) recurrence is essential after liver transplantation (LT) in HBV-associated recipients. We conducted real-world analysis of HBV prophylaxis after LT in the Korean population. METHODS: Korean Organ Transplantation Registry (KOTRY) database and additionally collected data (n = 326) were analyzed with special reference to types of HBV prophylaxis. RESULTS: The study cohort comprised 267 cases of living-donor LT and 59 cases of deceased-donor LT. Hepatocellular carcinoma (HCC) was diagnosed in 232 (71.2%) of these subjects. Antiviral agents were used in 255 patients (78.2%) prior to LT. HBV DNA was undetectable in 69 cases (21.2%) and detectable over wide concentrations in the other 257 patients (78.8%) prior to LT. Polymerase chain reaction analysis of the store blood samples detected HBV DNA in all patients, with 159 patients (48.9%) showing concentrations > 100 IU/mL. Post-transplant HBV regimens during the first year included combination therapy in 196 (60.1%), hepatitis B immunoglobulin (HBIG) monotherapy in 121 (37.1%), and antiviral monotherapy in 9 (2.8%). In the second post-transplant year, these regimens had changed to combination therapy in 187 (57.4%), HBIG monotherapy in 112 (34.4%), and antiviral monotherapy in 27 (8.3%). Trough antibody to hepatitis B surface antigen titers > 500 IU/mL and >1,000 IU/mL were observed in 61.7% and 25.2%, respectively. The mean simulative half-life of HBIG was 21.6 ± 4.3 days with a median 17.7 days. Up to 2-year follow-up period, HCC recurrence and HBV recurrence developed in 18 (5.5%) and 6 (1.8%), respectively. HCC recurrence developed in 3 of 6 patients with HBV recurrence. CONCLUSION Combination therapy is the mainstay of HBV prophylaxis protocols in a majority of Korean LT centers, but HBIG was often administered excessively. Individualized optimization of HBIG treatments using SHL is necessary to adjust the HBIG infusion interval.