Long coronavirus disease (COVID) is a condition in which coronavirus disease 2019 (COVID-19) symptoms persist for over 3 months, and currently poses a global public health challenge. Due to varying manifestations and lack of standardized definitions, diagnostic methods, and treatments, comprehensive clinical guidelines are required. This review article, summarizing research and expert consensus up to June 2023, provides recommendations for diagnosis and long-term management of long COVID symptoms. It emphasizes thorough patient evaluation, including medical history, physical examinations, and tests, and advocates vaccination and antiviral treatments to reduce risk. Guidelines for long COVID will be updated as new knowledge emerges.

Long coronavirus disease (COVID) is a condition in which coronavirus disease 2019 (COVID-19) symptoms persist for over 3 months, and currently poses a global public health challenge. Due to varying manifestations and lack of standardized definitions, diagnostic methods, and treatments, comprehensive clinical guidelines are required. This review article, summarizing research and expert consensus up to June 2023, provides recommendations for diagnosis and long-term management of long COVID symptoms. It emphasizes thorough patient evaluation, including medical history, physical examinations, and tests, and advocates vaccination and antiviral treatments to reduce risk. Guidelines for long COVID will be updated as new knowledge emerges.

Background: This study established sex-specific reference intervals (RIs) for hematological parameters, including the monocyte distribution width (MDW), in Korean adults and assessed the need for separate RIs according to sex in older adults. Methods: Hematological parameters were measured using a DxH 900 hematology analyzer (Beckman Coulter, USA) on 328 peripheral blood samples from 124 men and 204 women aged 19–93 years. Results: The RIs for white blood cells, red blood cells (RBCs), Hb, Hct, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, monocyte percentage, and neutrophil, eosinophil, lympho­cyte, and monocyte counts differed significantly by sex (P<0.05). Mean corpuscular volume was significantly positively associated with age, whereas RBC and platelet counts were significantly negatively correlated with age in both men and women. Age-based analysis revealed significant shifts in the RBC parameters beginning at 60 years of age in men and 70 years of age in women. The MDW did not show significant differences according to sex or age. Conclusions This study supports the use of sex-specific RIs and highlights the importance of considering age when interpreting results regarding hematological parameters in clinical practice.

Background/Aims: This study assessed the long-term efficacy and safety of tenofovir alafenamide (TAF) in real-world settings. Methods: Patients who were candidates for TAF treatment and were followed up at 12-week intervals over 192 weeks were enrolled in this study. Results: One hundred and forty-four patients (50 treatment-naive and 94 treatment-experienced) were included in this study. The cumulative incidence rates of cirrhosis and hepatocellular carcinoma at 192 weeks were 3.9% and 0.7%, respectively. In treatment-naive patients, the rates of a virological response, HBeAg conversion, and HBsAg loss at 192 weeks were 100%, 33.3%, and 2%, respectively. The treatment-naive patients exhibited higher baseline HBsAg levels than the treatment-experienced patients (4.31 log10IU/mL vs. 3.97 log10IU/mL). A significant decrease in the HBsAg levels from the baseline was observed at 144 and 192 weeks in the treatment-naive patients (p=0.01). The baseline body mass index (BMI) <25 kg/m2 (p=0.02) and HBsAg <3.3 log10IU/mL (p=0.04) were identified as predictive factors for a decrease in HBsAg ≥0.5 log10IU/mL at 48 weeks. The eGFR levels were consistently lower in the treatment-experienced patients throughout the study. Although the treatment-naive patients showed no abnormal increases in urinary URBP, the treatment-experienced patients showed elevated urinary β2MG and NAG levels at the baseline, which decreased over the treatment course. The total cholesterol, triglyceride, and low-density lipoprotein levels were similar in both groups. Conclusions Prolonging the TAF treatment duration enhances the virological response rate. The decline in HBsAg levels was more significant in the treatment-naive patients than in the treatment-experienced patients. The baseline BMI <25 kg/m2 and HBsAg <3.3 log10IU/mL were predictive factors for a significant decline in HBsAg at 48 weeks. TAF has high renal safety and no significant impact on lipid levels.

Background/Aims: Portal vein thrombosis (PVT) frequently occurs in patients with inflammatory bowel disease (IBD), particularly when influenced by factors such as abdominal infections, IBD flare-ups, or surgical procedures. The implications of PVT range from immediate issues such as intestinal ischemia to long-term concerns including portal hypertension and its complications. However, there is a notable gap in comprehensive studies on PVT in IBD, especially with the increasing incidence of IBD in Asia. This research aimed to evaluate the clinical features and outcomes of PVT in patients with IBD at a leading hospital in South Korea. Methods: This retrospective analysis reviewed adult patients diagnosed with both IBD and PVT from 1989 to 2021 at a renowned South Korean medical center. The study focused on patient characteristics, specifics of PVT, administered treatments, and outcomes, all confirmed through enhanced CT scans. Results: A total of 78 patients met the study’s criteria. Notably, only 20.5% (16/78) were treated with oral anticoagulants; however, a vast majority (96.2%; 75/78) achieved complete radiographic resolution (CRR). When comparing patients receiving anticoagulants to those who did not, a significant preference for anticoagulant use was observed in cases where the main portal vein was affected, as opposed to just the left or right veins (p = 0.006). However, multivariable analysis indicated that neither anticoagulant use nor previous surgeries significantly impacted CRR. Conclusions Patients with IBD and PVT generally had favorable outcomes, regardless of anticoagulant use.

Background: Active surveillance (AS) has emerged as a viable management strategy for low-risk papillary thyroid microcarcinoma (PTMC), following pioneering trials at Kuma Hospital and the Cancer Institute Hospital in Japan. Numerous prospective cohort studies have since validated AS as a management option for low-risk PTMC, leading to its inclusion in thyroid cancer guidelines across various countries. From 2016 to 2020, the Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) enrolled 1,177 patients, providing comprehensive data on PTMC progression, sonographic predictors of progression, quality of life, surgical outcomes, and cost-effectiveness when comparing AS to immediate surgery. The second phase of MAeSTro (MAeSTro-EXP) expands AS to low-risk papillary thyroid carcinoma (PTC) tumors larger than 1 cm, driven by the hypothesis that overall risk assessment outweighs absolute tumor size in surgical decision-making. Methods: This protocol aims to address whether limiting AS to tumors smaller than 1 cm may result in unnecessary surgeries for low-risk PTCs detected during their rapid initial growth phase. By expanding the AS criteria to include tumors up to 1.5 cm, while simultaneously refining and standardizing the criteria for risk assessment and disease progression, we aim to minimize overtreatment and maintain rigorous monitoring to improve patient outcomes. Conclusion This study will contribute to optimizing AS guidelines and enhance our understanding of the natural course and appropriate management of low-risk PTCs. Additionally, MAeSTro-EXP involves a multinational collaboration between South Korea and Australia. This cross-country study aims to identify cultural and racial differences in the management of low-risk PTC, thereby enriching the global understanding of AS practices and their applicability across diverse populations.

Background: s/Aims: Sarcomatoid hepatocellular carcinoma (HCC) is a rare histological subtype of HCC characterized by extremely poor prognosis; however, its molecular characterization has not been elucidated. Methods: In this study, we conducted an integrated multiomics study of whole-exome sequencing, RNA-seq, spatial transcriptome, and immunohistochemical analyses of 28 paired sarcomatoid tumor components and conventional HCC components from 10 patients with sarcomatoid HCC, in order to identify frequently altered genes, infer the tumor subclonal architectures, track the genomic evolution, and delineate the transcriptional characteristics of sarcomatoid HCCs. Results: Our results showed that the sarcomatoid HCCs had poor prognosis. The sarcomatoid tumor components and the conventional HCC components were derived from common ancestors, mostly accessing similar mutational processes. Clonal phylogenies demonstrated branched tumor evolution during sarcomatoid HCC development and progression. TP53 mutation commonly occurred at tumor initiation, whereas ARID2 mutation often occurred later. Transcriptome analyses revealed the epithelial–mesenchymal transition (EMT) and hypoxic phenotype in sarcomatoid tumor components, which were confirmed by immunohistochemical staining. Moreover, we identified ARID2 mutations in 70% (7/10) of patients with sarcomatoid HCC but only 1–5% of patients with non-sarcomatoid HCC. Biofunctional investigations revealed that inactivating mutation of ARID2 contributes to HCC growth and metastasis and induces EMT in a hypoxic microenvironment. Conclusions We offer a comprehensive description of the molecular basis for sarcomatoid HCC, and identify genomic alteration (ARID2 mutation) together with the tumor microenvironment (hypoxic microenvironment), that may contribute to the formation of the sarcomatoid tumor component through EMT, leading to sarcomatoid HCC development and progression.

Background: This study established sex-specific reference intervals (RIs) for hematological parameters, including the monocyte distribution width (MDW), in Korean adults and assessed the need for separate RIs according to sex in older adults. Methods: Hematological parameters were measured using a DxH 900 hematology analyzer (Beckman Coulter, USA) on 328 peripheral blood samples from 124 men and 204 women aged 19–93 years. Results: The RIs for white blood cells, red blood cells (RBCs), Hb, Hct, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, monocyte percentage, and neutrophil, eosinophil, lympho­cyte, and monocyte counts differed significantly by sex (P<0.05). Mean corpuscular volume was significantly positively associated with age, whereas RBC and platelet counts were significantly negatively correlated with age in both men and women. Age-based analysis revealed significant shifts in the RBC parameters beginning at 60 years of age in men and 70 years of age in women. The MDW did not show significant differences according to sex or age. Conclusions This study supports the use of sex-specific RIs and highlights the importance of considering age when interpreting results regarding hematological parameters in clinical practice.

Background/Aims: This study assessed the long-term efficacy and safety of tenofovir alafenamide (TAF) in real-world settings. Methods: Patients who were candidates for TAF treatment and were followed up at 12-week intervals over 192 weeks were enrolled in this study. Results: One hundred and forty-four patients (50 treatment-naive and 94 treatment-experienced) were included in this study. The cumulative incidence rates of cirrhosis and hepatocellular carcinoma at 192 weeks were 3.9% and 0.7%, respectively. In treatment-naive patients, the rates of a virological response, HBeAg conversion, and HBsAg loss at 192 weeks were 100%, 33.3%, and 2%, respectively. The treatment-naive patients exhibited higher baseline HBsAg levels than the treatment-experienced patients (4.31 log10IU/mL vs. 3.97 log10IU/mL). A significant decrease in the HBsAg levels from the baseline was observed at 144 and 192 weeks in the treatment-naive patients (p=0.01). The baseline body mass index (BMI) <25 kg/m2 (p=0.02) and HBsAg <3.3 log10IU/mL (p=0.04) were identified as predictive factors for a decrease in HBsAg ≥0.5 log10IU/mL at 48 weeks. The eGFR levels were consistently lower in the treatment-experienced patients throughout the study. Although the treatment-naive patients showed no abnormal increases in urinary URBP, the treatment-experienced patients showed elevated urinary β2MG and NAG levels at the baseline, which decreased over the treatment course. The total cholesterol, triglyceride, and low-density lipoprotein levels were similar in both groups. Conclusions Prolonging the TAF treatment duration enhances the virological response rate. The decline in HBsAg levels was more significant in the treatment-naive patients than in the treatment-experienced patients. The baseline BMI <25 kg/m2 and HBsAg <3.3 log10IU/mL were predictive factors for a significant decline in HBsAg at 48 weeks. TAF has high renal safety and no significant impact on lipid levels.