Background/Aims: This study aimed to identify the risk factors for chronic kidney disease (CKD) and end-stage renal disease (ESRD) following liver transplantation (LT), with a specific focus on tacrolimus levels and intrapatient variability (IPV). Methods: Among the 1,076 patients who underwent LT between 2000 and 2018, 952 were included in the analysis. The tacrolimus doses and levels were recorded every 3 months, and the IPV was calculated using the coefficient of variability. The cumulative incidence rates of CKD and ESRD were calculated based on baseline kidney function at the time of LT. The impact of tacrolimus levels and their IPV on the development of CKD and ESRD was evaluated, and the significant risk factors were identified. Results: Within a median follow-up of 97.3 months, the 5-year cumulative incidence rates of CKD (0.58 vs. 0.24) and ESRD (0.07 vs. 0.01) were significantly higher in the acute kidney injury group than in the normal glomerular filtration rate (GFR) group. In the normal GFR group, the tacrolimus levels were identified as a risk factor for CKD, with a level of ≤4.5 ng/mL suggested as optimal for minimizing the risk of CKD. Furthermore, the IPV of tacrolimus levels and doses emerged as a significant risk factor for CKD development in both groups (p<0.05), with tenofovir disoproxil fumarate also being a risk factor in HBV-infected patients. The IPV of tacrolimus levels was also a significant factor in ESRD development (p<0.05). Conclusions This study elucidated the optimal tacrolimus trough level and highlighted the impact of IPV on the CKD and ESRD development post-LT.

Background: and Purpose: This clinical practice guideline provides evidence-based recommendations for treatment of dementia, focusing on cholinesterase inhibitors and N-methyl-D-aspartate (NMDA) receptor antagonists for Alzheimer’s disease (AD) and other types of dementia. Methods: Using the Population, Intervention, Comparison, Outcomes (PICO) framework, we developed key clinical questions and conducted systematic literature reviews. A multidisciplinary panel of experts, organized by the Korean Dementia Association, evaluated randomized controlled trials and observational studies. Recommendations were graded for evidence quality and strength using Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. Results: Three main recommendations are presented: (1) For AD, cholinesterase inhibitors (donepezil, rivastigmine, galantamine) are strongly recommended for improving cognition and daily function based on moderate evidence; (2) Cholinesterase inhibitors are conditionally recommended for vascular dementia and Parkinson’s disease dementia, with a strong recommendation for Lewy body dementia; (3) For moderate to severe AD, NMDA receptor antagonist (memantine) is strongly recommended, demonstrating significant cognitive and functional improvements. Both drug classes showed favorable safety profiles with manageable side effects. Conclusions This guideline offers standardized, evidence-based pharmacologic recommendations for dementia management, with specific guidance on cholinesterase inhibitors and NMDA receptor antagonists. It aims to support clinical decision-making and improve patient outcomes in dementia care. Further updates will address emerging treatments, including amyloid-targeting therapies, to reflect advances in dementia management.

This paper discusses a rare case of a 49-year-old female diagnosed with a central nervous systemisolated neoplasm with histiocytic features, classified as histiocytic neoplasm, not otherwise specified (NOS). Despite comprehensive histopathological and genetic studies, accurately diagnosing the case proved challenging. Initial surgical findings and frozen biopsy suggested a low-grade glioma; however, subsequent immunohistochemistry and genetic analysis excluded known histiocytic subtypes such as ALK-positive histiocytosis and Erdheim-Chester disease. The patient’s condition improved following occupational rehabilitation therapy for right upper motor weakness, as well as anticonvulsant and radiation therapy, and her neurological condition remains stable. This case underscores the diagnostic challenges of Histiocytic Neoplasms and the necessity for interdisciplinary collaboration and sophisticated diagnostic techniques.

Background/Aims: Inflammatory bowel disease (IBD) affects health-related quality of life (HRQoL). The Short Inflammatory Bowel Disease Questionnaire (SIBDQ) score is strongly correlated with HRQoL in IBD patients. This study aimed to assess the factors influencing HRQoL in IBD patients. Methods: In this prospective study, all patients with ulcerative colitis (UC) and Crohn’s disease (CD) completed the SIBDQ at enrollment; some patients also completed a second SIBDQ at follow-up. Multiple linear regression analysis was used to determine associations between SIBDQ scores and clinical factors. Results: A total of 1,020 patients participated (UC, 67%; CD, 33%). The median SIBDQ score was 52 (interquartile range, 44 to 59). In UC patients, the stool frequency (β=–2.333, p<0.001), Physician Global Assessment score (β=–3.950, p<0.001), fecal calprotectin level (β=–4.014, p<0.001), and corticosteroid use (β=–4.809, p=0.006) were negatively correlated with the SIBDQ score. In CD patients, the number of diarrhea episodes per day (β=–1.467, p=0.024) and Crohn's Disease Activity Index score (β=–0.045, p<0.001) were negatively correlated with the SIBDQ score. A total of 202 patients completed the second SIBDQ within a mean of 3.4 years. The distributions of SIBDQ score changes were as follows: decrease >10%, 28%; –10%10%, 43%. In both the initial SIBDQ and follow-up SIBDQ, scores for items pertaining to systemic symptoms (tension and fatigue) were relatively low. Conclusions Bowel movement-related problems significantly affect the HRQoL of both UC and CD patients. IBD patients scored lower on SIBDQ items related to general well-being. After 3 years of follow-up at the IBD clinic, 43% of patients showed a significant improvement in HRQoL.

Background/Aims: Findings on the impact of Helicobacter pylori eradication on metabolic parameters are inconsistent. This study aimed to evaluate the effects of H. pylori eradication on metabolic parameters and body composition, including body fat mass and skeletal muscle mass. Methods: We retrospectively reviewed the data of asymptomatic patients who underwent health screenings, including bioelectrical impedance analysis, before and after H. pylori eradication between 2005 and 2021. After matching individuals based on key factors, we compared lipid profiles, metabolic parameters, and body composition between 823 patients from the eradicated group and 823 patients from the non-eradicated groups. Results: Blood pressure, erythrocyte sedimentation rate, and glycated hemoglobin values were significantly lower in the eradicated group than in the non-eradicated group. However, changes in body mass index (BMI), body fat mass, appendicular skeletal muscle mass (ASM), waist circumference, and lipid profiles were not significantly different between the two groups. In a subgroup analysis of individuals aged >45 years, blood pressure, erythrocyte sedimentation rate, and glycated hemoglobin changes were significantly lower in the eradicated group than in the noneradicated group. BMI values were significantly higher in the eradicated group than in the noneradicated group; however, no significant differences were observed between the two groups regarding changes in body weight, body fat mass, ASM, or waist circumference. Total cholesterol and low-density lipoprotein cholesterol levels were significantly lower in the eradicated group than in non-eradicated group. Conclusions H. pylori eradication significantly reduced blood pressure, glucose levels, and systemic inflammation and improved lipid profiles in patients aged >45 years. BMI, body fat mass, ASM, and waist circumference did not significantly differ between patients in the eradicated group and those in the non-eradicated group.

Background: Immunocompromised patients with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection often have prolonged viral shedding, and some are clinically suspected of reinfection with different SARSCoV-2 variants. However, data on this issue are limited. This study investigated the SARS-CoV-2 variants in serially collected respiratory samples from immunocompromised patients with prolonged viral shedding for over 12 weeks or relapsed viral shedding after at least 2 weeks of viral clearance. Materials and Methods: From February 2022 to September 2023, we prospectively enrolled immunocompromised patients with coronavirus disease 2019 who had hematologic malignancies or had undergone transplantation and were admitted to a tertiary hospital. Weekly saliva or nasopharyngeal swabs were collected from enrolled patients for at least 12 weeks after diagnosis. Genomic RNA polymerase chain reaction (PCR) was performed on samples, and those testing positive underwent viral culture to isolate the live virus. Spike gene full sequencing via Sanger sequencing and real-time reverse transcription-PCR for detecting mutation genes were conducted to identify SARSCoV-2 variants. Results: Among 116 enrolled patients, 20 with prolonged or relapsed viral shedding were screened to identify the variants. Of these 20 patients, 7 (35%) exhibited evidence of re-infection; one of 8 patients with prolonged viral shedding and 6 of 12 with relapsed viral shedding were reinfected with SARS-CoV-2. Conclusion Our data suggest that approximately one-third of immunocompromised patients with persistent or relapsed viral shedding had reinfection with different variants of SARS-CoV-2.

Background: The World Health Organization has declared the end of the coronavirus disease 2019 (COVID-19) public health emergency. However, this did not indicate the end of COVID-19. Several months after the infection, numerous patients complain of respiratory or nonspecific symptoms; this condition is called long COVID. Even patients with mild COVID-19 can experience long COVID, thus the burden of long COVID remains considerable. Therefore, we conducted this study to comprehensively analyze the effects of long COVID using multi-faceted assessments. Materials and Methods: We conducted a prospective cohort study involving patients diagnosed with COVID-19 between February 2020 and September 2021 in six tertiary hospitals in Korea. Patients were followed up at 1, 3, 6, 12, 18, and 24 months after discharge. Long COVID was defined as the persistence of three or more COVID-19-related symptoms. The primary outcome of this study was the prevalence of long COVID after the period of COVID-19. Results: During the study period, 290 patients were enrolled. Among them, 54.5 and 34.6% experienced long COVID within 6 months and after more than 18 months, respectively. Several patients showed abnormal results when tested for post-traumatic stress disorder (17.4%) and anxiety (31.9%) after 18 months. In patients who underwent follow-up chest computed tomography 18 months after COVID-19, abnormal findings remained at 51.9%. Males (odds ratio [OR], 0.17; 95% confidence interval [CI], 0.05–0.53; P=0.004) and elderly (OR, 1.04; 95% CI, 1.00–1.09; P=0.04) showed a significant association with long COVID after 12–18 months in a multivariable logistic regression analysis. Conclusion Many patients still showed long COVID after 18 months post SARS-CoV-2 infection. When managing these patients, the assessment of multiple aspects is necessary.

Background: and Purpose The National Brain Biobank of Korea (NBBK) is a brain bank consortium supported by the Korea Disease Control and Prevention Agency and the Korea National Institute of Health, and was launched in 2015 to support research into neurodegenerative disease dementia (NDD). This study aimed to introduce the NBBK and describes clinicopathological correlations based on analyses of data collected from the NBBK. Methods: Four hospital-based brain banks have been established in South Korea: Samsung Medical Center Brain Bank (SMCBB), Seoul National University Hospital Brain Bank (SNUHBB), Pusan National University Hospital Brain Bank (PNUHBB), and Myongji Hospital Brain Bank (MJHBB). Clinical and pathological data were collected from these brain banks using standardized protocols. The prevalence rates of clinical and pathological diagnoses were analyzed in order to characterize the clinicopathological correlations. Results: Between August 2016 and December 2023, 185 brain specimens were collected and pathologically evaluated (SNUHBB: 117; PNUHBB: 27; SMCBB: 34; MJHBB: 7). The age at consent was 70.8±12.6 years, and the age at autopsy was 71.7±12.4 years. The four-most-common clinical diagnoses were Alzheimer’s disease (AD) dementia (20.0%), idiopathic Parkinson’s disease (15.1%), unspecified dementia (11.9%), and cognitively unimpaired (CU) (11.4%).Most cases of unspecified dementia had a pathological diagnosis of central nervous system (CNS) vasculopathy (31.8%) or AD (31.8%). Remarkably, only 14.2% of CU cases had normal pathological findings. The three-most-common pathological diagnoses were AD (26.5%), CNS vasculopathy (14.1%), and Lewy body disease (13.5%). Conclusions These clinical and neuropathological findings provide a deeper understanding of the mechanisms underlying NDD in South Korea.

Background: and Purpose We aimed to determine the proportion of Korean patients with early Alzheimer’s disease (AD) who are eligible to receive lecanemab based on the United States Appropriate Use Recommendations (US AUR), and also identify the barriers to this treatment. Methods: We retrospectively enrolled 6,132 patients with amnestic mild cognitive impairment or mild amnestic dementia at 13 hospitals from June 2023 to May 2024. Among them, 2,058 patients underwent amyloid positron emission tomography (PET) and 1,199 (58.3%) of these patients were amyloid-positive on PET. We excluded 732 patients who did not undergo brain magnetic resonance imaging between June 2023 and May 2024. Finally, 467 patients were included in the present study. Results: When applying the criteria of the US AUR, approximately 50% of patients with early AD were eligible to receive lecanemab treatment. Among the 467 included patients, 36.8% did not meet the inclusion criterion of a Mini-Mental State Examination (MMSE) score of ≥22. Conclusions Eligibility for lecanemab treatment was not restricted to Korean patients with early AD except for those with an MMSE score of ≥22. The MMSE criteria should therefore be reconsidered in areas with a higher proportion of older people, who tend to have lower levels of education.