Background: Wilson’s disease (WD) is an autosomal recessive disorder in which copper (Cu) accumulates in organs, particularly in the liver and central nervous system. This study aimed to investigate the prevalence, incidence, and treatment patterns of WD patients in Korea. Methods: National Health Insurance System (NHIS) claims data from 2010 to 2020 were analyzed. patients with WD as a primary or additional diagnosis at least once were identified using the International Classification of Diseases (ICD)-10 disease code E83.0 and a record for a registration program for rare intractable diseases in Korea. Results: The average age- and sex-adjusted prevalence and incidence of WD between 2010 and 2020 were 3.06/100,000 and 0.11/100,000, respectively. The mean age of the patients with newly diagnosed WD was 21.0 ± 15.9 years. Among the 622 WD incident cases during the study period, 19.3% of the patients had liver cirrhosis and 9.2% had received liver transplantation. Psychological and neurological diseases were present in 40.7% and 48.1% of the patients, respectively. Regarding the diagnosis of WD, liver biopsy was performed in only 51.6% of new cases. D-penicillamine, trientine, or zinc were prescribed in 81.5% of the incident cases, and the treatment uptake rates decreased with increasing age. Conclusion The prevalence of WD in Korea is 3.06/100,000 and approximately 1,800 patients use medical services annually. A significant proportion of patients are diagnosed at the cirrhotic stage and not treated with Cu-chelating therapeutics, suggesting the need for early diagnosis and adequate treatment to improve prognosis.

Background/Aims: We used next-generation sequencing (NGS) to analyze resistance-associated substitutions (RASs) and retreatment outcomes in patients with chronic hepatitis C virus (HCV) infection who failed direct-acting antiviral agent (DAA) treatment in South Korea. Methods: Using prospectively collected data from the Korean HCV cohort study, we recruited 36 patients who failed DAA treatment in 10 centers between 2007 and 2020; 29 blood samples were available from 24 patients. RASs were analyzed using NGS. Results: RASs were analyzed for 13 patients with genotype 1b, 10 with genotype 2, and one with genotype 3a. The unsuccessful DAA regimens were daclatasvir+asunaprevir (n=11), sofosbuvir+ribavirin (n=9), ledipasvir/sofosbuvir (n=3), and glecaprevir/pibrentasvir (n=1). In the patients with genotype 1b, NS3, NS5A, and NS5B RASs were detected in eight, seven, and seven of 10 patients at baseline and in four, six, and two of six patients after DAA failure, respectively. Among the 10 patients with genotype 2, the only baseline RAS was NS3 Y56F, which was detected in one patient. NS5A F28C was detected after DAA failure in a patient with genotype 2 infection who was erroneously treated with daclatasvir+asunaprevir. After retreatment, 16 patients had a 100% sustained virological response rate. Conclusions NS3 and NS5A RASs were commonly present at baseline, and there was an increasing trend of NS5A RASs after failed DAA treatment in genotype 1b. However, RASs were rarely present in patients with genotype 2 who were treated with sofosbuvir+ribavirin. Despite baseline or treatment-emergent RASs, retreatment with pan-genotypic DAA was highly successful in Korea, so we encourage active retreatment after unsuccessful DAA treatment.

Background/Aims: To eliminate hepatitis B virus (HBV) and hepatitis C virus (HCV) according to the World Health Organization (WHO) criteria in 2021, this study investigated the national core indicators representing the current status of viral hepatitis B and C in South Korea. Methods: We analyzed the incidence, linkage-to-care, treatment, and mortality rates of HBV and HCV infection using the integrated nationwide big data of South Korea. Results: According to data from 2018–2020, the incidence of acute HBV infection in South Korea was 0.71 cases per 100,000 population; tthe linkage-to-care rate was only 39.4%. Among those who need hepatitis B treatment, the treatment rate was 67.3%, which was less than 80% reported in the WHO program index. The annual liver-related mortality due to HBV was 18.85 cases per 100,000 population, exceeding the WHO target of four; the most frequent cause of death was liver cancer (54.1%). The annual incidence of newly diagnosed HCV infection was 11.9 cases per 100,000 population, which was higher than the WHO impact target of five. Among HCV-infected patients, the linkage-to-care rate was 65.5% while the treatment rate was 56.8%, which were below the targets of 90% and 80%, respectively. The liver-related annual mortality rate due to HCV infection was 2.02 cases per 100,000 population. Conclusions Many of the current indicators identified in the Korean population did not satisfy the WHO criteria for validation of viral hepatitis elimination. Hence, a comprehensive national strategy should be urgently developed with continuous monitoring of the targets in South Korea.

Background/Aims: This study aimed to evaluate the cost-effectiveness of hepatitis C virus (HCV) screening compared to no screening in the Korean population from societal and healthcare system perspectives. Methods: A published decision-tree plus Markov model was used to compare the expected costs and quality-adjusted life years (QALY) between one-time universal HCV screening and no screening in the population aged 40–65 years using the National Health Examination (NHE) program. Input parameters were obtained from analyses of the National Health Insurance claims data, Korean HCV cohort data, or from the literature review. The population aged 40–65 years was simulated in a model spanning a lifetime from both the healthcare system and societal perspectives, which included the cost of productivity loss due to HCV-related deaths. The incremental cost-effectiveness ratio (ICER) between universal screening and no screening was estimated. Results: The HCV screening strategy had an ICER of $2,666/QALY and $431/QALY from the healthcare system and societal perspectives, respectively. Both ICERs were far less than the willingness-to-pay threshold of $25,000/QALY, showing that universal screening was highly cost-effective compared to no screening. In various sensitivity analyses, the most influential parameters on cost-effectiveness were the antibodies to HCV (anti-HCV) prevalence, screening costs, and treatment acceptance; however, all ICERs were consistently less than the threshold. If the anti-HCV prevalence was over 0.18%, screening could be cost-effective. Conclusions One-time universal HCV screening in the Korean population aged 40–65 years using NHE program would be highly cost-effective from both healthcare system and societal perspectives.

Background: and Purpose: In this study we aimed to find the association between neuropsychological performance and body mass index (BMI) in patients with mild cognitive impairment (MCI). In addition, we investigated the effects of the apolipoprotein E (APOE) genotype in the relationship between the BMI and cognition in MCI. Methods: We enrolled a cohort of 3,038 subjects with MCI aged 65–90 from the Clinical Research Center for Dementia of South Korea and a dementia cohort of the Ewha Womans University Mokdong Hospital. MCI patients were classified into three subgroups according to the Asian standard of BMI. We compared cognitive performances between groups by one-way analysis of variance. To investigate the effects of the APOE genotype, we used multivariate linear regression models after adjusting for possible confounders. Results: Even though normal BMI groups were younger, had more females, and had less comorbidities, the higher BMI groups had better cognitive functions. Among subjects with APOE ε4 carriers, there was a positive relationship between the BMI and the memory task alone. Conclusions Our findings suggested that higher BMI in patients with MCI were associated with better cognitive performance. The effects of the APOE ε4 genotype in the associations between BMI and cognition were distinguishing. Therefore, according to physical status, APOE ε4 genotype-specific strategies in the assessments and treatments may be necessary in elderly patients with MCI.

Objectives: This study aimed to evaluate the registered dentists’ program, from the dentist’s perspective, before its nationwide implementation. Methods: In-depth interviews were conducted with 18 dentists who had participated in the registered dentists’ program in G Province. A questionnaire was prepared based on previous research. The data were collected by transcription of interview recordings. Qualitative research methodology was implemented and the data were coded according to the grounded theory. A paradigm model was presented and the core categories were indicated. Results: The findings were organized into 6 categories, 25 subcategories, and 315 codes, based on open coding of the first categorization of collected data. The central phenomenon was found to be the experience of dissatisfaction with the program. The causal conditions were shown as problems of the program, while contextual and intervening conditions were shown as passive participation of dentists and positive effects of the program, respectively. The action/interaction strategies were summarized as an improvement plan and the consequence was an increased intention to participate. Conclusions The study proposes the need to strengthen primary dental care through this registered dentists’ program, by performing continuous evaluations. The standards and guidelines, cooperation of participants, and appropriate compensation should be considered to promote successful implementation.

Objectives: This study aimed to evaluate the registered dentists’ program, from the dentist’s perspective, before its nationwide implementation. Methods: In-depth interviews were conducted with 18 dentists who had participated in the registered dentists’ program in G Province. A questionnaire was prepared based on previous research. The data were collected by transcription of interview recordings. Qualitative research methodology was implemented and the data were coded according to the grounded theory. A paradigm model was presented and the core categories were indicated. Results: The findings were organized into 6 categories, 25 subcategories, and 315 codes, based on open coding of the first categorization of collected data. The central phenomenon was found to be the experience of dissatisfaction with the program. The causal conditions were shown as problems of the program, while contextual and intervening conditions were shown as passive participation of dentists and positive effects of the program, respectively. The action/interaction strategies were summarized as an improvement plan and the consequence was an increased intention to participate. Conclusions The study proposes the need to strengthen primary dental care through this registered dentists’ program, by performing continuous evaluations. The standards and guidelines, cooperation of participants, and appropriate compensation should be considered to promote successful implementation.

Background/Aims: The risk factors for the development of primary biliary cholangitis (PBC) is unclear. This study aimed to investigate the risk factors associated with PBC in Korea through a questionnaire survey. Methods: Consecutively enrolled 103 PBC patients from six referral hospitals and 100 age- and sex-matched community controls participated in this study. A standardized questionnaire survey including demographics, lifestyle, individual and familial medical history and reproductive history was prospectively collected and analyzed. Results: The PBC patients had a mean age of 58.3 years and a female proportion of 86.4%. The age- and sex-matched controls had a similar educational level and economic status to the PBC patients. Among the lifestyle factors, the multivariable analysis showed smoking including both first-hand and second-hand (odds ratio [OR], 2.03; 95% confidence interval [CI], 1.06 to 3.93), history of autoimmune diseases (OR, 2.46; 95% CI, 1.06 to 6.35), and family history of PBC (OR, 17.76; 95% CI, 1.77 to 2,418.74) were significantly associated with PBC, whereas alcohol intake was negatively associated with PBC. Among reproductive factors, the number of induced abortions was significantly associated with PBC, while the number of full-term deliveries was negatively associated with PBC. Conclusions A family history of PBC, accompanying autoimmune diseases, and smoking were significantly associated with PBC. More induced abortions and less full-term deliveries were associated with PBC in women. In contrast, mild to moderate alcohol intake was negatively associated with PBC. Further studies are warranted to validate the results of this study and to search for clues about the pathogenesis of PBC.

Background: /Aim: This study aimed to establish the real-world effectiveness and safety of grazoprevir/elbasvir (EBR/GZR) therapy in South Korea. Methods: A total of 242 patients with chronic hepatitis C virus (HCV) genotype 1 or 4 infection who started EBR/GZR were consecutively enrolled from seven tertiary hospitals. Retrospective analysis of the fractions of patients that achieved sustained virological response (SVR) was performed, and the incidence of adverse events was noted. Results: The mean age of enrolled patients was 59.0 ± 12.6 years and 47.5% were males. Patients with HCV genotype 1b accounted for 93.8% (n = 227), and patients with HCV of unspecified genotype 1 accounted for 5.8% (n = 14). Hypertension was the most common comorbid disease (29.8%) followed by diabetes (22.7%) and chronic kidney disease (CKD, 12.4%). SVR rates of treatment-naïve and treatment-experienced patients were 85.5% (182/213) and 93.1% (27/29), respectively, in the intention-to-treat analyses, whereas in the per-protocol analyses, those were 97.8% (179/183) and 100% (28/28), respectively. Fewer patients with HCV genotype 1 of unspecified subtype achieved SVR (81.8%, n = 11) compared to the patients with SVR infected with genotype 1b (99%, n = 198, p < 0.001). All patients with CKD showed SVR. Itching (12%) and dyspepsia (4.1%) were common adverse events. Of the four patients who discontinued the antiviral therapy, one experienced mild fatigue but neither treatment withdrawal was because of an adverse event. Conclusions EBR/GZR showed high real-world effectiveness and safety in Korean patients with chronic HCV infection regardless of the previous antiviral treatment, liver cirrhosis, or CKD status.