Purpose: Vascular endothelial growth factor tyrosine kinase inhibitors (TKIs) have been the standard of care for advanced and metastatic clear cell renal cell carcinoma (ccRCC). However, the therapeutic effect of TKI monotherapy remains unsatisfactory given the high rates of acquired resistance to TKI therapy despite favorable initial tumor response. Materials and Methods: To define the TKI-resistance mechanism and identify new therapeutic target for TKI-resistant ccRCC, an integrative differential gene expression analysis was performed using acquired resistant cohort and a public dataset. Sunitinib-resistant RCC cell lines were established and used to test their malignant behaviors of TKI resistance through in vitro and in vivo studies. Immunohistochemistry was conducted to compare expression between the tumor and normal kidney and verify expression of pathway-related proteins. Results: Integrated differential gene expression analysis revealed increased interferon-induced transmembrane protein 3 (IFITM3) expression in post-TKI samples. IFITM3 expression was increased in ccRCC compared with the normal kidney. TKI-resistant RCC cells showed high expression of IFITM3 compared with TKI-sensitive cells and displayed aggressive biologic features such as higher proliferative ability, clonogenic survival, migration, and invasion while being treated with sunitinib. These aggressive features were suppressed by the inhibition of IFITM3 expression and promoted by IFITM3 overexpression, and these findings were confirmed in a xenograft model. IFITM3-mediated TKI resistance was associated with the activation of TRAF6 and MAPK/AP-1 pathways. Conclusions These results demonstrate IFITM3-mediated activation of the TRAF6/MAPK/AP-1 pathways as a mechanism of acquired TKI resistance, and suggest IFITM3 as a new target for TKI-resistant ccRCC.

Background/Aims: Blocking the complement system is a promising strategy to impede the progression of metabolic dysfunction–associated steatotic liver disease (MASLD). However, the interplay between complement and MASLD remains to be elucidated. This comprehensive approach aimed to investigate the potential association between complement dysregulation and the histological severity of MASLD. Methods: Liver biopsy specimens were procured from a cohort comprising 106 Korean individuals, which included 31 controls, 17 with isolated steatosis, and 58 with metabolic dysfunction–associated steatohepatitis (MASH). Utilizing the Infinium Methylation EPIC array, thorough analysis of methylation alterations in 61 complement genes was conducted. The expression and methylation of nine complement genes in a murine MASH model were examined using quantitative RT-PCR and pyrosequencing. Results: Methylome and transcriptome analyses of liver biopsies revealed significant (p<0.05) hypermethylation and downregulation of C1R, C1S, C3, C6, C4BPA<, and SERPING1, as well as hypomethylation (p<0.0005) and upregulation (p<0.05) of C5AR1, C7, and CD59, in association with the histological severity of MASLD. Furthermore, DNA methylation and the relative expression of nine complement genes in a MASH diet mouse model aligned with human data. Conclusions Our research provides compelling evidence that epigenetic alterations in complement genes correlate with MASLD severity, offering valuable insights into the mechanisms driving MASLD progression, and suggests that inhibiting the function of certain complement proteins may be a promising strategy for managing MASLD.

Objectives: This study aimed to investigate differences in the anti-hepatitis A (HAV) antibody seropositivity rate by age and gender. Methods: We collected information on anti-HAV immunoglobulin G and immunoglobulin M status from samples submitted for HAV antibody testing in 2012–2022. A total of 1,333,615 cases were included in the analysis. Results: By age, the seropositivity rate was represented by a U-shaped curve, such that the rate was low for the group aged 20 to 39 years and higher in those who were younger or older. Over time, the curve shifted rightward, and the seropositivity rate declined gradually in the group aged 35 to 39 years and older. A gender-based difference in antibody seropositivity rate was especially noticeable in the group aged 20 to 29 years. This difference between genders widened in the participants’ early 20s—when men in the Republic of Korea enlist in the military—and the divergence continued subsequently for older individuals. Conclusion These results indicate a higher risk of severe infection among older individuals and a gender-based difference in seroprevalence. Therefore, it is necessary to implement policies to promote vaccination in adults.

Pembrolizumab is an immune checkpoint inhibitor that selectively blocks the programmed cell death (PD)-1 receptor. Although it has a dramatic effect on the treatment of advanced malignancies, instability of immune tolerance may cause immune-related adverse events in the skin. A 62-year-old male with a history of metastatic urothelial carcinoma was referred to the dermatology department and presented with a widespread mucocutaneous rash. Itching appeared 7 days after the first administration of pembrolizumab, and on the third day after the second administration, an erythematous maculopapular rash that coalesced into large flaccid bullae on the whole body with a positive Nikolsky’s sign developed. A biopsy revealed a subepidermal bulla with basal keratinocyte necrosis. Pembrolizumab was discontinued due to the diagnosis of toxic epidermal necrolysis (TEN), and intravenous methylprednisolone was started. Herein, we report a case of TEN induced by pembrolizumab to highlight immune-related cutaneous adverse events in patients receiving anti-PD-1 therapy.

Background: Postoperative thyroid stimulating hormone (TSH) suppression therapy is recommended for patients with intermediate- and high-risk differentiated thyroid cancer to prevent the recurrence of thyroid cancer. With the recent increase in small thyroid cancer cases, the extent of resection during surgery has generally decreased. Therefore, questions have been raised about the efficacy and long-term side effects of TSH suppression therapy in patients who have undergone a lobectomy. Methods: This is a multicenter, prospective, randomized, controlled clinical trial in which 2,986 patients with papillary thyroid cancer are randomized into a high-TSH group (intervention) and a low-TSH group (control) after having undergone a lobectomy. The principle of treatment includes a TSH-lowering regimen aimed at TSH levels between 0.3 and 1.99 μIU/mL in the low-TSH group. The high-TSH group targets TSH levels between 2.0 and 7.99 μIU/mL. The dose of levothyroxine will be adjusted at each visit to maintain the target TSH level. The primary outcome is recurrence-free survival, as assessed by neck ultrasound every 6 to 12 months. Secondary endpoints include disease-free survival, overall survival, success rate in reaching the TSH target range, the proportion of patients with major cardiovascular diseases or bone metabolic disease, the quality of life, and medical costs. The follow-up period is 5 years. Conclusion The results of this trial will contribute to establishing the optimal indication for TSH suppression therapy in low-risk papillary thyroid cancer patients by evaluating the benefit and harm of lowering TSH levels in terms of recurrence, metabolic complications, costs, and quality of life.

Background: Patients with stable psoriasis showing clearear-clear response can consider extending the dosing interval of biologics. However, few studies have reported the treatment outcomes following irregular dosing intervals of biologics in patients with psoriasis. Objective: We compared treatment outcomes after regular and irregular dosing intervals of biologics in patients with psoriasis. Methods: This single-center, retrospective observational study included patients who received biologics for treatment of plaque psoriasis between January 1, 2014 and December 31, 2019. We compared patient demographics, clinical characteristics, biologics administered, and treatment outcomes based on the regularity of the dosing interval. Results: Among 95 patients investigated, 63 (66.3%) received biologics at regular dosing intervals. We observed no significant intergroup differences in the final Psoriasis Area Severity Index (PASI) scores (1.2 vs. 1.8, p=0.16) and in the percentage improvement in PASI scores from baseline levels (−89.8% vs. −90.8%, p=0.68). The rate at which biologics were switched was higher in the irregular-dosing group than in the regular-dosing group; however, the difference was statistically nonsignificant (28.1% vs. 12.7%, p=0.06). We observed a significant intergroup difference in patients who were administered guselkumab at baseline (12 [21.8%] vs. 0 [0.0%], p=0.01). Conclusion This study showed that compared with regular dosing intervals, irregular dosing intervals of biologics were associated with high rates of switching of these agents, although we observed no statistically significant differences with regard to PASI scores. Therefore, it is important to adhere to the standard dosing schedule prescribed for biologics, and guselkumab may improve patient compliance.

Background: Postoperative thyroid stimulating hormone (TSH) suppression therapy is recommended for patients with intermediate- and high-risk differentiated thyroid cancer to prevent the recurrence of thyroid cancer. With the recent increase in small thyroid cancer cases, the extent of resection during surgery has generally decreased. Therefore, questions have been raised about the efficacy and long-term side effects of TSH suppression therapy in patients who have undergone a lobectomy. Methods: This is a multicenter, prospective, randomized, controlled clinical trial in which 2,986 patients with papillary thyroid cancer are randomized into a high-TSH group (intervention) and a low-TSH group (control) after having undergone a lobectomy. The principle of treatment includes a TSH-lowering regimen aimed at TSH levels between 0.3 and 1.99 μIU/mL in the low-TSH group. The high-TSH group targets TSH levels between 2.0 and 7.99 μIU/mL. The dose of levothyroxine will be adjusted at each visit to maintain the target TSH level. The primary outcome is recurrence-free survival, as assessed by neck ultrasound every 6 to 12 months. Secondary endpoints include disease-free survival, overall survival, success rate in reaching the TSH target range, the proportion of patients with major cardiovascular diseases or bone metabolic disease, the quality of life, and medical costs. The follow-up period is 5 years. Conclusion The results of this trial will contribute to establishing the optimal indication for TSH suppression therapy in low-risk papillary thyroid cancer patients by evaluating the benefit and harm of lowering TSH levels in terms of recurrence, metabolic complications, costs, and quality of life.

Background: Patients with stable psoriasis showing clearear-clear response can consider extending the dosing interval of biologics. However, few studies have reported the treatment outcomes following irregular dosing intervals of biologics in patients with psoriasis. Objective: We compared treatment outcomes after regular and irregular dosing intervals of biologics in patients with psoriasis. Methods: This single-center, retrospective observational study included patients who received biologics for treatment of plaque psoriasis between January 1, 2014 and December 31, 2019. We compared patient demographics, clinical characteristics, biologics administered, and treatment outcomes based on the regularity of the dosing interval. Results: Among 95 patients investigated, 63 (66.3%) received biologics at regular dosing intervals. We observed no significant intergroup differences in the final Psoriasis Area Severity Index (PASI) scores (1.2 vs. 1.8, p=0.16) and in the percentage improvement in PASI scores from baseline levels (−89.8% vs. −90.8%, p=0.68). The rate at which biologics were switched was higher in the irregular-dosing group than in the regular-dosing group; however, the difference was statistically nonsignificant (28.1% vs. 12.7%, p=0.06). We observed a significant intergroup difference in patients who were administered guselkumab at baseline (12 [21.8%] vs. 0 [0.0%], p=0.01). Conclusion This study showed that compared with regular dosing intervals, irregular dosing intervals of biologics were associated with high rates of switching of these agents, although we observed no statistically significant differences with regard to PASI scores. Therefore, it is important to adhere to the standard dosing schedule prescribed for biologics, and guselkumab may improve patient compliance.

Background: Accessory bones and tarsal coalitions are the most common developmental variations of the foot and ankle. However, their clinical implications are not well understood because there is no established prevalence data in the normal population and the reported prevalence varies widely. Therefore, we aimed to investigate the incidence of accessory ossicles and tarsal coalitions in a healthy, asymptomatic Korean population. Methods: A total of 448 healthy, asymptomatic participants (224 men and 224 women; 896 feet) were enrolled and stratified by age and sex. To investigate the presence of accessory bones and tarsal coalitions in the foot and ankle, we obtained the weight-bearing standing radiographs (anteroposterior and lateral views) from each participant. Results: Accessory ossicles were found in 49.2% of the healthy, asymptomatic Korean adults. The prevalence of accessory bones in adults was the highest with 34% for the accessory navicular, 5.8% for the os trigonum, 3.9% for the os peroneum, and 1.7% for the os subfibulare. The prevalence of tarsal coalitions in adults was 0.4% and that of symphalangism was 16% for the fourth toe and 80.6% for the fifth toe. The frequency of the accessory navicular and fifth toe symphalangism was significantly higher in women. Most of the accessory navicular and fourth and fifth toe symphalangism were bilateral, whereas the os subfibulare was mostly unilateral. Conclusions The prevalence of accessory bones and tarsal coalitions in the healthy, asymptomatic Korean population showed some variation according to age and sex.