Background/Aims: Immune checkpoint inhibitors (ICIs) can induce immune-related adverse events, including endocrine dysfunctions, which can have serious consequences on patient health and quality of life. The clinical course and characteristics of immune-related hypophysitis (irH) are not well established. This study aimed to analyze the clinical course and characteristics of irH. Methods: This single-center, retrospective study analyzed data from electronic medical records of Asan Medical Center, spanning January 2017 through June 2021. It included adult patients with solid tumors who underwent thyroid and adrenal function tests, along with gonadotropin and/or growth hormone evaluations, following the initiation of ICI treatment within the same period. The study explored the clinical characteristics of ICI-treated patients with and without irH, the incidence of irH, the time to irH onset, and the associated hormonal changes. Results: Twenty-one patients were included in this analysis. Clinical characteristics did not differ significantly between the irH (n = 13) and non-irH (n = 8) groups. Deficiency rates in the irH group were 23.1% for thyroid-stimulating hormone (n = 3), 76.9% for adrenocorticotropic hormone (n = 10), 61.5% for gonadotropin (n = 8), and 15.4% for growth hormone (n = 2). The overall incidence was 0.9 per person-year, with 6-month and 1-year cumulative incidences of 38.8% and 57.1%, respectively. The median time from ICI initiation to irH diagnosis was 7.7 months. Time to levothyroxine replacement was shorter in the irH group. Conclusions The findings provide evidence that could facilitate the prediction of ICI-induced irH based on clinical course and characteristics.

Background/Aims: While distal radial artery (DRA) access is increasingly being used for diagnostic coronary angiography, limited information is available regarding DRA size. We aimed to determine the DRA reference diameters of Korean patients and identify the predictors of DRA diameter < 2.3 mm. Methods: The outer bilateral DRA diameters were assessed using a linear ultrasound probe in 1,162 consecutive patients who underwent transthoracic echocardiography. The DRA diameter was measured by the perpendicular angle in the dorsum of the hand, and the average values were compared by sex. DRA diameter < 2.3 mm was defined as unsuitable for routine diagnostic coronary angiography using a 5 Fr introducer sheath. Results: The mean DRA diameters were 2.31 ± 0.43 mm (right) and 2.35 ± 0.45 mm (left). The DRA was smaller in women than men (right: 2.15 ± 0.38 mm vs. 2.43 ± 0.44 mm, p < 0.001; left: 2.18 ± 0.39 mm vs. 2.47 ± 0.45 mm, p < 0.001). The DRA diameter was approximately 20% smaller than the radial artery diameter. A total of 630 (54.2%) and 574 (49.4%) patients had DRA diameter < 2.3 mm in the right and left hands, respectively. Female sex, low body mass index (BMI), and low body surface area (BSA) were significant predictors of DRA diameter < 2.3 mm. Conclusions We provided reference DRA diameters for Korean patients. Approximately 50% of the studied patients had DRA diameter < 2.3 mm. Female sex, low BMI, and low BSA remained significant predictors of DRA diameter < 2.3 mm.

Background/Aims: Receptor tyrosine kinase-like orphan receptor 2 (ROR2) is a major regulator of Wnt signaling, which is involved in fibroblast dysfunction. Because its role has not been evaluated in idiopathic pulmonary fibrosis (IPF), we examined the clinical implications of ROR2 expression. Methods: ROR2 mRNA expression was measured using reverse transcription polymerase chain reaction in lung tissue-derived fibroblasts from IPF patients (n = 14) and from controls (n = 10). ROR2 protein was measured using enzyme-linked immunosorbent assay in primary fibroblasts from IPF patients (n = 14) and controls (n = 10), and in bronchoalveolar lavage (BAL) fluids obtained from normal controls (NC; n = 30). IPF patients (n = 84), and other patients with interstitial lung diseases, including nonspecific interstitial pneumonia (NSIP; n = 10), hypersensitivity pneumonitis (HP; n = 10), and sarcoidosis (n = 10). Results: ROR2 mRNA and protein levels were significantly higher in IPF fibroblasts than in controls (p = 0.003, p = 0.0017, respectively). ROR2 protein levels in BAL fluids from patients with IPF were significantly higher than in those from NC (p < 0.001), and from patients with NSIP (p = 0.006), HP (p = 0.004), or sarcoidosis (p = 0.004). Receiver operating characteristic curves showed a clear difference between IPF and NC in ROR2 protein level (area under the curve, 0.890; confidence interval, 0.829 to 0.950; p < 0.001). ROR2 protein levels were significantly higher in GAP stage III than in GAP stages I and II (p = 0.016). Conclusions ROR2 may be related to the development of IPF, and its protein level may be a useful and severity-dependent candidate marker for IPF.

Background: We aimed to evaluate the clinicopathological features and biological behaviors of Korean thyroid cancer patients with rare variants of papillary thyroid carcinoma (PTC) to address the ambiguity regarding the prognostic consequences of these variants. Methods: We retrospectively reviewed the medical records of 5,496 patients who underwent thyroid surgery for PTC, between January and December 2012, in nine tertiary hospitals. Rare PTC variants included tall cell (TCV), columnar cell (CCV), diffuse sclerosing (DSV), cribriform-morular (CMV), solid (SV), hobnail, and Warthin-like variants. Recurrence-free survival (RFS) was defined as the time from the date of thyroidectomy until recurrence. Results: Rare variants accounted for 1.1% (n=63) of the PTC patients; with 0.9% TCV, 0.02% CCV, 0.1% DSV, 0.1% CMV, and 0.1% SV. The mean age of patients and primary tumor size were 42.1±13.1 years and 1.3±0.9 cm, respectively. Extrathyroidal extension and cervical lymph node metastasis were observed in 38 (60.3%) and 37 (58.7%) patients, respectively. Ultrasonographic findings revealed typical malignant features in most cases. During a median follow-up of 7 years, 6.3% of patients experienced a locoregional recurrence. The 5-year RFS rates were 71.4% in patients with DSV or SV, 95.9% for TCV, or CCV, and 100% for other variants. DSV emerged an independent risk factor associated with shorter RFS. Conclusion In this multicenter Korean cohort, rare variants accounted for 1.1% of all PTC cases, with TCV being the most frequent subtype. DSV emerged as a significant prognostic factor for RFS.

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: This study evaluated the relationship between guideline adherence for heart failure (HF) with reduced ejection fraction (HFrEF) at discharge and relevant clinical outcomes in patients with acute HF with preserved ejection fraction (HFpEF) with or without atrial fibrillation (AF). Methods: We analyzed Korean Acute Heart Failure Registry data for 707 patients with HFpEF with documented AF and 687 without AF. Guideline adherence was defined as good or poor according to the prescription of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, β-blockers, and mineralocorticoid receptor antagonists. Anticoagulation adherence was also incorporated for the AF group. Results: Among patients with normal sinus rhythm, those with poor guideline adherence had a reduced prevalence of comorbidities and favorable clinical characteristics when compared with those with good guideline adherence. Using inverse probability of treatment weighting (IPTW) to address the bias of nonrandom treatment assignment, good adherence was associated with a poor 60-day composite endpoint in the multivariable Cox model (weighted hazard ratio [wHR], 1.74; 95% confidence interval [CI], 1.01–3.00; P = 0.045). For patients with AF, baseline clinical characteristics were similar according to the degree of adherence. The IPTW-adjusted analysis indicated that good adherence was significantly associated with the 60-day composite endpoint (wHR, 0.47; 95% CI, 0.27–0.79; P = 0.005). In the analysis excluding warfarin, good adherence was associated with 60-day rehospitalization (wHR, 0.60; 95% CI, 0.37–0.98; P = 0.040), 1-year re-hospitalization (wHR, 0.67; 95% CI, 0.48–0.93; P = 0.018), and the composite endpoint (wHR, 0.77; 95% CI, 0.59–0.99; P = 0.041). Conclusion Our findings indicate that good adherence to guidelines for HFrEF is associated with a better 60-day composite endpoint in patients with HFpEF with AF.

Immunoglobulin G4 (IgG4)-related kidney disease is a chronic immune-mediated fibro-inflammatory disorder characterized by multiple organ infiltration with IgG4-positive plasma cells, storiform fibrosis, and obliterative phlebitis or tumefactive lesions. Previous studies have explored IgG4-related kidney disease, increasing our understanding of its clinical manifestations, and pathological and radiologic findings. However, IgG4-related kidney disease can be misdiagnosed since it mimics malignancies. We report a case of a 77-year-old Korean man diagnosed with IgG4-related kidney disease with membranous proliferative glomerulonephritis, presenting with a renal pelvic mass suspected of being malignant.

Background: We aimed to evaluate the clinicopathological features and biological behaviors of Korean thyroid cancer patients with rare variants of papillary thyroid carcinoma (PTC) to address the ambiguity regarding the prognostic consequences of these variants. Methods: We retrospectively reviewed the medical records of 5,496 patients who underwent thyroid surgery for PTC, between January and December 2012, in nine tertiary hospitals. Rare PTC variants included tall cell (TCV), columnar cell (CCV), diffuse sclerosing (DSV), cribriform-morular (CMV), solid (SV), hobnail, and Warthin-like variants. Recurrence-free survival (RFS) was defined as the time from the date of thyroidectomy until recurrence. Results: Rare variants accounted for 1.1% (n=63) of the PTC patients; with 0.9% TCV, 0.02% CCV, 0.1% DSV, 0.1% CMV, and 0.1% SV. The mean age of patients and primary tumor size were 42.1±13.1 years and 1.3±0.9 cm, respectively. Extrathyroidal extension and cervical lymph node metastasis were observed in 38 (60.3%) and 37 (58.7%) patients, respectively. Ultrasonographic findings revealed typical malignant features in most cases. During a median follow-up of 7 years, 6.3% of patients experienced a locoregional recurrence. The 5-year RFS rates were 71.4% in patients with DSV or SV, 95.9% for TCV, or CCV, and 100% for other variants. DSV emerged an independent risk factor associated with shorter RFS. Conclusion In this multicenter Korean cohort, rare variants accounted for 1.1% of all PTC cases, with TCV being the most frequent subtype. DSV emerged as a significant prognostic factor for RFS.

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: This study evaluated the relationship between guideline adherence for heart failure (HF) with reduced ejection fraction (HFrEF) at discharge and relevant clinical outcomes in patients with acute HF with preserved ejection fraction (HFpEF) with or without atrial fibrillation (AF). Methods: We analyzed Korean Acute Heart Failure Registry data for 707 patients with HFpEF with documented AF and 687 without AF. Guideline adherence was defined as good or poor according to the prescription of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, β-blockers, and mineralocorticoid receptor antagonists. Anticoagulation adherence was also incorporated for the AF group. Results: Among patients with normal sinus rhythm, those with poor guideline adherence had a reduced prevalence of comorbidities and favorable clinical characteristics when compared with those with good guideline adherence. Using inverse probability of treatment weighting (IPTW) to address the bias of nonrandom treatment assignment, good adherence was associated with a poor 60-day composite endpoint in the multivariable Cox model (weighted hazard ratio [wHR], 1.74; 95% confidence interval [CI], 1.01–3.00; P = 0.045). For patients with AF, baseline clinical characteristics were similar according to the degree of adherence. The IPTW-adjusted analysis indicated that good adherence was significantly associated with the 60-day composite endpoint (wHR, 0.47; 95% CI, 0.27–0.79; P = 0.005). In the analysis excluding warfarin, good adherence was associated with 60-day rehospitalization (wHR, 0.60; 95% CI, 0.37–0.98; P = 0.040), 1-year re-hospitalization (wHR, 0.67; 95% CI, 0.48–0.93; P = 0.018), and the composite endpoint (wHR, 0.77; 95% CI, 0.59–0.99; P = 0.041). Conclusion Our findings indicate that good adherence to guidelines for HFrEF is associated with a better 60-day composite endpoint in patients with HFpEF with AF.