Idiopathic inflammatory myopathies (IIMs) are heterogeneous immune-mediated muscle disorders with variable extramuscular manifestations and outcomes. Myositis-specific auto-antibodies (MSAs) have transformed the IIM field by enabling a serology-informed taxonomy based on distinct clinical phenotypes, prognostic trajectories, and therapeutic responses. Anti-Jo-1 and other antisynthetase antibodies characterize interstitial lung disease (ILD)-prone forms of disease; anti-MDA5 identifies patients at risk of rapidly progressive ILD and early mortality; anti-TIF1-γ and anti-NXP2 are indicative of cancer-associated myositis; anti-SRP and anti-HMGCR delineate necrotizing myopathies; and anti-cN1A supports the diagnosis of inclusion-body myositis. Beyond diagnosis, MSA profiles provide prognostic information, including about survival, relapse risk, and organ-specific complications, and they are increasingly being used to guide treatment decisions and predict biologic responsiveness. This review summarizes the diagnostic, prognostic, and therapeutic implications of MSAs across the IIM spectrum and highlight their growing importance in clinical practice for risk stratification and patient management.

Purpose: To report a case of paracentral acute middle maculopathy (PAMM) as the initial ocular finding that led to the diagnosis of previously unrecognized diabetes mellitus and to highlight the importance of systemic evaluation in patients presenting with PAMM.Case summary: A 42-year-old woman with no known systemic or ocular history presented with recent-onset paracentral visual disturbance in the right eye. Best-corrected visual acuity was 20/25 in the right eye and 20/20 in the left eye. Fundus examination revealed subtle parafoveal whitish lesions in both eyes, and spectral-domain optical coherence tomography showed a hyperreflective band in the inner nuclear layer, consistent with PAMM. Wide-field fluorescein angiography demonstrated microaneurysms without significant nonperfusion, consistent with moderate non-proliferative diabetic retinopathy. Laboratory testing revealed an HbA1c level of 11.0%, confirming a new diagnosis of diabetes mellitus. Follow-up at three months showed partial resolution of PAMM lesions in both eyes. The patient was referred to endocrinology for systemic management, and regular ophthalmic monitoring was planned. Conclusions This case emphasizes the value of recognizing PAMM not only as a localized retinal ischemic event but also as a potential early marker of systemic microvascular disease. Prompt systemic evaluation in patients with PAMM can lead to early diagnosis and intervention for underlying conditions such as diabetes mellitus, contributing to better visual and systemic outcomes.

Background: We aimed to investigate the characteristics of pediatric ulcerative colitis (UC) at diagnosis in Korea. Methods: This was a multicenter, registry-based, inception cohort study conducted in Korea between 2021 and 2023. Children and adolescents newly diagnosed with UC < 18 years were included. Baseline clinicodemographics, results from laboratory, endoscopic exams, and Paris classification factors were collected, and associations between factors at diagnosis were investigated. Results: A total 205 patients with UC were included. Male-to-female ratio was 1.59:1, and the median age at diagnosis was 14.7 years (interquartile range 11.9–16.2). Disease extent of E1 comprised 12.2% (25/205), E2 24.9% (51/205), E3 11.2% (23/205), and E4 51.7% (106/205) of the patients. S1 comprised 13.7% (28/205) of the patients. The proportion of patients with a disease severity of S1 was significantly higher in patients with E4 compared to the other groups (E1: 0% vs. E2: 2% vs. E3: 0% vs. E4: 24.5%, P < 0.001). Significant differences between disease extent groups were also observed in Pediatric Ulcerative Colitis Activity Index (median 25 vs. 35 vs. 40 vs. 45, respectively, P < 0.001), hemoglobin (median 13.5 vs.13.2 vs. 11.6 vs. 11.4 g/dL, respectively, P < 0.001), platelet count (median 301 vs. 324 vs. 372 vs. 377 × 103 /μL, respectively, P = 0.001), C-reactive protein (median 0.05 vs. 0.10 vs. 0.17 vs. 0.38 mg/dL, respectively, P < 0.001), and Ulcerative Colitis Endoscopic Index of Severity (median 4 vs. 4 vs. 4 vs. 5, respectively, P = 0.006). No significant differences were observed in factors between groups divided according to sex and diagnosis age. Conclusion This study represents the largest multicenter pediatric inflammatory bowel disease cohort in Korea. Disease severity was associated with disease extent in pediatric patients with UC at diagnosis.

Background: We aimed to investigate the characteristics of pediatric ulcerative colitis (UC) at diagnosis in Korea. Methods: This was a multicenter, registry-based, inception cohort study conducted in Korea between 2021 and 2023. Children and adolescents newly diagnosed with UC < 18 years were included. Baseline clinicodemographics, results from laboratory, endoscopic exams, and Paris classification factors were collected, and associations between factors at diagnosis were investigated. Results: A total 205 patients with UC were included. Male-to-female ratio was 1.59:1, and the median age at diagnosis was 14.7 years (interquartile range 11.9–16.2). Disease extent of E1 comprised 12.2% (25/205), E2 24.9% (51/205), E3 11.2% (23/205), and E4 51.7% (106/205) of the patients. S1 comprised 13.7% (28/205) of the patients. The proportion of patients with a disease severity of S1 was significantly higher in patients with E4 compared to the other groups (E1: 0% vs. E2: 2% vs. E3: 0% vs. E4: 24.5%, P < 0.001). Significant differences between disease extent groups were also observed in Pediatric Ulcerative Colitis Activity Index (median 25 vs. 35 vs. 40 vs. 45, respectively, P < 0.001), hemoglobin (median 13.5 vs.13.2 vs. 11.6 vs. 11.4 g/dL, respectively, P < 0.001), platelet count (median 301 vs. 324 vs. 372 vs. 377 × 103 /μL, respectively, P = 0.001), C-reactive protein (median 0.05 vs. 0.10 vs. 0.17 vs. 0.38 mg/dL, respectively, P < 0.001), and Ulcerative Colitis Endoscopic Index of Severity (median 4 vs. 4 vs. 4 vs. 5, respectively, P = 0.006). No significant differences were observed in factors between groups divided according to sex and diagnosis age. Conclusion This study represents the largest multicenter pediatric inflammatory bowel disease cohort in Korea. Disease severity was associated with disease extent in pediatric patients with UC at diagnosis.

Background: We aimed to investigate the characteristics of pediatric ulcerative colitis (UC) at diagnosis in Korea. Methods: This was a multicenter, registry-based, inception cohort study conducted in Korea between 2021 and 2023. Children and adolescents newly diagnosed with UC < 18 years were included. Baseline clinicodemographics, results from laboratory, endoscopic exams, and Paris classification factors were collected, and associations between factors at diagnosis were investigated. Results: A total 205 patients with UC were included. Male-to-female ratio was 1.59:1, and the median age at diagnosis was 14.7 years (interquartile range 11.9–16.2). Disease extent of E1 comprised 12.2% (25/205), E2 24.9% (51/205), E3 11.2% (23/205), and E4 51.7% (106/205) of the patients. S1 comprised 13.7% (28/205) of the patients. The proportion of patients with a disease severity of S1 was significantly higher in patients with E4 compared to the other groups (E1: 0% vs. E2: 2% vs. E3: 0% vs. E4: 24.5%, P < 0.001). Significant differences between disease extent groups were also observed in Pediatric Ulcerative Colitis Activity Index (median 25 vs. 35 vs. 40 vs. 45, respectively, P < 0.001), hemoglobin (median 13.5 vs.13.2 vs. 11.6 vs. 11.4 g/dL, respectively, P < 0.001), platelet count (median 301 vs. 324 vs. 372 vs. 377 × 103 /μL, respectively, P = 0.001), C-reactive protein (median 0.05 vs. 0.10 vs. 0.17 vs. 0.38 mg/dL, respectively, P < 0.001), and Ulcerative Colitis Endoscopic Index of Severity (median 4 vs. 4 vs. 4 vs. 5, respectively, P = 0.006). No significant differences were observed in factors between groups divided according to sex and diagnosis age. Conclusion This study represents the largest multicenter pediatric inflammatory bowel disease cohort in Korea. Disease severity was associated with disease extent in pediatric patients with UC at diagnosis.

Background: We aimed to investigate the characteristics of pediatric ulcerative colitis (UC) at diagnosis in Korea. Methods: This was a multicenter, registry-based, inception cohort study conducted in Korea between 2021 and 2023. Children and adolescents newly diagnosed with UC < 18 years were included. Baseline clinicodemographics, results from laboratory, endoscopic exams, and Paris classification factors were collected, and associations between factors at diagnosis were investigated. Results: A total 205 patients with UC were included. Male-to-female ratio was 1.59:1, and the median age at diagnosis was 14.7 years (interquartile range 11.9–16.2). Disease extent of E1 comprised 12.2% (25/205), E2 24.9% (51/205), E3 11.2% (23/205), and E4 51.7% (106/205) of the patients. S1 comprised 13.7% (28/205) of the patients. The proportion of patients with a disease severity of S1 was significantly higher in patients with E4 compared to the other groups (E1: 0% vs. E2: 2% vs. E3: 0% vs. E4: 24.5%, P < 0.001). Significant differences between disease extent groups were also observed in Pediatric Ulcerative Colitis Activity Index (median 25 vs. 35 vs. 40 vs. 45, respectively, P < 0.001), hemoglobin (median 13.5 vs.13.2 vs. 11.6 vs. 11.4 g/dL, respectively, P < 0.001), platelet count (median 301 vs. 324 vs. 372 vs. 377 × 103 /μL, respectively, P = 0.001), C-reactive protein (median 0.05 vs. 0.10 vs. 0.17 vs. 0.38 mg/dL, respectively, P < 0.001), and Ulcerative Colitis Endoscopic Index of Severity (median 4 vs. 4 vs. 4 vs. 5, respectively, P = 0.006). No significant differences were observed in factors between groups divided according to sex and diagnosis age. Conclusion This study represents the largest multicenter pediatric inflammatory bowel disease cohort in Korea. Disease severity was associated with disease extent in pediatric patients with UC at diagnosis.

Recent studies have shown that patients with end-stage renal disease (ESRD) are at elevated risk of dementia. However, whether kidney transplantation (KT) lowers the risk for incident dementia remains unclear. Methods: From the Korean National Health Insurance Service database, we identified incident KT recipients aged ≥40 years without any history of dementia between 2007 and 2015. We also established a pair of age-, sex-, and inclusion year-matched control cohorts of patients with incident dialysis-dependent ESRD and members of the general population (GP) without a history of dementia, respectively. Cases of incident all-cause dementia, including Alzheimer disease (AD), vascular dementia (VD), and other kinds of dementia, were obtained from baseline until December 31, 2017. Results: We followed 8,841 KT recipients, dialysis-dependent ESRD patients, and GP individuals for 48,371, 28,649, and 49,149 patient- years, respectively. Their mean age was 52.5 years, and 60.6% were male. Over the observation period, 55/43/19 KT recipients, 230/188/75 dialysis-dependent ESRD patients, and 38/32/14 GP individuals developed all-cause dementia/AD/VD. The risks of incident all-cause dementia, AD, and VD in KT recipients were similar to those in GP (hazard ratio: 0.74 [p = 0.20], 0.74 [p = 0.24], and 0.59 [p = 0.18], respectively) and significantly lower than those in dialysis-dependent ESRD patients (hazard ratio: 0.17 [p < 0.001], 0.16 [p < 0.001], and 0.16 [p < 0.001], respectively). Older age and diabetes mellitus at the time of KT were risk factors for incident all-cause dementia and AD in KT recipients. Conclusion: This is the first study to show a beneficial impact of KT on incident dementia compared to dialysis dependency.

Background/Aims: We aimed to compare the differences in pediatric Crohn’s disease (CD) and ulcerative colitis (UC) at diagnosis in Korea. Methods: This was a multicenter, registry-based, inception cohort study conducted at five centers in Korea between 2013 and 2017. Baseline demographics, clinical characteristics, and results from laboratory, endoscopic, radiologic examinations were compared between pediatric CD and UC patients who were <19 years old at diagnosis. Results: A total 307 patients were included (227 CD [73.9%] and 80 UC [26.1%]). The male to female ratio was 2.49:1 for CD, and 1.49:1 for UC (p=0.019). Median age at diagnosis was 14.4 years (interquartile range, 12.4 to 16.2) for CD, and 14.4 years (interquartile range, 11.7 to 16.5) for UC (p=0.962). Hematochezia was the only dominant symptom in UC patients compared to CD patients (86.2% vs 30.8%, p<0.001). White blood cell counts, platelet counts, erythrocyte sedimentation rate, and C-reactive protein levels were significantly higher, and serum albumin level was significantly lower in CD patients than in UC patient. Anti-Saccharomyces cerevisiae antibody was positive in 44.5% and 16.2% of CD and UC patients, respectively (p<0.001), and antineutrophil cytoplasmic antibody was positive in 15.0% and 58.8% of CD and UC patients, respectively (p<0.001). Terminal ileal involvement was prominent in CD, while rectal involvement was more prominent in UC. Small bowel involvement and perianal perforating diseases were also more prominent in CD. Conclusions This is the first a multicenter study in Korea to compare the differences between pediatric CD and UC at diagnosis in Korea. A large-scale, national study is expected to better clarify these findings in the future.

Purpose: Acute kidney injury (AKI) in cancer patients is associated with increased morbidity and mortality. The incidence of AKI in lung cancer seems to be relatively higher compared with other solid organ malignancies, although its impact on patient outcomes remains unclear. Materials and Methods: The patients newly diagnosed with lung cancer from 2004 to 2013 were enrolled in this retrospective cohort study. The patients were categorized according to the presence and severity of AKI. We compared all-cause mortality and long-term renal outcome according to AKI stage. Results: A total of 3,202 patients were included in the final analysis. AKI occurred in 1,783 (55.7%) patients during the follow-up period, with the majority having mild AKI stage 1 (75.8%). During the follow-up of 2.6±2.2 years, total 1,251 patients (53.7%) were died and 5-year survival rate was 46.9%. We found that both AKI development and severity were independent risk factors for all-cause mortality in lung cancer patients, even after adjustment for lung cancer-specific variables including the stage or pathological type. In addition, patients suffered from more severe AKI tend to encounter de novo chronic kidney disease development, worsening kidney function, and end-stage kidney disease progression. Conclusion In this study, more than half of the lung cancer patients experienced AKI during their diagnosis and treatment period. Moreover, AKI occurrence and more advanced AKI were associated with a higher mortality risk and adverse kidney outcomes.

Cerebral amyloid angiopathy-related inflammation (CAA-RI) is a distinct subset of cerebral amyloid angiopathy characterized by the auto-inflammatory response to amyloid-laden small arteries of cerebral cortex and leptomeninges. Clinical features include cognitive-behavioral change, headache, focal neurologic deficits and seizure. Because anti-inflammatory treatments can rapidly relieve neurologic symptoms, early diagnosis is critical. Herein, we report a CAA-RI case with distinct laboratory findings of a decreased cerebrospinal fluid amyloid beta 1-42 level and relatively reduced florbetaben uptake in the focal inflammatory lesion during the acute phase of CAA-RI.