Background: We compared the immunoglobulin (IG) heavy chain (IGH) leader and FR1 primer sets to measure clone sizes and detect immunoglobulin heavy chain variable (IGHV) region somatic hypermutations (SHMs) in Korean patients with chronic lymphocytic leukemia (CLL). We also analyzed IGH and immunoglobulin kappa (IGK) to identify Korean-specific IGs in CLL. Methods: Next-generation sequencing (NGS)–based gene rearrangements and IGHV SHMs were assessed in 40 patients using IGH leader, IGH FR1, and IGK primers. Flow cytometry, karyotyping, interphase FISH, and NGS-based variant analyses were performed for 165 genes. Results: Clonal IGH and IGK rearrangements were detected in 100.0% and 97.5% of patients, respectively. Clonal size was generally smaller per NGS than per flow cytometry, particularly when using the IGH leader (median: 52.5%) versus the IGH FR1 primer set (73.2%). IGHV SHMs occurred in approximately 70% of patients; 10% showed primer set discrepancies. The incidence of IGHV SHMs was low in patients at high risk (i.e., with TP53 abnormalities; complex karyotypes; and ATM, NOTCH1, SF3B1, or BIRC3 variants). IGHV3 was the most common IGHV (58.3%), and IGHV4-34 was most frequently identified (14.6%). IGHV1 and IGHV1-69 usage differed significantly between Koreans and westerners. IGHJ4 was the most common IGHJ (56.3%). A single IGKV–IGKJ gene rearrangement was most frequently observed (18.9%), whereas intron-KDE was the most common rearrangement (30.6%). Conclusions NGS may underestimate CLL clonal size, particularly when using the IGH leader primer set. IGHV SHMs were inversely associated with negative prognostic factors.Our data suggest ethnic differences in CLL pathogenesis.

Objectives: Assessing healthcare quality at the national level is essential for evaluating health system performance and identifying areas requiring improvement. This study examined long-term trends in healthcare quality in Korea from 2008 to 2023 using internationally comparable indicators. Methods: We conducted a trend analysis of healthcare quality in Korea using the Organization for Economic Cooperation and Development (OECD) Health Care Quality and Outcomes framework and quality indicators. Indicators across multiple domains, including acute care, primary care, prescribing in primary care, mental healthcare, and patient experiences, were analyzed and compared with OECD averages. Results: Healthcare quality in Korea improved across several domains. Thirty-day mortality for acute myocardial infarction decreased from 14.2% in 2008 to 10.2% in 2023, while mortality for ischemic stroke declined from 8.7% to 5.5%. Avoidable hospitalizations decreased substantially, with hospitalizations for chronic obstructive pulmonary disease declining by 59.7%. The proportion of patients with diabetes receiving cholesterol-lowering treatment increased from 44.1% to 82.5%. However, the proportion of broad-spectrum antibiotic prescriptions remained substantially higher than the OECD average (40.3 vs. 15.5%). In mental healthcare, excess mortality ratios increased from 4.3 in 2010 to 4.9 in 2023 for schizophrenia and from 3.5 to 4.3 for bipolar disorder, while post-discharge suicide rates showed little improvement. Patient experience indicators related to patient-physician communication improved and approached OECD averages. Conclusions Healthcare quality in Korea improved substantially between 2008 and 2023, particularly in acute care outcomes and chronic disease management. However, persistent challenges remain in areas such as antibiotic use, polypharmacy, and mental healthcare. These findings provide internationally comparable evidence to inform future health policy and healthcare quality improvement efforts.

Replacing the retrohepatic inferior vena cava (IVC) following concurrent resection of the IVC and tumor-involved liver is an emerging surgical technique in living donor liver transplantation (LDLT), particularly for managing hepatocellular carcinomas near the IVC. This approach makes the extent of hepatectomy in LDLT comparable to that of deceased donor liver transplantation. We report a pediatric LDLT case involving IVC and portal vein (PV) replacement with an iliac vein homograft to treat advanced hepatoblastomas. The patient was a 24-month-old girl weighing 9.1 kg, presenting with large, multiple hepatoblastomas infiltrating the retrohepatic IVC and PV. After a 2-week waiting period, a cold-stored iliac vein graft was obtained, and the transplantation was performed using a left lateral section graft from her father.A 4-cm iliac vein homograft was anastomosed between the suprahepatic and suprarenal IVC stumps. The liver graft was implanted following standard procedures, with the PV reconstructed via a telescope-shaped anastomosis using the vein graft interposition. The patient experienced an uncomplicated recovery and is currently receiving scheduled adjuvant chemotherapy. In conclusion, IVC and PV replacement with vein homografts represents a feasible and effective surgical strategy for pediatric LDLT patients with advanced liver malignancies involving vascular invasion.

Purpose: Current guidelines recommend vaccination at least 2 weeks before chemotherapy initiation to optimize the immune response despite limited evidence. Our previous study indicated no differences in short-term immune response for the 13-valent pneumococcal conjugate vaccine (PCV13) according to the vaccination timing. This study aims to investigate the long-term efficacy of PCV13 and clinical factors associated with the respective antibody response. Materials and Methods: Patients with gastric or colorectal cancer who received adjuvant chemotherapy were enrolled and divided into two groups: vaccinated 2 weeks before chemotherapy (arm A) and vaccinated concurrently with chemotherapy (arm B). Serum samples were collected before vaccination and in one month, 3 years, and 5 years. Immune responses were measured using enzyme-linked immunosorbent assay and multiplex opsonophagocytosis assay. Results: Including 63 patients, both groups showed an initial increase in the geometric mean titers of opsonophagocytic activity and the geometric mean concentrations of serotype-specific IgG levels after one month, followed by a decline at 3 and 5 years, particularly for serotypes 1, 14, 18C, and 19A. Despite the decline, global protection was maintained for 5 years, although global response decreased. The two arms did not show significant differences in immunogenicity nor in factors such as vaccination timing, age, cancer type, or chemotherapy regimen. Conclusion Vaccination timing is not a significant factor for the immunogenicity of PCV13 in cancer patients undergoing adjuvant chemotherapy. Global protection against pneumococcal infection was sustained for > 5 years, and global response remained in over half of patients.

In children with biliary atresia, recurrent episodes of cholangitis often lead to portal vein (PV) phlebosclerosis. We report a case of pediatric living donor liver transplantation (LDLT) for biliary atresia with PV occlusion and a large splenorenal shunt. A 3-year-5-month-old girl was diagnosed with syndromic biliary atresia and polysplenia. Because the patient’s condition progressively deteriorated with worsening jaundice, we opted to perform LDLT using a left lateral section graft from her father. The recipient’s native PV was severely atrophic and completely occluded, and the collateral veins around the hepatoduodenal ligament were too small to serve as a viable source of portal inflow.Consequently, renoportal anastomosis (RPA) was selected as an alternative approach.Iliac vein interposition was performed to provide a new portal inflow source, and anatomy-compliant PV reconstruction was performed. The patient recovered from transplant surgery, but PV conduit stenosis occurred with the development of ascites 2 months posttransplant. This RPA-related vascular complication was resolved through percutaneous balloon angioplasty of the PV conduit. The patient has been doing well for 6 months posttransplantation. This case demonstrates that RPA can represent a viable reconstructive option for PV inflow in liver transplantation for pediatric patients with phlebosclerotic PV and prominent splenorenal shunt.

Coronary artery bypass grafting (CABG) remains a key revascularization strategy for ischemic heart disease; however, nationwide trends in the Republic of Korea have not been thoroughly investigated. Using data from the Korean National Health Insurance Service, we analyzed adult patients who underwent isolated CABG between 2005 and 2022. We evaluated surgical volume, patient demographics, procedural strategies (off-pump vs. onpump), and outcomes. International comparisons were conducted using national cardiac surgery registry data. A total of 51,923 CABG cases were identified. Annual surgical volume declined until 2013 but gradually increased thereafter, reaching 3,717 cases in 2022. Despite this recovery, Korea’s per capita CABG rate remains among the lowest worldwide.In contrast, more than 60% of procedures were performed off-pump—the highest rate worldwide. Over time, the average patient age and prevalence of diabetes increased, whereas in-hospital mortality showed a modest decline. Compared with other countries, the Republic of Korea demonstrated a uniquely low procedural volume and a strong preference for off-pump CABG. This nationwide analysis highlights Korea’s distinctive CABG practice patterns and provides valuable insights for optimizing future clinical and policy decisions in cardiac surgical care.

Lazertinib is an oral, third-generation, epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) for the treatment of non-small cell lung cancer (NSCLC). This case report presents a rare instance of small cell carcinoma transformation in pancreatic metastasis in a patient with EGFR-mutated NSCLC undergoing treatment with lazertinib. Small cell carcinoma transformation indicates a mechanism of treatment resistance, and tissue biopsy is essential to confirm this. When isolated progression of a lesion is suspected during TKI therapy in EGFR-mutated NSCLC, histological evaluation is necessary to confirm the transformation for the treatment strategy.

Objective: To assess the feasibility of ultrafast brain magnetic resonance imaging (MRI) in pediatric patients. Materials and Methods: We retrospectively reviewed 194 pediatric patients aged 0 to 19 years (median 10.2 years) who underwent both ultrafast and conventional brain MRI between May 2019 and August 2020. Ultrafast MRI sequences included T1 and T2-weighted images (T1WI and T2WI), fluid-attenuated inversion recovery (FLAIR), T2*-weighted image (T2*WI), and diffusion-weighted image (DWI). Qualitative image quality and lesion evaluations were conducted on 5-point Likert scales by two blinded radiologists, with quantitative assessment of lesion count and size on T1WI, T2WI, and FLAIR sequences for each protocol. Wilcoxon signed-rank tests and intraclass correlation coefficient (ICC) analyses were used for comparison. Results: The total scan times for equivalent image contrasts were 1 minute 44 seconds for ultrafast MRI and 15 minutes 30 seconds for conventional MRI. Overall, image quality was lower in ultrafast MRI than in conventional MRI, with mean quality scores ranging from 2.0 to 4.8 for ultrafast MRI and 4.8 to 5.0 for conventional MRI across sequences (P < 0.001 for T1WI, T2WI, FLAIR, and T2*WI for both readers; P = 0.018 [reader 1] and 0.031 [reader 2] for DWI). Lesion detection rates on ultrafast MRI relative to conventional MRI were as follows: T1WI, 97.1%; T2WI, 99.6%; FLAIR, 92.9%; T2*WI, 74.1%; and DWI, 100%. The ICC (95% confidence interval) for lesion size measurements between ultrafast and conventional MRI was as follows: T1WI, 0.998 (0.996–0.999); T2WI, 0.998 (0.997–0.999); and FLAIR, 0.99 (0.985–0.994). Conclusion Ultrafast MRI significantly reduces scan time and provides acceptable results, albeit with slightly lower image quality than conventional MRI, for evaluating intracranial abnormalities in pediatric patients.

Lazertinib is an oral, third-generation, epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) for the treatment of non-small cell lung cancer (NSCLC). This case report presents a rare instance of small cell carcinoma transformation in pancreatic metastasis in a patient with EGFR-mutated NSCLC undergoing treatment with lazertinib. Small cell carcinoma transformation indicates a mechanism of treatment resistance, and tissue biopsy is essential to confirm this. When isolated progression of a lesion is suspected during TKI therapy in EGFR-mutated NSCLC, histological evaluation is necessary to confirm the transformation for the treatment strategy.