Background: Cancer cell line-derived feeder cells enhance natural killer (NK) cell expansion; however, concerns regarding viable residual feeder cells in the final product limit their use. Evidence supporting the safety of NK-sensitive K562-based feeders, even when irradiated, is scarce. We optimized an NK cell expansion protocol using genetically engineered K562-mbIL-18/-21 (GE-K562) feeder cells and clinical-grade media and confirmed the absence of residual feeder cells. Methods: NK cell expansion efficiency was compared between feeder-free and feederbased systems using CTS NK-Xpander Medium. To achieve optimal NK expansion, various peripheral blood mononuclear cell (PBMC)-to-feeder ratios and re-stimulation frequencies were tested over 21 days. Flow cytometry and BCR::ABL1 quantitative reverse transcription PCR (RT-qPCR) were used to confirm the absence of feeder cells in the final NK cell product. Results: Feeder-based systems showed superior NK cell fold expansion compared with that of feeder-free systems. Among feeder-based conditions, NK cells expanded 5,224-fold at a 2:1 PBMC-to-feeder ratio after 3 weeks, relative to 1,450-fold at a 6:1 ratio (P < 0.05).Re-stimulation on days 7 and 14 further increased expansion up to 261,457-fold. Irradiated feeder cells showed no proliferation and were eliminated within 3–6 days. On day 21, flow cytometry and BCR::ABL1 RT-qPCR results confirmed the absence of residual feeder cells. Conclusions Our optimized NK cell expansion protocol using irradiated GE-K562 feeder cells and clinical-grade media offers a safe and scalable approach to generating large numbers of NK cells, supporting its potential use in clinical immunotherapy applications.

Natural killer (NK) cells play critical roles in immune surveillance and homeostasis maintenance through cytotoxicity and cytokine release. The ability of NK cells to eliminate target cells without the need for prior antigen recognition or antibody involvement has drawn considerable attention for translational and clinical applications. As clinical applications continue to broaden, interest in NK cell assays has been growing markedly. This review provides an in-depth discussion of current clinical applications of NK cell assays, including NK cell phenotype, frequency, and functional activity assessments. This review further highlights the diagnostic potential of these assays in terms of hemophagocytic lymphohistiocytosis and potential NK cell biomarker candidates in diverse pathological contexts, such as cancer, infection, autoimmune diseases, and other diseases. By integrating clinical insights with technological advancements, NK cell assays can serve as valuable tools for disease diagnosis, prognosis, and therapeutic monitoring.

This report provides a summary of the 2024 survey results on the external quality assessment (EQA) scheme for the general transfusion medicine test and the general transfusion antibody test programs in Korea. Proficiency testing materials were prepared at the Asan Medical Center for bi-annual distribution to participating laboratories. The accuracy rates and number of participating laboratories for the bi-annual EQAs were: ABO typing, 99.6%–99.9% (n=944, n=945); RhD typing, 99.9%–100.0% (n=929, n=930);crossmatching, 95.0%–99.2% (n=825, n=825); unexpected antibody scre ening, 99.5%–100.0% (n=363, n=367); direct antiglobulin test (DAT) using a polyspecific reagent, 99.3%–100.0% (n=296, n=299); DAT using an antiimmunoglobulin G monospecific reagent, 100.0% (n=74, n=72); and DAT using an anti-C3d monospecific reagent, 98.6%–100.0% (n=72, n=71). The 2024 EQA scheme for the transfusion medicine program has improved and maintained the standards of the participating laboratories.

This report provides a summary of the 2024 survey results on the external quality assessment (EQA) scheme for the general transfusion medicine test and the general transfusion antibody test programs in Korea. Proficiency testing materials were prepared at the Asan Medical Center for bi-annual distribution to participating laboratories. The accuracy rates and number of participating laboratories for the bi-annual EQAs were: ABO typing, 99.6%–99.9% (n=944, n=945); RhD typing, 99.9%–100.0% (n=929, n=930);crossmatching, 95.0%–99.2% (n=825, n=825); unexpected antibody scre ening, 99.5%–100.0% (n=363, n=367); direct antiglobulin test (DAT) using a polyspecific reagent, 99.3%–100.0% (n=296, n=299); DAT using an antiimmunoglobulin G monospecific reagent, 100.0% (n=74, n=72); and DAT using an anti-C3d monospecific reagent, 98.6%–100.0% (n=72, n=71). The 2024 EQA scheme for the transfusion medicine program has improved and maintained the standards of the participating laboratories.

This report provides a summary of the 2024 survey results on the external quality assessment (EQA) scheme for the general transfusion medicine test and the general transfusion antibody test programs in Korea. Proficiency testing materials were prepared at the Asan Medical Center for bi-annual distribution to participating laboratories. The accuracy rates and number of participating laboratories for the bi-annual EQAs were: ABO typing, 99.6%–99.9% (n=944, n=945); RhD typing, 99.9%–100.0% (n=929, n=930);crossmatching, 95.0%–99.2% (n=825, n=825); unexpected antibody scre ening, 99.5%–100.0% (n=363, n=367); direct antiglobulin test (DAT) using a polyspecific reagent, 99.3%–100.0% (n=296, n=299); DAT using an antiimmunoglobulin G monospecific reagent, 100.0% (n=74, n=72); and DAT using an anti-C3d monospecific reagent, 98.6%–100.0% (n=72, n=71). The 2024 EQA scheme for the transfusion medicine program has improved and maintained the standards of the participating laboratories.

This report provides a summary of the 2024 survey results on the external quality assessment (EQA) scheme for the general transfusion medicine test and the general transfusion antibody test programs in Korea. Proficiency testing materials were prepared at the Asan Medical Center for bi-annual distribution to participating laboratories. The accuracy rates and number of participating laboratories for the bi-annual EQAs were: ABO typing, 99.6%–99.9% (n=944, n=945); RhD typing, 99.9%–100.0% (n=929, n=930);crossmatching, 95.0%–99.2% (n=825, n=825); unexpected antibody scre ening, 99.5%–100.0% (n=363, n=367); direct antiglobulin test (DAT) using a polyspecific reagent, 99.3%–100.0% (n=296, n=299); DAT using an antiimmunoglobulin G monospecific reagent, 100.0% (n=74, n=72); and DAT using an anti-C3d monospecific reagent, 98.6%–100.0% (n=72, n=71). The 2024 EQA scheme for the transfusion medicine program has improved and maintained the standards of the participating laboratories.

This report provides a summary of the 2024 survey results on the external quality assessment (EQA) scheme for the general transfusion medicine test and the general transfusion antibody test programs in Korea. Proficiency testing materials were prepared at the Asan Medical Center for bi-annual distribution to participating laboratories. The accuracy rates and number of participating laboratories for the bi-annual EQAs were: ABO typing, 99.6%–99.9% (n=944, n=945); RhD typing, 99.9%–100.0% (n=929, n=930);crossmatching, 95.0%–99.2% (n=825, n=825); unexpected antibody scre ening, 99.5%–100.0% (n=363, n=367); direct antiglobulin test (DAT) using a polyspecific reagent, 99.3%–100.0% (n=296, n=299); DAT using an antiimmunoglobulin G monospecific reagent, 100.0% (n=74, n=72); and DAT using an anti-C3d monospecific reagent, 98.6%–100.0% (n=72, n=71). The 2024 EQA scheme for the transfusion medicine program has improved and maintained the standards of the participating laboratories.

Background: Diabetic nephropathy (DN) is a progressive complication among patients with diabetes and the most common cause of end-stage kidney disease. Neutrophil extracellular traps (NETs) are known to play a role in kidney disease, thus this study aimed to determine their role in the development of diabetic kidney disease using diabetic murine models. Results: Protein and histological analyses revealed that db/db mice and streptozotocin DN models expressed no significant NET-related proteins, myeloperoxidase, citrullinated histone H3 (citH3), neutrophil elastase, and lymphocyte antigen 6 complex locus G6D (Ly6G). However, the inflamed individuals in the DN model showed that citH3 and Ly6G were highly deposited in the renal system based on immunohistochemistry images. In vitro, NET treatment did not induce apoptosis in glomerular endothelial and renal tubular epithelial cells. NET inhibition by DNase administration demonstrated no significant changes in cell apoptosis. Conclusions NET-related proteins were only expressed in the DN model with tubulointerstitial inflammation. Our study revealed that NETs are only induced in mice with hyperglycemia-induced inflammation.

Background: Diabetic nephropathy (DN) is a progressive complication among patients with diabetes and the most common cause of end-stage kidney disease. Neutrophil extracellular traps (NETs) are known to play a role in kidney disease, thus this study aimed to determine their role in the development of diabetic kidney disease using diabetic murine models. Results: Protein and histological analyses revealed that db/db mice and streptozotocin DN models expressed no significant NET-related proteins, myeloperoxidase, citrullinated histone H3 (citH3), neutrophil elastase, and lymphocyte antigen 6 complex locus G6D (Ly6G). However, the inflamed individuals in the DN model showed that citH3 and Ly6G were highly deposited in the renal system based on immunohistochemistry images. In vitro, NET treatment did not induce apoptosis in glomerular endothelial and renal tubular epithelial cells. NET inhibition by DNase administration demonstrated no significant changes in cell apoptosis. Conclusions NET-related proteins were only expressed in the DN model with tubulointerstitial inflammation. Our study revealed that NETs are only induced in mice with hyperglycemia-induced inflammation.

This report aimed to provide a summary of the 2023 survey results on the external quality assessment (EQA) scheme for the general transfusion medicine test and general transfusion antibody test programs in Korea. Proficiency testing materials were prepared at the Asan Medical Center for biannual distribution to participating laboratories. The accuracy rates and number of participating laboratories were as follows: ABO typing, 99.8%–100.0% (n=940, n=940); RhD typing, 99.8%–100.0% (n=924, n=918); crossmatching, 95.6%–99.4% (n=802, n=825); unexpected antibody screening, 99.4–100.0% (n=358, n=358); direct antiglobulin test (DAT) using a polyspecific reagent, 99.3%–100.0% (n=296, n=292); DAT using anti-immuno globulin G monospecific reagent, 100.0% (n=76, n=76); and DAT using antiC3d monospecific reagent, 97.3%–100.0% (n=73, n=73). The 2023 EQA scheme for transfusion medicine program has improved and maintained the standards of the participating laboratories.