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.

Current ABO titration methods lack standardization and harmonization. We analyzed the consistency of ABO antibody titer testing among Korean laboratories and discussed future directions for standardization by analyzing external quality control data collected by the Korean Association of External Quality Assessment Service over 5 yrs (2019–2023). The analysis included the number of participating institutions and methods, as well as the proportion of acceptable results. To compare column agglutination technology (CAT) and tube methods, we created a normalized variable: ([log 2 titer of laboratory test result]–[mean of log 2 titer for the peer group]). The number of participating institutions and methods increased over time. The use of CAT methods expanded, whereas that of tube methods declined. The proportion of acceptable results ranged from 84.0% to 100%, with no significant differences between CAT and tube methods. An F-test revealed no significant variance differences among institutions using these methods. Tube methods demonstrated lower variance in anti-human globulin testing, and room temperature tube methods exhibited lower variance than that of CAT methods. Domestic laboratories demonstrated highquality performance in ABO antibody titer testing, with no significant differences in acceptable result rates or variance across methods. Continuous efforts toward standardization remain essential.

Little is known about alterations of the rotator cuff (RC) macroscopic vasculature associated with medical conditions and/or habits that predispose a person to diseases of the peripheral microcirculation. The high frequency of cuff tear and re-tear in patients with diabetes, hypercholesterolemia, uncontrolled arterial hypertension, or metabolic syndrome may be due to tissue hypovascularity. Methods: The macroscopic vasculature of both the articular and bursal sides of the posterosuperior RC was evaluated arthroscopically in 107 patients (mean age, 58.2 years) with no RC tear. Patients were divided into three groups according to medical comorbidities and lifestyle factors (group I, none; group II, smokers and/or drinkers and one comorbidity; and group III, two or more comorbidities). Pulsating vessels originating from both the myotendinous and osteotendinous junctions were assessed as “clearly evident,” “poorly evident,” or “not evident.” Results: Groups I, II, and III comprised 36, 45, and 26 patients, respectively. Within the myotendinous junction, vessels were visualized in 22 group I patients (61%), 25 group II patients (55%), and 6 group III patients (23%) (P=0.007). Pulsating arterial vessels originating from the osteotendinous junction were seen in 42%, 36%, and 0% of patients, respectively (P<0.001). Within the bursal side of the RC, a dense anastomotic network was visualized (either clearly or poorly) in 94% (34), 80% (36), and 35% (9) of patients, respectively (P<0.001). Conclusions: The macroscopic vasculature of the RC is influenced by pre-existing diseases and lifestyle factors, which may impair peripheral microcirculation. Level of evidence: III.

ABO-blood typing typically involves both front typing (cell typing) and back typing (serum typing) to ensure accurate determination of blood type. However, in neonates, back typing is frequently omitted due to their immature immune system. If an institution chooses red blood cells (RBCs) that match the neonate's blood type, omitting back typing could lead to unexplained cross-matching incompatibilities. Therefore, blood banks should be cautious with neonatal blood typing and transfusion practices to ensure transfusion safety.

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.

The unexpected antibody screening test is one of the most important pretransfusion tests. The tests are usually performed using commercial cells, which in Asia may not include clinically important antigens. To overcome this limitation, some laboratories use additional screening cells, including Di a or Mi a . However, these efforts are not supported by the Korean National Health Insurance system. The estimated total medical costs for using additional screening cells are less than the estimated total medical costs for the management of potential hemolytic transfusion reactions caused by missing clinically important antibodies. Hence, it is recommended that the Health Insurance system should be modified to take this into account and address the issue.