Mycophenolate mofetil (MMF) is usually prescribed with a reduced fixed dose in Asian kidney transplant recipients (KTRs). However, the clinical efficacy and safety of the fixed dose have not yet been investigated via therapeutic drug monitoring. We evaluated whether reduced fixed-dose MMF is an optimal dosing strategy to achieve the therapeutic target of mycophenolic acid (MPA) exposure in Korean KTRs. Methods: This open-label, prospective study enrolled 50 de novo KTRs prescribed with tacrolimus, corticosteroid, and fixed-dose MMF (1.0–1.5 g/day). The trough level (C0) and area under the curve (AUC0–12 hr) of MPA were measured at 1 and 24 weeks after kidney transplantation (KT). The relationship of body weight (BW)-adjusted MMF dose with MPA C0 and MPA AUC0–12 hr was assessed using linear regression analysis. Results: The initial fixed dose of MMF of 1.44 ± 0.16 g/day was adjusted in 24 patients (48.0%) and then reduced to a mean dose of 1.19 ± 0.31 g/day at 24 weeks after KT. Most patients (≥84.0%) attained the minimum required MPA C0 of 1.0 μg/mL and MPA AUC0–12 hr of 30 μg × hr/mL at 1 and 24 weeks. The BW-adjusted MMF dose demonstrated significant positive correlations with MPA C0 and MPA AUC0– 12 hr at 1 and 24 weeks after KT. Moreover, 14 patients (28.0%) reported MPA-related adverse events that were predictable based on MPA AUC0–12 hr (cutoff level, 46.4 μg × hr/mL). Conclusion: The current reduced fixed-dose MMF strategy can help achieve the therapeutic target of MPA exposure in tacrolimus- treated Korean KTRs during the early posttransplant period.

With the advancement of regenerative medicine, the demand for immune cell–derived blood components such as leukocytes is increasing. However, Article 3 of South Korea’s Blood Management Act prohibits financial compensation for blood donation. Moreover, nonconforming blood units, leftover specimens, and discarded leukocytes remain unavailable for commercial use. This study examined the current use of donated blood components, the potential application of leukocytes, regulatory barriers in producing reagent red blood cells, and donor compensation policies in countries such as the United States and Germany. We propose the establishment of a legal framework that enables the selective industrial use of cellular resources for therapeutic development, with safeguards in place to ensure adherence to ethical standards and the safety of donors. Such reforms could enhance the competitiveness of Korea’s bioindustry and expand access to novel therapies for patients with intractable diseases.

Background: Calcineurin inhibitor (CNI) toxicity is a significant cause of graft dysfunction in kidney transplant recipients, yet distinguishing it from acute rejection (AR) and acute tubular necrosis (ATN) remains challenging. This study investigated the use of urinary mRNA biomarkers as a noninvasive tool for identifying CNI toxicity. Methods: We retrospectively enrolled 110 kidney transplant recipients and classified them into four groups based on pathological findings: stable graft function (n=35), CNI toxicity (n=25), AR (n=30), and ATN (n=20). Candidate biomarkers were selected using the GEO database. Urinary mRNA was extracted from cell pellets, reverse-transcribed, and quantified by real-time polymerase chain reaction. Results: Estimated glomerular filtration rates were comparable among the CNI toxicity, AR, and ATN groups. Four transcripts (LTF, NNMT, WFDC2, and HIF1A) were identified as candidate biomarkers. Urinary mRNA levels of LTF, NNMT, and HIF1A were significantly lower in the CNI toxicity group than the AR group. NNMT and HIF1A levels were also significantly lower than those observed in the ATN group. In contrast, WFDC2 levels did not differ significantly across groups. A three-gene signature (LTF, NNMT, and HIF1A) effectively differentiated CNI toxicity from AR and ATN (area under the curve [AUC], 0.867;95% confidence interval [CI], 0.787–0.947) and significantly enhanced the diagnostic performance of the clinical variable-based model (AUC increased from 0.776; 95% CI, 0.660–0.892, to 0.934; 95% CI, 0.881–0.986). Conclusions Urinary mRNA levels of LTF, NNMT, and HIF1A may serve as useful biomarkers for identifying CNI toxicity in kidney transplant recipients with graft dysfunction.

Red blood cell concentrates, platelet concentrates, and fresh plasma are separated from whole blood through centrifugation. The main manufacturing methods, platelet-rich plasma (PRP) and buffy-coat (BC), are currently in use. The BC method has been increasingly adopted because of its high recovery rate of platelets and plasma, lower platelet activation, and reduced transfusion-related complications. Korea’s first Master Plan for Blood Management (2021∼2025) considered transitioning from the PRP method to the BC method and introducing automation to expand the supply of leukoreduced blood components. On the other hand, several issues have prevented this transition. In 2023, the US FDA cleared an automated system for the single centrifugation method without switching to the BC method. This paper discusses these approaches.

Since the mid-2000s, massive blood transfusion protocols and damage control resuscitation have improved the prognosis of trauma patients. As a part of damage control resuscitation, whole blood transfusion, especially using low titer group O whole blood (LTOWB), has been widely accepted in both military and civilian trauma settings based on its safety and significant advantages in terms of efficiency and efficacy. To implement LTOWB effectively, each institution should establish relevant policies which should simultaneously consider safety and accessibility factors, including titer threshold, blood management, blood supply, and transfusion protocols for LTOWB. These policies will need to be revised through continuous audits and monitoring. Additionally, whole blood and LTOWB may benefit hemorrhagic patients in non-trauma contexts, or in rural and pre-hospital settings. Further supporting evidence for these applications is needed.

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.

Red blood cell concentrates, platelet concentrates, and fresh plasma are separated from whole blood through centrifugation. The main manufacturing methods, platelet-rich plasma (PRP) and buffy-coat (BC), are currently in use. The BC method has been increasingly adopted because of its high recovery rate of platelets and plasma, lower platelet activation, and reduced transfusion-related complications. Korea’s first Master Plan for Blood Management (2021∼2025) considered transitioning from the PRP method to the BC method and introducing automation to expand the supply of leukoreduced blood components. On the other hand, several issues have prevented this transition. In 2023, the US FDA cleared an automated system for the single centrifugation method without switching to the BC method. This paper discusses these approaches.

Background: Flow cytometric immunophenotyping of hematolymphoid neoplasms (FCIHLN) is essential for diagnosis, classification, and minimal residual disease (MRD) monitoring. FCI-HLN is typically performed using in-house protocols, raising the need for standardization. Therefore, we surveyed the current status of FCI-HLN in Korea to obtain fundamental data for quality improvement and standardization. Methods: Eight university hospitals actively conducting FCI-HLN participated in our survey.We analyzed responses to a questionnaire that included inquiries regarding test items, reagent antibodies (RAs), fluorophores, sample amounts (SAs), reagent antibody amounts (RAAs), acquisition cell number (ACN), isotype control (IC) usage, positiveegative criteria, and reporting. Results: Most hospitals used acute HLN, chronic HLN, plasma cell neoplasm (PCN), and MRD panels. The numbers of RAs were heterogeneous, with a maximum of 32, 26, 12, 14, and 10 antibodies used for acute HLN, chronic HLN, PCN, ALL-MRD, and multiple myeloma-MRD, respectively. The number of fluorophores ranged from 4 to 10. RAs, SAs, RAAs, and ACN were diverse. Most hospitals used a positive criterion of 20%, whereas one used 10% for acute and chronic HLN panels. Five hospitals used ICs for the negative criterion. Positiveegative assignments, percentages, and general opinions were commonly reported. In MRD reporting, the limit of detection and lower limit of quantification were included. Conclusions This is the first comprehensive study on the current status of FCI-HLN in Korea, confirming the high heterogeneity and complexity of FCI-HLN practices. Standardization of FCI-HLN is urgently needed. The findings provide a reference for establishing standard FCI-HLN guidelines.

Background: Solid-organ transplant recipients (SOTRs) receiving immunosuppressive therapy are expected to have worse clinical outcomes from coronavirus disease 2019 (COVID-19). However, published studies have shown mixed results, depending on adjustment for important confounders such as age, variants, and vaccination status. Materials and Methods: We retrospectively collected the data on 7,327 patients hospitalized with COVID-19 from two tertiary hospitals with government-designated COVID-19 regional centers. We compared clinical outcomes between SOTRs and non-SOTRs by a propensity score-matched analysis (1:2) based on age, gender, and the date of COVID-19 diagnosis. We also performed a multivariate logistic regression analysis to adjust other important confounders such as vaccination status and the Charlson comorbidity index. Results: After matching, SOTRs (n=83) had a significantly higher risk of high-flow nasal cannula use, mechanical ventilation, acute kidney injury, and a composite of COVID-19 severity outcomes than non-SOTRs (n=160) (all P <0.05). The National Early Warning Score was significantly higher in SOTRs than in non-SOTRs from day 1 to 7 of hospitalization ( P for interaction=0.008 by generalized estimating equation). In multivariate logistic regression analysis, SOTRs (odds ratio [OR], 2.14; 95% confidence interval [CI], 1.12–4.11) and male gender (OR, 2.62; 95% CI, 1.26– 5.45) were associated with worse outcomes, and receiving two to three doses of COVID-19 vaccine (OR, 0.43; 95% CI, 0.24–0.79) was associated with better outcomes. Conclusion Hospitalized SOTRs with COVID-19 had a worse prognosis than non-SOTRs. COVID-19 vaccination should be implemented appropriately to prevent severe COVID-19 progression in this population.

Background: Solid-organ transplant recipients (SOTRs) receiving immunosuppressive therapy are expected to have worse clinical outcomes from coronavirus disease 2019 (COVID-19). However, published studies have shown mixed results, depending on adjustment for important confounders such as age, variants, and vaccination status. Materials and Methods: We retrospectively collected the data on 7,327 patients hospitalized with COVID-19 from two tertiary hospitals with government-designated COVID-19 regional centers. We compared clinical outcomes between SOTRs and non-SOTRs by a propensity score-matched analysis (1:2) based on age, gender, and the date of COVID-19 diagnosis. We also performed a multivariate logistic regression analysis to adjust other important confounders such as vaccination status and the Charlson comorbidity index. Results: After matching, SOTRs (n=83) had a significantly higher risk of high-flow nasal cannula use, mechanical ventilation, acute kidney injury, and a composite of COVID-19 severity outcomes than non-SOTRs (n=160) (all P <0.05). The National Early Warning Score was significantly higher in SOTRs than in non-SOTRs from day 1 to 7 of hospitalization ( P for interaction=0.008 by generalized estimating equation). In multivariate logistic regression analysis, SOTRs (odds ratio [OR], 2.14; 95% confidence interval [CI], 1.12–4.11) and male gender (OR, 2.62; 95% CI, 1.26– 5.45) were associated with worse outcomes, and receiving two to three doses of COVID-19 vaccine (OR, 0.43; 95% CI, 0.24–0.79) was associated with better outcomes. Conclusion Hospitalized SOTRs with COVID-19 had a worse prognosis than non-SOTRs. COVID-19 vaccination should be implemented appropriately to prevent severe COVID-19 progression in this population.