1.Bisphosphonates as a Tacrolimus-Sparing Strategy in Kidney Transplantation: Insights from a Retrospective Analysis
Hee Byung KOH ; Hyo Jeong KIM ; Ga Young HEO ; Namki HONG ; Yaeji LEE ; Seung Hwan SONG ; Hoon Young CHOI ; Chan-Young JUNG ; Hyung Woo KIM ; Jaeseok YANG ; Kyu Ha HUH ; Chung Mo NAM ; Beom Seok KIM
Yonsei Medical Journal 2026;67(1):17-26
Purpose:
Due to chronic toxicity, tacrolimus-sparing is an important issue in kidney transplant recipients (KTRs). Several studies have shown that bisphosphonate use is associated with favorable graft outcomes in KTRs. We investigated whether the association between tacrolimus trough levels (TTLs) and graft outcomes differed according to bisphosphonate use in KTRs.
Materials and Methods:
We conducted a retrospective study encompassing 1441 KTRs who were administered tacrolimus-based immunosuppressants. The primary exposure was a time-dependent cross-product of TTLs (low TTLs vs. normal-high TTLs with a reference of 6 ng/mL) and bisphosphonate use. Two primary outcomes were evaluated: overall graft loss (death or conversion to kidney replacement) and an estimated glomerular filtration rate (eGFR) <30 mL/min/1.73 m 2 .
Results:
During the median follow-up of 6.1 (3.4–9.7) years, overall graft loss occurred in 157 (10.9%) patients. Cox regression revealed that normal-high TTLs without bisphosphonate use were associated with a reduced risk of overall graft loss [adjusted hazard ratio (aHR), 0.65; 95% confidence interval (CI), 0.45–0.95] compared to low TTLs without bisphosphonate use. The use of bisphosphonate in conjunction with normal-high TTLs correlated with an even lower risk of overall graft loss (aHR, 0.25; 95% CI, 0.08–0.80) compared with low TTLs without bisphosphonate use. In patients with low TTLs, bisphosphonate use was associated with a reduced risk of overall graft loss compared with non-use (aHR, 0.20; 95% CI, 0.09–0.43). Similar trends were observed in the eGFR outcome.
Conclusion
The use of bisphosphonate was associated with favorable graft outcomes, even with low TTLs. Incorporating bisphosphonate into a conventional immunosuppressant regimen may potentially reduce tacrolimus requirement.
2.Heart Failure Statistics 2025 Update:A Report From the Korean Society of Heart Failure
Chan Joo LEE ; Hokyou LEE ; Kyu-Yong KO ; Min Gyu KONG ; Min Sun KIM ; SungA BAE ; Yuran AHN ; Kyeong-Hyeon CHUN ; Kang-Un CHOI ; Jah Yeon CHOI ; Jungkuk LEE ; Geun U PARK ; Byung Su YOO
International Journal of Heart Failure 2026;8(1):58-73
Background and Objectives:
We evaluated 20-year trends in heart failure (HF) epidemiology in Korea to quantify changes in its burden from 2002 to 2023.
Methods:
A nationwide analysis was conducted using a random 50% sample from the Korean National Health Information Database linked to mortality records (2002–2023). HF was defined using diagnostic codes recorded as a primary or secondary condition. We calculated crude and age-standardized rates of prevalence, incidence, hospitalization, and mortality. Survival was assessed using the Kaplan–Meier method, stratified by inpatient versus outpatient diagnosis.Trends in heart transplantation and left ventricular assist device implantations were also examined.
Results:
By 2023, approximately 1,750,228 individuals had HF (3.41% prevalence). The age-standardized prevalence has more than doubled from 2002 to 2023. The crude incidence increased over time; the age-standardized incidence remained stable in men and declined in women.Hospitalization rates for any cause or secondary HF diagnoses have increased substantially, whereas primary HF hospitalization rates have remained relatively stable. The annual mortality rate in patients with HF was approximately 6.0% in 2023, being markedly higher in older adults.Although short-term survival has improved, particularly in hospitalized patients, long-term survival remains limited. Use of advanced therapies significantly increased.
Conclusions
The burden of HF in Korea has increased substantially over the past two decades, driven primarily by population aging and improved survival rather than increasing age-adjusted incidence. Despite therapeutic advances, hospitalization and long-term mortality rates remain high, highlighting the need for comprehensive HF strategies in aging societies.
3.Association of Age, Sex and Education With Access to the Intravenous Thrombolysis for Acute Ischemic Stroke
Yoona KO ; Beom Joon KIM ; Youngran KIM ; Jong-Moo PARK ; Kyusik KANG ; Jae Guk KIM ; Jae-Kwan CHA ; Tai Hwan PARK ; Kyungbok LEE ; Jun LEE ; Keun-Sik HONG ; Byung-Chul LEE ; Kyung-Ho YU ; Dong-Eog KIM ; Joon-Tae KIM ; Jay Chol CHOI ; Jee Hyun KWON ; Wook-Joo KIM ; Kyu Sun YUM ; Sung-Il SOHN ; Hyungjong PARK ; Sang-Hwa LEE ; Kwang-Yeol PARK ; Chi Kyung KIM ; Sung Hyuk HEO ; Moon-Ku HAN ; Anjail Z. SHARRIEF ; Sunil A. SHETH ; Hee-Joon BAE ;
Journal of Korean Medical Science 2025;40(13):e49-
Background:
Barriers to treatment with intravenous thrombolysis (IVT) for patients with acute ischemic stroke (AIS) in South Korea remain incompletely characterized. We analyze a nationwide prospective cohort to determine patient-level features associated with delayed presentation and non-treatment of potential IVT-eligible patients.
Methods:
We identified consecutive patients with AIS from 01/2011 to 08/2023 from a multicenter and prospective acute stroke registry in Korea. Patients were defined as IVT candidates if they presented within 4.5 hours from the last known well, had no lab evidence of coagulopathy, and had National Institute of Health Stroke Scale (NIHSS) ≥ 4. Multivariable generalized linear mixed regression models were used to investigate the associations between their characteristics and the IVT candidates or the use of IVT among the candidates.
Results:
Among 84,103 AIS patients, 41.0% were female, with a mean age of 69 ± 13 years and presentation NIHSS of 4 [interquartile range, 1–8]. Out of these patients, 13,757 (16.4%) were eligible for IVT, of whom 8,179 (59.5%) received IVT. Female sex (adjusted risk ratio [RR], 0.90; 95% confidence interval [CI], 0.86–0.94) and lower years of education (adjusted RR, 0.90; 95% CI, 0.84–0.97 for 0–3 years, compared to ≥ 13 years) were associated with a decreased likelihood of presenting as eligible for IVT after AIS; meanwhile, young age (adjusted RR, 1.12; 95% CI, 1.01–1.24 for ≤ 44 years, compared to 75–84 years) was associated with an increased likelihood of being an IVT candidate. Among those who were eligible for IVT, only age was significantly associated with the use of IVT (adjusted RR, 1.09; 95% CI, 1.03–1.16 for age 65–74 and adjusted RR, 0.83; 95% CI, 0.76–0.90 for ≥ 85 years, respectively).
Conclusion
Most patients with AIS present outside IVT eligibility in South Korea, and only 60% of eligible patients were ultimately treated. We identified increased age, female sex and lower education as key features on which to focus interventions for improving IVT utilization.
4.Radiation-Induced Cavernous Malformation in the Cerebellum:Clinical Features of Two Cases
Hyoung Soo CHOI ; Chae-Yong KIM ; Byung Se CHOI ; Seung Hyuck JEON ; In Ah KIM ; Joo-Young KIM ; Kyu Sang LEE ; Gheeyoung CHOE
Brain Tumor Research and Treatment 2025;13(2):58-64
Radiation-induced cavernous malformations (RICMs) are rare but significant late complications of highdose radiation therapy, particularly in young survivors of brain tumors. This report presents two cases of RICMs following aggressive multimodal treatment, including surgery, chemotherapy, and radiation therapy. Case 1 was a 22-year-old male patient with medulloblastoma treated with craniospinal irradiation, tumor bed boost, and tandem autologous peripheral blood stem cell transplantation. Approximately 8 years after treatment completion, routine follow-up imaging revealed a small focal hemorrhage in the right cerebellum, consistent with an RICM. The lesion was asymptomatic and managed conservatively with regular imaging, showing spontaneous resolution over time, with a significant size reduction noted 9 years post-treatment. Case 2 describes a 32-year-old male with an intracranial germinoma treated with whole-ventricular irradiation. Three years after treatment, the patient developed a symptomatic hemorrhagic RICM near a pre-existing developmental venous anomaly. Surgical resection and Gamma Knife Surgery stabilized the lesion; however, residual symptoms, including tremors and gait disturbances, persisted, affecting the patient’s daily activities. These cases illustrate the diverse clinical courses of RICMs, ranging from spontaneous resolution to the necessity of surgical intervention, and emphasize the importance of long-term surveillance and tailored management strategies for late-onset complications.
5.Radiation-Induced Cavernous Malformation in the Cerebellum:Clinical Features of Two Cases
Hyoung Soo CHOI ; Chae-Yong KIM ; Byung Se CHOI ; Seung Hyuck JEON ; In Ah KIM ; Joo-Young KIM ; Kyu Sang LEE ; Gheeyoung CHOE
Brain Tumor Research and Treatment 2025;13(2):58-64
Radiation-induced cavernous malformations (RICMs) are rare but significant late complications of highdose radiation therapy, particularly in young survivors of brain tumors. This report presents two cases of RICMs following aggressive multimodal treatment, including surgery, chemotherapy, and radiation therapy. Case 1 was a 22-year-old male patient with medulloblastoma treated with craniospinal irradiation, tumor bed boost, and tandem autologous peripheral blood stem cell transplantation. Approximately 8 years after treatment completion, routine follow-up imaging revealed a small focal hemorrhage in the right cerebellum, consistent with an RICM. The lesion was asymptomatic and managed conservatively with regular imaging, showing spontaneous resolution over time, with a significant size reduction noted 9 years post-treatment. Case 2 describes a 32-year-old male with an intracranial germinoma treated with whole-ventricular irradiation. Three years after treatment, the patient developed a symptomatic hemorrhagic RICM near a pre-existing developmental venous anomaly. Surgical resection and Gamma Knife Surgery stabilized the lesion; however, residual symptoms, including tremors and gait disturbances, persisted, affecting the patient’s daily activities. These cases illustrate the diverse clinical courses of RICMs, ranging from spontaneous resolution to the necessity of surgical intervention, and emphasize the importance of long-term surveillance and tailored management strategies for late-onset complications.
6.Radiation-Induced Cavernous Malformation in the Cerebellum:Clinical Features of Two Cases
Hyoung Soo CHOI ; Chae-Yong KIM ; Byung Se CHOI ; Seung Hyuck JEON ; In Ah KIM ; Joo-Young KIM ; Kyu Sang LEE ; Gheeyoung CHOE
Brain Tumor Research and Treatment 2025;13(2):58-64
Radiation-induced cavernous malformations (RICMs) are rare but significant late complications of highdose radiation therapy, particularly in young survivors of brain tumors. This report presents two cases of RICMs following aggressive multimodal treatment, including surgery, chemotherapy, and radiation therapy. Case 1 was a 22-year-old male patient with medulloblastoma treated with craniospinal irradiation, tumor bed boost, and tandem autologous peripheral blood stem cell transplantation. Approximately 8 years after treatment completion, routine follow-up imaging revealed a small focal hemorrhage in the right cerebellum, consistent with an RICM. The lesion was asymptomatic and managed conservatively with regular imaging, showing spontaneous resolution over time, with a significant size reduction noted 9 years post-treatment. Case 2 describes a 32-year-old male with an intracranial germinoma treated with whole-ventricular irradiation. Three years after treatment, the patient developed a symptomatic hemorrhagic RICM near a pre-existing developmental venous anomaly. Surgical resection and Gamma Knife Surgery stabilized the lesion; however, residual symptoms, including tremors and gait disturbances, persisted, affecting the patient’s daily activities. These cases illustrate the diverse clinical courses of RICMs, ranging from spontaneous resolution to the necessity of surgical intervention, and emphasize the importance of long-term surveillance and tailored management strategies for late-onset complications.
7.Association of Age, Sex and Education With Access to the Intravenous Thrombolysis for Acute Ischemic Stroke
Yoona KO ; Beom Joon KIM ; Youngran KIM ; Jong-Moo PARK ; Kyusik KANG ; Jae Guk KIM ; Jae-Kwan CHA ; Tai Hwan PARK ; Kyungbok LEE ; Jun LEE ; Keun-Sik HONG ; Byung-Chul LEE ; Kyung-Ho YU ; Dong-Eog KIM ; Joon-Tae KIM ; Jay Chol CHOI ; Jee Hyun KWON ; Wook-Joo KIM ; Kyu Sun YUM ; Sung-Il SOHN ; Hyungjong PARK ; Sang-Hwa LEE ; Kwang-Yeol PARK ; Chi Kyung KIM ; Sung Hyuk HEO ; Moon-Ku HAN ; Anjail Z. SHARRIEF ; Sunil A. SHETH ; Hee-Joon BAE ;
Journal of Korean Medical Science 2025;40(13):e49-
Background:
Barriers to treatment with intravenous thrombolysis (IVT) for patients with acute ischemic stroke (AIS) in South Korea remain incompletely characterized. We analyze a nationwide prospective cohort to determine patient-level features associated with delayed presentation and non-treatment of potential IVT-eligible patients.
Methods:
We identified consecutive patients with AIS from 01/2011 to 08/2023 from a multicenter and prospective acute stroke registry in Korea. Patients were defined as IVT candidates if they presented within 4.5 hours from the last known well, had no lab evidence of coagulopathy, and had National Institute of Health Stroke Scale (NIHSS) ≥ 4. Multivariable generalized linear mixed regression models were used to investigate the associations between their characteristics and the IVT candidates or the use of IVT among the candidates.
Results:
Among 84,103 AIS patients, 41.0% were female, with a mean age of 69 ± 13 years and presentation NIHSS of 4 [interquartile range, 1–8]. Out of these patients, 13,757 (16.4%) were eligible for IVT, of whom 8,179 (59.5%) received IVT. Female sex (adjusted risk ratio [RR], 0.90; 95% confidence interval [CI], 0.86–0.94) and lower years of education (adjusted RR, 0.90; 95% CI, 0.84–0.97 for 0–3 years, compared to ≥ 13 years) were associated with a decreased likelihood of presenting as eligible for IVT after AIS; meanwhile, young age (adjusted RR, 1.12; 95% CI, 1.01–1.24 for ≤ 44 years, compared to 75–84 years) was associated with an increased likelihood of being an IVT candidate. Among those who were eligible for IVT, only age was significantly associated with the use of IVT (adjusted RR, 1.09; 95% CI, 1.03–1.16 for age 65–74 and adjusted RR, 0.83; 95% CI, 0.76–0.90 for ≥ 85 years, respectively).
Conclusion
Most patients with AIS present outside IVT eligibility in South Korea, and only 60% of eligible patients were ultimately treated. We identified increased age, female sex and lower education as key features on which to focus interventions for improving IVT utilization.
8.Association of Age, Sex and Education With Access to the Intravenous Thrombolysis for Acute Ischemic Stroke
Yoona KO ; Beom Joon KIM ; Youngran KIM ; Jong-Moo PARK ; Kyusik KANG ; Jae Guk KIM ; Jae-Kwan CHA ; Tai Hwan PARK ; Kyungbok LEE ; Jun LEE ; Keun-Sik HONG ; Byung-Chul LEE ; Kyung-Ho YU ; Dong-Eog KIM ; Joon-Tae KIM ; Jay Chol CHOI ; Jee Hyun KWON ; Wook-Joo KIM ; Kyu Sun YUM ; Sung-Il SOHN ; Hyungjong PARK ; Sang-Hwa LEE ; Kwang-Yeol PARK ; Chi Kyung KIM ; Sung Hyuk HEO ; Moon-Ku HAN ; Anjail Z. SHARRIEF ; Sunil A. SHETH ; Hee-Joon BAE ;
Journal of Korean Medical Science 2025;40(13):e49-
Background:
Barriers to treatment with intravenous thrombolysis (IVT) for patients with acute ischemic stroke (AIS) in South Korea remain incompletely characterized. We analyze a nationwide prospective cohort to determine patient-level features associated with delayed presentation and non-treatment of potential IVT-eligible patients.
Methods:
We identified consecutive patients with AIS from 01/2011 to 08/2023 from a multicenter and prospective acute stroke registry in Korea. Patients were defined as IVT candidates if they presented within 4.5 hours from the last known well, had no lab evidence of coagulopathy, and had National Institute of Health Stroke Scale (NIHSS) ≥ 4. Multivariable generalized linear mixed regression models were used to investigate the associations between their characteristics and the IVT candidates or the use of IVT among the candidates.
Results:
Among 84,103 AIS patients, 41.0% were female, with a mean age of 69 ± 13 years and presentation NIHSS of 4 [interquartile range, 1–8]. Out of these patients, 13,757 (16.4%) were eligible for IVT, of whom 8,179 (59.5%) received IVT. Female sex (adjusted risk ratio [RR], 0.90; 95% confidence interval [CI], 0.86–0.94) and lower years of education (adjusted RR, 0.90; 95% CI, 0.84–0.97 for 0–3 years, compared to ≥ 13 years) were associated with a decreased likelihood of presenting as eligible for IVT after AIS; meanwhile, young age (adjusted RR, 1.12; 95% CI, 1.01–1.24 for ≤ 44 years, compared to 75–84 years) was associated with an increased likelihood of being an IVT candidate. Among those who were eligible for IVT, only age was significantly associated with the use of IVT (adjusted RR, 1.09; 95% CI, 1.03–1.16 for age 65–74 and adjusted RR, 0.83; 95% CI, 0.76–0.90 for ≥ 85 years, respectively).
Conclusion
Most patients with AIS present outside IVT eligibility in South Korea, and only 60% of eligible patients were ultimately treated. We identified increased age, female sex and lower education as key features on which to focus interventions for improving IVT utilization.
9.Association of Age, Sex and Education With Access to the Intravenous Thrombolysis for Acute Ischemic Stroke
Yoona KO ; Beom Joon KIM ; Youngran KIM ; Jong-Moo PARK ; Kyusik KANG ; Jae Guk KIM ; Jae-Kwan CHA ; Tai Hwan PARK ; Kyungbok LEE ; Jun LEE ; Keun-Sik HONG ; Byung-Chul LEE ; Kyung-Ho YU ; Dong-Eog KIM ; Joon-Tae KIM ; Jay Chol CHOI ; Jee Hyun KWON ; Wook-Joo KIM ; Kyu Sun YUM ; Sung-Il SOHN ; Hyungjong PARK ; Sang-Hwa LEE ; Kwang-Yeol PARK ; Chi Kyung KIM ; Sung Hyuk HEO ; Moon-Ku HAN ; Anjail Z. SHARRIEF ; Sunil A. SHETH ; Hee-Joon BAE ;
Journal of Korean Medical Science 2025;40(13):e49-
Background:
Barriers to treatment with intravenous thrombolysis (IVT) for patients with acute ischemic stroke (AIS) in South Korea remain incompletely characterized. We analyze a nationwide prospective cohort to determine patient-level features associated with delayed presentation and non-treatment of potential IVT-eligible patients.
Methods:
We identified consecutive patients with AIS from 01/2011 to 08/2023 from a multicenter and prospective acute stroke registry in Korea. Patients were defined as IVT candidates if they presented within 4.5 hours from the last known well, had no lab evidence of coagulopathy, and had National Institute of Health Stroke Scale (NIHSS) ≥ 4. Multivariable generalized linear mixed regression models were used to investigate the associations between their characteristics and the IVT candidates or the use of IVT among the candidates.
Results:
Among 84,103 AIS patients, 41.0% were female, with a mean age of 69 ± 13 years and presentation NIHSS of 4 [interquartile range, 1–8]. Out of these patients, 13,757 (16.4%) were eligible for IVT, of whom 8,179 (59.5%) received IVT. Female sex (adjusted risk ratio [RR], 0.90; 95% confidence interval [CI], 0.86–0.94) and lower years of education (adjusted RR, 0.90; 95% CI, 0.84–0.97 for 0–3 years, compared to ≥ 13 years) were associated with a decreased likelihood of presenting as eligible for IVT after AIS; meanwhile, young age (adjusted RR, 1.12; 95% CI, 1.01–1.24 for ≤ 44 years, compared to 75–84 years) was associated with an increased likelihood of being an IVT candidate. Among those who were eligible for IVT, only age was significantly associated with the use of IVT (adjusted RR, 1.09; 95% CI, 1.03–1.16 for age 65–74 and adjusted RR, 0.83; 95% CI, 0.76–0.90 for ≥ 85 years, respectively).
Conclusion
Most patients with AIS present outside IVT eligibility in South Korea, and only 60% of eligible patients were ultimately treated. We identified increased age, female sex and lower education as key features on which to focus interventions for improving IVT utilization.
10.Current practices in peripheral blood stem cell processing and cryopreservation:a nationwide survey of Korean transplant centers
Soo‑Kyung KIM ; Jaeeun YOO ; Jong‑Han LEE ; Ha‑Eun LEE ; Jae‑Sook AHN ; Kyung‑Nam KOH ; Byung‑Sik CHO ; Seong‑Kyu PARK ; Ho Joon IM ; Hyunji LEE ; Sun‑Young KONG
Blood Research 2025;60():41-
Purpose:
Processing methods for hematopoietic stem cells vary significantly across institutions, with no standardized guidelines currently in place. This lack of standardization presents challenges in ensuring consistent quality and out‑ comes of stem cell transplantation procedures. This study investigated current practices in peripheral blood stem cell (PBSC) processing and storage among transplant centers in Korea to establish a foundation for the development of standardized guidelines.
Methods:
A comprehensive questionnaire was distributed to 46 hematopoietic stem cell transplantation centers in Korea, examining five key areas: PBSC collection procedures, use of cryopreservatives, cryopreservation protocols, quality control measures, and thawing protocols.
Results:
Analysis of the 29 responses revealed significant variations across different stages of PBSC handling. All centers used controlled-rate freezers, and 92.9% stored cells at temperatures below -150 ◦ C . However, other prac‑ tices varied widely. Additional post-collection processing was performed by 53.8% of respondents. DMSO concen‑ trations ranged from 5 to 15%, with diverse combinations of supplementary media. Notably, 28.6% of patients did not undergo post-thaw quality assessment tests.
Conclusion
This study identified significant heterogeneity in PBSC processing practices across Korean transplant centers. These findings underscore the need for evidence-based standardized guidelines to ensure consistent product quality and improve transplantation outcomes.

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