1.Serial KL-6 Changes in PD-1/PD-L1 Inhibitor-Related Pneumonitis in Non-small Cell Lung Cancer: A Single-Center Prospective Pilot Study
Jae Kyeom SIM ; Juwhan CHOI ; Sung Won CHANG ; Sang Hyuk KIM ; Jee Youn OH ; Kyung Hoon MIN ; Gyu Young HUR ; Hwan Seok YONG ; Jae Jeong SHIM ; Sung Yong LEE
Tuberculosis and Respiratory Diseases 2026;89(2):257-265
Background:
Programmed cell death 1/programmed cell death ligand 1 (PD-1/PD-L1) inhibitors are effective treatments for non-small cell lung cancer (NSCLC), but their use can lead to severe pneumonitis. This study aims to evaluate the utility of Krebs von den Lungen-6 (KL-6) for predicting and diagnosing PD-1/PD-L1 inhibitor-related pneumonitis in NSCLC patients.
Methods:
We conducted a prospective observational study at a university-affiliated tertiary hospital in Korea from February 2022 to June 2023. Baseline KL-6 levels were measured immediately before initiating PD-1/PD-L1 inhibitor therapy. In patients who developed pneumonitis, KL-6 levels were monitored every 1–2 weeks from the onset of pneumonitis. For patients without pneumonitis, KL-6 levels were measured every 6 weeks. We compared clinical characteristics and serial KL-6 levels between the pneumonitis and non-pneumonitis groups.
Results:
Eighteen patients were enrolled, with 11 developing pneumonitis. Baseline KL-6 levels did not significantly differ between the two groups (261 U/mL in the pneumonitis group vs. 373 U/mL in the non-pneumonitis group, p=0.375). In the pneumonitis group, KL-6 levels generally showed an upward trend, with a median of 412 U/mL at pneumonitis onset. Conversely, KL-6 levels in the non-pneumonitis group showed no clear overall change.
Conclusion
In this pilot study, baseline KL-6 was not clearly linked to PD-1/PD-L1 inhibitor-related pneumonitis in NSCLC patients. However, increases in KL-6 levels post-baseline were more frequently observed in patients who developed pneumonitis, including cases of all-cause pneumonitis.
2.Factors influencing the use of implantable cardioverter-defibrillators for primary prevention in ischemic cardiomyopathy according to implantation volume: a prospective multicenter registry
Tae-Hoon KIM ; Hee Tae YU ; Il-Young OH ; Eue-Keun CHOI ; Jung-Hoon SUNG ; Young Soo LEE ; Jong-Youn KIM ; Yong-Soo BAEK ; Junbeom PARK ; Boyoung JOUNG ;
International Journal of Arrhythmia 2026;27(1):e8-
Background and Objectives:
Primary prevention (PP) implantable cardioverter-defibrillator (ICD) therapy for ischemic cardiomyopathy (ICM) is underused in Asian countries, including South Korea. Both clinical and hospital factors may influence appropriate ICD use. We evaluated whether determinants of PP ICD implantation differ by hospital implantation volume.
Methods:
In this prospective, multicenter observational registry (blinded for review), patients eligible for PP ICD were enrolled. Factors associated with ICD implantation—clinical characteristics and hospital-level systems—were examined across 4 large-volume hospitals (≥ 15 implants during the study) and 12 small-volume hospitals (< 15). Multivariable logistic regression identified independent predictors.
Results:
Among 3,083 ICM patients (2,403 men; median age 70 years), PP ICD implantation rates were 10.8% in large-volume and 5.7% in small-volume hospitals. Across groups, male sex and chronic kidney disease independently predicted ICD implantation. Regarding hospital factors, non-monetary incentives for referral were the sole independent predictor in large-volume centers (odds ratio [OR], 3.55; 95% confidence interval [CI], 2.07–6.10;P < 0.001). In small-volume centers, heart failure conferences (OR, 12.73; 95% CI, 1.72–94.37;P = 0.013), structured education systems (OR, 11.72; 95% CI, 2.45–56.12; P = 0.02), and pacemaker clinics (OR, 11.4; 95% CI, 2.24–58.39; P = 0.003) were independently associated with implantation.
Conclusions
Clinical predictors of PP ICD use were consistent across hospital volumes, but hospital-level determinants differed. Referral incentives characterized large-volume centers, whereas conferences, education systems, and pacemaker clinics were key in smallvolume centers. Tailored institutional strategies by hospital volume may help close the PP ICD underuse gap and improve evidence-based implementation.
3.Prevalence and characteristics of impacted teeth in Korean orthodontic patients at ten university dental hospitals
Youn-Kyung CHOI ; Sung-Hun KIM ; Yong-Il KIM ; Seong-Sik KIM ; Soo-Byung PARK ; Dong-Soon CHOI ; Ho-Jin KIM ; Kyung-A KIM ; Mo-Hyeon LEE ; Sung-Hwan CHOI ; Sung-Kwon CHOI ; Kyungmin Clara LEE ; Young-Mi JEON ; Sewoong OH ; Seorin JEONG
The Korean Journal of Orthodontics 2025;55(3):234-241
Objective:
This study aimed to investigate the prevalence and characteristics of impacted teeth (ITs) in orthodontic patients at university dental hospitals in Korea.
Methods:
This study included 14,774 patients who visited the Department of Orthodontics at 10 university dental hospitals in Korea between 2020 and 2022 and underwent orthodontic diagnosis. The prevalence and characteristics of ITs were investigated using orthodontic diagnostic records, radiographs, and diagnostic casts.
Results:
The prevalence of ITs, excluding third molar impaction, in Korean orthodontic patients was 13.6% (n = 2,014).The prevalence of ITs in pediatric orthodontic patients was 24.5% (n = 1,614).Of these patients, 68.2% had one IT, 27.5% had two ITs, 24.3% had bilateral IT, and 75.7% had unilateral IT. The most frequent IT was the maxillary canine (50.1%), followed by the mandibular second molar (11.7%), and maxillary second premolar (9.6%). An abnormal eruption path (46.5%) was the most frequent etiology. Orthodontic traction after surgical exposure (70.6%) was the most frequent treatment option. Among the patients with ITs, 29.8% had other dental anomalies, such as tooth agenesis (8.7%), microdontia (8.0%), and supernumerary teeth (5.1%). Furthermore, 50.8% had complications such as cystic lesions (18.3%), transposition (17.7%), and root resorption (14.8%).Among the patients with maxillary canine impaction, 62.2% had labial maxillary canine impaction and 21.1% had palatal maxillary canine impaction.
Conclusions
The prevalence of ITs in Korean orthodontic patients at university dental hospitals was high, particularly in pediatric orthodontic patients.
4.A single center experience on clinical outcome of fundoplication in pediatric patients: a retrospective cohort study
Yuyoung OH ; Joong Kee YOUN ; Hee-Beom YANG ; Hyun-Young KIM ; Dayoung KO
Annals of Surgical Treatment and Research 2025;108(3):177-185
Purpose:
The study aimed to evaluate the characteristics and operative-related factors in children who underwent fundoplication, analyze surgical outcomes categorized by disease entity and surgical indication, and identify prognostic factors for reoperation risk.
Methods:
A total of 109 pediatric patients who underwent fundoplication between 2008 and 2022 were retrospectively analyzed. Patients were grouped by disease entity and surgical indication. Underlying diseases, comorbidities, sex, gestational age, birth weight, preoperative symptoms, and operation-related factors were examined. Outcomes were classified as short-term and long-term adverse events. We investigated differences in clinical outcomes according to disease entity and surgical indication. Then we statistically identified preoperative predictors for the risk of reoperation.
Results:
The most common disease entity was neurological impairment (n = 92). Pulmonary comorbidity (42.2%) and aspiration/regurgitation (87.2%) were the most common. Most surgeries were performed laparoscopically (86.2%). There were 12 short-term and 25 long-term adverse events, with long-term events occurred more frequently in the neurological impairment (NIP) group compared to the non-NIP group (P = 0.04). None of the factors showed a significant relationship with the risk of reoperation.
Conclusion
Neurologically impaired children were more likely to experience long-term adverse events postfundoplication. However, no significant predictors for reoperation risk were identified.
5.Post-blepharoplasty ectropion management: therapeutic benefits of platelet-rich plasma and polydeoxyribonucleotide injections
Hyung Woo WANG ; Han Earl LEE ; Seong Oh PARK ; Youn Hwan KIM
Archives of Aesthetic Plastic Surgery 2025;31(2):41-45
Background:
Ectropion, a common complication after lower blepharoplasty, causes significant patient discomfort and dissatisfaction, yet effective treatments remain lacking. In this study, we evaluated the efficacy of intradermal injections of polydeoxyribonucleotide (PDRN) and platelet-rich plasma (PRP) for scar regeneration and the rapid recovery of temporary ectropion following lower blepharoplasty.
Methods:
This retrospective study analyzed 21 cases of ectropion among 420 patients who underwent transcutaneous lower blepharoplasty between January 2020 and October 2022. PDRN and PRP were injected intradermally into the lower eyelid, with patients monitored at 1- or 2-week intervals. We investigated patient satisfaction, the total number of injections administered, and the time to complete improvement of the ectropion.
Results:
The average time for complete ectropion resolution was 9.3 weeks, with a relatively high patient satisfaction rating (mean, 4.3 out of 5). Ten primary cases responded well to a single injection, whereas all six patients with previous operations required two or more injections. The rate of improvement was faster than previously reported, likely due to the enhanced collagen synthesis and anti-inflammatory effects of PDRN, along with the tissue repair and angiogenic properties of PRP.
Conclusions
Intradermal injections of PDRN and PRP demonstrated promising results in rapidly resolving ectropion after lower blepharoplasty, thereby reducing patient discomfort and increasing overall satisfaction.
6.Prevalence and characteristics of impacted teeth in Korean orthodontic patients at ten university dental hospitals
Youn-Kyung CHOI ; Sung-Hun KIM ; Yong-Il KIM ; Seong-Sik KIM ; Soo-Byung PARK ; Dong-Soon CHOI ; Ho-Jin KIM ; Kyung-A KIM ; Mo-Hyeon LEE ; Sung-Hwan CHOI ; Sung-Kwon CHOI ; Kyungmin Clara LEE ; Young-Mi JEON ; Sewoong OH ; Seorin JEONG
The Korean Journal of Orthodontics 2025;55(3):234-241
Objective:
This study aimed to investigate the prevalence and characteristics of impacted teeth (ITs) in orthodontic patients at university dental hospitals in Korea.
Methods:
This study included 14,774 patients who visited the Department of Orthodontics at 10 university dental hospitals in Korea between 2020 and 2022 and underwent orthodontic diagnosis. The prevalence and characteristics of ITs were investigated using orthodontic diagnostic records, radiographs, and diagnostic casts.
Results:
The prevalence of ITs, excluding third molar impaction, in Korean orthodontic patients was 13.6% (n = 2,014).The prevalence of ITs in pediatric orthodontic patients was 24.5% (n = 1,614).Of these patients, 68.2% had one IT, 27.5% had two ITs, 24.3% had bilateral IT, and 75.7% had unilateral IT. The most frequent IT was the maxillary canine (50.1%), followed by the mandibular second molar (11.7%), and maxillary second premolar (9.6%). An abnormal eruption path (46.5%) was the most frequent etiology. Orthodontic traction after surgical exposure (70.6%) was the most frequent treatment option. Among the patients with ITs, 29.8% had other dental anomalies, such as tooth agenesis (8.7%), microdontia (8.0%), and supernumerary teeth (5.1%). Furthermore, 50.8% had complications such as cystic lesions (18.3%), transposition (17.7%), and root resorption (14.8%).Among the patients with maxillary canine impaction, 62.2% had labial maxillary canine impaction and 21.1% had palatal maxillary canine impaction.
Conclusions
The prevalence of ITs in Korean orthodontic patients at university dental hospitals was high, particularly in pediatric orthodontic patients.
7.Clinical Profiles of Multidrug-Resistant and Rifampicin-Monoresistant Tuberculosis in Korea, 2018–2021: A Nationwide Cross-Sectional Study
Jinsoo MIN ; Yousang KO ; Hyung Woo KIM ; Hyeon-Kyoung KOO ; Jee Youn OH ; Doosoo JEON ; Taehoon LEE ; Young-Chul KIM ; Sung Chul LIM ; Sung Soon LEE ; Jae Seuk PARK ; Ju Sang KIM
Tuberculosis and Respiratory Diseases 2025;88(1):159-169
Background:
This study aimed to identify the clinical characteristics of multidrug-resistant/ rifampicin-resistant tuberculosis (MDR/RR-TB) in the Republic of Korea.
Methods:
Data of notified people with tuberculosis between July 2018 and December 2021 were retrieved from the Korea Tuberculosis Cohort database. MDR/RR-TB was further categorized according to isoniazid susceptibility as follows: multidrug-resistant tuberculosis (MDR-TB), rifampicin-monoresistant tuberculosis (RMR-TB), and RR-TB if susceptibility to isoniazid was unknown. Multivariable logistic regression analysis was conducted to identify the factors associated with MDR/RR-TB.
Results:
Between 2018 and 2021, the proportion of MDR/RR-TB cases among all TB cases and TB cases with known drug susceptibility test results was 2.1% (502/24,447). The proportions of MDR/RR-TB and MDR-TB cases among TB cases with known drug susceptibility test results were 3.3% (502/15,071) and 1.9% (292/15,071), respectively. Among all cases of rifampicin resistance, 31.7% (159/502) were RMR-TB and 10.2% (51/502) were RR-TB. Multivariable logistic regression analyses revealed that younger age, foreigners, and prior tuberculosis history were significantly associated with MDR/ RR-TB.
Conclusion
Rapid identification of rifampicin resistance targeting the high-risk populations, such as younger generations, foreign-born individuals, and previously treated patients are necessary for patient-centered care.
8.Clinical Profiles of Multidrug-Resistant and Rifampicin-Monoresistant Tuberculosis in Korea, 2018–2021: A Nationwide Cross-Sectional Study
Jinsoo MIN ; Yousang KO ; Hyung Woo KIM ; Hyeon-Kyoung KOO ; Jee Youn OH ; Doosoo JEON ; Taehoon LEE ; Young-Chul KIM ; Sung Chul LIM ; Sung Soon LEE ; Jae Seuk PARK ; Ju Sang KIM
Tuberculosis and Respiratory Diseases 2025;88(1):159-169
Background:
This study aimed to identify the clinical characteristics of multidrug-resistant/ rifampicin-resistant tuberculosis (MDR/RR-TB) in the Republic of Korea.
Methods:
Data of notified people with tuberculosis between July 2018 and December 2021 were retrieved from the Korea Tuberculosis Cohort database. MDR/RR-TB was further categorized according to isoniazid susceptibility as follows: multidrug-resistant tuberculosis (MDR-TB), rifampicin-monoresistant tuberculosis (RMR-TB), and RR-TB if susceptibility to isoniazid was unknown. Multivariable logistic regression analysis was conducted to identify the factors associated with MDR/RR-TB.
Results:
Between 2018 and 2021, the proportion of MDR/RR-TB cases among all TB cases and TB cases with known drug susceptibility test results was 2.1% (502/24,447). The proportions of MDR/RR-TB and MDR-TB cases among TB cases with known drug susceptibility test results were 3.3% (502/15,071) and 1.9% (292/15,071), respectively. Among all cases of rifampicin resistance, 31.7% (159/502) were RMR-TB and 10.2% (51/502) were RR-TB. Multivariable logistic regression analyses revealed that younger age, foreigners, and prior tuberculosis history were significantly associated with MDR/ RR-TB.
Conclusion
Rapid identification of rifampicin resistance targeting the high-risk populations, such as younger generations, foreign-born individuals, and previously treated patients are necessary for patient-centered care.
9.A single center experience on clinical outcome of fundoplication in pediatric patients: a retrospective cohort study
Yuyoung OH ; Joong Kee YOUN ; Hee-Beom YANG ; Hyun-Young KIM ; Dayoung KO
Annals of Surgical Treatment and Research 2025;108(3):177-185
Purpose:
The study aimed to evaluate the characteristics and operative-related factors in children who underwent fundoplication, analyze surgical outcomes categorized by disease entity and surgical indication, and identify prognostic factors for reoperation risk.
Methods:
A total of 109 pediatric patients who underwent fundoplication between 2008 and 2022 were retrospectively analyzed. Patients were grouped by disease entity and surgical indication. Underlying diseases, comorbidities, sex, gestational age, birth weight, preoperative symptoms, and operation-related factors were examined. Outcomes were classified as short-term and long-term adverse events. We investigated differences in clinical outcomes according to disease entity and surgical indication. Then we statistically identified preoperative predictors for the risk of reoperation.
Results:
The most common disease entity was neurological impairment (n = 92). Pulmonary comorbidity (42.2%) and aspiration/regurgitation (87.2%) were the most common. Most surgeries were performed laparoscopically (86.2%). There were 12 short-term and 25 long-term adverse events, with long-term events occurred more frequently in the neurological impairment (NIP) group compared to the non-NIP group (P = 0.04). None of the factors showed a significant relationship with the risk of reoperation.
Conclusion
Neurologically impaired children were more likely to experience long-term adverse events postfundoplication. However, no significant predictors for reoperation risk were identified.
10.Post-blepharoplasty ectropion management: therapeutic benefits of platelet-rich plasma and polydeoxyribonucleotide injections
Hyung Woo WANG ; Han Earl LEE ; Seong Oh PARK ; Youn Hwan KIM
Archives of Aesthetic Plastic Surgery 2025;31(2):41-45
Background:
Ectropion, a common complication after lower blepharoplasty, causes significant patient discomfort and dissatisfaction, yet effective treatments remain lacking. In this study, we evaluated the efficacy of intradermal injections of polydeoxyribonucleotide (PDRN) and platelet-rich plasma (PRP) for scar regeneration and the rapid recovery of temporary ectropion following lower blepharoplasty.
Methods:
This retrospective study analyzed 21 cases of ectropion among 420 patients who underwent transcutaneous lower blepharoplasty between January 2020 and October 2022. PDRN and PRP were injected intradermally into the lower eyelid, with patients monitored at 1- or 2-week intervals. We investigated patient satisfaction, the total number of injections administered, and the time to complete improvement of the ectropion.
Results:
The average time for complete ectropion resolution was 9.3 weeks, with a relatively high patient satisfaction rating (mean, 4.3 out of 5). Ten primary cases responded well to a single injection, whereas all six patients with previous operations required two or more injections. The rate of improvement was faster than previously reported, likely due to the enhanced collagen synthesis and anti-inflammatory effects of PDRN, along with the tissue repair and angiogenic properties of PRP.
Conclusions
Intradermal injections of PDRN and PRP demonstrated promising results in rapidly resolving ectropion after lower blepharoplasty, thereby reducing patient discomfort and increasing overall satisfaction.

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