Resistance to hypomethylating agents (HMAs) in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) is a concerning problem. Polo-like kinase 1 (PLK1) is a key cell cycle modulator and is known to be associated with an activation of the PI3K pathway, which is related to the stabilization of DNA methyltransferase 1 (DNMT1), a target of HMAs. We investigated the effects of volasertib on HMA-resistant cell lines (MOLM/AZA-1 and MOLM/DEC-5) derived from MOLM-13, and bone marrow (BM) samples obtained from patients with MDS (BM blasts >5%) or AML evolved from MDS (MDS/AML). Volasertib effectively inhibited the proliferation of HMA-resistant cells with suppression of DNMTs and PI3K/AKT/mTOR and ERK pathways. Volasertib also showed significant inhibitory effects against primary BM cells from patients with MDS or MDS/AML, and the effects of volasertib inversely correlated with DNMT3B expression. The DNMT3B-overexpressed AML cells showed primary resistance to volasertib treatment. Our data suggest that volasertib has a potential role in overcoming HMA resistance in patients with MDS and MDS/ AML by suppressing the expression of DNMT3 enzymes and PI3K/AKT/mTOR and ERK pathways. We also found that DNMT3B overexpression might be associated with resistance to volasertib.

Background and Objectives: De-escalation of dual-antiplatelet therapy through dose reduction of prasugrel improved net adverse clinical events (NACEs) after acute coronary syndrome (ACS), mainly through the reduction of bleeding without an increase in ischemic outcomes. Whether the benefits of de-escalation are sustained in highly thrombotic conditions such as ST-elevation myocardial infarction (STEMI) is unknown. We aimed to assess the efficacy and safety of de-escalation therapy in patients with STEMI or non-STsegment elevation ACS (NSTE-ACS). Methods: This is a pre-specified subgroup analysis of the HOST-REDUCE-POLYTECH-ACS trial. ACS patients were randomized to prasugrel de-escalation (5 mg daily) or conventional dose (10 mg daily) at 1-month post-percutaneous coronary intervention. The primary endpoint was a NACE, defined as a composite of all-cause death, non-fatal myocardial infarction, stent thrombosis, clinically driven revascularization, stroke, and bleeding events of grade ≥2 Bleeding Academic Research Consortium (BARC) criteria at 1 year. Results: Among 2,338 patients included in the randomization, 326 patients were diagnosed with STEMI. In patients with NSTE-ACS, the risk of the primary endpoint was significantly reduced with de-escalation (hazard ratio [HR], 0.65; 95% confidence interval [CI], 0.48– 0.89; p=0.006 for de-escalation vs. conventional), mainly driven by a reduced bleeding. However, in those with STEMI, there was no difference in the occurrence of the primary outcome (HR, 1.04; 95% CI, 0.48–2.26; p=0.915; p for interaction=0.271). Conclusions Prasugrel dose de-escalation reduced the rate of NACE and bleeding, without increasing the rate of ischemic events in NSTE-ACS patients but not in STEMI patients.

Immune thrombocytopenia (ITP) is an autoimmune condition characterized by platelet destruction through antibody-mediated mechanism. ITP is one of the manifestations of a coronavirus disease, as well as an adverse event occurring after vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Several cases of ITP have been described after vaccination with two mRNA-based vaccines—BTN162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna)—against SARS-CoV-2. Herein, we report a case of ITP occurring after vaccination with ChAdOx1 adenovirus vector nCoV-19 (AstraZeneca) vaccine in Korea. A 66-year-old woman presented with multiple ecchymoses on both upper and lower extremities and gingival bleeding, appearing 3 days after receiving the first dose of ChAdOx1 nCoV-19. Her laboratory results showed isolated severe thrombocytopenia without evidence of combined coagulopathy. She was diagnosed with ITP and successfully treated with high-dose dexamethasone and intravenous immunoglobulin. Clinical suspicion to identify vaccinerelated ITP is important to promptly initiate appropriate treatment.

The optimal dose of beta blockers after acute myocardial infarction (MI) remains uncertain. We evaluated the effectiveness of low-dose nebivolol, a beta1 blocker and a vasodilator, in patients with acute MI. A total of 625 patients with acute MI from 14 teaching hospitals in Korea were divided into 2 groups according to the dose of nebivolol (nebistol®, Elyson Pharmaceutical Co., Ltd., Seoul, Korea): low-dose group (1.25 mg daily, n=219) and usual- to high-dose group (≥2.5 mg daily, n=406). The primary endpoints were major adverse cardiac and cerebrovascular events (MACCE, composite of death from any cause, non-fatal MI, stroke, repeat revascularization, rehospitalization for unstable angina or heart failure) at 12 months. After adjustment using inverse probability of treatment weighting, the rates of MACCE were not different between the low-dose and the usual- to high-dose groups (2.8% and 3.1%, respectively; hazard ratio: 0.92, 95% confidence interval: 0.38 to 2.24, p=0.860). The low-dose nebivolol group showed higher rates of MI than the usual- to high-dose group (1.2% and 0%, p=0.008). The 2 groups had similar rates of death from any cause (1.1% and 0.3%, p=0.273), stroke (0.4% and 1.1%, p=0.384), repeat PCI (1.2% and 0.8%, p=0.428), rehospitalization for unstable angina (1.2% and 1.0%, p=0.743) and for heart failure (0.6% and 0.7%, p=0.832). In patients with acute MI, the rates of MACCE for low-dose and usual- to high-dose nebivolol were not significantly different at 12-month follow-up.

BACKGROUND AND OBJECTIVES: In this second report from Korean percutaneous coronary intervention (K-PCI) registry, we sought to describe the updated information of PCI practices and Korean practice pattern of PCI (KP3). METHODS: In addition to K-PCI registry of 2014, new cohort of 2016 from 92 participating centers was appended. Demographic and procedural information, as well as in-hospital outcomes, of PCI was collected using a web-based reporting system. KP3 class C was defined as any strategy with less evidence from randomized trials and more aggressive for PCI than medical therapy or bypass-surgery. RESULTS: In 2016, total 48,823 PCI procedures were performed at 92 participating centers. Mean age of the patients was 65.7±11.6 years, and 71.7% were males. Overall patient characteristics and PCI practices in 2016 were similar to those in 2014. The biggest change was the decrease in the in-hospital occurrence of myocardial infarction (MI;1.6%→0.7%, p<0.001). Many associations between PCI volumes and demographic/procedural characteristics observed in 2014 have disappeared. The median of door-to-balloon time was 62 minutes, and 83.3% of ST-elevation MI patients received primary PCI within 90 minutes, while the median of total ischemic time was 168 minutes and patients who had total ischemic time within 120 and 180 minutes were 29.1% and 54.1%, respectively. The proportion of KP3 class C cases in non-acute coronary syndrome patients decreased from 13.5% in 2014 to 12.1% in 2016 (p<0.001). CONCLUSIONS: In this second report from K-PCI registry, we described the current practices of PCI and changes from 2014 to 2016 in Korea.
Cohort Studies ; Coronary Artery Disease ; Humans ; Korea ; Male ; Myocardial Infarction ; Percutaneous Coronary Intervention

BACKGROUND AND OBJECTIVES: In this second report from Korean percutaneous coronary intervention (K-PCI) registry, we sought to describe the updated information of PCI practices and Korean practice pattern of PCI (KP3). METHODS: In addition to K-PCI registry of 2014, new cohort of 2016 from 92 participating centers was appended. Demographic and procedural information, as well as in-hospital outcomes, of PCI was collected using a web-based reporting system. KP3 class C was defined as any strategy with less evidence from randomized trials and more aggressive for PCI than medical therapy or bypass-surgery. RESULTS: In 2016, total 48,823 PCI procedures were performed at 92 participating centers. Mean age of the patients was 65.7±11.6 years, and 71.7% were males. Overall patient characteristics and PCI practices in 2016 were similar to those in 2014. The biggest change was the decrease in the in-hospital occurrence of myocardial infarction (MI;1.6%→0.7%, p<0.001). Many associations between PCI volumes and demographic/procedural characteristics observed in 2014 have disappeared. The median of door-to-balloon time was 62 minutes, and 83.3% of ST-elevation MI patients received primary PCI within 90 minutes, while the median of total ischemic time was 168 minutes and patients who had total ischemic time within 120 and 180 minutes were 29.1% and 54.1%, respectively. The proportion of KP3 class C cases in non-acute coronary syndrome patients decreased from 13.5% in 2014 to 12.1% in 2016 (p<0.001). CONCLUSIONS In this second report from K-PCI registry, we described the current practices of PCI and changes from 2014 to 2016 in Korea.

The detailed kinetics of the cytomegalovirus (CMV)-specific T cell response in hematopoietic stem cell transplant (HCT) recipients have not yet been fully assessed. We evaluated these kinetics of CMV-specific T cell response and factors associated with high CMV-specific T cell responses 1 year after HCT. In HCT recipients, CMV pp65 and IE1-specific ELISPOT assay were performed before HCT (D0), and at 30 (D30), 90 (D90), 180 (D180), and 360 (D360) days after HCT. Of the 51 HCT recipients with donor-positive (D+)/recipient-positive (R+) serology, 26 (51%) developed CMV infections after HCT. The patterns of post-transplantation reconstitution for CMV-specific T cell response were classified into 4 types: 1) an initial decrease at D30 followed by gradual T cell reconstitution without CMV infection (35%), 2) an initial decrease at D30 followed by gradual T cell reconstitution preceded by CMV infection (35%), 3) failure of gradual or constant T cell reconstitution (26%), and 4) no significant T cell reconstitution (4%). There was no significant difference between ELISPOT counts of D360 and those of D0. High CMV-specific T cell responses at D360 were not associated with high CMV-specific T cell response at D0, CMV infection, ganciclovir therapy, graft versus host disease (GVHD), and immunosuppressant use. In conclusion, there are 4 distinct patterns of reconstitution of the CMV-specific T cell response after HCT. In addition, reconstituted donor-origin CMV-specific T cell responses appeared to be constant until day 360 after HCT, regardless of the level of the pre-transplant CMV-specific T cell response, CMV infection, and immunosuppressant use.
Cytomegalovirus ; Enzyme-Linked Immunospot Assay ; Follow-Up Studies* ; Ganciclovir ; Graft vs Host Disease ; Hematopoietic Stem Cell Transplantation* ; Hematopoietic Stem Cells* ; Kinetics* ; Theophylline

In the article, “The Practice Pattern of Percutaneous Coronary Intervention in Korea.Based on Year 2014 Cohort of Korean Percutaneous Coronary Intervention (K-PCI) Registry.” in Volume 47(3), page 320-327, indexed color of Class A and Class C has been changed.

PURPOSE: Malignant peripheral nerve sheath tumors (MPNSTs) are a rare subtype of sarcoma that occur spontaneously or in association with neurofibromatosis type 1 (NF-1). This study aimed to clinically differentiate these types of MPNSTs. MATERIALS AND METHODS: The study reviewed 95 patients diagnosed with and treated for MPNST at Yonsei University Health System, Seoul, Korea over a 27-year period. The clinical characteristics, prognostic factors, and treatment outcomes of sporadic MPNST (sMPNST) and NF-1 associated MPNST (NF-MPNST) cases were compared. RESULTS: Patients with NF-MPNST had a significantly lower median age (32 years vs. 45 years for sMPNST, p=0.012), significantly larger median tumor size (8.2 cm vs. 5.0 cm for sMPNST, p < 0.001), and significantly larger numbers of imaging studies and surgeries (p=0.004 and p < 0.001, respectively). The 10-year overall survival (OS) rate of the patients with MPNST was 52±6%. Among the patients with localized MPNST, patients with NF-MPNST had a significantly lower 10-year OS rate (45±11% vs. 60±8% for sMPNST, p=0.046). Univariate analysis revealed the resection margin, pathology grade, and metastasis to be significant factors affecting the OS (p=0.001, p=0.020, and p < 0.001, respectively). Multivariate analysis of the patients with localized MPNST identified R2 resection and G1 as significant prognostic factors for OS. CONCLUSION: NF-MPNST has different clinical features from sMPNST and requires more careful management. Further study will be needed to develop specific management plans for NF-MPNST.
Humans ; Korea ; Multivariate Analysis ; Neoplasm Metastasis ; Neurilemmoma* ; Neurofibromatoses* ; Neurofibromatosis 1* ; Pathology ; Sarcoma ; Seoul