Clinical and Genetic Characteristics of Early and Advanced Gastric Cancer.

Gastric cancer (GC) persists as the fourth most prevalent cause of global cancer-related mortality, presenting a challenge due to the scarcity of available therapeutic strategies. Precision medicine is crucial not only in the treatment but also in the management of GC. We performed gene panel sequencing with Oncomine focus assay comprising 52 cancer-associated genes and MSI analysis in 100 case-matched gastric cancer cases. A comprehensive analysis of clinical and genetic characteristics was conducted on these genetic results and clinicopathological findings. Upon comparison of clinicopathological characteristics, significant differences between early gastric cancer (EGC) and advanced gastric cancer (AGC) were observed in tumor location (p = 0.003), Lauren classification (p = 0.015), T stage (p = 0.000), and N stage (p = 0.015). The six most frequently mutated genes were PIK3CA (29%, 10/35), ERBB2 (17%, 6/35), KRAS (14%, 5/35), ALK (6%, 2/35), ESR1 (6%, 2/35), and FGFR3 (6%, 2/35). Regarding genetic variation, there was a tendency for the N stage to be higher in GC patients with mutated genes (p = 0.014). The frequency of mutations in GC patients was statistically significantly higher in AGC (n = 24) compared to EGC (n = 11) (odds ratio, 2.792; 95% confidence interval, 1.113 to 7.007; p = 0.026). Six of the ten GC patients carrying mutated genes and exhibiting MSI were classified into intestinal-type and undifferentiated GC, with the location of the tumor being in the lower-third. Among these patients, five harbored mutated PIK3CA, while the remaining patient had a mutation in ALK. Conclusions: AGC patients more frequently exhibited alterations of PIK3CA, KRAS, and ERBB2 as somatic oncogenic drivers, and displayed a higher prevalence of cumulative genetic events, including increased rates of PIK3CA mutations, enhanced detection of immunotherapy biomarkers, and mutations of the ESR1 gene.

Diversity of Clinical and Molecular Characteristics in Korean Patients with 16p11.2 Microdeletion Syndrome.

16p11.2 copy number variations (CNVs) are increasingly recognized as one of the most frequent genomic disorders, and the 16p11.2 microdeletion exhibits broad phenotypic variability and a diverse clinical phenotype. We describe the neurodevelopmental course and discordant clinical phenotypes observed within and between individuals with identical 16p11.2 microdeletions. An analysis with the CytoScan Dx Assay was conducted on a GeneChip System 3000Dx, and the sample signals were then compared to a reference set using the Chromosome Analysis Suite software version 3.1. Ten patients from six separate families were identified with 16p11.2 microdeletions. Nine breakpoints (BPs) 4-5 and one BP2-5 of the 16p11.2 microdeletion were identified. All patients with 16p11.2 microdeletions exhibited developmental delay and/or intellectual disability. Sixty percent of patients presented with neonatal hypotonia, but muscle weakness improved with age. Benign infantile epilepsy manifested between the ages of 7-10 months (a median of 8 months) in six patients (60%). Vertebral dysplasia was observed in two patients (20%), and mild scoliosis was noted in three patients. Sixty percent of patients were overweight. We present six unrelated Korean families, among which identical 16p11.2 microdeletions resulted in diverse developmental trajectories and discordant phenotypes. The clinical variability and incomplete penetrance observed in individuals with 16p11.2 microdeletions remain unclear, posing challenges to accurate clinical interpretation and diagnosis.

Accuracy Validation of the Elecsys HBsAg II Quant Assay and Its Utility in Resolving Equivocal Qualitative HBsAg Results.

Background and Objectives: There are reports of false qualitative HBsAg results, because of various causes, such as samples with low HBsAg concentrations that may produce false positives. The main aims of this study were to validate the analytical accuracy and to assess the utility of the Elecsys assay compared to that of the qualitative HbsAg assay as a screening test in resolving equivocal qualitative HbsAg results. Materials and Methods: The limit of blank (LoB), the limit of detection (LoD), the limit of quantification (LoQ), and linearity were estimated to validate the analytical accuracy of the Elecsys HBsAg II Quant assay. A total of 449 serum samples showing initial equivocal results (1-50 index) were evaluated by Elecsys HBsAg II Quant and ADVIA Centaur HBsAg II assays. Results: The LoQ of the assay was determined to be 0.050 IU/mL, as provided by the manufacturer. The Kappa agreement between the two assays was almost perfect, at 0.9669, despite seven discordant results. With a specificity of 100% at new cut-off index value ≥5.42, about 78 samples (17%, 78/449) with index value ≥5.42 were interpreted as positives without further duplicate tests, however the remaining 371 samples with index value <5.42 need to be confirmed with additional HBV marker assays. Conclusions: We confirm that the Elecsys HBsAg II Quant assay is accurate and sensitive for HBV infection and recommend it as an alternative confirmatory HBsAg assay for resolving equivocal qualitative HBsAg results.

N-acetylcysteine reduce the stress induced by cold storage of platelets: A potential way to extend shelf life of platelets.

The room temperature storage used for platelets worldwide leads to platelet storage lesion (PSL) and risk of bacterial growth, limiting platelet shelf life and safety in transfusion. Thus, there is a need for an alternative storage method that can serve as effective temperature storage for platelet concentrates (PCs). In the previous investigation, we have shown that N-acetylcysteine (NAC) is a potential candidate for an additive solution to retain platelet characteristics during cold storage for up to 5 days. However, the study partially describes the efficacy and has drawbacks to address. Here, we used the apheresis platelet product with 50 mM NAC and stored up to 10 days under refrigerated condition (4 ± 1 °C). Stored platelet concentrates were analyzed for critical parameters such as platelet activation, annexin V binding, sialic acid, reactive oxygen species (ROS), neuraminidase activity, and in vivo efficacy using Prkdcscid mice. Investigation observations revealed that PCs with NAC showed reduced platelet activation, annexin V binding, ROS production, and sialic acid levels. in vivo recovery of PCs showed similar recovery rates stored PCs irrespective of treatment or storage condition. However, on the tenth day after 24 h, recovery in room temperature stored concentrates was about 32 %, whereas in NAC treated refrigerated concentrates, it stands at 47 %. These observations indicate that NAC addition protects refrigerated concentrates during long-term storage retaining the platelet integrity. The study also suggests that extending PC storage beyond 10 days is practically accomplishable with efficacy similar to room temperature (RT) stored PCs.

SPA0355 prevents ovariectomy-induced bone loss in mice.

Estrogen withdrawal in post-menopausal women leads to overactivation of osteoclasts, which contributes to the development of osteoporosis. Inflammatory cytokines are known as one of mechanisms of osteoclast activation after estrogen deficiency. SPA0355 is a thiourea derivative that has been investigated for its antioxidant and anti-inflammatory activities. However, its efficacy in bone resorption has not been previously investigated. The aim of this study was to investigate the impact of SPA0355 on the development of osteoporosis and to explore its mode of action. In vitro experiments showed that SPA0355 inhibited receptor activator of NF-κB ligand (RANKL)-induced osteoclastogenesis in primary bone marrow-derived macrophages. This effect appears to be independent of estrogen receptor activation as ICI 180,782 failed to abrogate its effects on osteoclasts. Further signaling studies revealed that SPA0355 suppressed activation of the MAPKs, Akt, and NF-κB pathways. SPA0355 also increased osteoblastic differentiation, as evidenced by its effects on alkaline phosphatase activity and mineralization nodule formation. Intraperitoneal administration of SPA0355 to ovariectomized mice prevented bone loss, as verified by three-dimensional images and bone morphometric parameters derived from µCT analysis. Noticeably, SPA0355 did not show hepatotoxicity and nephrotoxicity and also had little effect on hematological parameters. Taken together, the results indicate that SPA0355 may protect against bone loss in ovariectomized mice by stimulation of osteoblast differentiation and by inhibition of osteoclast resorption. Therefore, SPA0355 is a safe and potential candidate for management of postmenopausal osteoporosis.

Dermabacter jinjuensis sp. nov., a novel species of the genus Dermabacter isolated from a clinical specimen.

A Gram-stain-positive, catalase-positive, facultatively anaerobic, non-motile, coryneform bacterium, designated strain 32T, was isolated from a closed pus sample from a patient having finger necrosis in Korea. Strain 32T was considered as representing a novel species according to its initial identification by matrix-assisted laser desorption/ionization-time-of-flight MS. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain 32T belonged to the genus Dermabacter and was closely related to Dermabacter hominis DSM 7083T (=ATCC 49369T) (98.34 % similarity). Optimal growth was observed at 30-40 °C and pH 7. Growth occurred in the presence of 0-6 % (w/v) NaCl. Menaquinones MK-8, MK-7 and MK-9 were the major respiratory quinones. The major polar lipids were phosphatidylethanolamine, phosphatidylcholine, glycolipid and two unknown lipids. The major cellular fatty acids were anteiso-C17 : 0, anteiso-C15 : 0, iso-C16 : 0 and iso-C15 : 0. The DNA G+C content of strain 32T was 62.58 mol%, and the mean level of DNA-DNA relatedness between strain 32T and D. hominis ATCC 49369T was 49±1.6 %. Based on the phenotypic and genotypic characteristics, strain 32T is confirmed to represent a novel species of the genus Dermabacter, for which the name Dermabacter jinjuensis sp. nov. is proposed. The type strain is 32T (=NCCP 16133T=DSM 101003T).

Evaluation of in vitro storage characteristics of cold stored platelet concentrates with N acetylcysteine (NAC).

Platelets play a vital role in hemostasis and thrombosis, and their demand and usage has multiplied many folds over the years. However, due to the short life span and storage constraints on platelets, it is allowed to store them for up to 7 days at room temperature (RT); thus, there is a need for an alternative storage strategy for extension of shelf life. Current investigation involves the addition of 50 mM N acetylcysteine (NAC) in refrigerated concentrates. Investigation results revealed that addition of NAC to refrigerated concentrates prevented platelet activation and reduced the sialidase activity upon rewarming as well as on prolonged storage. Refrigerated concentrates with 50 mM NAC expressed a 23.91 ± 6.23% of CD62P (P-Selectin) and 22.33 ± 3.42% of phosphotidylserine (PS), whereas RT-stored platelets showed a 46.87 ± 5.23% of CD62P and 25.9 ± 6.48% of phosphotidylserine (PS) after 5 days of storage. Further, key metabolic parameters such as glucose and lactate accumulation indicated reduced metabolic activity. Taken together, investigation and observations indicate that addition of NAC potentially protects refrigerated concentrates by preventing platelet activation, stabilizing sialidase activity, and further reducing the metabolic activity. Hence, we believe that NAC can be a good candidate for an additive solution to retain platelet characteristics during cold storage and may pave the way for extension of storage shelf life.

STS and PUDP Deletion Identified by Targeted Panel Sequencing with CNV Analysis in X-Linked Ichthyosis: A Case Report and Literature Review.

X-linked recessive ichthyosis (XLI) is clinically characterized by dark brown, widespread dryness with polygonal scales. We describe the identification of STS and PUDP deletions using targeted panel sequencing combined with copy-number variation (CNV) analysis in XLI. A 9-month-old infant was admitted for genetic counseling. Since the second day after birth, the infant's skin tended to be dry and polygonal scales had accumulated over the abdomen and upper extremities. The infant's maternal uncle and brother (who had also exhibited similar skin symptoms from birth) presented with polygonal scales on their trunks. CNV analysis revealed a hemizygous deletion spanning 719.3 Kb on chromosome Xp22 (chrX:7,108,996-7,828,312), which included a segment of the STS gene and exhibited a Z ratio of -2 in the proband. Multiplex ligation-dependent probe amplification (MLPA) confirmed this interstitial Xp22.31 deletion. Our report underscores the importance of implementing CNV screening techniques, including sequencing data analysis and gene dosage assays such as MLPA, to detect substantial deletions that encompass the STS gene region of Xq22 in individuals suspected of having XLI.

Evaluation of the Analytical Performance of Oncomine Lung cfDNA Assay for Detection of Plasma EGFR Mutations.

BACKGROUND: The clinical utility of circulating tumor DNA (ctDNA) in the early detection of tumor mutations for targeted therapy and the monitoring of tumor recurrence has been reported. However, the analytical validation of ctDNA assays is required for clinical application. METHODS: This study evaluated the analytical performance of the Oncomine Lung cfDNA Assay compared with the cobas®EGFR Mutation Test v2. The analytical specificity and sensitivity were estimated using commercially pre-certified reference materials. The comparative evaluation of the two assays was carried out using reference materials and plasma derived from patients diagnosed with lung cancer. RESULTS: Using 20 ng of input cell-free DNA (cfDNA), the analytical sensitivities for EGFR mutations with variant allele frequencies (VAFs) of 1% and 0.1% were 100% and 100%, respectively. With VAFs of 1.2% and 0.1% using 20 ng of input cfDNA, seven out of nine different mutations in six driver genes were identified in the Oncomine Lung cfDNA Assay. The two assays showed 100% concordance in 16 plasma samples clinically. Furthermore, various PIK3CA and/or TP53 mutations were identified only in the Oncomine Lung cfDNA Assay. CONCLUSIONS: The Oncomine Lung cfDNA Assay can be used to identify plasma EGFR mutations in patients with lung cancer, although further large-scale studies are required to evaluate the analytical validity for other types of aberrations and genes using clinical samples.

A Novel c.800G>C Variant of the ITM2B Gene in Familial Korean Dementia.

Mutations in ITM2B have been reported to be associated with several familial dementias, such as Familial British dementia and familial Danish dementia. These are autosomal dominant disorders characterized by progressive dementia with an onset at around the fifth decade of life. We describe a family with cognitive impairment caused by a novel ITM2B p.*267Serext*11 mutation. The probands presented with cognitive impairment and cerebral infarction. MRI revealed diffuse white matter hyperintensity and microbleeds. Amyloid deposition was not observed on amyloid positron emission tomography. Our case suggests that the BRI2 mutation impacts cognition regardless of amyloid-ß accumulation.

Acute myelomonocytic leukemia and T-lymphoblastic lymphoma as simultaneous bilineage hematologic malignancy treated with decitabine: A case report.

BACKGROUND: Simultaneous bilineage hematologic malignancies are rare; however, several cases of acute myeloid leukemia (AML) and T-lymphoblastic lymphoma (T-LBL) co-occurrence have been reported. A standard treatment for simultaneous AML and T-LBL has not yet been established, and its prognosis is very poor. Further studies to develop standard treatments are required to increase patient survival rates. CASE SUMMARY: A 69-year-old man complaining of pleuritic chest pain visited the emergency room. Computed tomography revealed multiple enlarged lymph nodes (LNs) in the neck and groin and pulmonary thromboembolism with pulmonary infarction. Furthermore, a peripheral blood smear performed due to leukocytosis revealed circulating blasts. Acute myelomonocytic leukemia (AMML) was diagnosed after bone marrow examination, and T-LBL positivity for terminal deoxynucleotidyl transferase, cluster of differentiation (CD)34, and CD4 was confirmed by cervical LN biopsy. Decitabine and dexamethasone were administered because he could not receive intensive chemotherapy due to poor performance status. Complete remission of AMML and T-LBL was achieved after 4 cycles of decitabine plus dexamethasone. CONCLUSION: We report the therapeutic effect of decitabine, a hypomethylating agent (HMA), in patients with concurrent bilineage hematologic malignancies and suggest that further studies are required to evaluate the therapeutic effect of HMAs on both lymphoid and bilineage hematologic malignancies.

Copy number variation analysis using next-generation sequencing identifies the CFHR3/CFHR1 deletion in atypical hemolytic uremic syndrome: a case report.

OBJECTIVES: Atypical hemolytic uremic syndrome (aHUS) is characterized by a triad of thrombocytopenia, microangiopathic hemolytic anemia, and acute renal failure resulting from platelet thrombi in the microcirculation of the kidney and other organs, in the absence of a preceding diarrheal illness. This report describes a case in which copy number variation (CNV) analysis using next-generation sequencing (NGS) identified the CFHR3/CFHR1 deletion in a patient with aHUS. METHODS: A 49-year-old Korean female was diagnosed with aHUS based on clinical findings, including schistocytes in peripheral blood and marked thrombocytopenia, suggesting the presence of thrombotic microangiopathy, elevated serum lactate dehydrogenase, and acute kidney injury. Sequence variants and CNV generated from NGS data were estimated to determine if there was a potential genetic cause. Multiplex ligation-dependent probe amplification (MLPA) was conducted to confirm the CFHR3/CFHR1 deletion identified by NGS with CNV analysis. RESULTS: No known or novel pathogenic single nucleotide variant or small insertion/deletion that would be predicted to have damaging effects that could lead to aHUS were identified. However, CNV analysis of NGS data identified the heterozygous CFHR3/CFHR1 deletion. MLPA confirmed this loss of one copy number between the CFHR3 and the CFHR1 genes on chromosome 1q31.3. CONCLUSION: We genetically diagnosed a Korean woman harboring a heterozygous CFHR3/CFHR1 deletion of a known causative gene for aHUS. Our report emphasizes the need for CNV analysis of NGS data and gene dosage assays, such as MLPA, to evaluate large-scale deletions or duplications and generate hybrid CFH genes in patients with suspected aHUS.

Targeted Panel Sequencing Identifies an Intronic c.5225-3C>G Variant of the FBN1 Gene Causing Sporadic Marfan Syndrome with Annuloaortic Ectasia.

Marfan syndrome (MFS) is a hereditary connective tissue disease whose clinical severity varies widely. Mutations of the FBN1 gene encoding fibrillin-1 are the most common genetic cause of Marfanoid habitus; however, about 10% of MFS patients are unaware of their genetic defects. Herein, we report a Korean patient with MFS and annuloaortic ectasia caused by an intronic c.5225-3C>G variant of the FBN1 gene identified by targeted panel sequencing. The reverse transcription analysis of FBN1 revealed that the intron 43 sequence from positions c.5297-1516 to c.5297-1 was retained at the coding sequence as a consequence of the c.5225-3C>G variant enhancing a cryptic splice acceptor site (c.5297-1518_5297-1517AG) in intron 43. The retained sequence of the part of intron 43 caused the same effect as insertion mutation (NM_000138.5:c.5297_c.5298ins5297-1516_5297-1), resulting in a frameshift mutation resulting in p.Ile1767Trpfs*3. The patient underwent an urgent modified Bentall operation with a 29 mm mechanical valve for annuloaortic ectasia and severe aortic valve regurgitation. This report emphasizes the need for functional investigations into the diagnostic workflows of certain diseases or gene panels with suspected high rates of intronic variants and potential pathogenic effects. Hence, further descriptions of individuals with intronic variants causing alternative splicing expected to have pathogenic effects at different transcript levels are crucial for improving our understanding.

Gene Panel Sequencing Identifies a Novel RYR1 p.Ser2300Pro Variant as Candidate for Malignant Hyperthermia with Multi-Minicore Myopathy.

Malignant hyperthermia (MH), a rare autosomal dominant pharmacogenetic disorder of skeletal muscle calcium regulation, is triggered by sevoflurane in susceptible individuals. We report a Korean having MH with multi-minicore myopathy functionally supported by RYR1-mediated intracellular Ca2+ release testing in B lymphocytes. A 14-year-old boy was admitted for the evaluation of progressive torticollis accompanied by cervicothoracic scoliosis. During the preoperative drape of the patient for the release of the sternocleidomastoid muscle under general anesthesia, his wrist and ankle were observed to have severe flexion contracture. The body temperature was 37.1 °C. To treat MH, the patient was administered a bolus of dantrolene intravenously (1.5 mg/kg) and sodium bicarbonate. After a few minutes, muscle rigidity, tachycardia, and EtCO2 all resolved. Next-generation panel sequencing for hereditary myopathy identified a novel RYR1 heterozygous missense variant (NM_000540.2: c.6898T > C; p.Ser2300Pro), which mapped to the MH2 domain of the protein, a hot spot for MH mutations. Ex vivo RYR1-mediated intracellular Ca2+ release testing in B lymphocytes showed hypersensitive Ca2+ responses to isoflurane and caffeine, resulting in an abnormal Ca2+ release only in the proband, not in his family members. Our findings expand the clinical and pathological spectra of information associated with MH with multi-minicore myopathy.

Case report: Compound heterozygosity in PKLR gene with a large exon deletion and a novel rare p.Gly536Asp variant as a cause of severe pyruvate kinase deficiency.

Red cell pyruvate kinase (PK) deficiency is the most common cause of hereditary nonspherocytic hemolytic anemia and the most frequent enzyme abnormality of the glycolytic pathway. To the best of our knowledge, this is the first Korean PK deficiency study that analyzes copy number variation (CNV) using next-generation sequencing (NGS). A 7-year-old girl with jaundice was admitted for evaluation of a persistent hemolytic anemia. The proband appeared chronically ill, showing a yellowish skin color, icteric sclera, hepatomegaly, and splenomegaly on physical examination. Sequence variants and CNV generated from NGS data were estimated to determine if there was a potential genetic cause. As a result, compound heterozygosity in the PKLR gene for a large exon deletion between exon 3 and exon 9 accompanied with a novel rare p.Gly536Asp variant located on exon 10 was identified as a cause of severe PK deficiency in the proband. The PK activity of the proband had been measured at the time of day 1, 21, and 28 after receiving transfusion to indirectly assume the effect of the transfused blood, and the results were 100.9%, 73.0%, and 48.5%, compared with average of normal controls, respectively. Our report emphasizes the need to perform complete CNV analysis of NGS data and gene dosage assays such as multiplex ligation-dependent probe amplification to evaluate large deletions or duplications/insertions of the PKLR gene in patients with suspected PK deficiency.

The Korean undiagnosed diseases program phase I: expansion of the nationwide network and the development of long-term infrastructure.

BACKGROUND: Phase I of the Korean Undiagnosed Diseases Program (KUDP), performed for 3 years, has been completed. The Phase I program aimed to solve the problem of undiagnosed patients throughout the country and develop infrastructure, including a data management system and functional core laboratory, for long-term translational research. Herein, we share the clinical experiences of the Phase I program and introduce the activities of the functional core laboratory and data management system. RESULTS: During the program (2018-2020), 458 patients were enrolled and classified into 3 groups according to the following criteria: (I) those with a specific clinical assessment which can be verified by direct testing (32 patients); (II) those with a disease group with genetic and phenotypic heterogeneity (353 patients); and (III) those with atypical presentations or diseases unknown to date (73 patients). All patients underwent individualized diagnostic processes based on the decision of an expert consortium. Confirmative diagnoses were obtained for 242 patients (52.8%). The diagnostic yield was different for each group: 81.3% for Group I, 53.3% for Group II, and 38.4% for Group III. Diagnoses were made by next-generation sequencing for 204 patients (84.3%) and other genetic testing for 35 patients (14.5%). Three patients (1.2%) were diagnosed with nongenetic disorders. The KUDP functional core laboratory, with a group of experts, organized a streamlined research pipeline covering various resources, including animal models, stem cells, structural modeling and metabolic and biochemical approaches. Regular data review was performed to screen for candidate genes among undiagnosed patients, and six different genes were identified for functional research. We also developed a web-based database system that supports clinical cohort management and provides a matchmaker exchange protocol based on a matchbox, likely to reinforce the nationwide clinical network and further international collaboration. CONCLUSIONS: The KUDP evaluated the unmet needs of undiagnosed patients and established infrastructure for a data-sharing system and future functional research. The advancement of the KUDP may lead to sustainable bench-to-bedside research in Korea and contribute to ongoing international collaboration.

Case Report: Novel Likely Pathogenic ACTN2 Variant Causing Heterogeneous Phenotype in a Korean Family With Left Ventricular Non-compaction.

Left ventricular non-compaction (LVNC) is a very rare primary cardiomyopathy with a genetic etiology, resulting from the failure of myocardial development during embryogenesis, and it carries a high risk of left ventricular dysfunction, thromboembolic phenomenon, and malignant arrhythmias. Here, we report the first case of familial LVNC in Korea, caused by a novel ACTN2 missense variant. We performed duo exome sequencing (ES) to examine the genome of the proband and his father. A 15-year-old boy was admitted for the evaluation of exertional dyspnea for 2 weeks. He was diagnosed with LVNC with a dilated cardiomyopathy phenotype [left ventricular end-diastolic dimension 60 mm, interventricular septal dimension 8.2 mm by transthoracic echocardiography (TTE)]. For the screening of familial cardiomyopathy, TTE and cardiac magnetic resonance imaging (cMRI) were performed, which revealed hypertrophic and isolated LVNC in the proband's father and sister, respectively. In particular, the cMRI revealed dense hypertrabeculation with focal aneurysmal changes in the apical septal wall in the proband's father. ES of the father-son duo identified a novel heterozygous c.668T>C variant of the ACTN2 gene (NM_001103.3:c.668T>C, p.Leu223Pro; no rsID) as the candidate cause of autosomal dominant LVNC. Sanger sequencing confirmed this novel variant in the proband, his father, and sister, but not in the proband's grandmother. Even within families harboring the same variant, a variable risk of adverse outcomes is common. Therefore, familial screening for patients with LVNC associated with ACTN2 variant should be performed for early detection of the LVNC phenotype associated with poor outcomes, such as dilated LVNC.

Paper-based multiplex analytical device for simultaneous detection of Clostridioides difficile toxins and glutamate dehydrogenase.

We report a new paper-based multiplex analytical device (mPAD) for simultaneous screening of three analytes (glutamate dehydrogenase, toxin A, and toxin B) known as biomarkers for Clostridioides difficile infection (CDI). To overcome the limitation of common rapid assays (e.g. lateral flow immunochromatographic and enzyme immunoassays) in terms of multiplexing, sensitivity, simplicity, and ease-of-use, the mPAD is constructed with a three dimensional (3D) configuration of paper components with a multi-channel design. Multiple fluidic paths developed with wax-patterned paper allow the simultaneous detection of glutamate dehydrogenase, toxin A, and toxin B without any cross-reactivity. The 3D fluidic network on the mPAD facilitates a self-operating test procedure for the mixing and addition of amplification reagents with a one-step sliding operation. The results of the multiplex CDI assay can be easily interpreted by the naked eye within 10 min, and are visually intensified over time resulting in up to 3-fold signal amplification. Our device exhibited remarkable analytical performances for the simultaneous detection of three CDI biomarkers, providing a sensitivity of 97%, specificity of 88%, accuracy of 95%, and limits of detection for glutamate dehydrogenase, toxin A, and toxin B of 0.16 ng mL-1, 0.09 ng mL-1, and 0.03 ng mL-1, respectively. These results indicate the high applicability and feasibility of mPAD for multiplex testing for CDI with the advantages of being simple, sensitive, inexpensive, user-friendly, and equipment-free.

Clinical Features and Risk Factors Associated With 30-Day Mortality in Patients With Pneumonia Caused by Hypervirulent Klebsiella pneumoniae (hvKP).

BACKGROUND: Reports on metastatic or invasive infections by hypervirulent Klebsiella pneumoniae (hvKP) have increased recently. However, the effects of its virulence on clinical course and outcomes in pneumonia patients have rarely been addressed. We assessed and compared the clinical features of hvKp and classic K. pneumoniae (cKP) strains isolated from patients with pneumonia caused by K. pneumoniae. We also investigated the effects of virulence factors and the K. pneumoniae capsular serotypes K1 and K2 on mortality. METHODS: In this retrospective study, we enrolled 91 patients diagnosed as having pneumonia caused by K. pneumoniae and obtained their demographic and clinical data from medical records. We evaluated genes for K1 and K2, antimicrobial susceptibility, and the virulence genes rmpA, iutA, entB, ybtS, kfu, mrkD, and allS. Strains that possessed rmpA and iutA were defined as hvKP (N=39), while the remaining were classified as cKP (N=52). Odds ratio (OR) for the risk factors associated with 30-day mortality was calculated using the binary logistic regression model. RESULTS: The 30-day mortality in all patients was 23.1%; it was 17.9% (7/39) in the hvKP group and 26.9% (14/52) in the cKP group (P=0.315). Bacteremia (OR=38.1; 95% confidence interval [CI], 2.5-570.2), altered mental status (OR=8.8; 95% CI, 1.7-45.0), and respiratory rate >30 breaths/min (OR=4.8; 95% CI, 1.2-20.0) were independent risk factors for 30-day mortality in all patients. CONCLUSIONS: Our results suggest that hypervirulence determinants do not have a significant effect on 30-day mortality in patients with pneumonia caused by K. pneumoniae.

Seroprevalence of Neutralizing Antibodies against Japanese Encephalitis Virus among Adolescents and Adults in Korea: A Prospective Multicenter Study.

The immunization schedule for the Japanese encephalitis (JE) vaccine in Korea is a two-dose primary series at 12-24 months of age, followed by booster doses 12 months after the second dose and at the ages of 6 and 12 years. Although the number of JE cases has markedly decreased after the universal vaccination program, JE predominantly occurs in adults. The aim of this study was to assess the age-specific prevalence of the JE-neutralizing antibody (NTAb) among adolescents and adults in Korea. A total of 1603 specimens were collected from a healthy Korean population above 15 years old in five provinces. The JE-NTAb titers were measured with the pseudotyped virus assay and considered to be positive at ≥ 1:50. The seropositivity of JE-NTAb was the highest in the 15-29 years category (>95%) and gradually began to decrease in the age group of 30-44 years (89.42%). The lowest and second lowest JE-NTAb seropositive rates were observed among those aged 70 years or older (59.77%) and those aged 55-59 years (75.24%), respectively. Subjects from Seoul exhibited the highest JE-NTAb titer in all age groups compared to other provinces. In conclusion, the JE-NTAb seropositive rates and titers have maintained appropriate levels in the general Korean population. We propose that adult immunization and boosters at 12 years of age against JE are not strongly recommended in Korea.