The immunologic phenotype of thrombi is associated with future vascular events after cerebral infarction

BACKGROUND

Thrombi retrieved from patients with acute ischemic stroke may contain prognostic information.

OBJECTIVE

To investigate the relationship between the immunologic phenotype of thrombi and future vascular events in patients with a stroke.

METHODS

This study included patients with acute ischemic stroke who underwent endovascular thrombectomy at Chung-Ang University Hospital in Seoul, Korea, between February 2017 and January 2020. Laboratory and histological variables were compared between patients with and without recurrent vascular events (RVEs). Kaplan-Meier analysis followed by the Cox proportional hazards model was used to identify factors related to RVE. Receiver operating characteristic (ROC) analysis was conducted to evaluate the performance of the immunologic score by combining immunohistochemical phenotypes to predict RVE.

RESULTS

A total of 46 patients were included in the study with 13 RVEs (mean±SD age, 72.8±11.3 years; 26 (56.5%) men). Thrombi with a lower percentage of programmed death ligand-1 expression (HR=11.64; 95% CI 1.60 to 84.82) and a higher number of citrullinated histone H3 positive cells (HR=4.19; 95% CI 0.81 to 21.75) were associated with RVE. The presence of high-mobility group box 1 positive cell was associated with reduced risk of RVE, but the association was lost after adjustment for stroke severity. The immunologic score, which consists of the three immunohistochemical phenotypes, showed good performance in predicting RVE (area under the ROC curve, 0.858; 95% CI 0.758 to 0.958).

CONCLUSIONS

The immunological phenotype of thrombi could provide prognostic information after stroke.

Analytical performance of the digital morphology analyzer Sysmex DI-60 for body fluid cell differential counts

BACKGROUND

Sysmex DI-60 (Sysmex, Kobe, Japan) is a digital morphology (DM) analyzer widely used in clinical laboratories and supports body fluid (BF) applications. We evaluated analytical performance of DI-60 compared with XN-350 (Sysmex) and manual counting for BF cell differential counts.

METHODS

A total of 213 BF samples were collected (47 cerebrospinal fluid [CSF], 80 pleural fluid, and 86 ascites samples). The analytical performance of DI-60 for BF cell differential counts was evaluated based on sensitivity, specificity, accuracy, and agreement. BF cell differential counts obtained by DI-60 were compared with those obtained by XN-350 and manual counting.

RESULTS

The overall sensitivity was high for neutrophils, lymphocytes, and macrophages (range, 83.1-99.4%). The overall specificity and overall accuracy were high for all cell types (range, 95.3-99.7% and 94.3-99.3%, respectively). The agreement between DI-60 pre-classification and verification was strong (κ = 0.89). The absolute mean differences between DI-60 verification and XN-350 ranged from 0.26 to 11.05, and differences between DI-60 verification and manual counting ranged from 0.01 to 4.76.

CONCLUSIONS

This is the first study to evaluate the performance of DI-60 compared with XN-350 and manual counting for BF cell differential counts. DI-60 showed reliable performance with CSF, pleural fluid, and ascites samples. For BF cell differential counts, DI-60 may be a better option than XN-350 and could be used for screening purposes in understaffed laboratories. To improve the hematology workflow for BF cell differential counting, the DM analyzer needs to be optimized by taking into account the laboratory situation and unmet needs, and the clinical laboratory needs to establish criteria for verification and manual slide review.

Erratum: Relationship Between MicroRNA Signature and Arterial Stiffness in Patients With Ischemic Stroke

This corrects the article on p. 28 in vol. 19, PMID: 36606643.

Relationship Between MicroRNA Signature and Arterial Stiffness in Patients With Ischemic Stroke

BACKGROUND AND PURPOSE

We investigated whether circulating microRNAs (miRNAs) is associated with arterial stiffness in patients with acute ischemic stroke.

METHODS

We recruited patients with acute ischemic stroke who were admitted to a university hospital stroke center and underwent carotid-femoral pulse wave velocity (cfPWV) measurement using SphygmoCor (AtCor Medical, Sydney, Australia) and brachial-ankle PWV using a volume-plethysmography device (VP-1000, Omron Colin, Komaki, Japan). Circulating miRNAs were measured in venous blood samples stored in EDTA. We selected five miRNAs (miR-17, miR-93, miR-450, miR-629, and let-7i) related to atherosclerosis based on a literature review. Pearson's correlation analysis was applied to the correlations between miRNAs and arterial stiffness parameters. Finally, multivariable linear regression analysis was performed to identify the independent factors for cfPWV.

RESULTS

This study included 70 patients (age=71.1±10.3 years [mean±SD], 29 females). The expression levels of miR-93 (r=-0.27, p=0.049) and let-7i (r=-0.27, p=0.039) were inversely correlated with cfPWV. Multivariable linear regression analysis including age, hypertension, and estimated glomerular filtration rate showed that let-7i was independently related with cfPWV (standardized coefficient=-0.262, p=0.036). Correlation analysis indicated that let-7i was positively associated with visceral muscle Hounsfield units on computed tomography (r=0.264, p=0.043).

CONCLUSIONS

The expression level of let-7i was independently related to arterial stiffness in patients with cerebral infarction, suggesting that it plays a pathophysiological role in atherosclerosis.

Impact of Metabolic Activity of Vertebra and Amygdala on Stroke Recurrence: A Prospective Cohort Study

BACKGROUND

Elevated metabolic activity of amygdala is known to be related to atherosclerotic cardiovascular event by increasing inflammatory cell production from bone marrow. We tried to identify the factors of metabolic activity in the amygdala, vertebrae, liver, spleen, and internal carotid artery related to the future vascular events after stroke.

METHODS

A total of 110 patients with acute stroke were included (72±10 years of age, 39% women) and underwent whole-body ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography between August 1, 2015 and February 28, 2020. We compared the FDG uptake in the amygdala, vertebrae, liver, spleen, and internal carotid artery between patients with and without recurrent vascular event. Cox proportional hazards model was used to identify factors related to recurrent stroke and vascular event.

RESULTS

During the median follow-up period of 18 months, 22 patients experienced vascular events, including 15 stroke recurrence. Patients with recurred vascular event had a significantly higher FDG uptake in the amygdala and vertebrae than those without. The Cox proportional hazard model including diabetes, renal function, and carotid stenosis showed that a higher FDG uptake in the amygdala was independently associated with total vascular events (hazard ratio, 3.11 [95% CI, 1.11-8.70]) and higher FDG uptake in the vertebrae with stroke recurrence (hazard ratio, 4.94 [95% CI, 1.29-18.9]).

CONCLUSIONS

The increased metabolic activities of the vertebrae and amygdala are related to future vascular event among stroke survivors.

Establishment of Reference Intervals of Cytokeratin 19 Fragment Antigen 21-1 in Korean Adults

Cytokeratin 19 fragment antigen 21-1 (CYFRA 21-1) is useful for predicting and monitoring non-small cell lung cancer prognosis. We established reference intervals (RIs) of CYFRA 21-1 in Korean adults, including those older than 60 years. Data of 4,098 apparently healthy subjects (age range, 20-87 years) were analyzed after excluding those with a history of malignancy, high tumor marker concentrations (except CYFRA 21-1), and/or abnormal findings on a chest computed tomography scan through medical chart review. After removing two outliers, RIs of CYFRA 21-1 were determined using data of 4,096 subjects based on the non-parametric method (2.5th and 97.5th percentiles) according to CLSI guidelines EP28-A3c. The subjects were divided into two and four groups according to sex and age (20-40, 41-50, 51-60, and >60 years), respectively, and the median CYFRA 21-1 concentration was compared between the groups. The RI of CYFRA 21-1 was 0.66-3.84 ng/mL, applicable to both men and women. Regardless of sex, the CYFRA 21-1 concentration increased with age, suggesting that age-dependent RIs of CYFRA 21-1 should be applied. Rather than using a single RI provided by the manufacturer, the RI of CYFRA 21-1 should be continually verified and established in each clinical laboratory.

Prevalence and detection of Tropheryma whipplei in the stools of Korean patients with diarrhea using real-time PCRs

BACKGROUND

The prevalence of Tropheryma whipplei varies depending on age, region, and underlying disease. We estimated the prevalence of T. whipplei in the stools of Korean patients with diarrhea using real-time PCR (RT-PCR) and compared three RT-PCR targets, rpoB, hsp65, and Dig15.

METHODS

A total of 1404 nucleic acid samples extracted from the stools of Korean patients with diarrhea were tested using an initial RT-PCR targeting T. whipplei-specific regions of 16S-23S rRNA intergenic spacer. Subsequently, the samples positive for the initial RT-PCR were tested using the follow-up RT-PCRs targeting rpoB, hsp65, and Dig15 and analyzed by sequencing to confirm the presence of T. whipplei. We estimated the prevalence of T. whipplei and compared them according to gender and age. We also compared the performance of three targets in the follow-up RT-PCRs.

RESULTS

T. whipplei was detected in 1.4% of all samples (20 of 1404), and there were no differences according to gender and age. In pediatric samples (≤ 19 years), T. whipplei was detected higher in children aged 6-19 than in those aged 1-5 (2.7% vs. 0.7%, P = 0.01). Sensitivities of the rpoB, hsp65, and Dig15 RT-PCR were 50.0%, 85.0%, and 95.0%, respectively; specificities were 100.0%, 100.0%, and 84.6%, respectively.

CONCLUSIONS

This is the first study that estimated the prevalence of T. whipplei in the stools of Korean patients with diarrhea. This study demonstrated the presence of T. whipplei in stools of Koreans, even though the bacterium was detected low. The RT-PCRs targeting hsp65 and Dig15 showed reliable performance, and a multiplex PCR including these targets is expected to be useful for T. whipplei detection.

Prediction of amyloid PET positivity via machine learning algorithms trained with EDTA-based blood amyloid-β oligomerization data

Background

The tendency of amyloid-β to form oligomers in the blood as measured with Multimer Detection System-Oligomeric Amyloid-β (MDS-OAβ) is a valuable biomarker for Alzheimer’s disease and has been verified with heparin-based plasma. The objective of this study was to evaluate the performance of ethylenediaminetetraacetic acid (EDTA)-based MDS-OAβ and to develop machine learning algorithms to predict amyloid positron emission tomography (PET) positivity.

Methods

The performance of EDTA-based MDS-OAβ in predicting PET positivity was evaluated in 312 individuals with various machine learning models. The models with various combinations of features (i.e., MDS-OAβ level, age, apolipoprotein E4 alleles, and Mini-Mental Status Examination [MMSE] score) were tested 50 times on each dataset.

Results

The random forest model best-predicted amyloid PET positivity based on MDS-OAβ combined with other features with an accuracy of 77.14 ± 4.21% and an F1 of 85.44 ± 3.10%. The order of significance of predictive features was MDS-OAβ, MMSE, Age, and APOE. The Support Vector Machine using the MDS-OAβ value only showed an accuracy of 71.09 ± 3.27% and F−1 value of 80.18 ± 2.70%.

Conclusions

The Random Forest model using EDTA-based MDS-OAβ combined with the MMSE and apolipoprotein E status can be used to prescreen for amyloid PET positivity.

Real-World Accuracy of a SARS-CoV-2 Rapid Diagnostic Tests in the Republic of Korea

Antigen rapid diagnostic tests (RDTs) became the most important tool for the diagnosis of the coronavirus disease 2019 (COVID-19), however there have been very few evaluations of the accuracy of the RDTs in actual use. In this study, we investigated the performance accuracy of the RDT, the STANDARD Q COVID-19 Ag (STANDARD Q), in the Republic of Korea. We collected a total of 5,792 results that underwent both RDT and reverse transcription polymerase chain reaction simultaneously, and overall sensitivity and specificity of the STANDARD Q were 57.6% and 99.9%, respectively. With binomial logistic regression analysis, we estimated that about half of the COVID-19 patients with a cycle threshold value of 25 for E and RdRP were RDT-negative. These results suggest that the clinical sensitivity of RDTs against severe acute respiratory syndrome coronavirus 2 is considerably low in a real-world setting, and we recommend that limitations of RDTs should be considered when setting up COVID-19 test strategies.

Arsenicicoccus cauae sp. nov., isolated from the blood of a pediatric gastroenteritis patient

A Gram-stain-positive coccus was isolated from the blood of a paediatric patient suffering from gastroenteritis. The taxonomic position of this catalase-positive, non-motile, non-spore-forming facultative anaerobe designated as strain MKL-02T was investigated using a polyphasic approach. Colonies grown on tryptic soy agar with 10 % sheep blood were circular, creamy yellow, and convex. Phylogenetic analysis based on 16S rRNA gene and whole-genome sequences revealed that this strain was most closely related to Arsenicicoccus bolidensis CCUG 47306T within the cluster of the genus Arsenicicoccus . Average nucleotide identity and digital DNA–DNA hybridization values between strain MKL-02T and A. bolidensis DSM 15745T, A. dermatophillus DSM 25571T and A. piscis DSM 22760T were 89.5 and 37.0 %, 79.6 and 22.4 %, and 75.9 and 21.0 %, respectively. The genomic size of strain MKL-02T was 3 423 857 bp with a 72.7 mol% G+C content. Growth was observed at 10–45 °C (optimum, 37–40 °C) and pH 6.0–10.0 (optimum, pH 7.0), in the presence of 0–10 % (w/v) NaCl (optimum, 0.5 %). Cells of strain MKL-02T were non-motile cocci and 0.50–0.60 µm long, as determined by transmission electron microscopy. The strain was catalase-positive and oxidase-negative. The major fatty acid type (>10 % of total) was C15 : 0. The polar lipid profile consisted of two unidentified phospholipids, three unidentified lipids and an unidentified aminophospholipid. The strain contained MK-8 (H4) as the predominant menaquinone. Based on phylogenetic and phenotypic considerations, it is proposed that strain MKL-02T be classified as a new species, named Arsenicicoccus cauae sp. nov. The type strain is MKL-02T (=NCCP 16967T=JCM 34624T).

Effect of iron deficiency without anaemia on days alive and out of hospital in patients undergoing valvular heart surgery

Comprehensive evidence regarding the treatment of non-anaemic iron deficiency in patients undergoing valvular heart surgery is lacking. This study aimed to investigate the association between non-anaemic iron deficiency and postoperative outcomes in these patients. We retrospectively analysed 321 patients of which 180 (56%) had iron deficiency (defined as serum ferritin < 100 ng.ml^-1 or < 300 ng.ml^-1 with transferrin saturation < 20%). While the iron-deficient group had lower pre-operative haemoglobin levels than the non-iron deficient group (median (IQR [range]) 134 (127-141 [120-172]) g.l^-1 , 143 (133-150 [120-179]) g.l^-1 , p = 0.001), there was no between-group difference in allogeneic red blood cell transfusion. Median (IQR [range]) days alive and out of hospital at postoperative day 90 was 1 day shorter in the iron-deficient group (80 (77-82 [9-85]) days vs. 81 (79-83 [0-85]) days, p = 0.026). In multivariable analysis, only cardiopulmonary bypass duration (p = 0.032) and intra-operative allogeneic red blood cell transfusion (p = 0.011) were significantly associated with reduced days alive and out of hospital at postoperative day 90. Iron deficiency did not exert any adverse influence on secondary outcomes except length of hospital stay. Our findings indicate that non-anaemic iron deficiency alone is not associated with adverse effects in patients undergoing valvular heart surgery when it does not translate into an increased risk of allogeneic transfusion.

Field evaluation of seven SARS-COV-2 antigen assays

There is a global demand for rapid diagnostic tests (RDTs) for Coronavirus disease 2019 (COVID-19), and the interest in their clinical compliance is growing. In this study, we evaluated the clinical compliance of seven different severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigen RDTs. Nasopharyngeal/oropharyngeal swab specimens from COVID-19-confirmed cases and reverse-transcription PCR (RT-PCR) screening were used to evaluate the performance of seven RDTs. Using the RT-PCR and RDT results, we predicted the cycle threshold (Ct) of each target gene (E, RdRP, and N genes) which 50% (Ct₅₀) and 95% (Ct₉₅) detection rates were achieved in the RDTs. A total of 482 specimens were enrolled in our study: 316 specimens from COVID-19-confirmed cases and 166 RT-PCR-negative specimens. The median values of Ct₅₀ and Ct₉₅ for the seven RDTs were in the ranges of ranged 24.3-30.9 and 19.3-22.6 for E, 25.5-31.5 and 20.9-24.0 for RdRP, and 26.8-32.3 and 22.7-25.7 for N, respectively. The RDTs showed acceptable compliance only for specimens with high viral burdens (Ct < 20). However, the false-negative rate increased by more than 50% for most of the RDTs in low-viral burden specimens (Ct> 30). These results suggest that RDTs should not be used without molecular assays for COVID-19 screening for asymptomatic patients because of their high false-negative rates.

Pan-Asian adaptation of the EHNS-ESMO-ESTRO Clinical Practice Guidelines for the diagnosis, treatment and follow-up of patients with squamous cell carcinoma of the head and neck

The most recent version of the European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, treatment and follow-up of squamous cell carcinoma (SCC) of the oral cavity, larynx, oropharynx and hypopharynx was published in 2020. It was therefore decided by both the ESMO and the Korean Society of Medical Oncology (KSMO) to convene a special, virtual guidelines meeting in July 2021 to adapt the ESMO 2020 guidelines to consider the potential ethnic differences associated with the treatment of SCCs of the head and neck (SCCHN) in Asian patients. These guidelines represent the consensus opinions reached by experts in the treatment of patients with SCCHN (excluding nasopharyngeal carcinomas) representing the oncological societies of Korea (KSMO), China (CSCO), India (ISMPO), Japan (JSMO), Malaysia (MOS), Singapore (SSO) and Taiwan (TOS). The voting was based on scientific evidence and was independent of the current treatment practices and drug access restrictions in the different Asian countries. The latter was discussed when appropriate. This manuscript provides a series of expert recommendations (Clinical Practice Guidelines) which can be used to provide guidance to health care providers and clinicians for the optimisation of the diagnosis, treatment and management of patients with SCC of the oral cavity, larynx, oropharynx and hypopharynx across Asia.

Estimation of Measurement Uncertainty of Factor Assays Using the Monte Carlo Simulation

OBJECTIVES

We aimed to quantify the measurement uncertainty (MU) for factor activities using the Monte Carlo simulation (MCS), which is a computational algorithm that simulates statistical sampling to obtain numerical results through complex mathematical calculations.

METHODS

The uncertainties of factor V (FV), factor VIII (FVIII), and factor X (FX) were simulated with two coagulation testing systems: ACL TOP 750 CTS (Instrumentation Laboratory) and STA Compact (Diagnostica Stago).

RESULTS

When the factor activities were 74% (FV), 68% (FVIII), and 89% (FX), the MUs were 3.5% (FV), 9.3% (VIII), and 2.8% (FX) for ACL TOP and 8.5% (FV), 18.2% (FVII), and 6.5% (FX) for STA Compact. MCS MUs were compared with MUs obtained from running actual samples (not simulated) using a method called the top-down approach. The MCS MU results were interchangeable with MUs from the top-down approach, except for FVIII from STA Compact.

CONCLUSIONS

The MCS procedure is well suited for the quantification of MUs for factor assays over the entire measurement range.

A Novel Species of the Genus Arsenicicoccus Isolated From Human Blood Using Whole-Genome Sequencing

Whole-genome sequencing (WGS) is an easily accessible and valuable tool in clinical microbiology, which can be used for identifying novel and rare species. We isolated gram-positive cocci from the blood of a pediatric patient, which could not be phenotypically identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) (BioMérieux, Marcy-l'Étoile, France). We could not identify the isolate to the species level using 16S ribosomal RNA (rRNA) sequencing. WGS was performed using the Illumina MiSeq platform (Illumina, San Diego, CA, USA); however, the subsequent genomic sequence database search using the TrueBac ID-Genome system (ChunLab, Inc., Seoul, Korea) did not yield any hits with an average nucleotide identity value >95.0%, which is the cut-off for species-level identification. Phylogenetic analysis suggested that the isolate belonged to a new Arsenicicoccus species, forming a subcluster with Arsenicicoccus bolidensis. Our data demonstrate that WGS allows a more accurate annotation of microbial genomes than other clinical microbiology tools, such as MALDI-TOF MS and 16S rRNA sequencing. This is the first report of the isolation of a novel Arsenicicoccus species from a clinical sample.

Clinical and epidemiologic characteristics of inconclusive results in SARS-CoV-2 RT-PCR assays

Background

Inconclusive results in SARS-CoV-2 molecular assays cause confusion among clinicians and delay appropriate infection prevention and control. In this study, we aimed to characterize the respiratory specimens associated with inconclusive SARS-CoV-2 molecular assay results.

Methods

We re-evaluated inconclusive specimens by 3 additional RT-PCR assays and attempted to detect subgenomic RNA (sgRNA) in these specimens.

Results

Among follow-up tests from confirmed SARS-CoV-2 cases, 36.3% of the inconclusive results were classified as presumptive positive results (45/124). However, none of the specimens from 36 screening cases was classified as a presumptive positive result. Among 160 inconclusive specimens, sgRNAs were detected in 78 samples (48.8%): 58 were confirmed cases (58/124, 46.8%) and 20 were screening cases (20/36, 55.6%).

Conclusions

The results of our study suggest the recommendation of considering inconclusive results as positive results for confirmed SARS-CoV-2 cases. In screening cases, viral remnants could be partially amplified in PCR assays, and these inconclusive results could be related to previous infections. In addition, sgRNAs were detected in about half of the inconclusive specimens; however, the clinical significance of sgRNA is not yet clear.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06534-5.

Characterization of the novel HLA-B*15:598 allele identified in a Korean individual by sequence-based typing

One nucleotide substitution in codon 169 of B*15:01:01:01 results in a novel allele, HLA-B*15:598.

Analysis of microRNA signatures in ischemic stroke thrombus

BACKGROUND

We investigated the microRNA expression pattern from thrombus retrieved by mechanical thrombectomy in acute stroke patients to understand the stroke mechanism.

METHODS

This study included acute ischemic stroke patients who had undergone intra-arterial thrombectomy at Chung-Ang University Hospital in Seoul, Korea between February 2016 and March 2019. The thrombus was retrieved and stored at -70℃ after obtaining informed consent. MicroRNA microarray analysis was performed for the patients with identified stroke mechanisms including (1) large artery atherosclerosis, (2) cardioembolism with atrial fibrillation, and (3) cardioembolism with valvular heart disease. The microRNAs derived from microarray analysis were validated by quantitative real-time polymerase chain reaction (qRT-PCR) from different patient populations. The correlation analysis was performed between microRNA levels and laboratory data to understand the functional relevance of the altered microRNA.

RESULTS

In total, 55 thrombi were obtained from 74 patients, and the microRNAs were analyzed in 45 samples. Microarray analysis of 2578 microRNAs revealed that 50 microRNAs were significantly altered among the three groups. Validation using qRT-PCR showed that miR-378f and miR-450b-5p were significantly elevated among the cardioembolic thrombi; both microRNAs were inversely correlated with the ejection fraction from echocardiography. Thrombi from patients with early neurological deterioration exhibited higher levels of miR-93-5p and lower levels of miR-629-5p than those from neurologically stable patients.

CONCLUSIONS

The microRNA expression pattern can provide information regarding the mechanism of stroke by reflecting the underlying pathological status of the organ from which the thrombus was derived.

Nivolumab with carboplatin, paclitaxel, and bevacizumab for first-line treatment of advanced nonsquamous non-small-cell lung cancer

BACKGROUND

This international, randomized, double-blind phase III study (ONO-4538-52/TASUKI-52) evaluated nivolumab with bevacizumab and cytotoxic chemotherapy as first-line treatment for nonsquamous non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Between June 2017 and July 2019, this study enrolled treatment-naïve patients with stage IIIB/IV or recurrent nonsquamous NSCLC without sensitizing EGFR, ALK, or ROS1 alterations. They were randomly assigned in a 1 : 1 ratio to receive nivolumab or placebo in combination with carboplatin, paclitaxel, and bevacizumab every 3 weeks for up to six cycles, followed by nivolumab/placebo with bevacizumab until progressive disease or unacceptable toxicity. The primary endpoint was progression-free survival (PFS) assessed by an independent radiology review committee (IRRC).

RESULTS

Overall, 550 patients from Japan, Korea, and Taiwan were randomized; of these patients, 273 and 275 received the nivolumab and placebo combinations, respectively. In the present preplanned interim analysis with a median follow up of 13.7 months, the IRRC-assessed median PFS was significantly longer in the nivolumab arm than in the placebo arm (12.1 versus 8.1 months; hazard ratio 0.56; 96.4% confidence interval 0.43-0.71; P < 0.0001). The PFS benefit was observed across all patients with any programmed death-ligand 1 (PD-L1) expression levels including PD-L1-negative patients. The IRRC-assessed objective response rates were 61.5% and 50.5% in the nivolumab and placebo arms, respectively. The incidence of treatment-related adverse events of grade 3 or 4 was comparable between the two arms; treatment-related adverse events leading to death were observed in five and four patients in the nivolumab and placebo arms, respectively.

CONCLUSION

The TASUKI-52 regimen should be considered a viable new treatment strategy for treatment-naïve patients with advanced nonsquamous NSCLC.

A novel germline mutation in hMLH1 in three Korean women with endometrial cancer in a family of Lynch syndrome: case report and literature review

BACKGROUND

Endometrial cancer is often the sentinel cancer in women with Lynch syndrome, among which endometrioid endometrial cancer is the most common. We found a Korean case of uterine carcinosarcoma associated with Lynch syndrome. And we reviewed 27 Korean women with endometrial cancer associated with Lynch syndrome already released in case report so far.

CASE PRESENTATION

The proband, a 45-year-old Korean woman received treatment for endometrioid adenocarcinoma. Her older sister and niece were treated for endometrioid adenocarcinoma and carcinosarcoma, respectively. Family history met the Amsterdam II criteria and immunohistochemical analysis revealed a loss of MLH1 and PMS2. They all harbored a previously unreported germline likely pathogenic variant in c.1367delC in MLH1. They underwent staging operations including total hysterectomy, bilateral salpingo-oophorectomy, pelvic/paraaortic lymph node dissection, and washing cytology. All three women were healthy without evidence of relapse for over 4 years.

CONCLUSION

This report indicates a novel germline c.1367delC variant in MLH1, and presents a Korean case of uterine carcinosarcoma associated with Lynch syndrome. Furthermore, the c.1757_1758insC variant in MLH1 was suggested as a founder mutation in Lynch syndrome in Korean women.

Performance evaluation of EuDx™ ufPCR Flu & RSV detection kit for detection of influenza A/B and respiratory syncytial virus

EuDx™ ufPCR Flu & RSV Detection Kit (EUDIPIA, Chungcheongbuk-do, Republic of Korea) is a recently developed molecular assay for simultaneously detecting influenza A/B and respiratory syncytial virus (RSV). We evaluated this assay in a clinical setting and demonstrated its excellent performance for diagnosing influenza A/B and RSV infections.

Performance evaluation of newly developed fluorescence immunoassay-based interferon-gamma release assay for the diagnosis of latent tuberculosis infection in healthcare workers

The ichroma™ IGRA-TB (Boditech Med Inc., Chuncheon, Republic of Korea) is an automated fluorescent immunoassay-based point-of-care interferon-gamma release assay for detecting latent tuberculosis infection. We evaluated this assay with 408 health care workers, and demonstrated its acceptable performances comparing to QuantiFERON-TB Gold-Plus (QFT-Plus; Qiagen, Germantown, MD).

Convolutional Neural Network to Stratify the Malignancy Risk of Thyroid Nodules: Diagnostic Performance Compared with the American College of Radiology Thyroid Imaging Reporting and Data System Implemented by Experienced Radiologists

BACKGROUND AND PURPOSE

Comparison of the diagnostic performance for thyroid cancer on ultrasound between a convolutional neural network and visual assessment by radiologists has been inconsistent. Thus, we aimed to evaluate the diagnostic performance of the convolutional neural network compared with the American College of Radiology Thyroid Imaging Reporting and Data System (TI-RADS) for the diagnosis of thyroid cancer using ultrasound images.

MATERIALS AND METHODS

From March 2019 to September 2019, seven hundred sixty thyroid nodules (≥10 mm) in 757 patients were diagnosed as benign or malignant through fine-needle aspiration, core needle biopsy, or an operation. Experienced radiologists assessed the sonographic descriptors of the nodules, and 1 of 5 American College of Radiology TI-RADS categories was assigned. The convolutional neural network provided malignancy risk percentages for nodules based on sonographic images. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were calculated with cutoff values using the Youden index and compared between the convolutional neural network and the American College of Radiology TI-RADS. Areas under the receiver operating characteristic curve were also compared.

RESULTS

Of 760 nodules, 176 (23.2%) were malignant. At an optimal threshold derived from the Youden index, sensitivity and negative predictive values were higher with the convolutional neural network than with the American College of Radiology TI-RADS (81.8% versus 73.9%, P = .009; 94.0% versus 92.2%, P = .046). Specificity, accuracy, and positive predictive values were lower with the convolutional neural network than with the American College of Radiology TI-RADS (86.1% versus 93.7%, P < .001; 85.1% versus 89.1%, P = .003; and 64.0% versus 77.8%, P < .001). The area under the curve of the convolutional neural network was higher than that of the American College of Radiology TI-RADS (0.917 versus 0.891, P = .017).

CONCLUSIONS

The convolutional neural network provided diagnostic performance comparable with that of the American College of Radiology TI-RADS categories assigned by experienced radiologists.

Blood Amyloid-β Oligomerization as a Biomarker of Alzheimer's Disease: A Blinded Validation Study

BACKGROUND

Oligomeric amyloid-β (Aβ) is one of the major contributors to the pathomechanism of Alzheimer's disease (AD); Aβ oligomerization in plasma can be measured using a Multimer Detection System-Oligomeric Aβ (MDS-OAβ) after incubation with spiked synthetic Aβ.

OBJECTIVE

We evaluated the clinical sensitivity and specificity of the MDS-OAβ values for prediction of AD.

METHODS

The MDS-OAβ values measured using inBlood™ OAβ test in heparin-treated plasma samples from 52 AD patients in comparison with 52 community-based subjects with normal cognition (NC). The inclusion criterion was proposed by the NINCDS-ADRDA and additionally required at least 6 months of follow-up from the initial clinical diagnosis in the course of AD.

RESULTS

The MDS-OAβ values were 1.43±0.30 ng/ml in AD and 0.45±0.19 (p < 0.001) in NC, respectively. Using a cut-off value of 0.78 ng/ml, the results revealed 100% sensitivity and 92.31% specificity.

CONCLUSION

MDS-OAβ to measure plasma Aβ oligomerization is a valuable blood-based biomarker for clinical diagnosis of AD, with high sensitivity and specificity.

Cupriavidus cauae sp. nov., isolated from blood of an immunocompromised patient

A novel Gram-stain-negative, facultative aerobic and rod-shaped bacterium, designated as MKL-01^T and isolated from the blood of immunocompromised patient, was genotypically and phenotypically characterized. The colonies were found to be creamy yellow and convex. Phylogenetic analysis based on 16S rRNA gene and whole-genome sequences revealed that strain MKL-01^T was most closely related to Cupriavidus gilardii LMG 5886^T, present within a large cluster in the genus Cupriavidus. The genome sequence of strain MKL-01^T showed the highest average nucleotide identity value of 92.1 % and digital DNA-DNA hybridization value of 44.8 % with the closely related species C. gilardii LMG 5886^T. The genome size of the isolate was 5 750 268 bp, with a G+C content of 67.87 mol%. The strain could grow at 10-45 °C (optimum, 37-40 °C), in the presence of 0-10 % (w/v) NaCl (optimum, 0.5%) and at pH 6.0-10.0 (optimum, pH 7.0). Strain MKL-01^T was positive for catalase and negative for oxidase. The major fatty acids were C_16 : 0, summed feature 3 (C_16 : 1  ω7c/C_16 : 1  ω6c and/or C_16 : 1  ω6c/C_16 : 1  ω7c) and summed feature 8 (C_18 : 1  ω7c and/or C_18 : 1  ω6c). The polar lipid profile consisted of phosphatidylglycerol, phosphatidylethanolamine, two unidentified phospholipids and one unidentified polar lipid. Moreover, strain MKL-01^T contained ubiquinone Q-8 as the sole respiratory quinone. Based on its molecular, phenotypic and chemotaxonomic properties, strain MKL-01^T represents a novel species of the genus Cupriavidus; the name Cupriavidus cauae sp. nov. is proposed for this strain. The type strain is MKL-01^T.

The impact of environmental variables on the spread of COVID-19 in the Republic of Korea

Corona virus disease 2019 (COVID-19) has been declared a global pandemic and is a major public health concern worldwide. In this study, we aimed to determine the role of environmental factors, such as climate and air pollutants, in the transmission of COVID-19 in the Republic of Korea. We collected epidemiological and environmental data from two regions of the Republic of Korea, namely Seoul metropolitan region (SMR) and Daegu-Gyeongbuk region (DGR) from February 2020 to July 2020. The data was then analyzed to identify correlations between each environmental factor with confirmed daily COVID-19 cases. Among the various environmental parameters, the duration of sunshine and ozone level were found to positively correlate with COVID-19 cases in both regions. However, the association of temperature variables with COVID-19 transmission revealed contradictory results when comparing the data from SMR and DGR. Moreover, statistical bias may have arisen due to an extensive epidemiological investigation and altered socio-behaviors that occurred in response to a COVID-19 outbreak. Nevertheless, our results suggest that various environmental factors may play a role in COVID-19 transmission.

Aβ Accumulation in Vmo Contributes to Masticatory Dysfunction in 5XFAD Mice

Alzheimer's disease (AD) shows various symptoms that reflect cognitive impairment and loss of neural circuit integrity. Sensory dysfunctions such as olfactory and ocular pathology are also observed and used as indicators for early detection of AD. Although mastication is suggested to correlate with AD progression, changes in the masticatory system have yet to be established in transgenic animal models of AD. In the present study, we have assessed pathologic hallmarks of AD with the masticatory behavior of 5XFAD mice. We found that masticatory efficiency and maximum biting force were decreased in 5XFAD mice, with no significant change in general motor function. Immunohistochemical analysis revealed significant accumulation of Aβ (amyloid β), increased microglia number, and cell death in Vmo (trigeminal motor nucleus) as compared with other cranial motor nuclei that innervate the orofacial region. Masseter muscle weight and muscle fiber size were also decreased in 5XFAD mice. Taken together, our results demonstrate that Aβ accumulation in Vmo contributes to masticatory dysfunction in 5XFAD mice, suggesting a close association between masticatory dysfunction and dementia.

Association of Bone Mineral Density to Cerebral Small Vessel Disease Burden

OBJECTIVE

To test the hypothesis that bone mineral loss is mechanistically related to cerebral small vessel disease (SVD), we investigated the relationship between bone mineral density and the prevalence and intensity of SVD among patients with stroke.

METHODS

We analyzed data of 1,190 consecutive patients with stroke who were >50 years of age and underwent both brain MRI and dual-energy x-ray absorptiometry from the stroke registry of Chung-Ang University Hospital in Seoul, Korea. The patients were categorized into 3 groups according to their bone mineral density (normal, osteopenia, and osteoporosis). White matter hyperintensities, silent lacunes, cerebral microbleeds, and extensive perivascular space were assessed from brain MRI. Multinomial logistic regression model was used to examine the association between osteoporosis and total SVD score. We also recruited 70 patients with stroke to study serum bone turnover markers and microRNAs related to both cerebral atherosclerosis and bone metabolism to understand bone and brain interaction.

RESULTS

Osteoporosis was determined among 284 patients (23.9%), and 450 patients (37.8%) had osteopenia. As bone mineral density decreased, total SVD score and the incidence of every SVD phenotype increased except strictly lobar cerebral microbleeds. Multinomial logistic regression analysis showed that osteoporosis was independently associated with severe SVD burden. The levels of microRNA-378f were significantly increased among the patients with osteoporosis and maximal total SVD score and positively correlated with parathyroid hormone and osteocalcin.

CONCLUSIONS

These findings suggest a pathophysiologic link between bone mineral loss and hypertensive cerebral arteriolar degeneration, possibly mediated by circulating microRNA.

Clinical Features, Epidemiology, and Climatic Impact of Genotype-specific Human Metapneumovirus Infections: Long-term Surveillance of Hospitalized Patients in South Korea

Background

Human metapneumovirus (hMPV) commonly causes upper and lower respiratory tract infections. Here, we performed long-term retrospective surveillance of hMPV infection among patients hospitalized in South Korea between 2007 and 2016 and investigated seasonal dynamics and clinical characteristics associated with each virus subtype/genotype.

Methods

Patient specimens were tested for hMPV and other respiratory viruses by commercial molecular assays. Medical records of hMPV-positive patients were reviewed, and hMPV subtype/genotype analysis was performed. We also collected meteorological data and analyzed relationships with hMPV activity.

Results

Of 23 694 specimens, 1275 (5.4%) were positive; among them, 94.0% were classified into 5 subtypes (A1, A2a, A2b, B1, and B2). Some clinical manifestations differed according to hMPV genotype; however, there was no correlation between hMPV subtype and clinical outcome. Viral activity peaked at 13–20 weeks (April and May) and was associated with climate-specific factors, including temperature, relative humidity, diurnal temperature variation, wind speed, and sunshine duration.

Conclusions

This large-scale, 10-year study provides valuable information about the clinical characteristics associated with hMPV subtypes and climate factors contributing to virus transmission.

Antibody kinetics and serologic profiles of SARS-CoV-2 infection using two serologic assays

Background

Coronavirus disease 2019 (COVID-19) is an emerging threat worldwide. This study aims to assess the serologic profiles and time kinetics of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in patients with COVID-19 using two immunoassays.

Methods

A total of 97 samples serially collected from 17 patients with COVID-19 and 137 negative control samples were analyzed for IgM and IgG against SARS-CoV-2 using the AFIAS COVID-19 Ab (Boditech Med Inc., Chuncheon, Republic of Korea) and the EDI^™ Novel Coronavirus COVID-19 ELISA Kit (Epitope Diagnostics, Inc., San Diego, CA).

Results

With both assays, IgM and IgG rapidly increased after 7 days post symptom onset (PSO). IgM antibody levels reached a peak at 15–35 d PSO and gradually decreased. IgG levels gradually increased and remained at similar levels after 22–35 d. The diagnostic sensitivities of IgM/IgG for ≤14d PSO were 21.4%/35.7~57.1% and increased to 41.2~52.9%/88.2~94.1% at >14 d PSO with specificities of 98.5%/94.2% for AFIAS COVID-19 Ab and 100.0%/96.4% for EDI^™ Novel Coronavirus COVID-19 ELISA Kit. Among 137 negative controls, 12 samples (8.8%) showed positive or indeterminate results.

Conclusions

The antibody kinetics against SARS-CoV-2 are similar to common findings of acute viral infectious diseases. Antibody testing is useful for ruling out SARS-CoV-2 infection after 14 d PSO, detecting past infection, and epidemiologic surveys.

Robot-Assisted Partial Nephrectomy for Treatment of Juxtaglomerular Cell Tumor of the Kidney: A Case Report

Background: A juxtaglomerular cell tumor (JGCT), or a reninoma, is a rare renal tumor that can cause secondary hypertension. This is the first reported JGCT that was resected through robotic surgery. Case: We present a case of a 27-year-old female patient with 1.35-cm-sized JGCT in the lower pole of the right kidney. We effectively removed a JGCT through robot-assisted partial nephrectomy without any complications. Conclusion: The robot-assisted partial nephrectomy procedure could be a suitable choice for JGCT resection.

A new aortoiliac calcification scoring system to predict grade C anastomotic leak following rectal cancer surgery

BACKGROUND

Aortoiliac calcification may be a surrogate marker of decreased visceral perfusion causing anastomotic leak (AL). The aim of this study was to evaluate the predictive role of aortoiliac calcification for AL after rectal cancer surgery.

METHODS

We enrolled patients with primary rectal cancer who had restorative resection at our institution between January 2013 and December 2015. An aortoiliac calcification score was calculated as the sum of calcification scores at the infrarenal aorta (0: no, 1: ≤ 3 cm, 2: > 3 cm) and the common iliac arteries (0: no, 1: unilateral, 2: bilateral). AL was classified into three grades: grade A, requiring no intervention; grade B, requiring therapeutic intervention without re-laparotomy; and grade C, requiring re-laparotomy. Clinicopathological characteristics were analyzed to identify risk factors for AL.

RESULTS

There were 583 patients. Three-hundred forty-five (59.2%) had an aortoiliac calcification score ≥ 3, and 37 (6.3%) patients experienced AL, in 30 cases (5.1%) grade C AL. Patients with an aortoiliac calcification score ≥ 3 had a higher incidence of grade C AL (6.7% vs. 2.9%, p = 0.045). Multivariate logistic regression analysis revealed that an aortoiliac calcification score ≥ 3 was an independent risk factor for grade C AL (odds ratio = 2.669, 95% confidence interval 1.066-6.686, p = 0.036).

CONCLUSIONS

Aortoiliac calcification may be considered a risk factor for grade C AL after rectal cancer surgery.

Comparative outcomes of robot-assisted minimally invasive versus open esophagectomy in patients with esophageal squamous cell carcinoma: a propensity score-weighted analysis

Robots are increasingly used in minimally invasive surgery. We evaluated the clinical benefits of robot-assisted minimally invasive esophagectomy (RAMIE) in comparison with the conventional open esophageal surgery. From 2012 to 2016, 371 patients with esophageal squamous cell carcinoma underwent an Ivor Lewis or McKeown procedure at our institution. Of these, 130 patients underwent laparoscopic gastric conduit formation followed by RAMIE, whereas 241 patients underwent conventional esophageal surgery, including laparotomy and open esophagectomy (OE). We compared the short- and long-term clinical outcomes of these patients using the propensity score-based inverse probability of treatment weighting technique (IPTW). Among the early outcomes, the OE group showed a higher incidence of pneumonia (P = 0.035) and a higher requirement for vasopressors (P = 0.001). Regarding the long-term outcomes, all-cause mortality was significantly higher (P = 0.001) and disease-free survival was lower (P = 0.006) in the OE group. Wound-related problems also occurred more frequently in the OE group (P = 0.020) during the long-term follow-up. There was no statistical intergroup difference in the recurrence rates (P = 0.191). The Cox proportional-hazard analysis demonstrated that wound problems (HR 0.16, 95% CI 0.02-0.57; P = 0.017), pneumonia (HR 0.23, 95% CI 0.06-0.68; P = 0.019), and use of vasopressors (HR 0.14, 95% CI 0.08-0.25; P = 0.001) were independent predictors of mortality. RAMIE could be a better surgical option for selected patients with esophageal squamous cell carcinoma.

Top-down and bottom-up approaches for the estimation of measurement uncertainty in coagulation assays

Background

The assessment of measurement uncertainty (MU) in clinical laboratories is essential to the reliable interpretation of results in clinical laboratories. However, despite the introduction of various methods for the expression of uncertainty in measurement, the MUs of coagulation tests have not been extensively studied. The aim of this study was to quantify the MU of various coagulation assays according to international guidelines and to report an expected confidence in the quality of coagulation assays.

Methods

We selected activated partial thromboplastin time, international normalized ratio (INR), protein C/S, antithrombin, fibrinogen, and Factor V/VIII/X to quantify the MUs of two coagulation testing systems: ACL TOP 750 CTS (Instrumentation Laboratory, Bedford, MA, USA) and STA Compact (Diagnostica Stago, Asnières-sur-Seine, France). We used international standards and interlaboratory comparison results in accordance with international guidelines in a top-down approach to the assessment of MU. For INR, MU was estimated in a bottom-up approach using reference thromboplastin and certified plasmas.

Results

Top-down approaches resulted in MUs between 3.3% and 21.3% for each measurand. In the bottom-up approach, MUs of INR values ranged from 10.9% to 26.4% and showed an upward trend as INR increased.

Conclusions

In this study, we were successful in quantifying MU of coagulation assays using practical methods. Our results demonstrated that top-down and bottom-up approaches were adequate for coagulation assays. However, some assays showed significant biases against international standards; therefore, standardization would be necessary to ensure more reliable patient results.

P1416 Clinical importance of consecutive transthoracic echocardiography in the patients with hypertrophic cardiomyopathy

Funding Acknowledgements

nothing

OnBehalf

nothing

Background

prediction of outcomes Hypertrophic cardiomyopathy (HCM) have been robustly analyzed with echocardiography. However, there is limited data of serial follow-up (FU) transthoracic echocardiography (TTE) to predict outcomes in patients with HCM.

Objectives

This study aim is to discover clinical predictors associated with consecutive TTE follow-up in patients with HCM.

Methods

From 2010 to 2016, 162 patients with HCM were enrolled retrospectively. Concentric LVH and others systolic disease related to wall thickness were excluded. Index TTE (baseline) was measured when firstly admitted in our hospital. FU TTE was analyzed at the end of follow-up, defined as the last recorded value in patients who did not develop events or the last recorded value before events developed.

Results

The average of FU TTE and clinical FU period was 3.7 ± 2.0 years. Clinical outcomes were defined as stroke, syncope, heart failure, arrhythmia and death. Interestingly, only baseline TR V max was a predictor for clinical outcome whereas the others echo parameters were not associated with events (Table 1). KM curve showed the TR Vmax ≥2.5m/s was also significant (log rank = 0.008, Fig 1.)

Conclusions Our study showed short-term FU TTE did not bring clinician with clinical benefits in the aspect of prediction for events. Only baseline TR V max was good correlation with cardiovascular outcomes and even in the survival analysis.

Serial TTE and changed values Total N = 162 index TTE (baseline) FU TTE Change of FU per year event no event p-value event no event p-value event no event p-value IVDd, mm 14 ± 4 15 ± 5 0.500 15 ± 5 14 ± 5 0.758 0.23 ± 0.51 -0.07 ± 1.27 0.200 LVIDd, mm 47 ± 5 48 ± 6 0.256 47 ± 7 48 ± 6 0.560 -0.22 ± 2.79 0.10 ± 2.27 0.444 LVEF, % 62 ± 5 61 ± 7 0.379 61 ± 6 61 ± 10 0.927 -0.43 ± 3.10 -0.04 ± 4.94 0.620 LAVI 43 ± 9 43 ± 8 0.879 57 ± 27 58 ± 23 0.849 0.53 ± 14.5 3.11 ± 7.2 0.134 EA ratio 0.9 ± 0.6 0.9 ± 0.6 0.782 1.0 ± 0.8 0.9 ± 0.6 0.595 -0.02 ± 0.76 0.003 ± 0.027 0.594 DT,ms 196 ± 58 201 ± 62 0.603 203 ± 91 217 ± 89 0.370 17 ± 57 5 ± 40 0.154 septal e` 4.4 ± 2.1 4.2 ± 1.6 0.585 4.4 ± 1.6 4.6 ± 1.7 0.438 0.24 ± 0.91 0.05 ± 0.65 0.190 E of e` 17 ± 11 17 ± 23 0.993 15 ± 9 15 ± 6 0.726 -0.48 ± 4.42 -1.66 ± 22.78 0.728 TR velocity 2.6 ± 0.5 2.4 ± 0.4 0.012 2.7 ± 0.6 2.6 ± 0.4 0.604 0.05 ± 0.30 0.04 ± 0.18 0.905 Max wall thickness 17 ± 3 18 ± 3 0.137 17 ± 4 17 ± 3 0.888 -0.01 ± 2.19 -0.18 ± 1.14 0.522

Abstract P1416 Figure. TR Vmax and CV outcomes in the KM curve

Assessing the measurement uncertainty of qualitative analysis in the clinical laboratory

Measurement uncertainty is a parameter that is associated with the dispersion of measurements. Assessment of the measurement uncertainty is recommended in qualitative analyses in clinical laboratories; however, the measurement uncertainty of qualitative tests has been neglected despite the introduction of many adequate methods. We herein provide an overview of three reasonable statistical methods for quantifying the measurement uncertainties of qualitative assays, namely Bayes’ theorem, the normal distribution method, and the information theoretic approach. Unlike in quantitative analysis, the measurement uncertainty of qualitative analysis is expressed using a conditional probability, likelihood ratio, and entropy. With the necessary theoretical background, the practical applications for clinical laboratories are also provided using statistical calculations. Using statistical approaches, we hope that our review will contribute to the use of measurement uncertainty in qualitative analyses in the clinical laboratory environment.

Hyperprogressive disease during PD-1/PD-L1 blockade in patients with non-small-cell lung cancer

BACKGROUND

Immune checkpoint blockade with Programmed cell death 1 (PD-1)/PD-L1 inhibitors has been effective in various malignancies and is considered as a standard treatment modality for patients with non-small-cell lung cancer (NSCLC). However, emerging evidence show that PD-1/PD-L1 blockade can lead to hyperprogressive disease (HPD), a flair-up of tumor growth linked to dismal prognosis. This study aimed to evaluate the incidence of HPD and identify the determinants associated with HPD in patients with NSCLC treated with PD-1/PD-L1 blockade.

PATIENTS AND METHODS

We enrolled patients with recurrent and/or metastatic NSCLC treated with PD-1/PD-L1 inhibitors between April 2014 and November 2018. Clinicopathologic variables, dynamics of tumor growth, and treatment outcomes were analyzed in patients with NSCLC who received PD-1/PD-L1 blockade. HPD was defined according to tumor growth kinetics (TGK), tumor growth rate (TGR), and time to treatment failure (TTF). Immunophenotyping of peripheral blood CD8+ T lymphocytes was conducted to explore the potential predictive biomarkers of HPD.

RESULTS

A total of 263 patients were analyzed. HPD was observed in 55 (20.9%), 54 (20.5%), and 98 (37.3%) patients according to the TGK, TGR, and TTF. HPD meeting both TGK and TGR criteria was associated with worse progression-free survival [hazard ratio (HR) 4.619; 95% confidence interval (CI) 2.868-7.440] and overall survival (HR, 5.079; 95% CI, 3.136-8.226) than progressive disease without HPD. There were no clinicopathologic variables specific for HPD. In the exploratory biomarker analysis with peripheral blood CD8+ T lymphocytes, a lower frequency of effector/memory subsets (CCR7-CD45RA- T cells among the total CD8+ T cells) and a higher frequency of severely exhausted populations (TIGIT+ T cells among PD-1+CD8+ T cells) were associated with HPD and inferior survival rate.

CONCLUSION

HPD is common in NSCLC patients treated with PD-1/PD-L1 inhibitors. Biomarkers derived from rationally designed analysis may successfully predict HPD and worse outcomes, meriting further investigation of HPD.

Age-Specific Cutoffs of the Sysmex UF-1000i Automated Urine Analyzer for Rapid Screening of Urinary Tract Infections in Outpatients

We investigated the usefulness of age-specific cutoffs for screening of urinary tract infections (UTIs) in Korean outpatients, using the automated urine analyzer UF-1000i (Sysmex, Kobe, Japan). We retrospectively reviewed outpatient medical records. Urine samples of 7,443 outpatients from January 2010 to December 2017 were analyzed using urine culture and UF-1000i. ROC curves were calculated for each UF-1000i parameter based on the culture results. There were 1,398 culture positive samples, 5,774 culture negative samples, and 271 contaminated samples. UF-1000i had an area under the curve of ≥0.9 in outpatients >15 years. The appropriate cutoffs, which are the sum of bacterial (B-A-C) and white blood cell (WBC) counts, were 297.10/µL (15–24 years), 395.65/µL (25–44 years), 135.65/µL (45–64 years), 67.95/µL (65–74 years), and 96.5/µL (≥75 years). B-A-C and WBC counts differed among the three most frequently identified bacteria (Escherichia coli, Klebsiella pneumoniae, and Enterococcus faecalis). The UF-1000i system is useful for applying age-specific cutoffs to screen for UTIs, thereby preventing antibiotic abuse and reducing antibiotic resistance. Future studies can explore how its B-A-C and WBC counts can facilitate selection of empirical antibiotics by distinguishing between gram-positive and gram-negative bacteria.

Analytical performance of newly developed rapid point-of-care test for the simultaneous detection of hepatitis A, B, and C viruses in serum samples

ABSTRACTBACKGROUND

Although immunoassays play a major role in the detection of hepatitis viruses, there is a need for a point-of-care (POC) test. We evaluated the EuDx-HE (A,B,C) kit (EUDIPIA, Cheongju, Korea), which detects anti-hepatitis A virus (HAV) immunoglobulin M (IgM), hepatitis B virus surface antigen (HBsAg), and anti-hepatitis C virus (HCV) immunoglobulin G (IgG) simultaneously using an immunochromatographic method within 15 minutes.

METHODS

A total of 1581 serum samples including 57, 477, and 451 samples positive for anti-HAV IgM, HBsAg, and anti-HBV IgG, respectively, were analyzed. We investigated the diagnostic accuracy of the EuDx-HE (A,B,C) kit by comparison with SD BIOLINE POC kits (Abbott, Chicago, IL) using Architect immunoassays as a reference method.

RESULTS

For anti-HAV IgM and HBsAg detection, the EuDx-HE (A,B,C) kit showed a higher sensitivity and a slightly lower specificity than the SD BIOLINE kit. For anti-HCV IgG detection, the EuDx-HE (A,B,C) kit had a higher sensitivity and a higher specificity than the SD BIOLINE kit. The agreement for positivity between the POC tests was >89.47%, with κ values of 0.844, 0.941, and 0.943 for HAV, HBV, and HCV, respectively.

CONCLUSION

The EuDx-HE (A,B,C) kit showed an acceptable clinical performance for detecting anti-HAV IgM, HBsAg, and anti-HCV.

Impact of bacterial and viral coinfection in community-acquired pneumonia in adults

Bacterial and viral coinfected community-acquired pneumonia (CAP) is poorly characterized in adults. The aim of this study was to investigate the influence of bacterial and viral coinfection in patients with CAP. A total of 235 adults who requested molecular tests of pneumonia and were diagnosed with CAP were enrolled in this study. Microbiological tests included blood and sputum cultures, PCR for bacterial and viral pathogens, antigen test for Streptococcus pneumoniae and the influenza virus, and antibody detection of Mycoplasma pneumonia. Of the 235 patients, 32 (13.6%) patients were coinfected with bacteria and virus. Among 64 severe CAP patients, the concurrent infections were confirmed in 14 patients (21.9%). The proportion of severe pneumonia was significantly higher in patients with coinfection, and they showed a significantly higher mortality rate. In conclusion, bacterial and viral coinfection in CAP is not a rare occurrence in adults. Viral and bacterial coinfections have an adverse impact on the severity of the pneumonia, and increase morbidity and mortality in patients with CAP.

•

13.6% CAP patients and 21.9% severe CAP patients were coinfected with bacteria and virus in adults.

•

Bacterial and viral coinfection may adversely impact the severity of pneumonia.

•

Concurrent infection also increases the morbidity in adult patients with CAP.

Effectiveness of Platelet Function Analyzer-100 for Laboratory Detection of Anti-Platelet Drug-Induced Platelet Dysfunction

BACKGROUND

High on-treatment platelet reactivity (HTPR) is the phenomenon wherein patients exhibit normal platelet activity in laboratory testing despite adequate adherence to anti-platelet treatment. We investigated the detection rates of Platelet Function Analyzer (PFA)-100 (Dade Behring AG, Düdingen, Switzerland) for drug-induced platelet dysfunction and analyzed potential contributors to HTPR with practical PFA-100 data over six years.

METHODS

We used data from 6,957 patients who underwent PFA-100 testing after receiving aspirin, clopidogrel, or non-steroidal anti-inflammatory drugs (NSAIDs). Of these, 6,163 patients were tested with only the collagen/epinephrine cartridge (Col/EPI) of PFA-100; 794 were tested with both Col/EPI and the collagen/ADP cartridge (Col/ADP). We calculated PFA-100 closure time (CT) for each drug and compared the clinical and laboratory characteristics of the patients with prolonged CTs and normal CTs (i.e., HTPR).

RESULTS

In Col/EPI, 73.2% (365/499), 72.6% (390/537), and 55.3% (3,442/6,228) patients showed prolonged CTs for aspirin, clopidogrel, and NSAIDs, respectively. In Col/ADP, prolonged CTs were observed in 37.4% (34/91), 43.2% (35/81), and 29.6% (200/676) of patients receiving aspirin, clopidogrel, and NSAIDs, respectively. Of the patients tested with both cartridges, 88.9% (48/54), 95.3% (41/43), and 89.0% (577/648) of the patients receiving aspirin, clopidogrel, and NSAIDs had prolonged CTs, and 10.0% (79/794) showed normal CTs regardless of drugs. For clopidogrel users (both cartridges), there were more patients with malignancies in the normal CT than prolonged CT group.

CONCLUSIONS

PFA-100 is not sufficiently effective for laboratory screening of drug-induced platelet dysfunction. Malignancy may contribute to clopidogrel-related HTPR in PFA-100.