Performance Validation of Three Scoring Systems for the Prediction of Thrombotic Microangiopathy Due to Severe ADAMTS13 Deficiency and the Response to Therapeutic Plasma Exchange: First Study in Korea.

Background: The BENTLEY score (B-S), French thrombotic microangiopathy (TMA) Reference Center score (FTMA-S), and PLASMIC score (PLASMIC-S) have been developed for TMA diagnostic prediction. We retrospectively validated their predictive performances in patients with severe (<10%) disintegrin and metalloprotease with thrombospondin type 1 motif, member 13 (ADAMTS13) deficiency in terms of the risk of TMA and response to therapeutic plasma exchange (TPE). Methods: The predictive performances of the three scoring systems were compared in 145 patients with suspected TMA who underwent ADAMTS13 activity tests between January 2014 and September 2022. The response to TPE and mortality in TMA-positive patients were compared after risk stratification, using the Mann-Whitney U and Fisher's exact tests. Results: The PLASMIC-S, FTMA-S, and B-S showed area under the curve values of 0.820, 0.636, and 0.513, respectively, for predicting TMA positivity in high-risk patients. The PLASMIC-S showed higher sensitivity (81.8%), negative predictive value (91.2%), positive predictive value (PPV; 66.7%), and accuracy (82.1%) than the FTMA-S (72.7%, 82.1%, 41.0%, and 60.0%, respectively) and B-S (4.6%, 70.2%, 50.0%, and 69.7%, respectively). The PLASMIC-S also showed higher specificity than the FTMA-S (82.2% vs. 54.5%). The modified PLASMIC-S, including lactate dehydrogenase/upper limit of normal ratios, increased the specificity, PPV, and accuracy to 97.0%, 92.3%, and 92.4%, respectively. In TMA-positive patients, high risk assessed by the PLASMIC-S predicted higher platelet recovery rates and less TPE sessions required for recovery than for those assessed at low-to-intermediate risk. Conclusions: PLASMIC-S is the preferred scoring system for detecting patients with TMA positivity and for prognosis before confirmation of ADAMTS13 activity.

Serotype Distribution and Antimicrobial Resistance of Streptococcus pneumoniae Causing Invasive Pneumococcal Disease in Korea Between 2017 and 2019 After Introduction of the 13-Valent Pneumococcal Conjugate Vaccine.

Background: Streptococcus pneumoniae is a serious pathogen causing various infections in humans. We evaluated the serotype distribution and antimicrobial resistance of S. pneumoniae causing invasive pneumococcal disease (IPD) after introduction of pneumococcal conjugate vaccine (PCV)13 in Korea and investigated the epidemiological characteristics of multidrug-resistant (MDR) isolates. Methods: S. pneumoniae isolates causing IPD were collected from 16 hospitals in Korea between 2017 and 2019. Serotyping was performed using modified sequential multiplex PCR and the Quellung reaction. Antimicrobial susceptibility tests were performed using the broth microdilution method. Multilocus sequence typing was performed on MDR isolates for epidemiological investigations. Results: Among the 411 S. pneumoniae isolates analyzed, the most prevalent serotype was 3 (12.2%), followed by 10A (9.5%), 34 (7.3%), 19A (6.8%), 23A (6.3%), 22F (6.1%), 35B (5.8%), 11A (5.1%), and others (40.9%). The coverage rates of PCV7, PCV10, PCV13, and pneumococcal polysaccharide vaccine (PPSV)23 were 7.8%, 7.8%, 28.7%, and 59.4%, respectively. Resistance rates to penicillin, ceftriaxone, erythromycin, and levofloxacin were 13.1%, 9.2%, 80.3%, and 4.1%, respectively. MDR isolates accounted for 23.4% of all isolates. Serotypes 23A, 11A, 19A, and 15B accounted for the highest proportions of total isolates at 18.8%, 16.7%, 14.6%, and 8.3%, respectively. Sequence type (ST)166 (43.8%) and ST320 (12.5%) were common among MDR isolates. Conclusions: Non-PCV13 serotypes are increasing among invasive S. pneumoniae strains causing IPD. Differences in antimicrobial resistance were found according to the specific serotype. Continuous monitoring of serotypes and antimicrobial resistance is necessary for the appropriate management of S. pneumoniae infections.

Research use only and cell population data items obtained from the Beckman Coulter DxH800 automated hematology analyzer are useful in discriminating MDS patients from those with cytopenia without MDS.

We investigated the performance of research use only/cell population data (RUO/CPD) items obtained from the Beckman Coulter DxH800 automated hematologic analyzer in discriminating MDS patients from cytopenic patients without MDS.Total of 14 routine CBC, 18 research use only (RUO) items, and 70 CPD items were obtained retrospectively at diagnosis. The results were then compared between 94 MDS patients and 100 cytopenic patients without MDS. In items with statistically significant differences, receiver operating characteristic (ROC) analysis was performed and the results were compared.Four CBC/RUO items [red cell distribution width-standard deviation (RDW-SD), immature reticulocyte fraction (IRF), mean sphered cell volume (MSCV), high light scatter reticulocytes (HLR)], and two CPD items [mean volume of neutrophils (NE-V-Mean) and mean volume of early granulated cells (EGC-V-Mean)] showed area-under the curve (AUC) scores > 0.750. Notably, four RUO/CPD items (MSCV > 81.4/HLR > 0.15%/NE-V-Mean > 145/EGC-V-Mean > 156) showed high sensitivity (91.9%/93.6%/88.1%/90.2%, respectively) in discriminating MDS patients from cytopenic patients without MDS. With these six items, scores ≥ 4 (defined as ≥ 4 items exceeding cutoff values out of six items) showed AUC scores/sensitivity/specificity/accuracy (0.891/87.3%/79.0%/83.0%, respectively).Six CBC/RUO/CPD items showed satisfactory AUC scores of > 0.750, and four RUO/CPD items showed high sensitivity in discriminating MDS patients from cytopenic patients without MDS. Scoring system with six items showed high sensitivity, specificity, and accuracy with decision criteria of ≥ 4 scores. Therefore, DxH800 RUO/CPD items would be useful in discriminating MDS patients from cytopenic patients without MDS.

Association of Carbapenemase-Producing Enterobacterales Detected in Stream and Clinical Samples.

Background: The spread of carbapenem-resistant Enterobacterales (CRE) strains has caused treatment failure and is a worldwide threat to public health. However, there are limited reports on the prevalence of carbapenemase-producing Enterobacterales (CPE) in aquatic environments and its association with clinical isolates. This study aimed to investigate the prevalence of CPE in a stream environment and its genetic relationship with clinical isolates in Korea. Methods: A total of 4,582 water samples were collected from 94 streams. Multiplex PCR and sequencing were used to detect and identify six carbapenemase genes. Multi-locus sequence typing (MLST) was performed to investigate the genetic relatedness between the environmental strains and clinical isolates. Results: A total of 133 CRE strains were isolated from the streams. Klebsiella pneumoniae was the most common CRE (45.9%), followed by Enterobacter cloacae complex (29.3%), Escherichia coli (13.5%), Raoultella ornithinolytica (5.3%), and Citrobacter freundii (2.3%). Ninety (67.7%) isolates carried carbapenemase genes. K. pneumoniae carbapenemase-2 (36.7%) and New Delhi metallo-ß-lactamase-5 (32.2%) were the common carbapenemases detected. Sequence type (ST)307 and ST11 K. pneumoniae strains harboring the bla KPC-2 gene were the most prevalent in stream and patient samples. Conclusion: CPE was highly prevalent in streams and closely related to the isolates obtained from patients. Therefore, continuous monitoring of stream environments is required to control the spread of carbapenem resistance.

Carbapenemase-producing Eenterobacterales from hospital environment and their relation to those from patient specimens.

BACKGROUND: The hospital environment can be an important source for the transmission of pathogens, However, there are rare reports revealing the contamination of carbapenemase-producing enterobacterales (CPE) in the hospital environment. The aim of this study was to investigate the presence of CPE in hospital environments and their relation to clinical strains. METHODS: Environmental samples were collected from three tertiary university hospitals between June 2017 and August 2019. The environmental samples were inoculated on CHROMagar™ KPC plates. A multiplex PCR and sequencing were used for six carbapenemase genes. Multi-locus sequence typing (MLST) was performed for CPE of Klebsiella pneumoniae, Escherichia coli, and Enterobacter cloacae complex from the environmental and clinical specimens. RESULTS: 20 carbapenem-resistant Enterobacteriaceae (CRE) strains were detected in the beds of patients, toilet bowl, sink, patient's gown, electromanometer, and keyboard. K. pneumoniae was the most common, followed by Serratia marcescens, E. cloacae complex, E. coli, and Citrobacter freundii. Nineteen CRE were CPE. Eighteen of 19 CPEs produced KPC-2 carbapenemase, and one CPE (E. coli) produced NDM-5. We confirmed that the STs of K. pneumoniae-producing KPC-2 (ST 307 and ST11) and E. coli producing KPC-2 (ST648) from hospital environment were the same as those from patients. CONCLUSION: We believe that the hospital environment can be an important route for CPE transmission. Therefore, continuous surveillance and management are needed to prevent hospital-acquired infections (HAI) by transmission of CPE.

Serotype Distribution and Antimicrobial Resistance of Salmonella Isolates in Korea between 2016 and 2017.

Salmonella is one of the major causes of food-borne infections. We investigated the serotype distribution and antimicrobial resistance of Salmonella isolates collected in Korea between January 2016 and December 2017. In total, 669 Salmonella isolates were collected from clinical specimens at 19 university hospitals. Serotyping was performed according to the Kauffmann-White scheme, and antimicrobial susceptibility was tested using Sensititre EUVSEC plates or disk diffusion. Among the strains, C (39.8%) and B (36.6%) were the most prevalent serogroups. In total, 51 serotypes were identified, and common serotypes were S. enterica serovar I 4,[5],12:i:- (16.7%), S. Enteritidis (16.1%), S. Bareilly (14.6%), S. Typhimurium (9.9%), and S. Infantis (6.9%). The resistance rates to ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole were 32.6%, 12.1%, and 8.4%, respectively. The resistance rates to cefotaxime and ciprofloxacin were 8.1% and 3.0%, respectively, while 5.4% were multidrug-resistant. S. enterica serovar I 4,[5],12:i:- and S. Enteritidis were highly prevalent, and there was an increase in rare serotypes. Multidrug resistance and ciprofloxacin resistance were highly prevalent. Periodic investigations of Salmonella serotypes and antimicrobial resistance are needed.

Neutrophil-Selective Fluorescent Probe Development through Metabolism-Oriented Live-Cell Distinction.

Human neutrophils are the most abundant leukocytes and have been considered as the first line of defence in the innate immune system. Selective imaging of live neutrophils will facilitate the in situ study of neutrophils in infection or inflammation events as well as clinical diagnosis. However, small-molecule-based probes for the discrimination of live neutrophils among different granulocytes in human blood have yet to be reported. Herein, we report the first fluorescent probe NeutropG for the specific distinction and imaging of active neutrophils. The selective staining mechanism of NeutropG is elucidated as metabolism-oriented live-cell distinction (MOLD) through lipid droplet biogenesis with the help of ACSL and DGAT. Finally, NeutropG is applied to accurately quantify neutrophil levels in fresh blood samples by showing a high correlation with the current clinical method.

Differences in Clinical Characteristics of Invasive Tracheobronchial Aspergillosis according to the Presence of Invasive Pulmonary Aspergillosis.

BACKGROUND: The association of invasive tracheobronchial aspergillosis (ITBA) with invasive pulmonary aspergillosis (IPA) is not well established. We aimed to compare clinical characteristics between patients who exhibited ITBA with IPA and those who exhibited isolated ITBA (iITBA). Additionally, the usefulness of serum or bronchial galactomannan (GM) tests in diagnosing ITBA was evaluated. METHODS: This retrospective single-center case-control study was conducted over a period of 4 years. Fifteen patients were enrolled after confirming the presence of ITBA using bronchoscopy-guided biopsy (iITBA, 7 vs. ITBA+IPA, 8). Clinical characteristics of patients and results obtained from serum or bronchial GM tests were compared between the two groups. Mortality was assessed using data collected from a 6-month follow-up period. RESULTS: The ITBA+IPA group showed a higher prevalence of hematologic malignancy (75% vs. 14%, p=0.029), a greater number of patients with multiple bronchial ulcers (75% vs. 14%, p=0.029), lower platelet counts (63,000/µL vs. 229,000/µL, p<0.001), and a mortality rate which was significantly higher (63% vs. 0%, p=0.026) than the iITBA group. In the ITBA+IPA group, 57% of patients tested positive according to the serum GM assay, whereas in the iITBA group, all patients tested negative (p=0.070). The bronchial GM level was high in both groups, but there was no significant difference between them. CONCLUSION: Patients with ITBA+IPA had a greater number of hematologic malignancies with lower platelet counts and a poorer prognosis than patients diagnosed with iITBA. Findings obtained from bronchoscopy and bronchial GM tests were more useful in diagnosing ITBA than the serum GM test results.

Prevalence and Characteristics of Carbapenemase-Producing Enterobacteriaceae in Three Tertiary-Care Korean University Hospitals between 2017 and 2018.

The aim of this study was to evaluate the prevalence and characteristics of carbapenemase-producing Enterobacteriaceae (CPE) from 3 tertiary-care Korean university hospitals between 2017 and 2018. Non-duplicated clinical isolates of Enterobacteriaceae showing resistance to any carbapenem agents were collected prospectively from 3 tertiary university hospitals between 2017 and 2018. The presence of carbapenemase genes was detected by multiplex PCR and sequencing for blaKPC, blaVIM, blaNDM, blaIMP, blaOXA, and blaGES was performed. Among the 690 potential carbapenem-resistant Enterobacteriaceae (CRE) isolates, 66.8% (N = 461) were CPE. The species distribution of CPE was as follows: Klebsiella pneumoniae was most common (75.9%), followed by Escherichia coli (15.0%), Citrobacter freundii (4.6%), Enterobacter cloacae (2.6%), Klebsiella. aerogenes (0.7%), and Klebsiella. oxytoca (0.4%). All 11 CPE genes were detected, particularly K. pneumoniae carbapenemase (KPC)-2 (87.6%), New Delhi metallo-ß-lactamase (NDM)-1 (7.4%), NDM-5 (1.7%), KPC-3 (1.3%), oxacillinase (OXA)-232 (1.1%), and OXA-181 (1.1%). Six isolates produced 2 or 3 carbapenemases. The majority of the carbapenemase-producing C. freundii tested positive for NDM-1. We confirmed a high proportion of CPE among the CRE isolates with a high prevalence of KCP-2-producing K. pneumoniae and E. coli. Therefore, there is a need for undertaking continuous surveillance to monitor the prevalence of CPE.

Distinct Clinical Features of Plasma Cell Myeloma Patients Exhibiting Dysmorphic Plasma Cells: Association with More Plasma Cells at Diagnosis.

Dysmorphic plasma cells are occasionally found in bone marrow (BM) aspirates of plasma cell myeloma (PCM) patients. We retrospectively analyzed the incidences of significant dysmorphic plasma cells (SDPC) presentations and their associations with clinical features in PCM patients. Total 91 PCM patients diagnosed from January 2013 to December 2017 at author's institution were enrolled. SDPC presentation was determined as ≥ 5% (SDPC5) or ≥ 10% (SDPC10) among total PC and clinical features of PCM patients were compared with respect to SDPC presentation status. Incidence of SDPC5/SDPC10 presentation was 39.6%/18.7%. Patients with SDPC5/SDPC10 showed significantly more BM PC (P = 0.004/0.020) and higher incidences of CKS1B gains (P = 0.022/0.001) and RB1 loss (P = 0.032 for SDPC10 only) at diagnosis than those without SDPC5/SDPC10. Patients with SDPC5/SDPC10 also showed significantly greater absolute BM PC (P = 0.007/0.034 and 0.047/0.049 for 1st and 2nd follow-up, respectively) and serum M-protein (P = 0.041/0.044 and 0.039/0.049 for 1st and 2nd follow-up, respectively) reductions after chemotherapy than those without SDPC5/SDPC10. SDPC5/SDPC10 presentation was confirmed as an independent predictor of BM PC ≥ 37.7% [hazard ratio (HR) 4.649/2.613, P = 0.005/0.039]. Our present study demonstrated that SDPC presentation would be an independent predictor of more BM PC at diagnosis in PCM patients. Associations between SDPC presentation and higher incidence of CKS1B gains and RB1 loss, greater PC/serum monoclonal protein reductions after chemotherapy were also identified. Association between SDPC presentation and favorable treatment response should be evaluated in more comprehensive study.

Performance Evaluation of Automated Immunohematology Analyzer IH-500 for Blood Bank Testing.

The automated immunohematology analyzer IH-500 (Bio-rad, Cressier FR, Switzerland) was developed recently for blood bank tests and this study evaluated performance of IH-500. 200 blood samples for ABO/Rh typing were collected. ABO/Rh typing results measured by IH-500 was compared with conventional manual methods. Antibody screening tests were performed with 100 samples using both IH-500 and the Ortho BioVue System, and results were compared. Antibody identification tests were conducted on 5 samples using both IH-500 and the Ortho BioVue System and results were compared. Crossmatching was performed with both IH-500 and conventional manual tube method using 4 patient serum samples and 10 blood cell donors, and 40 results were compared. Isoagglutinin titer of anti-A and anti-B was determined in 10 samples using both IH-500 and the automated analyzer Ortho AutoVue Innova and concordance rates were obtained. The concordance rates of ABO/Rh typing, antibody screening test, antibody identification test, and crossmatching between comparative manual methods and the IH-500 were all 100%. In the evaluation of isoagglutinin titer, 8 (80.0%) results out of 10 samples (80%) showed results within ± 1 titer between the IH-500 and the AutoVue Innova, which indicates the concordance rates of 80.0%. IH-500 reported results with two titers lower than Ortho AutoVue Innova in two samples. The IH-500 demonstrated good concordance rates and provided reliable results compared to comparative manual methods in the blood bank testing. IH-500 would be useful as a possible replacement for conventionally performed manual methods in blood bank testing.

Serotype Distribution and Antimicrobial Resistance of Invasive and Noninvasive Streptococcus pneumoniae Isolates in Korea between 2014 and 2016.

BACKGROUND: Several factors contribute to differences in Streptococcus pneumoniae serotype distribution. We investigated the serotype distribution and antimicrobial resistance of S. pneumoniae isolated between 2014 and 2016 in Korea. METHODS: We collected a total of 1,855 S. pneumoniae isolates from 44 hospitals between May 2014 and May 2016, and analyzed the serotypes by sequential multiplex PCR. We investigated the distribution of each serotype by patient age, source of the clinical specimen, and antimicrobial resistance pattern. RESULTS: The most common serotypes were 11A (10.1%), followed by 19A (8.8%), 3 (8.5%), 34 (8.1%), 23A (7.3%), and 35B (6.2%). The major invasive serotypes were 3 (12.6%), 19A (7.8%), 34 (7.8%), 10A (6.8%), and 11A (6.8%). Serotypes 10A, 15B, 19A, and 12F were more common in patients ≤5 years old, while serotype 3 was more common in patients ≥65 years old compared with the other age groups. The coverage rates of pneumococcal conjugate vaccine (PCV)7, PCV10, PCV13, and pneumococcal polysaccharide vaccine 23 were 11.8%, 12.12%, 33.3%, and 53.6%, respectively. Of the 1,855 isolates, 857 (46.2%) were multi-drug resistant (MDR), with serotypes 11A and 19A predominant among the MDR strains. The resistance rates against penicillin, cefotaxime, and levofloxacin were 22.8%, 12.5%, and 9.4%, respectively. CONCLUSIONS: There were significant changes in the major S. pneumoniae serotypes in the community. Non-PCV13 serotypes increased in patients ≤5 years old following the introduction of national immunization programs with the 10- and 13-polyvalent vaccines.

Risk factors for developing Mycobacterium kansasii lung disease: A case-control study in Korea.

Previous studies have suggested that development of Mycobacterium kansasii lung disease (MKLD) was associated with COPD, pneumoconiosis, aging, male, immunosuppression, alcohol, malignancy, and certain occupations such as mining and sandblasting. However, previous studies were outdated and used non-comparative statistical methods. We aimed to determine the current risk factors for developing MKLD in Korea by using appropriate statistical techniques.Eighty-six MKLD patients were identified through a search of the Ulsan University Hospital database between January 2010 and December 2014. These cases were matched with 172 controls who had normal respiratory systems in a health examination during the same period (matching variables, age and sex; case: control ratio of 1:2). Clinical and demographic characteristics were gathered by reviewing the medical record and telephone survey. Multivariate logistic regression analyses were performed to evaluate risk factors for developing MKLD.Multivariate analysis showed that occupation in heavy industries (adjusted odds ratio (aOR) 6.41, 95% confidence interval (CI) 2.19-18.74, P = .001) and low body mass index (BMI) (aOR [per kg/m] 0.73, 95% CI 0.63-0.85, P < .001) were independent risk factors for development of MKLD. Educational attainment more than high school was associated with a lower risk of MKLD development (aOR 0.22, 95% CI 0.08-0.63, P = .005).Employees in heavy industry and low BMI are independent risk factors for development of MKLD in Korea.

Induction of squamous cell carcinoma after MAP3K8 overexpression in murine salivry gland epithelial cells.

BACKGROUND: Salivary gland neoplasms are relatively rare and comprise only 1%-4% of all human neoplasms. Salivary gland neoplasms also show an extremely wide range of morphological diversity. Currently, the genetic alterations and corresponding molecular mechanisms underlying salivary gland neoplasms development remain largely unknown. METHOD: We generated an inducible Tet-MAP3K8::MMTV-rTA mouse model by crossing the MAP3K8 transgenic mice with MMTR-rTA transgenic mice to express MAP3K8 in the salivary gland. RESULTS: MAP3K8 overexpression in the murine salivary glands of Tet-MAP3K8::MMTR-rTA transgenic mice induces tumorigenesis. Pathological investigations reveal partial fibrosis and adenosis of salivary glands, and foci of atypical squamoid cellular proliferation, which represent invasive squamous cell carcinoma (SCC). CONCLUSION: MAP3K8 overexpression is associated with SCC development in murine salivary glands. It provides an in vivo framework for the understanding of molecular mechanisms underlying SCC development in the salivary glands and also for the development of a future therapeutic strategy targeting this tumor type.

Comparison of High Sensitivity and Conventional Flow Cytometry for Diagnosing Overt Paroxysmal Nocturnal Hemoglobinuria and Detecting Minor Paroxysmal Nocturnal Hemoglobinuria Clones.

BACKGROUND: High sensitivity flow cytometry (HS-FCM) was recently developed for diagnosing paroxysmal nocturnal hemoglobinuria (PNH). We compared its performance with conventional flow cytometry (C-FCM) for diagnosing overt PNH and detecting minor (0.1-1%) PNH clones in aplastic anemia (AA)/low-grade myelodysplastic syndrome (MDS) patients. METHODS: C-FCM and HS-FCM were performed simultaneously on 41 samples from healthy controls and 23 peripheral blood samples from 15 AA/low-grade MDS and eight PNH patients, using a Navios flow cytometer (Beckman Coulter, Miami, FL, USA). Results were compared. RESULTS: No healthy control samples had PNH clone size >0.01%. For granulocytes, C-FCM detected a smaller PNH clone size than HS-FCM (mean difference: 0.7-1.7%). In AA/low-grade MDS patients, three samples showed >1% PNH clones with C-FCM but not with HS-FCM. Seven samples showed minor PNH clones by C-FCM, but HS-FCM showed negative results for all these samples. In PNH patients, C-FCM detected a smaller PNH clone size than HS-FCM (mean difference: 1.9-5.0%). For red blood cells, C-FCM detected a greater PNH clone size than HS-FCM (mean difference: 1.5%). In AA/low-grade MDS patients, C-FCM showed >1% PNH clones in six samples, but HS-FCM showed >1% PNH clones in none of the samples. C-FCM detected minor PNH clones in nine samples, but six of them were negative by HS-FCM. In PNH patients, C-FCM detected a greater PNH clone size than HS-FCM (mean difference: 2.5%). CONCLUSIONS: HS-FCM can sensitively detect minor PNH clones and reduce false-positive C-FCM minor PNH clone cases in AA/low-grade MDS patients.