Evaluation of neutrophil extracellular traps as the circulating marker for patients with acute coronary syndrome and acute ischemic stroke.

INTRODUCTION: Neutrophil extracellular traps (NETs) are known to be induced by various factors. In this study, we tried to identify circulating levels of NETs in patients with acute coronary syndrome (ACS) and acute ischemic stroke (AIS) and to confirm its suitability as a new circulating marker in their detection. METHODS: We prospectively enrolled 95 patients with a diagnosis of ACS (N = 37) or AIS (N = 58) in Dong-A University Hospital, Busan, Korea. The control group was selected from healthy adults (N = 25) who visited the hospital for health screening. Circulating levels of NETs were evaluated by measuring plasma concentrations of double-stranded DNA (dsDNA) and DNA-histone complex. RESULTS: The concentrations of dsDNA were statistically higher in patients with ACS or AIS than those in the control group (both P < .001). In the univariable and multivariable analyses, statistically significant risk factors were troponin I (TnI) level and dsDNA concentration in the ACS group (P = .046 and P = .015, respectively) and only dsDNA concentration in the AIS group (P = .002). In the receiver operating characteristic curve analyses, the area under the curve values for TnI level and dsDNA concentration in the ACS group were 0.878 and 0.968, respectively, and the value for dsDNA concentration in the AIS group was 0.859. CONCLUSIONS: In this study, it was confirmed that the circulating level of NETs was increased in patients with ACS and AIS at initial presentation. Findings in this study show that NETs could be used as a new circulating marker for the initial diagnosis of ACS or AIS.

Performance evaluation of new Abbott Alinity hq hematology analyzer.

INTRODUCTION: Abbott Alinity hq is a next-generation automated hematology analyzer providing complete blood count (CBC) with 6-part white blood cells (WBC) differential counts. The purpose of this study was to evaluate the performance of the analyzer to verify the diagnostic and clinical utility of the Abbott Alinity hq automated system. METHODS: We evaluated specimen stability, precision, linearity, carry-over, and method comparison to assess the performance of Alinity hq. For comparison of the Alinity hq with Sysmex XN-9000, totally 314 samples from adult and pediatric patients including both normal and abnormal hematology profiles were analyzed in parallel. The Alinity hq was also compared with the manual differential counts for the same 314 samples. RESULTS: At 4°C, the Alinity hq analyzer showed no significant changes in CBC and WBC differential count up to 48 hours. When stored at room temperature (18-25°C), all parameters except the mean platelet volume (MPV) were stable up to 36 hours. The Abbott Alinity hq analyzer demonstrated excellent reproducibility and between-batch precision for all CBC and WBC differential parameters. WBC, red blood cells (RBC), hemoglobin (HGB), and platelets showed good linearity and acceptable carry-over. Comparison with a Sysmex XN-9000 analyzer and manual 400-cell differential showed excellent correlation for CBC and WBC differential count parameters (correlation coefficient = 0.815-0.999) except for mean corpuscular hemoglobin concentration (MCHC) and basophils. CONCLUSION: We performed initial validation studies and confirmed performance specifications on specimen stability, precision, linearity, carry-over, and method comparison. The Abbott Alinity hq analyzer showed good analytical performance for all standard CBC parameters.

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.

Concomitant Liver and Brain Abscesses Caused by Parvimonas Micra.

Anaerobic infections have been reported to be responsible for 3-10% of pyogenic liver abscesses in Korea, and reported anaerobes include Fusobacterium, Bacillus fragilis, and Bacteroides melaninogenicus. Parvimonas micra is an anaerobic, Gram-positive, non-spore-forming bacterial species and a constituent of normal flora on skin, vagina, gastrointestinal tract, and oral cavity that can cause opportunistic infections. However, it has only rarely been reported to be a cause of liver abscess; only one such case has been reported in Korea. We experienced a case of concomitant liver and brain abscesses caused by Parvimonas micra in a non-immunodeficient 65-year-old female patient without diabetes or periodontal disease. Parvimonas micra infection was confirmed by blood culture using VITEK® 2 cards and by bacterial 16s ribosomal RNA gene sequencing. We conclude that we should not overlook anaerobes as a cause of liver abscess.

Early prediction of severity in acute ischemic stroke and transient ischemic attack using platelet parameters and neutrophil-to-lymphocyte ratio.

BACKGROUND: It is still not easy to predict severity promptly in patients with acute ischemic stroke (AIS) and transient ischemic attack (TIA). We investigated that platelet parameters or combinations of them could be a useful tool for early prediction of severity of AIS and TIA at admission and after 3 months. METHODS: We prospectively recruited 104 patients newly diagnosed with AIS and TIA. We investigated their neutrophil-to-lymphocyte ratio (NLR) and platelet parameters. According to the Modified Rankin Scale scores, the patients were divided into two groups. RESULTS: In receiver operating characteristic (ROC) curve analyses, mean platelet volume (MPV), NLR/platelet count (PLT), MPV/PLT, MPV*NLR, and MPV*NLR/PLT showed statistically significant results in both at admission and after 3 months. Values of area under ROC curves for those tests at admission were 0.646, 0.697, 0.664, 0.708, and 0.722, respectively. Also, values after 3 months were 0.591, 0.661, 0.638, 0.662, and 0.689, respectively. CONCLUSION: MPV*NLR/PLT could be used as a relatively good tool for predicting severity at the time of admission and after 3 months than other parameters or combinations of them. Further studies have to be carried out to investigate the best parameter for predicting the severity of AIS and TIA.

Platelet Function Analyzer-200 P2Y Results Are Predictive of the Risk of Major Adverse Cardiac Events in Korean Patients Receiving Clopidogrel Therapy Following Acute Coronary Syndrome.

BACKGROUND: Clopidogrel is one of the most commonly used anti-platelet agents in cardiovascular diseases. We analyzed the relationship between the platelet function analyzer (PFA)-200 P2Y (INNOVANCE PFA-200 System, Siemens Healthcare, Germany) results and occurrence of major adverse cardiac events (MACEs) in Korean patients with recent-onset acute coronary syndrome (ACS) taking clopidogrel. METHODS: Between August 2013 and June 2016, we prospectively enrolled 106 patients with recent-onset ACS who had been treated with clopidogrel. We obtained blood samples and measured closure time (CT) using the PFA-200 P2Y test. Patients were divided into two groups on the basis of a CT cut-off value of 106 seconds. We compared patient characteristics and various MACEs that occurred during the follow-up period. RESULTS: The CTs for 78 patients exceeded the cut-off value. At the time of these analyses, 11 patients had been diagnosed with MACEs. In the time-to-event analysis, there was a difference between the two groups (P<0.001). After adjusting other variables associated with MACE occurrence, CT value was the strongest predictor of MACEs, with a 7.30-fold occurrence risk (P=0.002). CONCLUSIONS: We found a strong relationship between CT and MACE risk in Korean patients with recent-onset ACS taking clopidogrel. Accordingly, PFA-200 P2Y results could be used as a predictive marker for MACE risk in such patients.

The Diagnostic Utility of the Point-of-Care CYP2C19 Genotyping Assay in Patients with Acute Coronary Syndrome Dosing Clopidogrel: Comparison with Platelet Function Test and SNP Genotyping.

BACKGROUND: Clopidogrel is a widely used antiplatelet agent for dual antiplatelet therapy and metabolized by CYP2C19. The polymorphism of CYP2C19 is associated with the therapeutic effect of clopidogrel. METHODS: A total of 119 patients diagnosed with acute coronary syndrome (ACS) and underwent percutaneous coronary intervention (PCI) with drug-eluting stents was enrolled. Polymorphisms of CYP2C19 *2,*3,*17 were determined by the Spartan RX CYP2C19 and confirmed by SNP genotyping assay. Genotype was grouped as ultra-rapid metabolizer, extensive metabolizer, intermediate metabolizer, and poor metabolizer. The degree of platelet inhibition was assessed by the VerifyNow P2Y12 system (Accumetrics, USA). RESULTS: The CYP2C19 genotypes were distributed as 4 (3.3%) for UM, 39 (32.8%) for EM, 54 (45.4%) for IM, 22 (18.5%) for PM by evaluation with Spartan RX CYP2C19. The numbers of patients with the *1/*17, *1/*1, *1/*2, *1/*3, *3/*17, *2/*2, *2/*3, and *3/*3 genotype were 4 (3.3%), 39 (32.8%), 40 (33.6%), 13 (10.9%), 1 (0.9%), 11 (9.2%), 10 (8.4%), 1 (0.9%), respectively. The genotyping results between Spartan RX CYP2C19 and SNP genotyping assay showed discrepancy in 2 patients. The discrepancy appeared in *17 allele analysis in both patients as false-positive result. CONCLUSIONS: The false-positive *17 allele couldn't affect IM or PM group associated with thrombotic events, but it could affect UM group associated with bleeding events, which is relatively less investigated. Although the supplement of *17 allele detection should be accomplished, this novel point-of-care CYP2C19 genotyping instrument could determine the response to the clopidogrel and support the appropriate treatment of ACS patients.

A retrospective analysis of cytogenetic alterations in patients with newly diagnosed multiple myeloma: a single center study in Korea.

BACKGROUND: The accurate identification of cytogenetic abnormalities in multiple myeloma (MM) has become more important over recent years for the development of new diagnostic and prognostic markers. In this study, we retrospectively analyzed the cytogenetic aberrations in MM cases as an initial assessment in a single institute. METHODS: We reviewed the cytogenetic results from 222 patients who were newly diagnosed with MM between January 2000 and December 2015. Chromosomal analysis was performed on cultured bone marrow samples by standard G-banding technique. At least 20 metaphase cells were analyzed for karyotyping. RESULTS: Clonal chromosome abnormalities were detected in 45.0% (100/222) of the patients. Among these results, 80 cases (80.0%) had both numerical and structural chromosome abnormalities. Overall hyperdiploidy with structural cytogenetic aberrations was the most common finding (44.0%), followed by hypodiploidy with structural aberrations (28.0%). Amplification of the long arm of chromosome 1 and -13/del(13q) were the most frequent recurrent abnormalities, and were detected in 50 patients (50.0%) and 40 patients (40.0%) with clonal abnormalities, respectively. The most common abnormality involving 14q32 was t(11;14)(q13;q32), which was observed in 19 cases. CONCLUSION: These findings demonstrate that myeloma cells exhibit complex aberrations regardless of ploidy, even from a single center in Korea. Conventional cytogenetic analysis should be included in the initial diagnostic work-up for patients suspected of having MM.

Correlation between the CYP2C19 phenotype status and the results of three different platelet function tests in cardiovascular disease patients receiving antiplatelet therapy: an emphasis on newly introduced platelet function analyzer-200 P2Y test.

BACKGROUND: An association has been reported between CYP2C19 polymorphism and the altered antiplatelet activity of clopidogrel. We investigated this association using the newly introduced platelet function analyzer (PFA)-200 (INNOVANCE PFA-200 System; Siemens Healthcare, Germany) P2Y test. METHODS: Polymorphisms of CYP2C19*2, *3, *17 and the degree of inhibition of platelet function were determined in 83 patients. Three different platelet function tests were used to evaluate the degree of platelet inhibition and to check the association with genotype. RESULTS: The post-procedure PFA-200 values of extensive metabolizers (EM) patients (285.3±38.8) were higher than those of intermediate metabolizers (IM) and poor metabolizers (PM) patients (227.7±98.3 and 133.7±99.2, respectively; P=0.024). Light transmittance aggregometry (LTA) and the VerifyNow system showed that the post-procedure values for EM patients were lower than those of IM and PM patients (LTA: 24.4±15.7, 34.1±17.6, and 42.2±16.9, respectively, P<0.001; VerifyNow: 133.2±60.5, 171.5±42.6, and 218.7±59.3, respectively, P<0.001). The high residual platelet reactivity (HPR) rates were significantly different among the EM, IM, and PM groups using PFA-200 (PM:IM:EM=82.4:40.6:11.8, P<0.001). CONCLUSIONS: Approximately, 59.0% of Korean patients with cardiovascular disease receiving clopidogrel had CYP2C19 loss-of-function genotypes classified as IM or PM, and the frequency was similar to the data from Asian people. The PFA-200, LTA, and VerifyNow platelet function tests revealed evidence of a significant association between the efficacy of clopidogrel and CYP2C19 genotypes.

Neutrophil-to-Lymphocyte Ratio Is Associated with Impaired Interferon-Gamma Release to Phytohemagglutinin.

OBJECTIVE: The neutrophil-to-lymphocyte ratio (NLR) has been shown to predict adverse outcomes in several pathologic conditions. The majority of indeterminate interferon (IFN)-γ release assays were due to inadequate IFN-γ response to the phytohemagglutinin. We sought to study the value of NLR to predict an indeterminate result of QuantiFERON-TB Gold In-Tube (QFT-GIT) performed in routine laboratory practice. METHODS: Results from 2,773 QFT-GIT assays were analyzed. Data collection included demographic data, the level of IFN-γ to nil, mitogen, and TB antigen of QFT-GIT, total WBC, and a differential count. We calculated the absolute neutrophil count, lymphocyte count, and NLR. RESULTS: Of the total, 224 (8.1%) indeterminate results were observed. Twelve (1.8%) showed indeterminate results in the NLR range from 1.71 to 2.84, but 132 (19.2%) had indeterminate results in NLR ≥ 5.18 (p < 0.0001). The likelihood ratio for indeterminate results were 2.70 (95% CI, 2.36-3.08) in NLR ≥ 5.18 and 1.93 (95% CI, 1.64-2.27) in lymphocyte count ≤ 1050/µL. NLR and neutrophil count were independent predictors for indeterminate QFT-GIT result in multiple regression analysis. The IFN-γ response to PHA was negatively associated with NLR (r = -0.33, p < 0.001). CONCLUSION: We showed that the NLR is an independent predictor of indeterminate QFT-GIT result. Low frequency of indeterminate results in group with normal NLR may imply the importance of a balance between two cellular compartments in physiological and pathological conditions.

Clinical usefulness of serum cystatin C as a marker of renal function.

BACKGROUND: Accurate renal function measurements are important in the diagnosis and treatment of kidney diseases. In contrast to creatinine, the production of serum cystatin C has been extensively reported to be unaffected by body muscle mass, age, gender, and nutritional status. METHODS: Our study included 37 samples from diabetic chronic kidney disease (CKD) patients for whom serum creatinine tests had been requested and 40 samples from a healthy populations in Dong-A University Hospital between May 2010 and June 2010. The assay precision (i.e., the coefficient of variation) and the reference range of the serum cystatin C test were evaluated. We compared the estimated glomerular filtration rates (GFRs) based on cystatin C with those based on creatinine. Moreover, we investigated the influences of age, gender, weight, and muscle mass on serum creatinine and serum cystatin C. RESULTS: There was a positive correlation between GFR based on creatinine and that based on cystatin C (r=0.79, P<0.0001) among the diabetic CKD patients. Serum creatinine and cystatin C were significantly correlated with body weight and muscle mass, but the strengths of these correlations were greater for serum creatinine. The precision study revealed excellent results for both the high and low controls. The 95% reference interval of cystatin C in the healthy population was 0.371 to 1.236 mg/L. CONCLUSION: Based on these results, we conclude that, despite the strong correlation between serum creatinine and cystatin C, cystatin C is less affected by weight and muscle mass and might represent a better alternative for the assessment of renal function.

Diagnostic utility of multiprobe fluorescence in situ hybridization assay for detecting cytogenetic aberrations in acute leukemia.

BACKGROUND: Specific cytogenetic aberrations detected by conventional karyotyping or FISH play a major role in the diagnosis, prognosis, and treatment of patients with acute leukemia. The FISH technique enhances the capacity of conventional karyotyping to detect subtle chromosomal aberrations. Multiprobe FISH assay (Cytocell, UK) can hybridize multiple probes to a single slide, thereby increasing the detection rate of cytogenetic aberrations. This study aimed to evaluate multiprobe FISH in detecting cytogenetic abnormalities in acute leukemia. METHODS: Thirty newly diagnosed acute leukemia patients who attended the hematology clinic at Dong-A University Hospital from October 2008 to October 2012 were enrolled in the study. The multiprobe FISH results were compared with those of G-banding. RESULTS: Multiprobe FISH detected the chromosomal aberrations identified by G-banding, as well as additional aberrations in 6 of 30 (20.0%) cases, which included ETV6/RUNX1 translocation, p16 deletion, TP53 deletion, and IGH break-apart. CONCLUSIONS: The multiprobe FISH assay was a more sensitive and reliable technique compared with G-banding. It was also more cost-effective and yielded faster results.

Outbreak of pseudomonas oryzihabitans pseudobacteremia related to contaminated equipment in an emergency room of a tertiary hospital in Korea.

Pseudomonas oryzihabitans is frequently found in various sites within hospital settings, including sink drains and respiratory therapy equipment. Although it rarely causes human infections, P. oryzihabitans has recently been considered a potential nosocomial pathogen, especially in immunocompromised hosts. We report our experience of an outbreak of P. oryzihabitans pseudobacteremia, presumably due to faulty aseptic preparation of a saline gauze canister.