Associations of Perioperative Red Blood Cell Transfusion With Outcomes of Kidney Transplantation in Korea Over a 16-Year Period

Background@#This study investigated the associations between transfusion of different types of red blood cell (RBC) preparations and kidney allograft outcomes after kidney transplantation (KT) over a 16-year period in Korea using a nationwide population-based cohort. @*Methods@#We investigated the reported use of RBCs during hospitalization for KT surgery, rejection, and graft failure status using nationwide data from the National Health Information Database (2002–2017). The associations between the type of perioperative RBC product and transplant outcomes were evaluated among four predefined groups: no RBC transfusion, filtered RBCs, washed RBCs, and packed RBCs (pRBCs). @*Results@#A total of 17,754 KT patients was included, among which 8,530 (48.0%) received some type of RBC transfusion. Of the patients who received RBC transfusion, 74.9%, 19.7%, and 5.4% received filtered RBCs, pRBCs, or washed RBCs, respectively. Regardless of the type of RBC products, the proportions of acute rejection and graft failure was significantly greater in patients receiving transfusion (P < 0.001). Cox proportional hazards regression analyses showed that the filtered RBC and pRBC groups were significantly associated with both rejection and graft failure. The washed RBC group also had hazard ratios greater than 1.0 for rejection and graft failure, but the association was not significant. Rejection-free survival of the pRBC group was significantly lower than that of the other groups (P < 0.001, log-rank test), and graft survival for the no RBC transfusion group was significantly greater than in the other groups (P < 0.001, log-rank test). @*Conclusion@#Perioperative RBC transfusion was associated with poor graft outcomes.Notably, transfusion of pRBCs significantly increased transplant rejection. Therefore, careful consideration of indications for RBC transfusion and selection of the appropriate type of RBCs is necessary, especially for patients at high risk of rejection or graft failure.

Performances of CYFRA 21-1, Carcinoembryonic Antigen and Their Combination for Lung Cancer Diagnosis

Comparison of the QIAGEN artus HBV QS-RGQ Assay With the Roche COBAS AmpliPrep/COBAS TaqMan HBV Assay for Quantifying Viral DNA in Sera of Chronic Hepatitis B Patients

BACKGROUND: Hepatitis B virus DNA quantification is essential for managing chronic hepatitis B (CHB). We compared the performance of artus HBV QS-RGQ (QIAGEN GmbH, Germany) and CAP/CTM v2.0 HBV assays (Roche Molecular Diagnostics, USA) in CHB patients. METHODS: A comparative evaluation between two assays was performed with 508 clinical serum samples. Precision, linearity, and the limit of detection (LOD) of QS-RGQ assay was evaluated by using the WHO standard 97/750 and clinical samples. RESULTS: Detection rates and viral loads as determined QS-RGQ assay were significantly lower than those from the CAP/CTM v2.0 assay (52.8% vs 60.6%; 3.55±1.77 IU/mL vs 4.18±1.89 IU/mL, P<0.0001). The kappa coefficient between qualitative results was 0.79 (95% confidence interval, 0.74 to 0.85). Bland-Altman plot found a mean difference of (QS-RGQ − CAP/CTM v2.0)=−0.63 log₁₀ IU/mL (95% limit of agreement, −1.48 to 0.22). Repeatability and total imprecision (% CV) of the QS-RGQ assay were 1.0% and 1.1% at 2,000 IU/mL, and 0.7% and 1.4% at 20,000 IU/mL, respectively. Linearity of this assay ranged from 31.6 to 1.0±10⁷ IU/mL, and the LOD was 2.95 IU/mL. CONCLUSIONS: The artus HBV QS-RGQ assay showed good performance but significantly decreased detection rate and viral load compared with CAP/CTM v2.0 assays. This assay recommends using plasma; however, we used stored serum because of the retrospective study design. Usually HBV DNA quantification is performed in plasma or serum, but sample type and clinical relevance of quantitative values should be considered when determining the clinical application of this reagent.

Evaluation of Real-time PCR Kits for Epstein-Barr Virus DNA Assays

BACKGROUND: Epstein-Barr virus (EBV) is known to be the causative agent of infectious mononucleosis and EBV-related malignancies. In this study, we compared the results of three real-time PCR kits for EBV DNA assays. METHODS: A total of 300 whole blood samples submitted for quantitative EBV PCR between January 2013 and September 2014 at Severance Hospital were included. The samples were tested by using the Artus EBV RG PCR Kit (Qiagen, Germany), AccuPower EBV Quantitative PCR Kit (Bioneer, Korea), and Real-Q EBV Kit (BioSewoom, Korea). Samples with discordant results between the three kits were confirmed by direct sequencing. RESULTS: The result concordance rate and kappa coefficient (K) were 86.3% and 0.69 for Artus-AccuPower, 93.3% and 0.85 for Artus-Real-Q, and 92.3% and 0.83 for AccuPower-Real-Q, respectively. The correlations between the three kits were found to be significant, with a correlation coefficient of r=0.854 for Artus-AccuPower, -0.802 for Artus-Real-Q, and -0.977 for AccuPower-Real-Q, respectively (P<0.0001). If the real-time PCR concordant results of 258 samples and the direct sequencing results of 42 real-time PCR discordant samples were assumed to be true, the sensitivity/specificity values were 0.921/0.976 for Artus, 0.902/0.965 for AccuPower, and 0.967/1.000 for Real-Q. CONCLUSIONS: The three real-time PCR kits showed excellent sensitivities and specificities. All these kits would be acceptable for clinical and therapeutic management of EBV. However, some discordant results between the kits indicate the need for caution in clinical diagnosis and staging. Further implementation of standardized methodology would be needed for EBV DNA assays.

Anaerobic Bacteremia: Impact of Inappropriate Therapy on Mortality

BACKGROUND: Investigation on incidence and mortality of anaerobic bacteremia (AB) is clinically relevant in spite of its infrequent occurrence and not often explored, which report varies according to period and institutions. Therefore, it is necessary to analyze the incidence and risk factors related to mortality and assess clinical outcomes of AB in current aspect. MATERIALS AND METHODS: Characteristics of AB patients and anaerobic bacteria from blood culture at a university hospital in 2012 were reviewed retrospectively. The correlation between risk factors and 28-day patient mortality was analyzed. RESULTS: A total of 70 non-duplicated anaerobic bacteria were isolated from blood of 70 bacteremia patients in 2012. The history of cardiovascular disease as host's risk factor was statistically significant (P = 0.0344) in univariate and multivariate analysis. Although the inappropriate therapy was not statistically significant in univariate and multivariate analysis, the survival rate of bacteremia was significantly worse in patients who had inappropriate therapy compared with those underwent appropriate therapy (hazard ratio, 5.4; 95% confidence interval, 1.7-6.9; P = 0.004). The most frequently isolated organism was Bacteroides fragilis (32 isolates, 46%), followed by Bacteroides thetaiotaomicron (10, 14%), and non-perfringens Clostridium (7, 10%). CONCLUSION: The incidence of AB in 2012 was 2.3% (number of AB patients per 100 positive blood culture patients) and the mortality rate in patients with clinically significant AB was 21.4%. In addition, AB was frequently noted in patients having malignancy and the survival rate of AB was significantly worse in patients who received inappropriate therapy compared with those underwent appropriate therapy.

A 12-Month Single Arm Pilot Study to Evaluate the Efficacy and Safety of Sirolimus in Combination with Tacrolimus in Kidney Transplant Recipients at High Immunologic Risk

The optimal immunosuppressive strategy for renal transplant recipients at high immunologic risk remains a topic of investigation. This prospective single arm pilot study was undertaken to evaluate the safety and efficacy of a combined tacrolimus and sirolimus regimen in recipients at immunological high risk and to compare outcomes with a contemporaneous control group received tacrolimus and mycophenolate mofetil. Patients that received a renal allograft between 2010 and 2011 at high risk (defined as panel reactive antibodies > 50%, 4 or more human leukocyte antigen mismatches, or retransplantation) were enrolled. All patients received basiliximab induction and corticosteroids. A total of 28 recipients treated with tacrolimus and sirolimus were enrolled in this study and 69 recipients were retrospectively reviewed as a control group. The sirolimus group showed a higher, but not statistically significant, incidence of biopsy proven acute rejection and a lower glomerular filtration rate than the control group. Furthermore, sirolimus group was associated with significant increases in BKV infection (P = 0.031), dyslipidemia (P = 0.004), and lymphocele (P = 0.020). The study was terminated prematurely due to a high incidence of adverse events. A de novo tacrolimus/sirolimus combination regimen may not be an ideal choice for recipients at high immunological risk.

The Effect of Bortezomib on Antibody-Mediated Rejection after Kidney Transplantation

PURPOSE: Recently, bortezomib has been used to treat antibody-mediated rejection (AMR) refractory to conventional treatment such as plasmapheresis, intravenous immunoglobulin, and rituximab. The authors aimed to describe their experiences when bortezomib was used to treat refractory AMR. MATERIALS AND METHODS: Eleven refractory AMR episodes treated with bortezomib were included in this study. The patients received one or two cycles of bortezomib (1.3 mg/m2) on days 1, 4, 8, and 11. RESULTS: Bortezomib effectively reduced antibodies against various targets, including human leukocyte antigen (HLA) class I and II, ABO blood group antigen, and angiotensin II type 1 receptor. Antibodies were depleted or reduced significantly in eight AMR episodes. Overall, there was a significant improvement in the mean estimated glomerular filtration rate (eGFR) at 3 months after therapy (36.91+/-22.15 mL/min/1.73 m2) versus eGFR at time of AMR diagnosis (17.00+/-9.25 mL/min/1.73 m2; p=0.007). All six early-onset AMR episodes (within 6 months post-transplantation) showed full recovery of allograft function. Additionally, three of the five late-onset AMR episodes (>6 months post-transplantation) showed improved allograft function. CONCLUSION: Anti-humoral treatment based on bortezomib might be an effective strategy against refractory AMR caused by various types of antibodies. Notably, this treatment could be more effective in early-onset AMR than in late-onset AMR.

Resolution of Ambiguous HLA Genotyping in Korean by Multi-Group-Specific Sequence-Based Typing

PURPOSE: To evaluate a multi-group-specific sequence-based typing (SBT) method for resolving ambiguous results from human leukocyte antigen (HLA) genotyping. MATERIALS AND METHODS: A total of 50 samples that showed ambiguous genotypes for at least two HLA loci from HLA-A, -B, -C and -DRB1 by the conventional SBT assay were evaluated using a new SBT test, the AVITA plus assay. The most likely HLA genotypes for the respective samples considering allele frequencies in Korean were concordant between the AVITA and conventional SBT assays. RESULTS: An average of 3.3 loci among the HLA-A, -B, -C and -DRB1 loci per sample gave results with two or more possible allele combinations with the conventional SBT, and 48 (96.0%) out of 50 showed reduced numbers of possible genotypes for at least one HLA locus with the AVITA. A total of 41, 43, 42, and 38 cases among the 50 samples showed ambiguous results for HLA-A, -B, -C, and -DRB1 typing by the conventional SBT, respectively. The average numbers of possible allele combinations for the respective four HLA loci were 8.2, 6.7, 5.9, and 3.2, and they were reduced to 1.5, 2.2, 4.4, and 1.8, respectively, by the AVITA. Ambiguity was resolved by the AVITA in 33 (80.5%), 31 (72.1%), 17 (40.5%) and 28 (73.7%) samples among the ambiguous cases from the conventional SBT for HLA-A, -B, -C, and -DRB1 typing, respectively. CONCLUSION: The multi-group-specific SBT method considerably reduced the number of ambiguous results, and thus may be useful for accurate HLA typing in clinical laboratories.

Evaluation of Automated Assays for Measuring Serum Hyaluronic Acid: For the Diagnosis of Rheumatoid Arthritis

BACKGROUND: Hyaluronic acid (HA) is present in the connective tissues wherein it functions as a lubricant. HA is known to be increased in both synovial fluid and serum when inflammation occurs in the joint. We measured serum HA concentrations by automated assays and determined its reference interval and its usefulness as a diagnostic marker in patients with rheumatoid arthritis (RA). METHODS: Serum specimens collected from 121 healthy individuals and 253 patients with various arthritis were used for measuring HA with two automated assays, namely, LPIAACE (Mitsubishi, Japan) and LT Auto Wako (Wako, Japan). The association between serum HA concentration and the diagnosis of RA was estimated by receiver operator characteristic (ROC) analysis and multivariate logistic regression. RESULTS: The 95th percentile upper reference limit of serum HA was 57.28 ng/mL (90% confidence interval [CI], 46.30-68.20 ng/mL) for LPIAACE and 72.64 ng/mL (90%% CI, 57.30-85.70 ng/mL) for LT Auto Wako. Area under the ROC curve values of serum HA for discriminating the RA group from the non-RA group were 0.68 for LPIAACE and 0.70 for LT Auto Wako. The odds ratio for serum HA in predicting RA was 1.02 (95% CI, 1.02-1.04) for LPIAACE and 1.03 (95% CI, 1.02-1.05) for LT Auto Wako. CONCLUSIONS: This study provides a reference interval for serum HA concentrations in Koreans. This result suggests that the serum HA concentrations could be helpful as a complementary marker for discriminating RA from other types of arthritis, as well as distinguishing patients with RA from healthy controls.

Evaluation on the Stability of Pooled Sera for External Quality Assessment of Tumor Marker Assays / 임상검사와정도관리

BACKGROUND: Specimens for the external quality assessment (EQA) need to be highly stable during the EQA process. Therefore, we evaluated the stability of pooled sera (PS) for tumor markers including alpha fetoprotein (AFP), carcinoembryonic antigen (CEA), carbohydrate antigen 125 (CA 125), and carbohydrate antigen 19-9 (CA 19-9). METHODS: PS with 2 different levels (high and low) of each of the 4 tumor markers were collected and stored at -20degrees C, 4degrees C, and room temperature (RT). The concentration of each tumor marker was then measured after storage under these different conditions at baseline and on days 1, 3, 7, 14, 30, 90, and 181. Internal quality control (QC) results during the evaluation period were also analyzed. RESULTS: Irrespective of storage conditions, coefficients of variation (CVs) of AFP and CA 125 levels in the PS during the evaluation period ranged from 3.3% to 7.5% in EQA assays and were similar to the CVs of QC assays. However, the levels of CEA detected in PS stored at -20degrees C, and 4degrees C, showed higher variability, with CVs ranging from 4.0% to 10.4%, and samples stored at RT showed especially high CVs, i.e., >8.3%. Samples for CA 19-9 testing stored at RT also showed lower stability than the QC samples as well as samples stored at -20degrees C, after 3 days. CONCLUSIONS: CEA and CA 19-9 levels in PS showed higher variability than AFP and CA 125, especially when stored at RT. These results indicate that all EQA specimens for tumor marker assays need to be tested as soon as possible and not stored at RT for longer than 3 days during the EQA process.

Evaluation of the Performance of an Adiponectin ELISA-based Test and Establishing Serum Adiponectin Reference Intervals for Korean Population

BACKGROUND: Adiponectin is a plasma protein secreted by adipose tissues and low serum adiponectin concentration has been reported to be associated with insulin resistance and metabolic syndrome (MS). We evaluated the performance of an ELISA-based assay for measuring serum adiponectin levels and established reference intervals of adiponectin for Korean population. METHODS: Laboratory performance, including precision and linearity, of the AdipoMark Human Adiponectin ELISA kit (Mesdia Co., Korea) was assessed. Reference intervals of adiponectin concentration were determined after evaluation of 1200 subjects with no history of MS. Adiponectin was also measured in 100 patients with MS. RESULTS: The mean concentrations of serum samples tested for precision evaluation were 6.66, 12.61, and 23.42 microg/mL: the ELISA showed total imprecision of 13.6%, 9.3%, and 10.5% CV for the respective concentrations. The assay demonstrated linear responses in the range of 1.8-29.9 microg/mL serum adiponectin levels. The 95% reference intervals for Korean population were 3.6-19.2 microg/mL for men and 4.5-34.2 microg/mL for women. ROC-area under the curve values of adiponectin for the diagnosis of MS were 0.85 for men and 0.83 for women. Low adiponectin level was independently associated with MS in the multivariate analysis. CONCLUSIONS: The adiponectin quantitation assay evaluated in this study showed acceptable laboratory and clinical performances in an ELISA platform. To meet the ever-increasing demand for a reliable assay for measuring adiponectin levels in the study of various metabolic diseases, this assay could be further improved by the automation of the platform.

Evaluation of the UniCel(TM) DxI 800 Immunoassay Analyzer in Measuring Five Tumor Markers

PURPOSE: Tumor marker concentrations in a given specimen measured by different analyzers vary according to assay methods, epitopes for antibodies used, and reagent specificities. Although great effort in quality assessment has been instituted, discrepancies among results from different analyzers are still present. We evaluated the assay performance of the UniCel(TM) DxI 800 automated analyzer in measuring the alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA), carbohydrate antigen (CA) 125, CA 15-3 and CA 19-9 tumor markers. MATERIALS AND METHODS: The linearity and precision performance of the five tumor marker assays were evaluated, and concentrations of the respective markers as measured by DxI were compared to those measured by other conventional analyzers (ADVIA Centaur(TM) and Vitros(TM) ECi) using 200 specimens collected from 100 healthy persons and 100 patients with respective cancers. RESULTS: The linear fits for all five tumor markers were statistically acceptable (F=4648 for AFP, F=15846 for CEA, F=6445 for CA 125, F=2285 for CA 15-3, F=7459 for CA 19-9; p<0.0001 for all). The imprecision of each tumor marker assay was less than 5% coefficient of variation, except for low and high concentrations of AFP. The results from UniCel(TM) DxI 800 were highly correlated with those from other analyzers. CONCLUSION: Our results demonstrate that UniCel(TM) DxI 800 has good linearity and precision performance for the tumor markers assayed in this study. However, there were discrepancies between assaying methods. Efforts to standardize tumor marker assays should be undertaken, and the redetermination of cut-off levels is necessary when developing methods of analyzing tumor markers.

Comparison of the Diagnostic Performance of Elecsys Anti-HCV II and Elecsys and Vitros Anti-HCV Assays / 임상검사와정도관리

BACKGROUND: We evaluated the diagnostic performance of a newly developed Elecsys Anti-HCV II assay in Korean patients. METHODS: A total of 500 serum samples (400 antibody to hepatitis C virus [anti-HCV]-negative and 100 anti-HCV-positive samples) were collected after testing with Elecsys Anti-HCV assay (Roche Diagnostics, Germany). All the samples were tested for anti-HCV by using Vitros Anti-HCV (Ortho-Clinical Diagnostics, UK) and Elecsys Anti-HCV II (Elecsys II) (Roche Diagnostics, Germany) assays. Specimens that were found to be positive or negative in all the 3 assays were considered positive or negative for anti-HCV, respectively, and medical records of the patients, including results of previous HCV tests, were reviewed to determine the final results for anti-HCV when there were discrepancies among the results of the anti-HCV assays. RESULTS: Discrepancies between the results of the 3 anti-HCV assays were found for 4 of the 500 samples (0.8%). Sensitivity/specificity values for Elecsys II were 98.0%/100.0%, and the corresponding values for Elecsys and Vitros assays were 100.0%/100.0% and 100.0%/99.5%. Concordance rates between the results of any 2 of the 3 assays were equal or greater than 99.2%, with a kappa coefficient of 0.98 or greater (P < 0.0001). CONCLUSIONS: Sensitivities and specificities of the anti-HCV assays evaluated in this study were high enough for being used in clinical laboratories, and the results of the 3 assays showed good agreement. However, samples for which weak-positive results were obtained would need to be retested, considering the discrepancies between the anti-HCV assays.

Evaluation of an Automated Coagulation Analyzer Coapresta 2000

BACKGROUND: The Coapresta 2000 (Sekisui Medical CO., LTD, Japan) is a fully automated random-access multiparameter hemostasis coagulation analyzer, which is equipped with a photo-optical clot detection unit and a cap-piercing system. It is able to perform clotting time assays as well as colorimetric assays (synthetic substrate method and latex turbidimetric method). In this study, we evaluated the analytical performance of the Coapresta 2000 for coagulation test items and compared with that of the ACL-TOP (Instrumentation Laboratory, Lexingtion, MA, USA) analyzer, which is currently used for routine coagulation test items in our hospital. METHODS: The Coapresta 2000 was evaluated with respect to its technical characteristics in the determination of 8 routine coagulation test items: prothrombin time, activated partial thromboplastin time, fibrinogen, fibrin-degradation product (FDP) antithrombin III, D-dimer, factors VIII and IX. Analyse-it (Analyse-it Software Ltd, UK) and SigmaStat (Systat Software, Inc., USA) were used for statistical analysis between items on the Coapresta 2000 and the ACL-TOP analyzer. RESULTS: The intra-assay and inter-assay coefficients of variation (CV) were below 5% for both groups of samples having values within the reference interval and outside the reference interval. Significant interference was observed with hemolytic and icteric samples. Carryover was not detected. The results obtained by Coapresta 2000 were well correlated with those obtained by the ACL-TOP analyzer (r2 in the range from 0.781 to 0.969). CONCLUSIONS: We concluded that Coapresta 2000 analyzer was well correlated with ACL-TOP analyzer for the routine coagulation test items tested.

Analysis of the Patients with Indeterminate Results by Anti-HIV Western Blot Assay: Experience of a University Hospital During Recent 5 Years in Korea / 임상검사와정도관리

BACKGROUND: Interpretation of indeterminate results by anti-HIV Western blot assay, which is currently used as a confirmatory test for HIV infection, can be usually difficult. We analyzed outcomes of the patients with indeterminate results by anti-HIV Western blot. METHODS: Medical records of patients, who were indeterminate by the anti-HIV Western blot assay in a university hospital during recent 5 years, were retrospectively reviewed. HIV screening test was performed by chemiluminescent immunoassay autoanalyzer (Abbot Laboratories, USA) with HIV Ag/Ab Combo kits. Confirmatory Western blot assay for the positive samples by HIV screening test was committed to the Korean National Institute of Health. RESULTS: A total of 202,639 specimens were tested for HIV screening during the period, and 644 (0.32%) sera showed positive results. Among these, 46 (7.1%) cases were indeterminate by the Western blot, which were from 20 patients, and 13 of them converted to be anti-HIV positive, and 3 were lost to follow-up. Another four patients were turned out to be negative for HIV infection, including two neonates from HIV-positive mothers receiving antiviral treatment during pregnancy. CONCLUSIONS: Most of the patients who showed Western blot-indeterminate results converted to HIV positive after follow-up. Thus, careful monitoring of patients with indeterminate Western blot results should be essential.

Performance Characteristics of the UniCel DxI 800 Immunoassay for the Maternal Serum Quadruple Test, Including Median Values for Each Week of Gestation, in Korean Women / 대한진단검사의학회지

BACKGROUND: Maternal serum prenatal quadruple screening includes testing for alpha-fetoprotein (AFP), human chorionic gonadotrophin (hCG), unconjugated estriol (uE3), and dimeric inhibin A (DIA). We evaluated quadruple screening using an automated platform and looked for any ethnic differences in the median values of each marker. METHODS: We measured the concentrations of each quadruple test analyte using the UniCel DxI 800 system (Beckman Coulter, USA) in 788 Korean mid-trimester maternal serum samples and calculated their median values using Benetech software (Benetech, Canada). We also compared the results with those obtained using the Immulite 2000 assay (Siemens Healthcare Diagnostics, USA) or ELISA (DSL, USA) in 442 samples. RESULTS: We obtained mid-trimester median values for each marker. The following are the comparative results for each test using the Immulite 2000 assay or ELISA (x) and the UniCel DxI 800 immunoassay (y): AFP, y=1.10x+0.01, r=0.925; uE3, y=0.28x+0.24, r=0.885; hCG, y=1.22x-3047.8, r=0.944; and DIA, y=0.86x+15.31, r=0.833. Assay results for each of the four markers showed good correlations. However, significant biases necessitated new median calculations of prenatal risk estimates in all four tests. CONCLUSIONS: We established gestational age-specific second-trimester median values for four markers in Korean samples using the UniCel DxI 800 immunoassay system. Despite significant bias, there were good correlations between the results obtained using the UniCel DxI 800 immunoassay and those obtained using the Immulite 2000 assay.

Comparisons of Three Automated Systems for Genomic DNA Extraction in a Clinical Diagnostic Laboratory

PURPOSE: The extraction of nucleic acid is initially a limiting step for successful molecular-based diagnostic workup. This study aims to compare the effectiveness of three automated DNA extraction systems for clinical laboratory use. MATERIALS AND METHODS: Venous blood samples from 22 healthy volunteers were analyzed using QIAamp(R) Blood Mini Kit (Qiagen), MagNA Pure LC Nucleic Acid Isolation Kit I (Roche), and Magtration-Magnazorb DNA common kit-200N (PSS). The concentration of extracted DNAs was measured by NanoDrop ND-1000 (PeqLab). Also, extracted DNAs were confirmed by applying in direct agarose gel electrophoresis and were amplified by polymerase chain reaction (PCR) for human beta-globin gene. RESULTS: The corrected concentrations of extracted DNAs were 25.42 +/- 8.82 ng/microLiter (13.49-52.85 ng/microLiter) by QIAamp(R) Blood Mini Kit (Qiagen), and 22.65 +/- 14.49 ng/microLiter (19.18-93.39 ng/microLiter) by MagNA Pure LC Nucleic Acid Isolation Kit I, and 22.35 +/- 6.47 ng/microLiter (12.57-35.08 ng/microLiter) by Magtration-Magnazorb DNA common kit-200N (PSS). No statistically significant difference was noticed among the three commercial kits (p > 0.05). Only the mean value of DNA purity through PSS was slightly lower than others. All the extracted DNAs were successfully identified in direct agarose gel electrophoresis. And all the product of beta-globin gene PCR showed a reproducible pattern of bands. CONCLUSION: The effectiveness of the three automated extraction systems is of an equivalent level and good enough to produce reasonable results. Each laboratory could select the automated system according to its clinical and laboratory conditions.

Identification of Adenovirus, Influenza Virus, Parainfluenza Virus, and Respiratory Syncytial Virus by Two Kinds of Multiplex Polymerase Chain Reaction (PCR) and a Shell Vial Culture in Pediatric Patients with Viral Pneumonia

PURPOSE: Early identification of causative agents in lower respiratory infection of pediatric patients can reduce morbidity and prevent an overuse of antimicrobials. Two kinds of multiplex polymerase chain reaction (PCR) and a commercial shell vial viral culture were performed to identify causative agents in pediatric patients. MATERIALS AND METHODS: Nasopharyngeal aspirates of 220 children diagnosed with viral pneumonia were obtained. Two kinds of multiplex PCR (Seeplextrade mark RV detection kit, and Labopasstrade mark RV detection kit), and a shell vial culture by R-Mix were performed. RESULTS: Positive samples from 220 total samples by two multiplex PCRs were 52.7% and 46.4%, respectively. We also cultured 103 samples that showed positive results of the adenovirus, influenza virus, parainfluenza virus, and respiratory syncytial virus (RSV) by two multiplex PCR. The RSV was most frequently detected in 53.0% (Seeplex) and 51.7% (Labopass) of patients. The detection rate of adenovirus (AdV) was 10.3% and 12.1%, influenza virus (IFV) A and B was 12.5% and 3.4%, and parainfluenza virus (PIFV) 1, 2, and 3 were 2.9% and 2.6%. Shell vial cultures showed concordant results with each multiplex PCR by 96.1% and 77.7%, respectively. Sequencing results were 90% consistent with multiplex PCR. CONCLUSION: Multiplex PCR showed more positivity than the shell vial culture and it can be an effective primary test. Other complementary efforts such as viral cultures and sequencing analysis could be considered, according to clinical and laboratory conditions.

Arg72Pro Polymorphism and Exon 7 Codon 249 Mutation of Plasma DNA p53 Gene in Early Hepatocellular Carcinoma Patients with Hepatitis B Virus Infection in a Korean population / 임상검사와정도관리

BACKGROUND: This study was performed to investigate on the genotypic frequencies of p53 Arg72Pro polymorphism and the prevalence of p53 codon 249 mutation in hepatocellular carcinoma patients. METHODS: Plasma DNAs were extracted from the samples of 44 early HCC cases, 24 chronic B-viral hepatitis patients and 27 healthy individuals. Serum levels of AFP, PIVKA-II, and HBV DNA-positive rates among the study groups were also compared. PCR-based restriction fragment length polymorphism method was used to determine p53 Arg72Pro genotype and to detect codon 249 mutation. RESULTS: Serum AFP and PIVKA-II level, Edmondson grade, tumor size and frequency of HBV DNA-positivity among HCC group according to Arg72Pro genotypes showed no statistically significant difference. The frequencies of Arg72Pro genotypes (Arg/Arg, Arg/Pro, Pro/Pro) were respectively as follows: 34.1%, 47.7%, 18.2% in HCC group; 29.2%, 54.2%, 16.7% in hepatitis group; 29.6%, 55.6%, 14.8% in control group. Pro homozygote genotype had a higher risk for developing HCC by adjusted OR (1.529, 95% CI 0.325-7.193), but not statistically significant (P=0.591). No codon 249 mutation was found among 44 HCC cases. CONCLUSIONS: Pro homozygote was around 16% in all study groups, and did not statistically increase risks to developing HCC. We suggest that Arg72Pro polymorphism of p53 gene is not a significant risk factor in early hepatocarcinogenesis.

Recent Trends of Anaerobic Bacteria Isolated from Clinical Specimens and Clinical Characteristics of Anaerobic Bacteremia

BACKGROUND: Anaerobic bacteria can cause various infections, and their incidence may differ greatly, depending on the country or hospital. We investigated recent trends in anaerobe isolation and clinical characteristics of anaerobic bacteremia in one hospital in Korea to facilitate diagnosis and treatment of anaerobic infections. MATERIALS AND METHODS: Anaerobic bacteria isolated from blood, body fluids and abscess specimens at a university hospital in Korea during 2007 and 2008 were analyzed. The medical records of 82 anaerobic bacteremia patients were reviewed. A retrospective cohort study was conducted to determine the risk factors for in-hospital mortality of patients with anaerobic bacteremia. RESULTS: A total of 289 non-duplicated anaerobic isolates were recovered from blood, body fluids and abscess specimens. Bacteroides fragilis (73 isolates, 25.3%) was the most common organism followed by Clostridium perfringens (22 isolates, 7.6%), Peptoniphilus asaccharolyticus (21 isolates, 7.3%) and Anaerococcus prevotii (19 isolates, 6.6%). Eighty-four isolates were recovered from blood specimens, among which B. fragilis (24 isolates) and C. perfringens (21 isolates) were the most frequently isolated organisms. Among the 196 underlying diseases of anaerobic bacteremia patients, neoplastic, infectious, and gastrointestinal diseases accounted for 54 (27.6%), 46 (23.5%), and 41 (20.9%) cases, respectively. The alimentary tract was the most common suspected portal of entry. The in-hospital mortality rate of anaerobic bacteremia patients was 34.2%, and neutropenia at the time of blood culture was the only statistically significant factor associated with mortality in this study. Anaerobes were isolated in 1.4% of all positive blood cultures. CONCLUSIONS: B. fragilis and C. perfringens are expected to be commonly isolated from clinical specimens. Despite its low prevalence, anaerobic bacteremia displays a significant in-hospital mortality rate. Ongoing investigations into anaerobic bacteremia are necessary because of ambiguous risk factors for mortality.