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.
CA-125 Antigen/blood ; CA-19-9 Antigen/blood ; Carcinoembryonic Antigen/blood ; Humans ; Immunoassay/*instrumentation/*methods ; Tumor Markers, Biological/*blood ; alpha-Fetoproteins/metabolism

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.
DNA ; DNA, Viral* ; Hepatitis B virus ; Hepatitis B, Chronic* ; Hepatitis, Chronic* ; Humans ; Limit of Detection ; Pathology, Molecular ; Plasma ; Retrospective Studies ; Viral Load

Area Under Curve ; Biomarkers, Tumor ; Carcinoembryonic Antigen ; Carcinoma, Non-Small-Cell Lung ; Carcinoma, Squamous Cell ; Diagnosis ; Keratin-19 ; Lung Neoplasms ; Lung ; Medical Records ; Multivariate Analysis ; Retrospective Studies ; ROC Curve ; Sensitivity and Specificity

BACKGROUND: The domestic quantity of blood components consumed has been decreasing since 2002, but the rate of a single unit RBC transfusion (SUT) has been on the increase. In the past, a SUT was regarded as an uncesssary procedure, but currently is considered as an effective method to maintain a minimal hemoglobin concentration for physiological needs. We investigated the actual conditions of a SUT. METHODS: We analyzed 800 cases of SUTs performed at a tertiary care university hospital between March 2006 March and February 2007. The subjects of the study were divided into a surgical group (n=561) and medical group (n=239) for the purpose of RBC unit usage and were analyzed by groups and ordering departments, with an analysis of the pre and post-transfusion hemoglobin concentration and hematocrit values. The distribution according to the pre and post-transfusion hemoglobin ranges were calculated. RESULTS: The mean hemoglobin concentration increment of the surgical group was significantly lower than that of the medical group (P<0.0001) and the mean pre and post-transfusion hemoglobin concentrations of the medical group were lower than that of the surgical group (P<0.0001). Approximately 26% cases of the SUTs performed in the surgical group were appropriate, based on a post-transfusion hemoglobin concentration below 10 g/dL. In the medical group, about 75% of the SUTs were appropriate based on a pre-transfusion hemoglobin concentration below 9 g/dL. CONCLUSION: Most transfusions are decided based on various clinical situations and opinions of the clinicians. Therefore, continuous evaluation of the appropriateness of transfusion is necessary. In our study, the appropriateness of a SUT was estimated indirectly based on the pre and post-transfusion hemoglobin concentration. Consequently, policies and strategies for performing asingle unit RBC transfusion are required.
Hematocrit ; Tertiary Healthcare

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.
Hepacivirus ; Hepatitis C Antibodies ; Humans ; Medical Records

Clinical neuropsychological test were developed originally for the diagnosis of neurological and neuro-surgical diseased. Recently, these tests are being introduced to psychiatric patients. Authors had the experience to use these tests in pychiatric outpatient clinic. Results were as follows. There was a significantly increase in language and attentional function in residual schizophrenia compared to normal control. In chronic neurosis, as visuospatial function was reduced, language and attentional functions were enhanced. With these results, authors suggest that application of neuropsychological tests in psychiatric patients may be very helpful in classifying the subgroups of disease, in selecting the modality of treatment. and in expecting prognosis.
Ambulatory Care Facilities ; Diagnosis ; Humans ; Neuropsychological Tests* ; Neuropsychology ; Outpatients* ; Prognosis ; Schizophrenia

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.
Automation/methods ; DNA/blood/*isolation & purification ; Humans ; Polymerase Chain Reaction ; *Reagent Kits, Diagnostic ; Reproducibility of Results

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.
Antithrombin III ; Fibrin Fibrinogen Degradation Products ; Fibrinogen ; Hemostasis ; Latex ; Partial Thromboplastin Time ; Prothrombin Time

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.
Asian Continental Ancestry Group/genetics ; Base Sequence ; Gene Frequency/genetics ; Genotype ; HLA Antigens/*genetics ; Histocompatibility Testing ; Humans ; Polymerase Chain Reaction

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.
Adiponectin ; Automation ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Insulin Resistance ; Male ; Metabolic Diseases ; Plasma