BACKGROUND: The ComboStick Reader 720(R)(DFI Co., Ltd. Korda) is a newly developed automated urine analyzer. The objective of this analysis was to evaluate the analytical performance of the Combostick Reader 720 and ComboStick 10 reagent strips and to compare the results using the Uriscan Pro II and Uriscan Gen 10 SGL strips (YD Diagnostics, Korea). METHODS: The Dipstick urinalyses were performed on a ComboStick Reader 720(R) using ComboStick 10 strips and on a Uriscan Pro II(R) using Uriscan 10 SGL strips. Precision was evaluated with commercial control materials. The sets of results were analyzed for concordance with weighted kappa values or intraclass correlation coefficients (ICCs). The microscopic urine analysis was carried out to confirm the results from both automated urine analyzers. Agreement between the dipstick methods and the microscopic method was evaluated by kappa values and the McNemar test. RESULTS: Within and between-run precisions of the ComboStick Reader 720(R) were 90.0% to 100%. A comparison of results from 1,700 urine samples using the ComboStick Reader 720(R) and Uriscan Pro II(R) revealed a very high concordance rate of > or = 91.0% on consideration of neighboring blocks for all analytes of the dipstick urinalysis. There was a good association between the microscopic method and the dipstick methods of the two automated urine analyzers. The ComboStick Reader 720(R) revealed a statistically higher degree of agreement for leukocytes. CONCLUSIONS: The ComboStick Reader 720(R) and ComboStick 10 strips showed good precisions and revealed a statistically significant agreement with the Uriscan Pro II(R) and Uriscan 10 SGL strips. For leukocytes, the ComboStick Reader 720(R) was superior to the Uriscan Pro II(R) in comparing the agreement between the microscopic and dipstick methods. The overall performance of the ComboStick Reader 720(R) and ComboStick 10 strips were satisfactory.
Leukocytes ; Reagent Strips ; Urinalysis

BACKGROUND: We evaluated the performance of the GEM Premier 4000 (Instrumentation Laboratory, USA), a new blood gas/electrolytes/co-oximetry analyzer, according to the Clinical and Laboratory Standard Institute (CLSI) guidelines. METHODS: Within-run precision, total-run precision, linearity and sample-related carryover were analyzed using quality control materials at three different concentration levels for each analytes. Correlation was compared with the routinely used NOVA CCX2 (Nova Biomedical, USA) with patients' whole blood samples. RESULTS: The within-run and the total-run precisions of the GEM Premier 4000 showed very low CV of 0.04~4.40% and 0.06~4.11%, respectively, in all parameters except the lactate, which had CV of 5.58% in Level 1 QC material. The system showed a good linearity (r2=0.997~1.000, systemic error=0.00~0.20%) for all items. Sample-related carryover was -4.35%~0.15%. In comparison with the NOVA CCX2 instrument, correlation was high in all parameters with the r value ranging from 0.983-0.999 except for carboxyhemoglobin (r=0.804) and methemoglobin (r=0.010) whose concentrations were in the lower level. CONCLUSIONS: GEM Premier 4000 showed good analytical performance required for blood gas analyzer in its precision, linearity, sample-related carryover, and close correlation with NOVA CCX2. It fulfills most of the requirements for both point-of-care and laboratory use.
Carboxyhemoglobin ; Lactic Acid ; Methemoglobin ; Quality Control

BACKGROUND: Liquid chromatography-tandem mass spectrometry (LC-MS/MS) are used increasingly for tacrolimus monitoring. However, there are still variability of results due to home-brew reagents, so which cannot be warrantable data. We evaluated the analytical performance and clinical usefulness of a newly introduced MassTrak LC/MS/MS Tacrolimus kit (Waters Corporation, USA). METHODS: The performance of LC-MS/MS for determination of tacrolimus concentration were analyzed using patient samples and MassTrak LC/MS/MS Tacrolimus kit including calibrators, quality controls, internal standard, column and neat solution with respect to linearity, precision, lower limit of detection, lower limit of quantitation, sample carryover and comparison according to CLSI guidelines. The LC-MS/MS using home-brew reagents were performed for comparison test. RESULTS: The LC-MS/MS using MassTrak LC/MS/MS Tacrolimus kit showed a good linearity (R2> or =0.997) and precision (CV< 8%). Assigned LLOD (0.4 ng/mL) and LLOQ (0.8 ng/mL) were validated and carryover was estimated 0.5%. The system correlated well with the LC-MS/MS using home-brew reagents (R> or =0.974). CONCLUSIONS: LC-MS/MS using MassTrak LC/MS/MS Tacrolimus kit for determination of tacrolimus concentration showed good performance for linearity, precision, LLOD, LLOQ, carryover and comparison. Introduction of MassTrak LC/MS/MS Tacrolimus kit could be warranted results by manufacturer and useful for management of quality control.
Humans ; Indicators and Reagents ; Limit of Detection ; Mass Spectrometry ; Quality Control ; Tacrolimus

BACKGROUND: Bone turnover markers (BTMs) are widely used tool for monitoring the response to osteoporosis therapy, and the normal adult reference range is the baseline value for the treatment of osteoporosis with anti-resorptive agents. This study was aimed to establish age- and sex-specific reference ranges of serum osteocalcin and serum type I collagen C-telopeptide (S-CTX) in adults based on menstrual stage. METHODS: Serum osteocalcin, S-CTX and bone mineral density (BMD) were measured in 291 adults (men: 162, women: 129), and follicle stimulating hormone (FSH) in women. Seven women whose serum FSH levels were >30 IU/mL were categorized as perimenopausal despite their regular menses. RESULTS: Among females with normal BMD, there were no difference in serum osteocalcin and S-CTX levels between premenopausal and postmenopausal women. Females with osteopenia in pre- and postmenopausal stage showed higher serum osteocalcin and S-CTX levels than females with normal BMD. For subjects with normal BMD, reference ranges of serum osteocalcin and S-CTX were 6.4~21.6 ng/mL and 0.08~0.85 ng/mL for 30~59-year-old females. For males with normal BMD, reference ranges of serum osteocalcin were 10.1~24.3 ng/mL for 30~39 years old and 7.7~22.4 ng/mL for 40~59 years old, and reference range of CTX was 0.13~1.27 ng/mL for 30~59 years old. CONCLUSIONS: This study will provide a redefinition of the criteria required in order to establish the normal reference ranges for BTMs. Moreover, we believe that our data will come in handy when used as normal reference ranges of BTMs in premenopausal women.
Adult ; Bone Density ; Bone Diseases, Metabolic ; Collagen Type I ; Female ; Follicle Stimulating Hormone ; Humans ; Male ; Osteocalcin ; Osteoporosis ; Peptides ; Reference Values

BACKGROUND: The aim of this study was to compare a new stir method with the conventional refrozen method used to prepare pooled sera. METHODS: We prepared fifteen different pooled sera by using two pooled sera preparation methods. Twenty dispensed sera from each pooled serum were analyzed for glucose, total protein, albumin, aspartate aminotransferase, total bilirubin, triglyceride, blood urea nitrogen, creatinine, sodium, potassium, and chloride concentrations. For stability study, six different pooled sera were stored at room temperature, 4degrees C, and -70degrees C for 3 months and the eleven components were measured for each month. RESULTS: There was no difference in homogeneity between stir and refrozen pooled sera preparation methods and good stability was observed for -70degrees C storage of all measured components. CONCLUSIONS: The stir method might be more useful than refrozen method to prepare pooled sera.
Aspartate Aminotransferases ; Bilirubin ; Blood Urea Nitrogen ; Creatinine ; Glucose ; Potassium ; Quality Control ; Sodium

The quality control for genetic tests would be of great importance as the test volume and clinical demands increase dramatically. Diagnostic genetics subcommitee of KSQACP performed two trials for cytogenetic study in 2008. A total of 41 laboratories participated in the cytogenetic surveys, and most of them showed acceptable results. However, some laboratories showed unacceptable results for the karyotype nomenclature and detection of complex cytogenetic abnormalities in hematologic neoplasias. The molecular genetics surveys included various tests: M. tuberculosis detection, hepatitis B (HBV) and C virus (HCV) detection and quantification, human papilloma virus (HPV) genotyping, gene rearrangement tests for leukemias and lymphomas, apolipoprotein E (APOE) genotyping, methylenetetrahydrofolate reductase (MTHFR) genotyping, hereditary breast and ovarian cancer genes (BRCA1 and BRCA2), and genetic tests for hereditary disorders such as spinal muscular atrophy (SMA), Huntington disease (HD), spinocerebellar ataxia (SCA), Prader-Willi/Angelman syndrome (PWS/AS), mitochondrial encephalopathy with lactic acidosis and strokelike episodes (MELAS), myoclonic epilepsy ragged red fiber (MERRF), wilson disease (ATP7B) and cancer-associated genes (KRAS). Molecular genetic surveys showed excellent results in most of the participants. External quality assessment program for genetic analysis in 2008 was proved to be helpful in continuous education and evaluation of quality improvement.
Acidosis, Lactic ; Apolipoproteins ; Breast ; Chromosome Aberrations ; Cytogenetics ; Epilepsies, Myoclonic ; Gene Rearrangement ; Hepatitis B ; Hepatolenticular Degeneration ; Humans ; Huntington Disease ; Karyotype ; Korea ; Leukemia ; Lymphoma ; Methylenetetrahydrofolate Reductase (NADPH2) ; Mitochondrial Encephalomyopathies ; Molecular Biology ; Muscular Atrophy, Spinal ; Ovarian Neoplasms ; Papilloma ; Quality Control ; Quality Improvement ; Spinocerebellar Ataxias ; Tuberculosis ; Viruses

BACKGROUND: The association between HLA-DRB1 gene and severity of rheumatoid arthritis (RA) has been documented in various reports. Especially, DRB1*0405 allele shows significant association with RA in Korean patients. DRB1*0405 typing has been performed by the sequence based typing method (SBT), that is a difficult and expensive method. So we tried to replace it with a simple and inexpensive method. METHODS: We performed the HLA-DRB1*0405 typing using PCR-SSP technique with sequence specific primers of 3 pair in 298 Koreans. These results were compared with those of high resolution sequence based typing (SBT) method. RESULTS: Of 298 samples typed with the high resolution SBT method, 60 samples were HLA-DRB1*04 positive and showed 9 subgroups of HLA-DRB1*04 and 26 samples were HLA- DRB1*0405 positive. With the PCR-SSP method, same 26 samples were HLA-DRB1*0405 positive, showing 100% correspondence between two methods to detect HLA-DRB1*0405 CONCLUSIONS: Using PCR-SSP method to type HLA-DRB1*0405 is a very useful tools for studying the association between rheumatoid arthritis and HLA-DRB1*0405 from a practical and economic view.
Alleles ; Arthritis, Rheumatoid ; HLA-DR Antigens ; HLA-DRB1 Chains ; Humans

BACKGROUND: Mediace RPR test for chemistry autoanalyzer, a nontreponemal serologic test for syphilis, was recently introduced in Korea. We evaluated the performance of Mediace RPR test. METHODS: For the evaluation of precision, within-run and total coefficient variations were analyzed. Two hundred and one sera were tested by Mediace RPR test to investigate the distribution of Mediace RPR titers in healthy subjects. Mediace RPR test was compared with RPR card test using 126 sera. RESULTS: Total coefficient variations for positive control, negative control and pooled sera were 9.1%, 46.6% and 35.3%, respectively. The results of Mediace RPR test in healthy subjects showed 0.44+/-0.28 (mean+/-standard deviation) RPR unit (RU), and the positive rate was 3.5% (7/201). The agreement between Mediace RPR test and RPR card test was 73%. In some of the sera with a result of greater than 4.0 RU, Mediace RPR test showed markedly lower results than that of RPR card quantitative test. CONCLUSION: Mediace RPR test has the advantages that it is useful for screening large number of samples and the results are objective. Mediace RPR test can be used as a quantitative test in sera with low titers. Dilution is needed to determine high titers in sera. Adjusting cutoff for the setting of individual hospital is maybe helpful.
Chemistry* ; Korea ; Mass Screening ; Serologic Tests* ; Syphilis*

BACKGROUND: We evaluated the analytical performance of the recently developed glucometer Gluchec Fine (KMH Co., Ltd., Anyang, Gyeonggi, Korea) in Korea. METHODS: Within-run precision and total precision were assessed according to CLSI guideline EP5-A2 with control material of low and high level. Linearity was evaluated in the range of 51-473 mg/dL made by patient samples. Correlations with SureStep (Lifescan, Milpitas, CA, USA) and TBA200-FR (Toshiba, Tokyo, Japan) were evaluated using 99 patient samples in the range of 23-473 mg/dL. Interferences by acetaminophen, ascorbic acid, bilirubin, cholesterol, galactose, and uric acid were elvauated according to CLSI guideline EP7-A. Effect of hematocrit, user variability and reagent stability were assessed. RESULTS: The CVs of within-run precision were 2.5-3.0% and the CVs of total precision were 3.6-4.7%. The linearity was R(2)=0.998. The correlations with TBA200-FR (R=0.982) and Surestep (R=0.984) were acceptable. Glucose concentrations measured by Gluchec Fine were lower than those by TBA200-FR (mean 2.7%, 95% CI 0.3-5.1%) in the range of 23-473 mg/dL. Acetaminophen, galactose, and cholesterol did not interfere with glucose measurements on Gluchec Fine. High concentrations of ascorbic acid, bilirubin, and uric acid resulted in positive interferences. Hematocrit and user variability did not significantly influence the glucose concentration. Reagent was stable until one week after opening. CONCLUSIONS: Gluchec Fine glucometer showed acceptable and comparable analytical performance. This instrument can be used for therapeutic monitoring of diabetes patients.
Acetaminophen ; Ascorbic Acid ; Bilirubin ; Cholesterol ; Galactose ; Glucose ; Gyeonggi-do ; Hematocrit ; Humans ; Korea ; Uric Acid

BACKGROUND: Plastic tubes have recently been used for blood collection tubes in clinical laboratories. The silicone coated plastic tube is said to be very similar with the glass tube and to show no difference with the glass tube in routine blood test except for some tests such as hormone tests and drug monitoring. So, we investigated the influence of plastic tube on the thyroid hormone test using two types of plastic vacuum tubes. METHODS: A total of 105 cases for the total triiodothyronine (T3), total thyroxine (T4), and thyroid stimulating hormone (TSH) were studied. The glass tube was a plain glass tube, and the plastic tube was a serum separator tube with gel. The plastic vacuum tubes used in this study were the SST II plus tube (Becton Dickinson, Franklin Lakes, USA) and the Vacuette tube (Greiner Bio-One, Kremsmunster, Austria). An IMMULITE 2000 analyzer (Diagnostic Products Corporation, Los Angeles, USA) was used to measure the total T3, total T4 and TSH. RESULTS: Comparisons of the measured values within 1 hour of blood collection in the plastic tube with that in the glass tube are as follows. There was no difference between the Vacuette tube and the glass tube for the three tests, while there was statistically significant difference between the SST II plus tube and the glass tube for the total T3 and total T4. CONCLUSIONS: It might need more cautious interpretation of the results by a solid-phase, competitive chemiluminescent enzyme immunoassay, when the plastic vacuum tube is used as a blood collection tube instead of the glass tube.
Drug Monitoring ; Glass* ; Hematologic Tests ; Immunoenzyme Techniques ; Lakes ; Plastics* ; Silicones ; Thyroid Gland* ; Thyrotropin ; Thyroxine ; Triiodothyronine ; Vacuum*