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Laboratory Evaluation of Automated Urine Analyzer ComboStick Reader 720(R) and Reagent Strip ComboStick 10.

Min Jung KWON ; Hyup Woo LEE ; Ga Yeong KIM ; Myeong Hyeon NAM ; Chang Kyu LEE ; Young Kee KIM

Journal of Laboratory Medicine and Quality Assurance.2009;31(1):215-223.

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

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Evaluation of the Blood Gas Analyzer GEM Premier 4000.

Hee Young CHUNG ; Hee Jung CHUNG ; Sail CHUN ; Woochang LEE ; Won Ki MIN

Journal of Laboratory Medicine and Quality Assurance.2009;31(1):207-214.

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

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Performance Evaluation of MassTrak LC/MS/MS Tacrolimus Kit.

Jaekwang NOH ; Heewon MOON ; Mina HUR ; Yeomin YUN

Journal of Laboratory Medicine and Quality Assurance.2009;31(1):199-205.

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

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Age and Sex Specific Reference Ranges of Serum Type I Collagen C-telopeptide and Osteocalcin Based on Menstrual Stage.

Ohgun KWON ; Young UH ; Gyu Yul HWANG ; An Sook JUNG ; Kap Jun YOON

Journal of Laboratory Medicine and Quality Assurance.2009;31(1):187-198.

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

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Preparation of Pooled Sera by Using Stirrer.

Joonhong PARK ; Yeongsic KIM

Journal of Laboratory Medicine and Quality Assurance.2009;31(1):183-186.

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

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Annual Report on External Quality Assessment in Diagnostic Genetics in Korea (2008).

Sun Hee KIM ; Chang Seok KI ; Byung Ryul JEON ; Seung Tae LEE ; Eun Hyung YOO ; Jong Won KIM ; Sung Sup PARK ; Jae Seok KIM ; You Kyung LEE ; Sun Young KONG ; Seung Jung KI ; Sung Hee HAN ; Eul Ju SEO

Journal of Laboratory Medicine and Quality Assurance.2009;31(1):161-181.

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

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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.

Yongjung PARK ; Jong Han LEE ; Eun Young LEE ; Hyon Suk KIM

Journal of Laboratory Medicine and Quality Assurance.2010;32(2):255-262.

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.
Biomarkers ; Carcinoma, Hepatocellular ; Codon ; DNA ; Exons ; Genes, p53 ; Genotype ; Hepatitis ; Hepatitis B ; Hepatitis B virus ; Homozygote ; Humans ; Plasma ; Polymorphism, Restriction Fragment Length ; Prevalence ; Protein Precursors ; Prothrombin ; Risk Factors

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Lot-to-lot Reagent Variation in Immunoassay: Retrospective Analysis of Daily Quality Control Results.

Hyun Soo KIM ; Hee Jung KANG ; Dong Hee WHANG ; Seong Gyu LEE ; Min Jeong PARK ; Ji Young PARK ; Hyoun Chan CHO ; Kyu Man LEE

Journal of Laboratory Medicine and Quality Assurance.2010;32(2):243-253.

BACKGROUND: Lot-to-lot reagent reproducibility is an important issue in immunoassays. However, there have been no universal criteria for acceptable lot-to-lot reproducibility. We sought to evaluate the inter-lot reagent difference by analyzing the results of various quality control materials during a certain period of time. METHODS: The results of control materials using different reagent lots and same control lots for immunoassays of HBsAg, anti-HBs, alpha-fetoprotein (AFP), ferritin, and CA 19-9 were analyzed. The average value, standard deviation, and coefficient of variation obtained from each reagent lot were calculated and differences in mean control values between two different reagent lots were assessed. We also analyzed the difference between the last control result using one reagent and the first control result using a new reagent. RESULTS: There was no significant difference in control values among reagent lots during this study period in all immunoassays of HBsAg, anti-HBs, AFP, ferritin, and CA 19-9. Some of the reagents showed statistical differences in QC values, but the difference was not considered clinically different. Also, at the time of reagent lot change, there was no significant difference in reagent parallel tests. CONCLUSIONS: Lot-to-lot reagent variation was not significant in immunoassays evaluated in this study. However, this study has been performed during relatively short period by one to three reagent lot changes, parallel testing should be continuously checked at reagent lot changes in each laboratory for continuous quality assurance. These results can be used as basic data for setting the criteria of acceptance on inter-lot difference in reagent parallel tests.
alpha-Fetoproteins ; Collodion ; Ferritins ; Hepatitis B Surface Antigens ; Immunoassay ; Indicators and Reagents ; Quality Control ; Retrospective Studies

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Evaluation of Hemo Techt NS-plus C15 Automatic Analyzer for Fecal Occult Blood Test.

Jeong Hyun KIM ; Seong Youn HWANG ; Young Jae KIM

Journal of Laboratory Medicine and Quality Assurance.2010;32(2):237-241.

BACKGROUND: Fecal occult blood tests have been widely used for colorectal cancer screening. In recent years, many laboratories have used automated fecal occult blood test analyzers using immunologic techniques for convenience, fast reporting and quantitative handling. Hemo Techt NS-Plus C15 (NS-Plus C) (Alfresa pharma Co., Japan) is a newly-introduced automated fecal occult blood test analyzer using colloidal gold agglutination methods. We evaluated the performance of NS-Plus C. METHODS: The linearity, precision and carry-over rate of NS-Plus C were evaluated. We performed parallel test between NS-Plus C and HM-JACK (Kyowa Medix Co., Japan) using 219 stool specimens. RESULTS: The linearity was good (R2=0.998) and coefficient of variation (CVs) of within-day precision were 2.61% and 2.07% in low and high concentration, and between-day CVs for each group were 3.18% and 1.63%, respectively. Carry over rate was 0% and concordance rate between NS-Plus C and HM-JACK was 98.6%. CONCLUSIONS: NS-Plus C showed good performance for linearity, precision, carry over rate and comparison study. Therefore, this is believed to be a highly reliable measurement system for fecal occult blood test.
Agglutination ; Colorectal Neoplasms ; Gold Colloid ; Handling (Psychology) ; Immunologic Techniques ; Mass Screening ; Occult Blood

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Evaluation of CareSens(R) N Glucometer Glucose Monitoring System.

Hee Jae HUH ; Hyung Doo PARK ; Soo Youn LEE ; Jong Won KIM

Journal of Laboratory Medicine and Quality Assurance.2010;32(2):229-236.

BACKGROUND: Point-of-care testing (POCT) glucometers are widely being used for management of diabetes. We examined the analytical performance of the recently developed glucometer CareSens(R) N Glucometer (i-SENS Inc., Korea). METHODS: CareSens N was evaluated for linearity, precision, and the effect of hematocrit. Method comparison using the laboratory reference method, hexokinase method by Hitachi 7600 (Hitachi Co., Japan) was also performed. Other glucometers, Accu-Chek(R) inform (Roche Diagnostics LTD., Germany) and Onetouch(R) ultra(TM) (Lifescan Inc., USA) were evaluated for the same categories according to CLSI guidelines. RESULTS: CareSens N Glucometer showed a good linearity and precision. The linearity was r=0.9965. The coefficients of variations (CVs) of within-run precision were 0.73-1.98% and CVs of total precision were 1.65-2.71%. A high correlation (glucose by CareSens N = 0.9767 x glucose by Hitachi 7600 + 4.1734, r=0.9614) was also shown between the CareSens N glucometer and Hitachi 7600 in the central laboratory. Other glucometers showed a good linearity. The within-run and total-run CVs of other glucometers were within 10%. Although differences with the reference method were within allowable ranges, all glucometers showed variable bias compared with the reference method. Overestimation or underestimation of glucose values were observed by change of hematocrit in range of 31.1 to 51.2%. CONCLUSIONS: CareSens N showed good linearity, precision, and correlation with reference method. CareSens N provided reliable result of blood glucose and seems appropriate for clinical use in the management of diabetic patients.
Bias (Epidemiology) ; Blood Glucose ; Glucose ; Hematocrit ; Hexokinase ; Humans ; Korea

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