Background and Objectives: Recent guidelines from the Korean Thyroid Association have proposed a threshold of 6.8 mIU/L for diagnosing subclinical hypothyroidism based on local research findings. However, due to the lack of standardization/harmonization, thyroid-stimulating hormone (TSH) testing yields varying results across different reagent manufacturers. Hence, the use of uniform reference intervals is challenging. We aimed to establish assay-specific Korean reference interval for TSH. Materials and Methods: We performed duplicate measurements on 100 serum samples with varying TSH concentrations (0-23 mIU/L) using eight different TSH reagents including Alinity I TSH (Abbott), Access TSH (Beckman Coulter), Elecsys TSH (Roche), TSH3UL (Siemens),TSH IRMA (Beckman Coulter), TSH1 RIA (Brahms), TSH IRMA TUBE II (Riakey), Turbo TSH IRMA (Izotop).Correlation and simple linear regression analyses were conducted among 8 reagents with Roche as the reference. Results The correlation coefficient for each reagent was notably high at 0.99. Through regression analysis, TSH values equivalent to the 6.8 mIU/L (Roche) were determined for each reagent as follows: Abbott 5.2 mIU/L, Beckman 6.5 mIU/L, Siemens 6.9 mIU/L, Beckman-Radioimmunoassay 7.4 mIU/L, Brahms 5.7 mIU/L, Riakey 5.3 mIU/L, Izotop 6.0 mIU/L. Conclusion: Given the observed differences in TSH values associated with different reagents, it is imperative to consider these differences when interpreting results within various clinical contexts and adapting them to clinical practice.

ELISAs and rapid diagnostic tests (RDTs) are widely used for diagnosing dengue virus (DENV) infection. Using 138 single blood samples, we compared the ability to detect non-structural (NS)-1 antigen and anti-DENV IgM/IgG antibodies among (1) DENV Detect NS1 ELISA, DENV Detect IgM capture ELISA and DENV Detect IgG ELISA (InBios International, Inc.); (2) Anti-Dengue virus IgM Human ELISA and Anti-Dengue virus IgG Human ELISA (Abcam); (3) Dengue virus NS1 ELISA, Anti-Dengue virus ELISA (IgM) and Anti-Dengue virus ELISA (IgG) (Euroimmun); (4) Asan Easy Test Dengue NS1 Ag 100 and Asan Easy Test Dengue IgG/IgM (Asan Pharm); (5) SD BIOLINE Dengue Duo (Standard Diagnostics); and (6) Ichroma Dengue NS1 and Ichroma Dengue IgG/IgM (Boditech Med). For NS1 antigen detection, InBios and Euroimmun showed higher sensitivities (100%) than the RDTs (42.9–64.3%). All tests demonstrated variable sensitivities for IgM (38.1–90.5%) and IgG (65.7–100.0%). InBios and Boditech Med demonstrated higher sensitivity (95.6% and 88.2%, respectively) than the other tests for combined NS1 antigen and IgM antibody. Five NS1 antigen tests had good agreement (92.8–98.6%) without showing positivity for chikungunya. However, all IgG tests demonstrated potential false-positivity with variable ranges. Clinical laboratories should note performance variations across tests and potential cross-reactivity.
Antibodies ; Chungcheongnam-do ; Dengue Virus ; Dengue ; Diagnosis ; Diagnostic Tests, Routine ; Enzyme-Linked Immunosorbent Assay ; Humans ; Immunoglobulin G ; Immunoglobulin M

BACKGROUND: In Korea, the Korean Laboratory Accreditation Program (KLAP) has set minimum standards for verification of clinical test performance. This verification process is time-consuming and labor-intensive when performed manually. We developed a free, statistical software program for KLAP, using the R language (R Foundation for Statistical Computing, Vienna, Austria). METHODS: We used CLSI guidelines for the algorithm. We built graphic user interfaces, including data input, with Embarcadero Delphi EX4 (Embarcadero Technologies, Inc., Texas, USA). The R Base Package and MCR Package for Method Comparison Regression were used to implement statistical and graphical procedures. RESULTS: Our program LaboStats has six modules: parallel test, linearity, method comparison, precision, reference interval, and cutoff. Data can be entered into the field either manually or by copying and pasting from an MS Excel worksheet. Users can print out precise reports. CONCLUSIONS: LaboStats can be useful for evaluating clinical test performance characteristics and preparing documents requested by KLAP.
Accreditation ; Korea ; Mathematical Computing ; Methods ; Texas

No abstract available.
Immunoassay ; Prostate ; Prostate-Specific Antigen

Bone turnover markers (BTMs) have important role in the management of osteoporosis. Recently the clinical application of BTMs has achieved significant progress and measurement of BTMs give us better understanding of pathogenesis of osteoporosis. However, the use of BTMs is still insufficient in Korea. We summarized the available methods and standard interval of the BTMs in Korea. Also we reviewed published literatures on pre-analytical variability in the measurement of BTMs and provided recommendations for standardized sample handling and patient preparation for reducing those pre-analytical variabilities. The clinical application of BTMs in patients with chronic kidney disease who have a higher fracture risk than the general population is summarized.
Biomarkers ; Bone Remodeling ; Humans ; Korea ; Osteoporosis ; Renal Insufficiency, Chronic

BACKGROUND: There has been interest in the clinical potential of bone turnover markers (BTMs) as tools both for assessing fracture risk and for monitoring treatment. However, the practical use of BTMs has been limited by their biological variability and difficulties in the interpretation of results. We investigated the current situation of application of BTMs by clinicians in Korea for the management of osteoporosis through a survey asking the patterns of BTMs prescription in clinical practice.METHODS: The survey was conducted online using the “google survey” by the BTM committee authorized by the Korean Society for Bone and Mineral Research.RESULTS: Total 108 clinicians responded the survey. Most of the respondents prescribed BTMs (80.6%) when they prescribed anti-osteoporotic medications (AOMs). The most frequently prescribed bone resorption and formation markers were serum C-terminal telopeptide of type I collagen (90.7%) and osteocalcin (65.1%), respectively. BTMs were mostly prescribed before starting AOMs (90.8%) and used for the purpose of evaluating treatment response (74.4%). Treatment response and compliance to AOMs were evaluated according to the change of absolute value of BTMs (55.1%). The respondents complained difficulties in the interpretation of BTMs (33.3%), the choice of proper BTMs (17.2%), and the proper sample preparation and handling (13.8%).CONCLUSIONS: In Korea, most of clinicians recognized the benefit of BTMs in the management of osteoporosis. However, there are limitations in the broad use of these markers in clinical practice. Therefore, a clear recommendation for BTM in Korea enhances their use in clinical practice.
Biomarkers ; Bone Remodeling ; Bone Resorption ; Collagen Type I ; Compliance ; Korea ; Miners ; Osteocalcin ; Osteoporosis ; Prescriptions ; Surveys and Questionnaires

Current evidences continue to support the clinical application of bone turnover markers (BTMs) in the management of postmenopausal osteoporosis. The limitations of bone mineral density measured by dual energy X-ray absorptiomet especially emphasize the beneficial roles of BTMs, such as serum C-terminal telopeptide of type I collagen and serum procollagen type I N-propeptide, as monitoring tools to assess the responses to treatment. Therefore, the proper application and assessment of BTM in clinical practice is very important. However, their use in Korea is still insufficient. Therefore, the BTM committee has set up by the Korean Society for Bone and Mineral Research have been constituted and provided a position statement which will suggest on the clinical application of BTM for the management of postmenopausal osteoporosis in Korea.
Bone Density ; Bone Remodeling ; Collagen Type I ; Female ; Humans ; Korea ; Miners ; Osteoporosis ; Osteoporosis, Postmenopausal ; Republic of Korea

PURPOSE: Symptomatic spontaneous isolated splanchnic artery dissection (SSISAD) is a rare disease entity. The treatment guideline for SSISAD has not been established. Isolated dissection of splanchnic artery can be clinically asymptomatic or symptomatic. Symptomatic dissection is more important because it can indicate ischemia of abdominal organ. METHODS: A retrospective study was conducted on 15 consecutive patients (mean age, 47.0 years; male, 87%) with SSISAD from January 2006 to July 2013. Each patient had acute onset abdominal pain and was diagnosed with SSISAD by abdominal-pelvic computed tomography. RESULTS: Median follow-up duration was 14.5+/-27.7 months (range, 1 to 79 months). Splanchnic arterial dissection involved celiac artery in three patients and superior mesentery artery in 12 patients. Conservative management (including bowel rest, hypertension medication, anticoagulation, and prophylactic antibiotics) was done in 14 patients. Endovascular treatment with stent insertion was performed in one patient. We experienced favorable clinical outcomes with SSISAD, even though one case needed endovascular treatment. CONCLUSION: Conservative management and selective revascularization could be a treatment option in patients with SSISAD.
Abdominal Pain ; Arteries* ; Celiac Artery ; Follow-Up Studies ; Humans ; Hypertension ; Ischemia ; Male ; Mesenteric Artery, Superior ; Mesentery ; Rare Diseases ; Retrospective Studies ; Stents

BACKGROUND: We evaluated the analytical performance of Wako assays for albumin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), complement C3 and C4, calcium, creatine kinase (CK), C-reactive protein (CRP), direct bilirubin (DBIL), iron, gamma-glutamyl transferase (GGT), HDL cholesterol (HDLC), inorganic phosphorus (IP), LDL cholesterol (LDLC), total bilirubin (TBIL), total protein (TP), and uric acid (UA), as well as the performance of Sekisui assays for albumin, BUN, calcium, CRP, HDLC, IP, LDLC, TP, and UA by using Hitachi LABOSPECT 008 (Hitachi High-Tech Co., Japan). METHODS: Liquid Assayed Multiqual Control (Bio-Rad Laboratories, USA) and pooled patients' sera were analyzed for 20 days. Wako linearity material (Wako Pure Chemical Industries, Ltd., Japan) and Sysmex Interference Check A Plus kit (Sysmex Co., Japan) were used to test linearity and interference, respectively. Concentrations of the target analytes were measured using Hitachi LABOSPECT 008 in 100 residual patient specimens and compared to those in Pureauto S series reagent (Sekisui Medical, Japan), which were measured using Hitachi 7600 (Hitachi High-Tech Co., Japan). RESULTS: Total coefficients of variation (CVs) for the tested analytes were 0.91-9.26% in Wako and 1.04-7.46% in Sekisui assays. Linearity was demonstrated up to the highest concentration within the analytical range in all the assays except for Wako albumin and Sekisui TP. Wako and Sekisui albumin, BUN, CRP, HDLC, and LDLC assays, and in Wako C3, C4, calcium, and UA assays showed no interference with the test concentrations used. All the tested assays, except for Wako AST, LDLC, and TP, and Sekisui calcium and TP, demonstrated comparability with comparative method for at least one medical decision level. CONCLUSIONS: Our study results showed that the analytical performances of Wako and Sekisui chemistry assays evaluated using Hitachi LABOSPECT 008 had appropriate analytical performance for clinical use.
Alanine Transaminase ; Aspartate Aminotransferases ; Bilirubin ; Blood Urea Nitrogen ; C-Reactive Protein ; Calcium ; Chemical Industry ; Chemistry Techniques, Analytical ; Chemistry, Clinical ; Cholesterol, HDL ; Cholesterol, LDL ; Clinical Chemistry Tests ; Complement C3 ; Creatine Kinase ; Humans ; Iron ; Phosphorus ; Transferases ; Uric Acid

BACKGROUND: Measurement of HbA1c levels is widely used to diagnose diabetes mellitus and to evaluate and monitor plasma-glucose concentrations over 6-8 weeks. In this study, we evaluated the diagnostic performance of the newly developed latex immunoturbidimetric method by using Autolab HbA1c. METHODS: We analyzed and compared the diagnostic performance of Autolab HbA1c with that of Toshiba 200FR between April 2009 and July 2009. According to guidelines (EP5-A2, EP6-P, EP9-A2) of the clinical and laboratory standards institute (CLSI), we compared linearity, precision and correlation of Autolab HbA1c with those of G7 (Tosoh Corp., Kyoto, Japan) by using high-performance liquid chromatography (HPLC) method. RESULTS: Data obtained using Autolab HbA1c showed good linearity in mixtures of samples with low (3.1%) and high (15.1%) levels of HbA1c (r2 = 0.9997). In the analysis of within-run precision of the samples with HbA1c levels of 5.1% and 12.1%, the SDs were 0.04 and 0.06 and covariances of these samples were 0.8% and 0.5%, respectively. In the Deming regression model, the regression equation was as follows: Autolab HbA1c = 1.0859xTosoh HPLC-0.6957. CONCLUSIONS: In this study, Autolab HbA1c method showed better performance characteristics than Tosoh G7 did. In reference review, there was no interference of variant hemoglobin. The data acquisition time of Autolab HbA1c was lower than that of Tosoh G7. The advantages of Autolab HbA1c are that it can be used as an autoanlyzer in routine chemical analysis, it does not require pre-analytical treatment, and the samples are automatically treated with distilled water for hemolysis.
Chromatography, High Pressure Liquid ; Chromatography, Liquid ; Diabetes Mellitus ; Hemoglobins ; Hemolysis ; Latex ; Organothiophosphorus Compounds ; Water