Clinical and Laboratory Standard Institute's guidelines. Test results from clinical samples were compared between Tosoh G11 and the routine testing systems, Tosoh G8 and Capillarys 2 Flex Piercing.RESULTS: With respect to the precision of Tosoh G11, the test results for low- and high-concentration controls showed a coefficient of variation of less than 1.1%. Furthermore, the new device exhibited good linearity for HbA(1c) values ranging from 3.4% to 18.8%, and carry-over was not observed. HbA(1c) results for Tosoh G11 (N=143) correlated well with those for Tosoh G8 (r=0.9971) and Capillarys 2 Flex Piercing (r=0.9918).CONCLUSIONS: Tosoh G11 demonstrated reliable analytical performance with good precision and linearity, and no carry-over results. In addition, its results were comparable to those of the existing instruments. Thus, the results of this evaluation suggest that Tosoh G11 is suitable for the routine diagnostic testing of HbA(1c) levels in clinical chemistry laboratories.]]>
Chemistry, Clinical ; Diagnostic Tests, Routine ; Hemoglobin A, Glycosylated ; Humans

No abstract available.
Chemistry, Clinical ; Clinical Chemistry Tests ; Methods

The main goal of transfusion medicine is safe and appropriate blood transfusion in all situations. To accomplish this, it is essential to have a high level quality management system for the entire process from blood donation to transfusion. Regulations regarding blood management have been adopted and strictly managed in Korea since 2007. Blood center's blood management tasks should establish appropriate quality management systems to ensure the safe supply of blood, as well as the basic resources of personnel, facilities and equipment in accordance with laws and regulations governed by the Ministry of Health and Welfare in Korea. The purpose of this review is to examine the contents and processes for quality control of clinical chemistry tests in Korean blood centers.
Blood Donors ; Blood Transfusion ; Chemistry, Clinical* ; Clinical Chemistry Tests* ; Humans ; Jurisprudence ; Korea ; Quality Control ; Social Control, Formal ; Transfusion Medicine

BACKGROUND: Medical laboratories play a central role in health care. Many laboratories are taking a more focused and stringent approach to quality system management. In Korea, laboratory standardization efforts undertaken by the Korean Laboratory Accreditation Program (KLAP) and the Korean External Quality Assessment Scheme (KEQAS) may have facilitated an improvement in laboratory performance, but there are no fundamental studies demonstrating that laboratory standardization is effective. We analyzed the results of the KEQAS to identify significant differences between laboratories with or without KLAP and to determine the impact of laboratory standardization on the accuracy of diagnostic tests. METHODS: We analyzed KEQAS participant data on clinical chemistry tests such as albumin, ALT, AST, and glucose from 2010 to 2013. As a statistical parameter to assess performance bias between laboratories, we compared 4-yr variance index score (VIS) between the two groups with or without KLAP. RESULTS: Compared with the group without KLAP, the group with KLAP exhibited significantly lower geometric means of 4-yr VIS for all clinical chemistry tests (P<0.0001); this difference justified a high level of confidence in standardized services provided by accredited laboratories. Confidence intervals for the mean of each test in the two groups (accredited and non-accredited) did not overlap, suggesting that the means of the groups are significantly different. CONCLUSIONS: These results confirmed that practice standardization is strongly associated with the accuracy of test results. Our study emphasizes the necessity of establishing a system for standardization of diagnostic testing.
Accreditation* ; Bias (Epidemiology) ; Clinical Chemistry Tests ; Delivery of Health Care ; Diagnostic Tests, Routine* ; Glucose ; Korea

BACKGROUND: Psoriasis is a chronic inflammatory disease. In the treatment of psoriasis, cyclosporine is commonly prescribed systemic agents. However, long-term use of cyclosporine is not recommended because of side effects such as nephrotoxicity or hypertension. OBJECTIVE: To ascertain the improved safety of rotational therapy using cyclosporine and methotrexate, we investigated the frequency of abnormal results in laboratory test after long term rotational therapy using cyclosporine and methotrexate. METHODS: From January 2009 to June 2014, patients who were treated with cyclosporine or methotrexate were enrolled. The clinical data and usage of medications were reviewed. Laboratory tests were conducted before starting the treatment and regularly follow-up. The occurrences of any laboratory abnormalities during the treatments were investigated. RESULTS: A total of 21 psoriatic patients were enrolled. The mean of medication period and cumulative dose of cyclosporine and methotrexate were 497.81±512.06 days and 115.68±184.34 g in cyclosporine and 264.19±264.71 days and 448.71±448.63 mg in methotrexate. Laboratory abnormalities were found in total two patients after rotational therapy: two patients (9.5%) in aspartate aminotransferase/alanine aminotransferase and one patient (4.8%) in uric acid. No laboratory abnormalities were found in renal function test. CONCLUSION: We found that the rotational approaches using cyclosporine and methotrexate reduced the possibility of the development of nephrotoxicity. In addition to other advantage such as quick switching from one agent to another, the rotational therapy using cyclosporine and methotrexate can minimize the adverse events during the systemic treatment of chronic plaque psoriasis.
Aspartic Acid ; Clinical Chemistry Tests ; Combined Modality Therapy ; Cyclosporine* ; Follow-Up Studies ; Humans ; Hypertension ; Methotrexate* ; Psoriasis* ; Uric Acid

BACKGROUND: Psoriasis is a chronic inflammatory disease. In the treatment of psoriasis, cyclosporine is commonly prescribed systemic agents. However, long-term use of cyclosporine is not recommended because of side effects such as nephrotoxicity or hypertension. OBJECTIVE: To ascertain the improved safety of rotational therapy using cyclosporine and methotrexate, we investigated the frequency of abnormal results in laboratory test after long term rotational therapy using cyclosporine and methotrexate. METHODS: From January 2009 to June 2014, patients who were treated with cyclosporine or methotrexate were enrolled. The clinical data and usage of medications were reviewed. Laboratory tests were conducted before starting the treatment and regularly follow-up. The occurrences of any laboratory abnormalities during the treatments were investigated. RESULTS: A total of 21 psoriatic patients were enrolled. The mean of medication period and cumulative dose of cyclosporine and methotrexate were 497.81±512.06 days and 115.68±184.34 g in cyclosporine and 264.19±264.71 days and 448.71±448.63 mg in methotrexate. Laboratory abnormalities were found in total two patients after rotational therapy: two patients (9.5%) in aspartate aminotransferase/alanine aminotransferase and one patient (4.8%) in uric acid. No laboratory abnormalities were found in renal function test. CONCLUSION: We found that the rotational approaches using cyclosporine and methotrexate reduced the possibility of the development of nephrotoxicity. In addition to other advantage such as quick switching from one agent to another, the rotational therapy using cyclosporine and methotrexate can minimize the adverse events during the systemic treatment of chronic plaque psoriasis.
Aspartic Acid ; Clinical Chemistry Tests ; Combined Modality Therapy ; Cyclosporine* ; Follow-Up Studies ; Humans ; Hypertension ; Methotrexate* ; Psoriasis* ; Uric Acid

Medical diagnostics plays a significant role in clinical decisions. The first medical laboratory test to be developed was urine analysis, in which urine properties were analyzed for diagnosis. Urine analysis has been long used as a routine laboratory test that was improved with the development of sampling and test methods. As the field of hematology progressed with the invention of the microscope, blood tests were developed. Demands for tests based on clinical chemistry have existed since the 17th century, and research using patient blood began in the 18th century. In the 20th century, with the development of the spectrophotometer, chemical analyses were performed for diagnostic purposes. With the appearance of cholera outbreaks, the identification of microorganisms was necessary for patient diagnosis, and the development of specific test methods contributed to microorganism detection in the laboratory. Blood transfusion, which started with blood collection in the 15th century, is currently used as a therapeutic method in medicine. Moreover, once the hypothesis of acquired immunity was proven in the 18th century, various methods for measuring immunity were developed. Molecular diagnosis, which was established during the 20th century after the presentation of Mendel's Genetic Laws in the 19th century, developed rapidly and became the predominant field in medical laboratory diagnostics. Thus, medical laboratory technology became an academic field, with foundations based on basic sciences. Modern medicine will further progress thanks to medical advancements, leading to an extension of average human lifespan up to 100 years. Laboratory medicine will provide significant support for this development.
Adaptive Immunity ; Blood Transfusion ; Chemistry, Clinical ; Cholera ; Diagnosis ; Disease Outbreaks ; Foundations ; Hematologic Tests ; Hematology ; History, Modern 1601- ; Humans ; Inventions ; Jurisprudence ; Medical Laboratory Science ; Methods ; Pathology, Molecular

BACKGROUND: Reference intervals need to be established according to age. We established reference intervals of hematology and chemistry from community-based healthy 1-yr-old children and analyzed their iron status according to the feeding methods during the first six months after birth. METHODS: A total of 887 children who received a medical check-up between 2010 and 2014 at Boramae Hospital (Seoul, Korea) were enrolled. A total of 534 children (247 boys and 287 girls) were enrolled as reference individuals after the exclusion of data obtained from children with suspected iron deficiency. Hematology and clinical chemistry analytes were measured, and the reference value of each analyte was estimated by using parametric (mean±2 SD) or nonparametric methods (2.5-97.5th percentile). Iron, total iron-binding capacity, and ferritin were measured, and transferrin saturation was calculated. RESULTS: As there were no differences in the mean values between boys and girls, we established the reference intervals for 1-yr-old children regardless of sex. The analysis of serum iron status according to feeding methods during the first six months revealed higher iron, ferritin, and transferrin saturation levels in children exclusively or mainly fed formula than in children exclusively or mainly fed breast milk. CONCLUSIONS: We established reference intervals of hematology and clinical chemistry analytes from community-based healthy children at one year of age. These reference intervals will be useful for interpreting results of medical check-ups at one year of age.
Breast Feeding ; Clinical Chemistry Tests/*standards ; Female ; Hematologic Tests/*standards ; Humans ; Infant ; Iron/*blood/standards ; Male ; Reference Values ; Republic of Korea

BACKGROUND: For convenience, multiple instruments can be used to measure the same laboratory results within one health care system. However, the laboratory must verify the comparability of the results. In this study, we evaluated a method for verifying the comparability of patient results obtained from two instruments within one health care system, EP31-A-IR, proposed by the Clinical and Laboratory Standards Institute. METHODS: Using the range test proposed by the EP31-A-IR, we evaluated the comparability of 17 clinical chemistry test results from the HITACHII/MODULAR system (Roche Diagnostics, Switzerland) and the TOSHIBA/200FR system (Toshiba Medical Systems Co., Japan). The 0.33× biological variability, allowable total error, and standards of the Clinical Laboratory Improvement Amendments were used to determine the acceptance criteria. RESULTS: Among 16 test parameters, the differences of means between the two instruments were less than their range rejection limit in 15 tests, and so the comparability between the two instruments was considered acceptable. Creatinine was not evaluated using this protocol because its range rejection limit was not deducible from the EP31-A-IR statistics table. CONCLUSIONS: The EP31-A-IR guideline is useful for verifying the comparability of results between two instruments. However, not all parameters are covered by the guideline. With consideration of the characteristics of each test parameter, each laboratory should devise its own method for evaluating comparability.
Clinical Chemistry Tests ; Creatinine ; Delivery of Health Care* ; Humans ; Methods ; Quality Control

The Clinical Chemistry Subcommittee of the Korean Association for External Quality Assessment Service conducted external quality assessments in 2015. This included general chemistry and blood gas measurements as part of a scheme of six trials, comprising three samples each. All control materials were included at the same time. The overall response rates were 94.4% for general chemistry and 92.2% for blood gas. The parameters tested included sodium, potassium, chloride, blood urea nitrogen, glucose, calcium, phosphorus, uric acid, creatinine, bilirubin, total protein, albumin, total cholesterol, triglyceride, aspartate aminotransferase (AST), alanine transaminase (ALT), alkaline phosphatase, lactate dehydrogenase, gamma glutamyl transferase, high-density lipoprotein (HDL) cholesterol, and low-density lipoprotein (LDL) cholesterol for general chemistry, and pH, partial pressure of carbon dioxide (pCO₂), and partial pressure of oxygen (pO₂) for blood gas assessments. Two types of reports were generated: a method summary, including mean, standard deviation, and coefficient of variation for each test method; and a result summary of each participating laboratory, including mean, standard deviation, number of peer groups, and standard deviation index and variance index scores of each laboratory. The overall quality performance in 2015 was similar to that of previous years, and showed lower interlaboratory variation than that in 2014. The requisite continual improvement in clinical chemistry testing quality can be achieved through participation in similar proficiency testing programs.
Alanine Transaminase ; Alkaline Phosphatase ; Aspartate Aminotransferases ; Bilirubin ; Blood Urea Nitrogen ; Calcium ; Carbon Dioxide ; Chemistry ; Chemistry, Clinical* ; Cholesterol ; Clinical Chemistry Tests ; Creatinine ; Glucose ; Hydrogen-Ion Concentration ; Korea* ; L-Lactate Dehydrogenase ; Lipoproteins ; Methods ; Oxygen ; Partial Pressure ; Peer Group ; Phosphorus ; Potassium ; Sodium ; Transferases ; Triglycerides ; Uric Acid