1.Analyses of the Proficiency Testing Program and the Performance of Qualitative Reagents for Rheumatoid Factor
Journal of Laboratory Medicine and Quality Assurance 2019;41(2):105-110
BACKGROUND: Rheumatoid factor (RF) is used as one of the diagnostic criteria for rheumatoid arthritis. The purpose of this study was to evaluate qualitative RF reagents used in clinical laboratories in Korea, and to provide basic data that can be used as a reference to improve the quality of RF testing. METHODS: We reviewed the proficiency testing results for RF from the Korean Association of External Quality Assessment Service (KEQAS) and College of American Pathologists. Moreover, we evaluated five commercially available RF qualitative reagents, including LabSlide RF (IVD Lab Co., Korea), ASAN RA Latex Reagents (Asan Pharmaceuticals Co., Korea), RaPET RF (Stanbio Laboratory, USA), RF Latex Test (Pulse Scientific Inc., Canada), and RF-100 (Teco Diagnostics, USA). Commercially available quality control materials, calibrators, and pooled sera were used in this study. The consistency of qualitative reagents and Kappa statistics were calculated based on the quantitative values of the quality control materials and the mixed sera. RESULTS: Up to 51.5% of high concentration samples were reported as negative in KEQAS. RF qualitative reagent test results were not consistent among reagent types. The consistency of the qualitative and quantitative test results was between 51% and 100%, and the kappa statistics varied depending on the reagent manufacturer. CONCLUSIONS: Measurement of RF qualitative reagents used in domestic clinical laboratories was not consistent with the quantitative values, and hence it is necessary to improve the consistency and verify the adequacy of the cut-off value.
Arthritis, Rheumatoid
;
Chungcheongnam-do
;
Indicators and Reagents
;
Korea
;
Latex
;
Quality Control
;
Rheumatoid Factor
2.Comparison of Three Blood Collection Tubes for 35 Biochemical Analytes: The Becton Dickinson Barricor Tube, Serum Separating Tube, and Plasma Separating Tube
Sunghwan SHIN ; Jongwon OH ; Hyung-Doo PARK
Annals of Laboratory Medicine 2021;41(1):114-119
The Barricor tube (Becton Dickinson [BD], Sunnyvale, CA, USA) was recently developed to mechanically separate plasma by increasing the centrifugation rate. We compared the Barricor tube with existing serum- and plasma-based tubes based on 35 biochemical analytes and preanalytical turnaround time (TAT). Blood samples were collected from 30 healthy volunteers in a Barricor tube, serum separating tube (SST, Vacutainer SST II Tube 8.5 mL, #368972; BD), or plasma separating tube (PST, Vacutainer PST Tube 8.0 mL, #367964; BD) in random order. Next, 27 chemistry analytes, six immunochemistry analytes, and two cardiac markers were compared using Passing-Bablok regression and the Bland-Altman method. Preanalytical TAT was measured for each tube.The Barricor tube exhibited bias exceeding the desirable limit for nine and four analytes compared with the SST and PST, respectively. The Barricor tube lactate dehydrogenase value showed a bias of -10.29% and -9.86% compared with that of the SST and PST, respectively. The preanalytical TAT of Barricor tube was 8.8 minutes, which was the shortest among the three tubes. The clinical performance of the Barricor tube was equivalent to that of the SST and PST for most analytes, with an apparent advantage in preanalytical TAT. When using the Barricor tube, the reference range needs to be changed for some analytes that exceed the desirable bias limit.
3.Comparison of Serum Creatinine Measurements among Roche Modular D, Cobas 8000 c702, and Beckman Coulter AU5800, by Jaffe and Enzymatic Methods
Laboratory Medicine Online 2020;10(1):39-45
0.99, slope: 0.965 and 0.955). When Modular D and Cobas 8000c 702 were compared, the slope and y-intercept were 0.9928 (95% confidence interval [CI]: 0.9802 to 1.000) and -0.0156 (95% CI: −0.0200 to −0.0054), respectively. The slope and y-intercept were 0.9811 (95% CI: 0.9570 to 0.9951) and -0.0484 (95% CI: −0.0638 to −0.0297) when Modular D and Au5800 were compared. Serum Cr measured by Cobas 8000 c702 and AU5800 using the Jaffe method were 3.2% and 6.9% lower than the values measured by Modular D, respectively. Both Modular D and Cobas 8000 c702 showed acceptable accuracies.CONCLUSIONS: Serum Cr measurements using Cobas 8000 c702 and AU5800 were comparable to those measured by Modular D, and showed satisfactory precision and linearity; thus, these techniques could be useful for clinical laboratories.]]>
Creatinine
;
Methods
4.Delayed Meningitis Complicated by the Frontal Sinus Opening to the Dura Mater in a Patient with Intracranial Injury Fifteen Years Ago.
Jaesik SHIN ; Sunghan OH ; Bongsub CHUNG ; Jongkook RHIM ; Chungjae LEE ; Jongwon CHOI
Korean Journal of Neurotrauma 2013;9(2):142-145
Meningitis is the inflammation of the membranes of the brain and spinal cord. This disease is considered life threatening and classified as a medical and emergency. Here we report a case of delayed meningitis occurred in a patient with craniotomy for traumatic brain injury fifteen years ago. Meanwhile, he had been well, however he complained of headache for five days. A brain computed tomographic scan showed air density on the frontal lobe with frontal sinus defect and pansinusitis. His mental state was suddenly changed to stuporous, despite a day of empirical antibiotics. Therefore, a successful cranialization was performed and he was gradually improved. This is a rare case report. Our case shows that surgical intervention is to be considered in some cases of posttraumatic meningitis for effective and rapid control of infection.
Anti-Bacterial Agents
;
Brain
;
Brain Injuries
;
Craniotomy
;
Dura Mater*
;
Emergencies
;
Frontal Lobe
;
Frontal Sinus*
;
Headache
;
Humans
;
Inflammation
;
Membranes
;
Meningitis*
;
Spinal Cord
;
Stupor
5.Delayed Meningitis Complicated by the Frontal Sinus Opening to the Dura Mater in a Patient with Intracranial Injury Fifteen Years Ago.
Jaesik SHIN ; Sunghan OH ; Bongsub CHUNG ; Jongkook RHIM ; Chungjae LEE ; Jongwon CHOI
Korean Journal of Neurotrauma 2013;9(2):142-145
Meningitis is the inflammation of the membranes of the brain and spinal cord. This disease is considered life threatening and classified as a medical and emergency. Here we report a case of delayed meningitis occurred in a patient with craniotomy for traumatic brain injury fifteen years ago. Meanwhile, he had been well, however he complained of headache for five days. A brain computed tomographic scan showed air density on the frontal lobe with frontal sinus defect and pansinusitis. His mental state was suddenly changed to stuporous, despite a day of empirical antibiotics. Therefore, a successful cranialization was performed and he was gradually improved. This is a rare case report. Our case shows that surgical intervention is to be considered in some cases of posttraumatic meningitis for effective and rapid control of infection.
Anti-Bacterial Agents
;
Brain
;
Brain Injuries
;
Craniotomy
;
Dura Mater*
;
Emergencies
;
Frontal Lobe
;
Frontal Sinus*
;
Headache
;
Humans
;
Inflammation
;
Membranes
;
Meningitis*
;
Spinal Cord
;
Stupor
6.Factors Influencing Family's Organ Donation Decision.
Jaesook OH ; Minsun KANG ; Kyung Sook JANG ; Hyun Jin KANG ; Wonhyun CHO ; Jongwon HA
The Journal of the Korean Society for Transplantation 2017;31(3):133-142
BACKGROUND: The main factor limiting the increase in brain dead organ donors is low consent rates for organ donation. METHODS: This study is a retrospective analysis of donor records of Korea Organ Donation Agency from 2013 to 2015. Factors related before providing information about organ donation and process of explaining organ donation were analyzed. RESULTS: Donor gender, marital status, religious affiliation, residence area, knowledge of patients' wishes, understanding of brain death status, and the referring system, providing initial information about donation and initial medical staff providing information about donation had a significant influence on decision to donate. Organ donation greatly increased when the donor family knew the patient's intent to donate. As the degree of family understanding of brain death status and the referring system increased, organ donation rate significantly increased. CONCLUSIONS: Providing sufficient information about brain death during the period of delivering medical services as well as activating campaign and public education are essential to improving the positive attitude toward organ donation.
Brain Death
;
Education
;
Humans
;
Korea
;
Marital Status
;
Medical Staff
;
Retrospective Studies
;
Tissue and Organ Procurement*
;
Tissue Donors
7.Cyclosporine Sparing Effect of Enteric-Coated Mycophenolate Sodium in De Novo Kidney Transplantation.
Su Hyung LEE ; Jae Berm PARK ; Chang Kwon OH ; Myoung Soo KIM ; Sung Joo KIM ; Jongwon HA
Yonsei Medical Journal 2017;58(1):217-225
PURPOSE: The increased tolerability of enteric-coated mycophenolate sodium (EC-MPS), compared to mycophenolate mofetil, among kidney transplant recipients has the potential to facilitate cyclosporine (CsA) minimization. Therefore, a prospective trial to determine the optimum EC-MPS dose in CsA-based immunosuppression regimens is necessary. MATERIALS AND METHODS: A comparative, parallel, randomized, open-label study was performed for 140 patients from four centers to compare the efficacy and tolerability of low dose CsA with standard dose EC-MPS (the investigational group) versus standard dose CsA with low dose EC-MPS (the control group) for six months in de novo kidney transplant recipients. Graft function, the incidence of efficacy failure [biopsy-confirmed acute rejection (BCAR), death, graft loss, loss to follow-up], and adverse events were compared. RESULTS: The mean estimated glomerular filtration rate (eGFR) of the investigational group at six months post-transplantation was non-inferior to that of the control group (confidence interval between 57.3 mL/min/1.73m² and 67.4 mL/min/1.73 m², p<0.001). One graft loss was reported in the control group, and no patient deaths were reported in either group. The incidence of BCAR of the investigational group was 8.7%, compared to 18.8% in the control group (p=0.137), during the study period. There were no significant differences (p>0.05) in the incidence of discontinuations and serious adverse events (SAE) between the groups. CONCLUSION: CsA minimization using a standard dose of EC-MPS kept the incidence of acute rejection and additional risks as low as conventional immunosuppression and provided therapeutic equivalence in terms of renal graft function and safety issues.
Adult
;
Aged
;
Cyclosporine/*administration & dosage
;
Female
;
Graft Rejection/*prevention & control
;
Humans
;
Immunosuppressive Agents/*administration & dosage
;
Incidence
;
Kidney Transplantation
;
Male
;
Middle Aged
;
Mycophenolic Acid/*administration & dosage
;
Prospective Studies
;
Tablets, Enteric-Coated
;
Time Factors
8.Vancomycin and Aminoglycoside Antibiotic Drug Concentration Measurement: Current Status in Clinical Laboratories in Korea
Won Kyung KWON ; Jongwon OH ; Soo-Youn LEE ; Hyung-Doo PARK
Laboratory Medicine Online 2020;10(4):265-275
Background:
Therapeutic drug monitoring (TDM) is clinically recommended for vancomycin and aminoglycoside antibiotics owing to their narrow therapeutic range and nephrotoxicity at high concentrations in the blood. This study was conducted to investigate the current status of TDM of vancomycin and aminoglycosides in Korean clinical laboratories.
Methods:
Ten organizations participated in this survey. Vancomycin, amikacin, gentamicin, and tobramycin were prepared in three samples of five or six different concentrations. Data from each institution were calculated for the mean, standard deviation, within-day, between-day, and within-laboratory precision. The results from each institution were compared in various ways.
Results:
Six instruments from three manufacturers were used. Samples with the lowest drug concentration were reported as below the lower limit of quantitation in most laboratories. Coefficients of variation for within-laboratory values ranged from 1.1% to 10.9% for vancomycin, 0.8% to 18.2% for amikacin, 1.2% to 7.8% for gentamicin, and 1.3% to 6.1% for tobramycin. Based on the overall results of the participants, only one institution’s vancomycin samples standard deviation index exceeded 3, with all other values below 2. The College of American Pathologist criteria were met by all institutions; however, measurement of vancomycin in one laboratory and of gentamycin in three laboratories failed to meet the Royal College of Pathologists of Australasia acceptance criteria.
Conclusions
Although the precision of the antibiotic test in individual institutions was excellent, there was a difference in the measured values between laboratories. Harmonization of antibiotic TDM is needed to reduce inconsistencies in results.
9.Clinical Utility and Cross-Reactivity of Insulin and C-Peptide Assays by the Lumipulse G1200 System.
Jongwon OH ; Jae Hyeon KIM ; Hyung Doo PARK
Annals of Laboratory Medicine 2018;38(6):530-537
BACKGROUND: Measurement of insulin and C-peptide concentrations is important for deciding whether insulin treatment is required in diabetic patients. We aimed to investigate the analytical performance of insulin and C-peptide assays using the Lumipulse G1200 system (Fujirebio Inc., Tokyo, Japan). METHODS: We examined the precision, linearity, and cross-reactivity of insulin and C-peptide using five insulin analogues and purified proinsulin. A method comparison was conducted between the Lumipulse G1200 and Roche E170 (Roche Diagnostics, Mannheim, Germany) systems in 200 diabetic patients on insulin treatment. Reference intervals for insulin and C-peptide concentrations were determined in 279 healthy individuals. RESULTS: For insulin and C-peptide assays, within-laboratory precision (% CV) was 3.78–4.14 and 2.89–3.35%, respectively. The linearity of the insulin assay in the range of 0–2,778 pmol/L was R2=0.9997, and that of the C-peptide assay in the range of 0–10 nmol/L was R2=0.9996. The correlation coefficient (r) between the Roche E170 and Lumipulse G1200 results was 0.943 (P < 0.001) for insulin and 0.996 (P < 0.001) for C-peptide. The mean differences in insulin and C-peptide between Lumipulse G1200 and the Roche E170 were 19.4 pmol/L and 0.2 nmol/L, respectively. None of the insulin analogues or proinsulin showed significant cross-reactivity with the Lumipulse G1200. Reference intervals of insulin and C-peptide were 7.64–70.14 pmol/L and 0.17–0.85 nmol/L, respectively. CONCLUSIONS: Insulin and C-peptide tests on the Lumipulse G1200 show adequate analytical performance and are expected to be acceptable for use in clinical areas.
C-Peptide*
;
Diabetes Mellitus
;
Humans
;
Insulin*
;
Methods
;
Proinsulin
10.Vancomycin and Aminoglycoside Antibiotic Drug Concentration Measurement: Current Status in Clinical Laboratories in Korea
Won Kyung KWON ; Jongwon OH ; Soo-Youn LEE ; Hyung-Doo PARK
Laboratory Medicine Online 2020;10(4):265-275
Background:
Therapeutic drug monitoring (TDM) is clinically recommended for vancomycin and aminoglycoside antibiotics owing to their narrow therapeutic range and nephrotoxicity at high concentrations in the blood. This study was conducted to investigate the current status of TDM of vancomycin and aminoglycosides in Korean clinical laboratories.
Methods:
Ten organizations participated in this survey. Vancomycin, amikacin, gentamicin, and tobramycin were prepared in three samples of five or six different concentrations. Data from each institution were calculated for the mean, standard deviation, within-day, between-day, and within-laboratory precision. The results from each institution were compared in various ways.
Results:
Six instruments from three manufacturers were used. Samples with the lowest drug concentration were reported as below the lower limit of quantitation in most laboratories. Coefficients of variation for within-laboratory values ranged from 1.1% to 10.9% for vancomycin, 0.8% to 18.2% for amikacin, 1.2% to 7.8% for gentamicin, and 1.3% to 6.1% for tobramycin. Based on the overall results of the participants, only one institution’s vancomycin samples standard deviation index exceeded 3, with all other values below 2. The College of American Pathologist criteria were met by all institutions; however, measurement of vancomycin in one laboratory and of gentamycin in three laboratories failed to meet the Royal College of Pathologists of Australasia acceptance criteria.
Conclusions
Although the precision of the antibiotic test in individual institutions was excellent, there was a difference in the measured values between laboratories. Harmonization of antibiotic TDM is needed to reduce inconsistencies in results.