ABSTRACT
Background@#Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) is increasingly used for immunosuppressive drug tests. However, most LC-MS/MS tests are laboratory-developed and their agreement is unknown in different Korean laboratories.This interlaboratory comparison study evaluated test reproducibility and identified potential error sources. @*Methods@#Test samples containing three concentrations of tacrolimus, sirolimus, everolimus, cyclosporine, and mycophenolic acid were prepared by pooling surplus samples from patients undergoing routine therapeutic drug monitoring and tested in duplicate in the participating 10 clinical laboratories. Reconstitution and storage experiments were conducted for the commonly used commercial calibrator set. The robust estimators of reproducibility parameters were calculated. Spearman’s rank correlation coefficient (rho, ρ) was used to evaluate the correlation between drugs. Multiple linear regression was used to determine whether the experimental conditions alter the calibration curves. @*Results@#The reproducibility coefficient of variation exceeded 10% only for sirolimus concentrations 1 and 2 (10.8% and 12.5%, respectively) and everolimus concentrations 1 and 2 (12.3% and 11.4%, respectively). The percent difference values showed weak correlations between sirolimus and everolimus (ρ = 0.334, P = 0.175). The everolimus calibration curve slope was significantly altered after reconstitution following prolonged 5°C storage (P = 0.015 for 14 days; P = 0.025 for 28 days); the expected differences at 6 ng/mL were 0.598% for 14 days and 0.384% for 28 days. @*Conclusions@#LC-MS/MS test reproducibility for immunosuppressive drugs seems to be good in the Korean clinical laboratories. Continuous efforts are required to achieve test standardization and harmonization, especially for sirolimus and everolimus.
ABSTRACT
No abstract available.
Subject(s)
Humans , Leukemia, Myelogenous, Chronic, BCR-ABL PositiveABSTRACT
No abstract available.
Subject(s)
Aged , Female , Humans , Base Sequence , Bone Marrow/metabolism , DNA Mutational Analysis , Fusion Proteins, bcr-abl/genetics , Gene Duplication , In Situ Hybridization, Fluorescence , Leukemia, Myeloid, Acute/diagnosis , Multiplex Polymerase Chain Reaction , Mutation , Nuclear Proteins/genetics , Philadelphia Chromosome , fms-Like Tyrosine Kinase 3/geneticsABSTRACT
No abstract available.
Subject(s)
Aged , Humans , Male , Antineoplastic Agents/therapeutic use , Bone Marrow/pathology , Fusion Proteins, bcr-abl/genetics , Imatinib Mesylate/therapeutic use , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/complications , Leukocyte Count , Multiple Myeloma/complications , Platelet Count , Polymerase Chain Reaction , Thrombocytosis/etiologyABSTRACT
BACKGROUND: Blood CD4+ T-lymphocyte (T4) count is a major clinical marker for the diagnosis and management of AIDS, and flow cytometry is considered the gold standard for T4 enumeration. Our aim was to compare the 2-color and 4-color flow cytometric methods for T-cell subset analysis in HIV-infected patients. METHODS: T-cell subsets such as T3, T4, T8, and CD3+CD4-CD8- double negative T cells (DN T) were analyzed from the whole blood of 40 HIV-infected patients by using both 2-color and 4-color methods on a Cytomics FC500 analyzer. Statistical analyses using simple linear regression, paired t-tests, and Bland-Altman plots were performed. RESULTS: The measured T3 (%), T4 (%), T4 (/microL), T8 (%), T8 (/microL), and DN T (%) differed significantly between the 2 methods (P<0.05), whereas the T4/T8 ratio did not. T3 (%), T4 (%), T4 (/microL), T8 (%), T8 (/microL), and T4/T8 measured by the 2 methods showed good correlation, with correlation coefficients above 0.96, whereas DN T (%) did not. The mean differences in T4 (%) and T8 (%) were 0.39% (limit of agreement (LoA), -1.64~2.43) and 1.26% (LoA, -3.37~5.89), respectively. CONCLUSIONS: Although there were statistically significant differences in the T cell subsets measured between the 2 methods, the differences were minor, and the 2 methods showed good correlation. As confirmed in this study, DN T (%) estimated by the 2-color method is lower than the actual value. We suggest that although the 2 methods can be used interchangeably, the 4-color method is recommended for the analysis of some specific subpopulations such as DN T (%).
Subject(s)
Humans , Biomarkers , Flow Cytometry , HIV , Linear Models , T-Lymphocyte Subsets , T-LymphocytesABSTRACT
BACKGROUND: Acute promyelocytic leukemia (APL) can be life threatening, necessitating emergency therapy with prompt diagnosis by morphologic findings, immunophenotyping, cytogenetic analysis, or molecular studies. This study aimed to assess the current routine practices in APL and the clinico-pathologic features of APL. METHODS: We reviewed the medical records of 48 Korean patients (25 men, 23 women; median age, 51 (20-80) years) diagnosed with APL in 5 university hospitals between March 2007 and February 2012. RESULTS: The WBC count at diagnosis and platelet count varied from 0.4 to 81.0 (median 2.0)x10(9)/L and 2.7 to 124.0 (median 54.5)x10(9)/L, respectively. The median values for prothrombin time and activated partial thromboplastin time were 14.7 (11.3-44.1) s and 29 (24-62) s, respectively. All but 2 patients (96%) showed a fibrin/fibrinogen degradation product value of >20 microg/mL. The D-dimer median value was 5,000 (686-55,630) ng/mL. The t(15;17)(q22;q12 and PML-RARA fusion was found in all patients by chromosome analysis and/or multiplex reverse transcriptase-polymerase chain reaction (RT-PCR), with turnaround times of 8 (2-19) d and 7 (2-13) d, respectively. All patients received induction chemotherapy: all-trans retinoic acid (ATRA) alone (N=11, 26%), ATRA+idarubicin (N=25, 58%), ATRA+cytarabine (N=3, 7%), ATRA+idarubicin+cytarabine (N=4, 9%). CONCLUSION: Since APL is a medical emergency and an accurate diagnosis is a prerequisite for prompt treatment, laboratory support to implement faster diagnostic tools to confirm the presence of PML-RARA is required.
Subject(s)
Humans , Male , Cytogenetic Analysis , Emergencies , Emergency Treatment , Fibrin Fibrinogen Degradation Products , Hospitals, University , Immunophenotyping , Korea , Leukemia, Promyelocytic, Acute , Medical Records , Partial Thromboplastin Time , Platelet Count , Prothrombin Time , TretinoinABSTRACT
BACKGROUND: Acute promyelocytic leukemia (APL) can be life threatening, necessitating emergency therapy with prompt diagnosis by morphologic findings, immunophenotyping, cytogenetic analysis, or molecular studies. This study aimed to assess the current routine practices in APL and the clinico-pathologic features of APL. METHODS: We reviewed the medical records of 48 Korean patients (25 men, 23 women; median age, 51 (20-80) years) diagnosed with APL in 5 university hospitals between March 2007 and February 2012. RESULTS: The WBC count at diagnosis and platelet count varied from 0.4 to 81.0 (median 2.0)x10(9)/L and 2.7 to 124.0 (median 54.5)x10(9)/L, respectively. The median values for prothrombin time and activated partial thromboplastin time were 14.7 (11.3-44.1) s and 29 (24-62) s, respectively. All but 2 patients (96%) showed a fibrin/fibrinogen degradation product value of >20 microg/mL. The D-dimer median value was 5,000 (686-55,630) ng/mL. The t(15;17)(q22;q12 and PML-RARA fusion was found in all patients by chromosome analysis and/or multiplex reverse transcriptase-polymerase chain reaction (RT-PCR), with turnaround times of 8 (2-19) d and 7 (2-13) d, respectively. All patients received induction chemotherapy: all-trans retinoic acid (ATRA) alone (N=11, 26%), ATRA+idarubicin (N=25, 58%), ATRA+cytarabine (N=3, 7%), ATRA+idarubicin+cytarabine (N=4, 9%). CONCLUSION: Since APL is a medical emergency and an accurate diagnosis is a prerequisite for prompt treatment, laboratory support to implement faster diagnostic tools to confirm the presence of PML-RARA is required.