ABSTRACT
INTRODUCTION: Standardization of BCR-ABL1 messenger RNA quantification by real-time PCR on the International Scale (IS) is critical for monitoring therapy response in chronic myelogenous leukaemia. Since 2006, BCR-ABL1 IS standardization is propagated along reference laboratories by calculating a laboratory-specific conversion factor (CF), co-ordinated in Europe through the European Treatment and Outcome Study project. Although this process has proven successful to some extent, it has not been achievable for all laboratories due to the complexity of the process and the stringent requirements in terms of numbers of samples to be exchanged. In addition, several BCR-ABL1 IS quantification methods and secondary reference materials became commercially available. However, it was observed that different IS methods generate consistently different results. METHODS: To overcome these difficulties, we have developed an alternative and simple approach of CF calculation, based on the retrospective analysis of existing external quality assessment (EQA) data. Our approach does not depend on the exchange of samples and is solely based on the mathematical CF calculation using EQA results. RESULTS AND CONCLUSION: We have demonstrated by thorough statistical validation that this approach performs well in converting BCR-ABL1 measurements to improve IS estimation. In expectation of a true golden standard method for BCR-ABL1 IS quantification, the proposed method is a valuable alternative.
Subject(s)
Fusion Proteins, bcr-abl/genetics , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/diagnosis , RNA, Messenger/analysis , Genetic Testing , International Cooperation , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics , Methods , Observer Variation , Reference Standards , Retrospective StudiesABSTRACT
INTRODUCTION: The CS5100 analyzer (Sysmex) was validated for the determination of routine coagulation parameters. This fully automated coagulation analyzer uses multiple wavelength technology to perform coagulation (e.g., activated partial thromboplastin time - APTT, prothrombin time - PT, fibrinogen - FBG), chromogenic (e.g., antithrombin - AT) and immunological (e.g., D-dimers - DDi) assays. METHODS: A comparison with the currently used STA-R Evolution (Stago) was performed. Validation and verification of reference values of the CS5100 was performed in accordance to CLSI guidelines (H57-A, H47-A2, and C28-A3). RESULTS: As a different detection system and reagents were used, significant differences were observed (e.g. APTT). The within-day and between-day imprecision, accuracy and total error were all acceptable. The reference values defined by the manufacturer could be used except for APTT. In our settings, the therapeutic anti-Xa range of 0.3-0.7 IU/mL corresponded to an APTT range of 60-100 s (Dade actin FS reagent). The APTT reagent showed factor sensitivities between 46 and 72% for FVIII, IX, XI and XII while the PT reagent showed sensitivities between 34 and 52% for FII, FV, FXII, and FX. CONCLUSION: In conclusion, the CS5100 instrument is suitable for the determination of the APTT, PT, FBG, DDi and AT in routine analysis.
Subject(s)
Blood Coagulation Tests/instrumentation , Blood Coagulation Tests/methods , Blood Coagulation Tests/standards , Humans , Reference Values , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
A Belgian traveller was diagnosed with human African trypanosomiasis (HAT) due to Trypanosoma brucei rhodesiense nine days after visiting the Masai Mara area in Kenya. He presented with an inoculation chancre and was treated with suramin within four days of fever onset. Two weeks earlier, HAT was also reported in a German traveller who had visited the Masai Mara area. Because no cases have occurred in the area for over 12 years, this may indicate a focal cluster of HAT.
