TY - JOUR
T1 - Conversion, correction, and international scale standardization
T2 - Results from a multicenter external quality assessment study for BCR-ABL1 testing
AU - Griffiths, Michael
AU - Patton, Simon J.
AU - Grossi, Alberto
AU - Clark, Jordan
AU - Paz, Maria Fe
AU - Labourier, Emmanuel
AU - Akiki, Susanna
AU - Ayala, Rosa
AU - Barragan, Eva
AU - Basso, Daniela
AU - Beaufils, Nathalie
AU - Bories, Dominique
AU - Cayuela, Jean Michel
AU - Füllgrabe, Marc
AU - Gabert, Jean
AU - Kizilors, Aytug
AU - Lea, Nicholas
AU - Lombardia, Luis
AU - Maute, Carole
AU - McCarron, Sarah L.
AU - Nickless, Guillermina
AU - Piva, Elisa
AU - Pott, Christiane
AU - Rabascio, Cristina
AU - Rueda, Daniel
AU - Schmitt, Christoph
AU - Wachter, Oliver
AU - Zamora, Lurdes
PY - 2015/4/1
Y1 - 2015/4/1
N2 - Context.-Monitoring BCR-ABL1 expression levels relative to clinically validated response criteria on the International Scale (IS) is vital in the optimal management of patients with chronic myeloid leukemia, yet significant variability remains across laboratories worldwide. Objective.-To assess method performance, interlaboratory precision, and different IS standardization modalities in representative laboratories performing routine BCRABL1 testing. Design.-Fifteen blinded test specimens with 5-level nominal BCR-ABL1 to ABL1 IS percentage ratios ranging from 5% to 0.0005% and 4-level secondary IS reference panels, the ARQ IS Calibrator Panels, were tested by relative quantitative polymerase chain reaction in 15 laboratories in 5 countries. Both raw and IS percentage ratios calculated by using local conversion factors (CFs) or analytic correction parameters (CPs) were collected and analyzed. Results.-A total of 670 valid positive results were generated. BCR-ABL1 detection was associated with variable ABL1 quality metric passing rates (P <.001) and reached at least 0.01% in 13 laboratories. Intralaboratory precision was within 2.5-fold for all sample levels combined with a relative mean difference greater than 5-fold across laboratories. International Scale accuracy was increased by using both the CF and CP standardization methods. Classification agreement for major molecular response status was 90% after CF conversion and 93% after CP correction, with precision improved by 3-fold for the CP method. Conclusions.-Despite preanalytic and analytic differences between laboratories, conversion and correction are effective IS standardization methods. Validated secondary reference materials can facilitate global diffusion of the IS without the need to perform sample exchange and improve the accuracy and precision of BCR-ABL1 quantitative measurements, including at low levels of residual disease.
AB - Context.-Monitoring BCR-ABL1 expression levels relative to clinically validated response criteria on the International Scale (IS) is vital in the optimal management of patients with chronic myeloid leukemia, yet significant variability remains across laboratories worldwide. Objective.-To assess method performance, interlaboratory precision, and different IS standardization modalities in representative laboratories performing routine BCRABL1 testing. Design.-Fifteen blinded test specimens with 5-level nominal BCR-ABL1 to ABL1 IS percentage ratios ranging from 5% to 0.0005% and 4-level secondary IS reference panels, the ARQ IS Calibrator Panels, were tested by relative quantitative polymerase chain reaction in 15 laboratories in 5 countries. Both raw and IS percentage ratios calculated by using local conversion factors (CFs) or analytic correction parameters (CPs) were collected and analyzed. Results.-A total of 670 valid positive results were generated. BCR-ABL1 detection was associated with variable ABL1 quality metric passing rates (P <.001) and reached at least 0.01% in 13 laboratories. Intralaboratory precision was within 2.5-fold for all sample levels combined with a relative mean difference greater than 5-fold across laboratories. International Scale accuracy was increased by using both the CF and CP standardization methods. Classification agreement for major molecular response status was 90% after CF conversion and 93% after CP correction, with precision improved by 3-fold for the CP method. Conclusions.-Despite preanalytic and analytic differences between laboratories, conversion and correction are effective IS standardization methods. Validated secondary reference materials can facilitate global diffusion of the IS without the need to perform sample exchange and improve the accuracy and precision of BCR-ABL1 quantitative measurements, including at low levels of residual disease.
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U2 - 10.5858/arpa.2013-0754-OA
DO - 10.5858/arpa.2013-0754-OA
M3 - Article
C2 - 25061833
AN - SCOPUS:84926369404
VL - 139
SP - 522
EP - 529
JO - Archives of Pathology and Laboratory Medicine
JF - Archives of Pathology and Laboratory Medicine
SN - 0003-9985
IS - 4
ER -