Relapsed Chronic Myeloid Leukemia: new players in targeted therapy
Transcript of Relapsed Chronic Myeloid Leukemia: new players in targeted therapy
YAZHEN QIN, MS
China Associate Professor, Peking University People’s
Hospital, Peking University Institute of Hematology
Dr. Qin specializes in the molecular diagnostics in
hematologic malignancies. Her field of research
focuses on mechanism of leukemogenesis.
“China Standardization Project of BCR-ABL
detection in CML”
——an efficient way for multi-centers to
simultaneously derive and validate CFs
Ya-Zhen Qin
Peking University People's Hospital,
Peking University Institute of Hematology,
Beijing, China
Standardization of BCR-ABL detection in CML
BCR-ABL transcript levels detected by real-time PCR
(RQ-PCR)reflect molecular response to TKI for CML
patients
Variation exists among the individual laboratory’s
report, which limits its clinical application
BCR-ABLIS
Proposed in October 2005
Harmonizing the differing methodologies for measuring
BCR-ABL transcripts
using an individual laboratory’s conversion factor (CF)
to express BCR-ABL transcript levels on an
internationally agreed scale
MMR: BCR-ABLIS=0.1%
Blood 2006; 108: 28-37
Great variation existed in the BCR-ABL
results from different laboratories in China
Four samples (same BCR-ABL levels prepared in TRIzolby one lab)
Detected in 10 labs in China, May 2010
Variation caused by:
different protocols
problems in protocol
0.01
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sample 1BC
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sample 2BC
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0 0.00001
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sample 4BC
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levels
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)
“China Standardization Project of RQ-
PCR detected BCR-ABL in CML”
Initiated in 2010
Aim
To test the accuracy and stability of BCR-ABL
detection of the participated laboratories and
help to improve the performance of those
laboratories not well done
To derive and validate laboratory specific CFs
of the participants to make the results from
different laboratories comparable
Participants of Project
A regional reference laboratory:
Peking University People’s Hospital, Peking
University Institute of Hematology (PUIH)
3 batches of laboratories :
36 laboratories from hospitals and
commercial organizations
Summary of the five comparisons of the 1st batch
laboratories
0.000001
0.00001
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样本稀释度
BC
R-A
BL
/AB
L
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样本稀释度B
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-AB
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样本稀释度
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样本稀释度
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R-A
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样本细胞稀释度
BC
R-A
BL
/AB
LSamples May 2010 Samples August 2010 Samples April 2011
Samples July 2011 Samples September 2012
Accuracy of
BCR-ABL
detection by RQ-
PCR is greatly
improved
Acquisition of
CF
Qin, YZ. et al. Chinese J of Hematology 34: 104-108 (2013)
A sample exchange between Adelaide international
reference laboratory (IMVS) and PKUPH in 2012
PUIH: regional reference lab
Distributing samples for calculating CF
Preparing and distributing samples by PUIH
Performing BCR-ABL detection according to the laboratory’s
own protocols
Analyzing results and calculating CF by PUIH
Usual method of validation in the world
Participating laboratory sends 20-30 samples to reference laboratory, they simultaneously test these samples and CF is validated
Validation is a heavy work for a reference laboratory
we used a simultaneously distributing
same prepared samples method to
perform validation
Validating CF in China
Preparing validation samples by PUIH
20~30 times of dilution of fresh BCR-ABL (+) nucleated
cells by BCR-ABL (-) cells.
The dilutions covered 3-log BCR-ABL levels range, with
the highest level lower than 10%IS
Each set contained 21 samples with different BCR-ABL
levels
The samples were distributed and were
simultaneously tested by PUIH and the other
participating laboratories over 2-3 months
Difference and agreement analysis
Bias(fold)=1/10-0.0032
Lower limit(fold)= 1+(-1/10-0.0032)-10((0.42+0.41)/2)
Higher limit(fold)=1+(-1/10-0.0032)+10((0.42+0.41)/2)
Bias -0.00322306
SD of bias 0.211994
95% Limits of Agreement
From -0.418731
To 0.412285
0.4
0.2
0.0
-0.2
-0.4
Difference
Average
QiLu13.12
-3 -2 -1 0 1 2
Log(QL)IS
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-2
-1
0
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-3 -2 -1 0 1 2
PUIH vs QiLuLog(PKUPH)IS
Next step
There are still some more laboratories which want to acquire a validated CF for conversion
of BCR-ABLIS
The stability of BCR-ABL detection of the
laboratories that have validated their CFs
needs to be tested regularly——revalidation
Summary
The approach we derive and validate CF is practical and efficient when a number of centers need to be performed simultaneously
Our simultaneously distributing same prepared samples method is also the way to regularly test the stability of BCR-ABL detection of multi-centers
Acknowledgements
Hospitals involved in the Project
Adelaide reference laboratory
Susan Branford
Novartis China