TRAINING and EDUCATION
You Make the Call
Each month in “You Make the Call,” we’ll pick a challenging clinical question
submitted through the Consult-a-Colleague program and post the expert’s
response. But, what would YOU do? We’ll also pose a submitted question
and ask you to send your responses. See how your answer matches up to the
experts in the next print issue.
This month, Carol S. Portlock, MD, advises on gene studies to establish
clonality in B-cell lymphoproliferative disorders.
Clinical Dilemma:
I perform T-cell receptor gene studies to establish clonality if abnormalities in the T-cell population are
detected. Do I need to order both beta and gamma analyses? I frequently order flow cytometry to establish
clonality and to rule out B-cell lymphoproliferative processes. When do I need to order immunoglobulin
heavy chain (IgH) gene rearrangement by fluorescent polymerase chain reaction?
Experts Make the Call
Carol S. Portlock, MD
Attending, Lymphoma Service
Department of Medicine
Memorial Sloan Kettering Cancer Center
New York, NY
You are correct that generally IgH
gene rearrangement is not needed to
define B-cell clonality – given that
flow cytometry demonstrates clonality simply through an abnormal
kappa-lambda immunoglobulin
light chain ratio.
There are certain cases where, if
needed, IgH gene rearrangement
can be performed; for example, if
flow cytometric instrumentation is
not available or if the amount of tissue
for a sample is limited. Then, IgH gene
rearrangement may be used to establish the
clonal relationship between an initial disease
presentation and relapse or transformation.
Recently, advances in T-cell flow cytometry
with multi-parameter flow technology have improved
detection of T-cell clonality and monitoring minimal residual
disease following therapy. T-cell clonality can be established by using a kit to interrogate Vβ repertoire
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