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Acute
Leukemia Profile
Test
Includes:
Initial
profile of B-cell, T-cell, and myeloid markers (CD2,
CD3, CD7, CD10, CD13, CD14, CD19, CD20, CD33, CD34,
CD45, CD71, CD117, HLA-DR); supplemental markers added
as needed (CD1a, CD4, CD5, CD8, CD61, glycophorin A,
TdT)
Special Instructions:
Pathologist consultation is available Monday through
Friday.
Specimen:
Whole blood or
bone marrow aspirate
Volume:
Two 7-mL EDTA whole
blood tubes or one 7-mL EDTA whole blood tube and 2 cc
EDTA or heparinized bone marrow aspirate. One EDTA
whole blood tube is for an optional CBC.
Container:
Lavender-stopper (EDTA whole blood or bone marrow) tube or
green-stopper (heparinized bone marrow aspirate) tube
Collection:
Submit at
room temperature using Leukemia/Lymphoma Specimen
Transport Kit. Draw specimen so
it will arrive in the laboratory Monday through
Saturday and within 24 hours of collection. Specimens
cannot be held over the weekend. Please state date and
time of collection and the name and telephone/fax
number of the physician to whom results are to be
called/transmitted on the test request form.
Storage:
Maintain specimen at room temperature.
Causes for Rejection:
Specimen frozen; specimen in formalin or other
fixative; clotted specimen; hemolysis; blood more than
72 hours old; bone marrow aspirates older than 5 days
Use:
Lineage assignment in
acute leukemia is necessary for selecting appropriate
therapy and is useful in assessing prognosis.
Multiparameter analysis using three- and four-color
immunophenotyping techniques is a rapid and specific
method of assigning lineage in acute leukemia. This
profile is also useful in distinguishing lymphoid from
myeloid blast crisis in CML and immunophenotyping
lymphoblastic lymphoma in blood or bone marrow.
Limitations:
This
immunophenotyping profile should not be used as a
diagnostic test for leukemia. In most cases, this
profile is not useful in monitoring residual disease
after treatment. Tdt is available only as a
supplemental marker to distinguish null-cell ALL from
acute undifferentiated leukemia and to characterize
cases of apparent mixed lineage leukemia further. When
the morphology and immunophenotype suggest a diagnosis
of acute promyelocytic leukemia (APL), confirmation by
testing for the retinoic acid receptor gene
rearrangement by cytogenetic or molecular methods is
recommended.
Methodology:
Immunophenotyping
by flow cytometry
Additional Information:
Immunophenotyping and cytogenetic
analysis are increasingly being used to supplement the
traditional methods (morphology and cytochemistry) of
classifying acute leukemias and to provide prognostic
information. Acute lymphoblastic leukemia (ALL) can be
classified into undifferentiated null T- and B-cell
lineages. In ALL of B-cell lineage, expression of CD10
(CALLA) is a favorable prognostic factor. Acute
myelogenous leukemias (AML) are a heterogeneous group.
In cases where morphology and cytochemical staining is
equivocal, immunophenotyping can be useful.
Immunophenotyping is particularly useful in
classifying megakaryoblastic leukemia (FABM7). A
combination of characteristic light scattering
properties and myeloid phenotype can suggest a
diagnosis of acute promyelocytic leukemia (FABM3).
Confirmation of the retinoic acid receptor gene
rearrangement by cytogenetic or molecular methods is
recommended.
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