NCCN Guidelines for Patients® | Chronic Myelogenous Leukemia - page 16

16
NCCN Guidelines for Patients
®
: Chronic Myelogenous Leukemia
Version 1.2014
2.3 Lab tests
Complete blood count with differential
A CBC (
c
omplete
b
lood
c
ount) measures the number
of white blood cells, red blood cells, and platelets in a
sample of blood. For CML, the CBC should include a
differential. The differential measures the different types
of white blood cells in the sample. A high white blood cell
count and low red blood cell count may be signs of CML.
This is because CML causes too many white blood cells
to be made. These white blood cells may overcrowd the
bone marrow so that too few normal blood cells are made.
Blood chemistry profile
A blood chemistry profile measures the levels of different
chemicals in the blood. Organs such as the liver and
kidneys naturally release chemicals into the blood.
Abnormal levels of certain chemicals in the blood may be
a sign that an organ isn’t working well. This test is done
along with other initial tests when CML is first diagnosed.
Cytochemistry
A cytochemistry test uses chemical stains (dyes)
to show which types of leukemia cells—myeloid or
lymphoid—are present in a blood sample. The chemical
dyes cause a color change in one type of leukemia
cell and not another. This color change can be seen
with a microscope—a tool that uses lenses to see
things the eyes can’t. Myeloperoxidase is a chemical
found in myeloid cells but not in lymphoid cells. TdT
(
t
erminal
d
eoxynucleotidyl
t
ransferase) is a chemical
found in lymphoid cells but not in myeloid cells. For
CML, cytochemistry tests use dyes that only react with
these two chemicals. This type of test may be used to
help guide treatment options once CML is in advanced
phases. This type of test is not used to diagnose CML.
Human leukocyte antigen testing
HLAs (
h
uman
l
eukocyte
a
ntigens) are special proteins
on the surface of white blood cells. These proteins help
the body to identify its own cells from foreign cells. An
HLA type is a unique set of HLA proteins on a person’s
white blood cells. HLA types differ among people just
like blood types differ among people. HLA testing is used
to determine a person’s HLA type. HLA testing is done
before a type of treatment that transfers blood stem cells
from another person to the patient (See Part 4). It’s very
important that their HLA types are a near-perfect match
for this treatment to work. This is because the HLA type
affects how the body responds to foreign substances.
Cell assessment
The pathologist will examine the blood and bone marrow
samples with a microscope to assess the features of
the cells. A pathologist is a doctor who’s an expert in
testing cells and tissue for signs of disease. Staining the
samples with dyes helps show the differences between
parts of a single cell and differences between multiple
cells. The pathologist will assess the size, shape, type,
and maturity of the cells. The number of immature blood
cells (blasts) and basophils should be noted. Basophils
are a type of white blood cell. In a person without CML,
there are no blast cells in the circulating (peripheral)
1...,6,7,8,9,10,11,12,13,14,15 17,18,19,20,21,22,23,24,25,26,...100
Powered by FlippingBook