10. Granulocyte CD antigens
.
The specific types of granulocytes are
neutrophils, eosinophils, and basophils.
Basophils express several adhesion
molecules which play a critical role in
homing, including LFA-1 (CD11a/CD18),
Mac-1 (CD11b/CD18), and CD44.
12. Immunophenotyping
A process that uses antibodies to identify cells based
on the types of antigens or markers on the surface of
the cells. This process is used to diagnose specific
types of leukemia lymphoma and other cells of the
immune system.
Clusters of Differentiation (CD) markers are widely
used for immunophenotyping, using various methods
including flow cytometry.
14. Example of how CD Markers are used to define cell populations in flow cytometry. The picture
shows the Gating tree of CD4+
and CD8+
T cells. In the left panel leukocytes (CD45+
cells) are
gated into gate 1. In the middle panel only shows cells of gate 1 which are all the leukocytes of the
sample. In this panel T cells (CD3+
) are gated into Gate 2. The right panel shows CD3+
T cells and
seperates CD4+
and CD8-
T Helper cells (upper left quadrant) and C8+
and Cd4-
cytotoxic cells
(lower right panel)
15.
16. 1. Analysis of leukaemias and lymphomas:
A leukaemia or lymphoma will express a specific set of
markers depending on the stage and pathway of
differentiation and they are classified accordingly
17. 2. Detection of minimal residual disease
Minimal residual disease (MRD) was
defined as disease beyond the limit of
morphological detection using conventional
microscopy.
Patients with acute leukaemia were considered
to be in remission when bone marrow
samples contained <5% neoplastic cells.
Flow cytometric methods can detect far
lower levels of disease,
18. 3. Stem cell enumeration
ď´ Haemopoietic stem cells in the bone marrow can be
identified by their expression of CD34. Normally, the
number of such cells in bone marrow is low and is
negligible in peripheral blood. However, if mobilisation of
CD34 positive cells from the bone marrow is stimulated,
stem cells can be harvested from the peripheral blood
as well as the marrow.
4. Solid organ transplantation
ď´ T cell cross-match: Flow cytometry can be used to
crossmatch a recipient's serum with donor lymphocytes.
ď´ analysis of the peripheral blood lymphocytes may help
to indicate early rejection
19. 5. Â Immunodeficiency diseases
ď´ Diseases resulting from primary immunodeficiencies,
can be a result of defects in T-cells, B-cells,
granulocytes or monocytes.
ď´ In many of these diseases surface or cytoplasmic
proteins are missing or have impaired function. They
are characterized by immunophenotyping, the
selection of antibodies being based on the clinical
presentation.
20. 6. HIV infection.
ď´ Determination of the numbers of CD4 +ve
lymphocytes in the peripheral blood is used to
monitor patients with HIV infections .
ď´ The percentage of CD4 +ve cells can be obtained in
a single tube by staining for CD45/CD3/CD4.
7. Paroxysmal nocturnal haemoglobinuria
ď´ The white cells and red cells produced are
dysfunctional and are susceptible to lysis. Analysis of
this clonal abnormality by flow cytometry, in general,
can be accomplished by analysis of CD55 and CD59
on red cells .
21. 8. Immunotherapy
ď§ Rituxan (Rituximab) - a monoclonal antibody
against CD20.
ď§ Gazyva (Obinutuzumab): targets CD20 antigen, used in
initial treatment for small lymphocytic
lymphoma/chronic lymphocytic leukemia.
ď§ Arzerra (Ofatumumab): targets CD 20 antigen, used in
SLL/CLL.
ď§ Campath (Alemtuzumab): targets CD52 antigen in
SLL/CLL and peripheral T-cell lymphomas.
ď§ Adcetris (Brentuximab vedotin): targets CD30 and is
attached to a chemotherapy drug. Used in anaplastic
large cell lymphoma.