|
|
 Previous Article | Table of Contents | Next Article 
Blood, 1 January 2002, Vol. 99, No. 1, pp. 391-393
CORRESPONDENCE
To the editor:
Diagnostic utility of flow cytometric immunophenotyping in
myelodysplastic syndrome
We read with great interest the article of Stetler-Stevenson et
al,1 which brings surface-marker analysis in
myelodysplastic syndrome (MDS) to the attention of the scientific
community and provides evidence for its possible utilization. However,
we have some comments and questions related to this study. First, the authors seem to have relied on pattern recognition and
"eyeballing" of flow cytometry scattergraphs to identify abnormalities without establishing objective criteria to differentiate MDS from other entities. Although this approach may work in obvious cases, borderline cases may be difficult to discern. Orthogonal light
scatter (SSC), discrete clusters of blasts, CD11b/CD16 abnormal pattern, and CD13/CD16 abnormal pattern are examples. Second, the authors may have used inappropriate control for
comparison. For example, to identify abnormalities in SSC, the authors
compared patients' bone marrows (BM) with normal peripheral blood
(PB). Bone marrow granulocytes change their light scatter properties
with maturation2,3 and the use of PB granulocytes as a
control for BM granulocytic scatter properties may not be appropriate. Third, the definition of megakaryocytic dsyplasia by flow cytometry is
not persuasive. The authors used a numerical value derived from
patients with aplastic anemia. Although the authors acknowledge that
this value does not differentiate normal marrow from dysplastic marrow,
they continue to apply this value to all patients to identify
dysplastic megakaryopoiesis. Fourth, the authors provide no indication that at least a
semiquantitative correlation between BM morphology and flow cytometry maturation pattern was performed. CD64 granulocytes are
normally present in the bone marrow since CD64 is lost at the band and
segmented-neutrophil stages.4,5 In our experience,
approximately 30% of cells in the granulocytic gate of non-MDS marrows
are CD64.6 Similarly, CD10 is usually
detected in the bone marrow granulocytes at the segmentation stage and
may not be observed with granulocytic left shift. We have encountered
several non-MDS bone marrows showing virtually no segmented neutrophils
on the marrow aspirate and no CD10+ cells within the
granulocytic gate. The pattern of increased CD11b and decreased CD16
can be seen with granulocytic left shift and with G-CSF therapy as
well.7(Fig2F) Finally, the authors report an interesting finding of myeloid cells
expressing lymphoid markers, such as CD22 and CD7, in as many as 38%
of cases. Our recent literature review identified only rare reports
with similar findings.8 We will be interested in knowing
the definition of positivity used by the authors. We agree with the authors' conclusion that flow cytometry is
more sensitive than morphology in assessing granulocytic dysplasia and
that flow cytometry can support the diagnosis of MDS in equivocal cases.
M. Tarek Elghetany
Correspondence: M. Tarek Elghetany, Department of Pathology,
University of Texas Medical Branch, 301 University Blvd, Galveston, TX
77555-0743
References
1.
Stetler-Stevenson M, Arthur DC, Jabbour N, et al.
Diagnostic utility of flow cytometric immunophenotyping in myelodysplastic syndrome.
Blood.
2001;98:979-987[Abstract/Free Full Text].
2.
Terstappen LWMM, Safford M, Loken MR.
Flow cyometric analysis of human bone marrow. III neutrophil maturation.
Leukemia.
1990;4:657-663[Medline]
[Order article via Infotrieve].
3.
Lund-Johansen F, Terstappen LWMM.
Differential surface expression of cell adhesion molecules during graulocyte maturation.
J Leukoc Biol.
1993;54:47-55[Abstract].
4.
Fleitt HB, Wright SD, Durie CJ, Valinsky JE, Unkeless JC.
Ontogony of Fc receptors and complement receptor (CR3) during human myeloid differentation.
J Clin Invest.
1984;73:516-525.
5.
Ball ED, McDermott J, Griffin JD, Davey FR, Davis R, Bloomfield CD.
Expression of the three myeloid cell-associated immunoglobulin G Fc receptors defined by murine monoclonal antibodies on normal bone marrow and acute leukemia cells.
Blood.
1989;73:1951-1956[Abstract/Free Full Text].
6.
Elghetany MT, Martinez J, Patel J, Sackey K, Alter BP.
Granulocytic surface marker abnormalities are detected only in patients with myelodysplastic syndrome and patients with shwachman diamond syndrome but not other bone marrow failure syndromes [abstract].
Blood.
2000;96(suppl):357a.
7.
Fujimoto H, Sakata T, Hamagushi Y, et al.
Flow cytometric method for enumeration and classification of reactive immature granulocytic population.
Cytometry.
2000;42:371-378[CrossRef][Medline]
[Order article via Infotrieve].
8.
Elghetany MT.
Surface marker abnormalities in myelodysplastic syndromes.
Haematologica.
1998;83:1104-1115[Abstract/Free Full Text].
Response:
Diagnostic flow cytometric immunophenotyping in myelodysplastic
syndrome: the US-Canadian consensus recommendations on the
immunophenotypic analysis of hematological neoplasia by flow
cytometry apply
Elghetany's questions and comments
concerning our recent study on the utility of flow cytometric
immunophenotyping in myelodysplastic syndrome (MDS) highlight several
important issues in flow cytometric evaluation of hematological
diseases. His comments underline the differences between the
immunology-based (eg, CD4/CD8 enumeration) approach to flow cytometry
and the more hematopathology-based pattern-recognition approach
recommended in the US-Canadian Consensus Recommendations on the
Immunophenotypic Analysis of Hematologic Neoplasia by Flow
Cytometry.1,2 When one is studying nonneoplastic lymphoid
cells, it is reasonable to set analysis parameters on the normal
lymphoid cells (usually based upon light scatter) and report the number
of cells staining more intensely than negative controls. However, in
neoplasia, this type of information is not useful. Current
state-of-the-art evaluation for hematological malignancies involves
extensive knowledge of normal patterns as a basis for identification
and characterization of abnormal patterns. What Elghetany refers to as
"eyeballing of flow scatter graphs to identify abnormalities,"
rather than setting an analysis gate and generating numbers, is
precisely what is done and what was recommended by the leaders in the
US and Canada at the consensus meeting in 1997. Although one can argue
whether or not MDS is a premalignant or malignant condition, the
pattern-recognition-based approach is the one we find useful in MDS. If
the clinician interpreting flow cytometric data knows normal patterns,
abnormal patterns are easily detected with this approach, even in
borderline cases. There is another important point brought to light in Elghetany's
comments. One cannot perform diagnostic flow cytometry in the absence
of clinical history and morphologic evaluation. The need to correlate
results with history and morphology is stressed in the US-Canadian
Consensus Recommendations on the Immunophenotypic Analysis of
Hematologic Neoplasia by Flow Cytometry.2 Therefore, we
review the patient's history and morphology before making a diagnosis.
We exercise appropriate caution with recent granulocyte colony-stimulating factor (G-CSF) treatment and do not consider a
diagnosis of MDS in a healthy individual with normal complete blood
count results. For example, the discrete cluster of blasts seen based upon side scatter versus CD45 in MDS can also be residual malignant blasts in a patient with acute myelogenous leukemia following
treatment. However, the history indicates the appropriate diagnosis.
Elghetany's example of a bone marrow with a marked left shift in which
no segmented neutrophils were observed would not be mistaken for MDS.
Usually we find that the cases that benefit from flow cytometric
immunophenotypic analysis are those in which the marrow is hypocellular
and aspirates are not adequate to fully evaluate all lineages
morphologically. Complete cytogenetic analyses may not be possible in
these cases either. The history is often consistent with aplastic
anemia or MDS. In these specimens the observed differences in numbers
of megakaryocytes are useful. Since a diagnosis of MDS would not be
entertained in a normal bone marrow, the inability to distinguish MDS
from normal based upon numbers of megakaryocytes is irrelevant. Elghetany points out that reports of myeloid cells expressing lymphoid
markers in MDS are rare. Clearly this is due to the panels previously
utilized in studying MDS. In general, lymphoid markers are paired with
other lymphoid markers. As we were looking for myeloid abnormalities in
our study, we designed our panel to detect expression of T- and B-cell
antigens by myeloid cells. This is a more sensitive method to detect
this abnormality. Concerning the minor points raised in the letter, Elghetany is
incorrect in stating that normal peripheral blood was used as a
control. As stated in "Patients, materials, and methods," bone
marrow aspirates from healthy volunteers were used as the normal
controls.3 Furthermore, bone marrow aspirates from
patients with aplastic anemia and patients who have completed
chemotherapy for nonmyeloid neoplasia were utilized, as we
believe these are more useful. On another minor point, when we report
the granulocytic cells as being negative for CD64 or CD10, we mean that
all of the granulocytic cells are negative, not just a subset.
This is a highly abnormal pattern. Because we stress that it is not a single abnormality but multiple ones in more than one lineage that are
characteristic of MDS, whether one might observe one of these
abnormalities in an individual without appropriate history or
morphology is again irrelevant. In summary, we utilize a pattern-recognition-based approach to
diagnosis of MDS. Detection of abnormal patterns of antigen expression
is a very powerful approach but requires an extensive knowledge of what
is normal. We also feel correlation with clinical history and
morphology is absolutely necessary in making a diagnosis of any
hematologic disease utilizing flow cytometric immunophenotyping. Furthermore, we stress that it is a pattern of multiple
immunophenotypic abnormalities in more than one lineage and in the
appropriate clinical setting that leads to a diagnosis of MDS. Lastly,
we would like to repeat our reported conclusion that flow cytometric immunophenotyping is not a screening test for MDS. An astute
morphologist and access to an excellent cytogenetics laboratory is
sufficient to render a correct diagnosis in the majority of cases. Flow
cytometric immunophenotyping is useful when these fail.
Maryalice Stetler-Stevenson, Margaret Rick, and Diane Arthur
Correspondence: Maryalice Stetler-Stevenson, Laboratory of
Pathology, NCI, NIH, Bldg 10, Rm 2N-108, Bethesda, MD 20895
References
1.
Stelzer GT, Marti G, Hurley A, et al.
U.S.-Canadian consensus recommendations on the immunophenotypic analysis of hematologic neoplasia by flow cytometry: standardization and validation of laboratory procedures.
Cytometry.
1997;30:214-230[CrossRef][Medline]
[Order article via Infotrieve].
2.
Borowitz MJ, Bray R, Gascoyne R, et al.
U.S.-Canadian consensus recommendations on the immunophenotypic analysis of hematologic neoplasia by flow cytometry: data analysis and interpretation.
Cytometry.
1997;30:236-244[CrossRef][Medline]
[Order article via Infotrieve].
3.
Stetler-Stevenson M, Arthur DC, Jabbour N, et al.
Diagnostic utility of flow cytometric immunophenotyping in myelodysplastic syndrome.
Blood.
2001;98:979-987.
 CiteULike  Connotea  Del.icio.us  Digg  Reddit  Technorati What's this?
Related Article in Blood Online:
-
Diagnostic utility of flow cytometric immunophenotyping in myelodysplastic syndrome
- Maryalice Stetler-Stevenson, Diane C. Arthur, Nicholas Jabbour, Xiu Y. Xie, Jeff Molldrem, A. John Barrett, David Venzon, and Margaret E. Rick
Blood 2001 98: 979-987.
[Abstract]
[Full Text]
[PDF]
This article has been cited by other articles:
|
|
|
|
 
K. Shannon and L. R. Silverman
Myelodysplastic syndrome and overlap syndromes
ASH Self-Assessment Program,
January 1, 2007;
2007(1):
228 - 242.
[Full Text]
[PDF]
|
|
|
|
|
|
|
K. Ogata, Y. Kishikawa, C. Satoh, H. Tamura, K. Dan, and A. Hayashi
Diagnostic application of flow cytometric characteristics of CD34+ cells in low-grade myelodysplastic syndromes
Blood,
August 1, 2006;
108(3):
1037 - 1044.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Maynadie, F. Picard, B. Husson, B. Chatelain, Y. Cornet, G. Le Roux, L. Campos, A. Dromelet, P. Lepelley, H. Jouault, et al.
Immunophenotypic clustering of myelodysplastic syndromes
Blood,
September 18, 2002;
100(7):
2349 - 2356.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
