1. CYTOGENERIC ASSESSMENT IN MDS
NOTE: These slides are for use in educational oral presentations only. If any published figures/tables from these slides are
to be used for another purpose (e.g. in printed materials), it is the individual’s responsibility to apply for the relevant permission. Specific local use requires local approval.

2. Outline MDS Classification and prognosis scoring
Practical guide to bone marrow aspirate analysis in MDS
Cytogenetics of MDS in bone marrow aspirates
Summary
LIC = liver iron concentration; MRI = magnetic resonance imaging;
SF = serum ferritin; SIR = signal intensity ratio;
SQUID = superconducting quantum interface device.

3. What are the myelodysplastic syndromes (MDS)?
MDS are a spectrum of heterogeneous myeloid clonal disorders
Occurrence:
De novo (primary MDS)
Secondary or treatment-related MDS
MDS are associated with significant morbidity and mortality due to:
Risk of transformation to acute myeloid leukemia (AML)
Cytopenias
Impaired quality of life (frequent transfusions, iron overload, etc) 3

4. Common features of MDS
MDS are marked by ineffective haematopoiesis and defective development of blood cells, e.g.:
dyserythropoiesis (affects red blood cells production)
dysgranulopoiesis (affects granulocytes production)
dysmegakaryopoiesis (affects platelet production)
Ineffective haematopoiesis and maturation of the blood cells results in one or more cytopenias, e.g.:
anaemia (reduced red blood cell count)
neutropenia (reduced absolute neutrophil count)
thrombocytopenia (reduced number of platelets)

5. Minimal diagnostic criteria in MDS consensus, Vienna 2006
Prerequisite criteria
constant cytopenia in one or more cell lineages
complete blood count
exclusion of all other causes of cytopenia / dysplasia
MDS-related (decisive) criteria
dysplasia in > 10% of all bone marrow cells in one or more of the lineages, or > 15% ringed sideroblasts
iron staining of bone marrow smears
5–19% blast cells
bone marrow smears
typical chromosomal abnormality
karyotyping or FISH
FISH = fluorescence in situ hybridization.
Loken MR, et al. Leuk Res. 2008;32:5-17. Nimer SD. Blood. 2008;111: Valent P, et al. Leuk Res. 2007;31:

6. Minimal diagnostic criteria in MDS consensus, Vienna 2006 (cont.)
Additional criteria (for patients not fulfilling the decisive MDS criteria)
abnormal phenotype of bone marrow cells
flow cytometry
molecular signs of a monoclonal cell population
HUMARA assay, gene chip profiling, point mutation or SNP analysis
markedly and persistently reduced colony formation
CFU assay
CFU = colony-forming unit; SNP-a = single-nucleotide polymorphism.
Loken MR, et al. Leuk Res. 2008;32:5-17. Van de Loosdrecht AA. Leuk Res. 2008;32: Van de Loosdrecht AA, et al. Blood. 2008;111: Van de Loosdrecht AA, et al. Haematologica. 2009;94: Nimer SD. Blood. 2008;111: Valent P, et al. Leuk Res. 2007;31:

7. MDS classification and prognostic scoring

8. Diagnostic and prognostic of MDS
Classification system
Basis of evaluation
Derived prognostic score system
FAB (1982)
Cellular morphology
IPSS (1997)
WHO (2002)
Cellular morphology, cytogenetics
WPSS (2007)
Risk-stratification is necessary for clinical decision-making:
predicts treatment outcomes
predicts survival
predicts risk of progression to AML
FAB, French-American-British; IPSS, International Prognostic Scoring System; WPSS, WHO-based Prognostic Scoring System.
Bennett JM, et al. Br J Haematol 1982;51:189–199; Jaffe, et al, eds. Lyon: IARC Press; 2001; Greenberg P, et al. Blood 1997;89:2079–2088; Malcovati L, et al. J Clin Oncol 2007;23:3503–3510. 8

9. French-American-British (FAB) classification
Blast percentage
MDS Subtype
Peripheral blasts (%)
Bone marrow blasts (%)
Additional features
AML transformation (%) RA
Refractory anaemia ≤1
<5
10–20
RARS
Refractory anaemia with ringed sideroblasts
>15% ringed sideroblasts in bone marrow
10–35
RAEB
Refractory anaemia with excess blasts
5–20
>50
RAEB-T
Refractory anaemia with excess blasts in transformation ≥5
21–29
optional Auer-rods
60–100
CMML
Chronic myelomonocytic leukaemia
≤20
Peripheral monocytosis (>103/µl)
>40
Bennett JM, et al. Br J Haematol 1982;51:189–199. 9

10. Survival by cytogenetic presentation in MDS patients
100 90 80 70 60 50 40 30 20 10
Patients n
(%) −Y 17
(2)
del(5q) 48
(6)
Normal
489
(69)
del(20q) 16
Misc. single 74
(9) +8 38
(5)
Double 29
(3)
Misc. double 14
Chrom 7 abn. 10
(1)
Misc. complex 15
Complex 66
(8)
Time (years) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
Greenberg P, et al. Blood. 1998;89:

11. Risk stratification and prognosis scoring for MDS: IPSS
IPSS score
Variable
0.5
1.0
1.5
2.0
BM blasts (%)
< 5
5–10 –
11–20
21–30
Karyotype
Good
Int.
Poor
Cytopenia(s)
0/1
2/3
Influence of karyotype according to IPSS
Good = normal, −Y, del(5q), del(20q)
Poor = complex (≥ 3 abnormalities) or chromosome 7 anomalies
Int. = all other abnormalities
Greenberg P, et al. Blood. 1998;89: 11

12. Cumulative survival of MDS patients by IPSS
AML Evolution 10 20 30 40 50 60 70 80 90
100 10 20 30 40 50 60 70 80 90
100
Low
Int-1
Int-2
High
Low
Int-1
Int-2
High
Percent
Percent 2 4 6 8 10 12 14 16 18 2 4 6 8 10 12 14 16 18
Years
Years
Greenberg P, et al. Blood 1997;89:2079–2088.

13. MDS: WHO classification 2008
Blast percentage
MDS Subtype
Dysplasia
Peripheral blasts (%)
Bone marrow blasts (%)
Ringed sideroblasts (%)
Cytogenetics
5q− syndrome
Mostly DysE
< 1%
< 5%
< 15%
5q− sole
RA, RN, RT, RCUD
DysE, N, T
Various
RARS
> 15%
RCMD
2–3 lineages
rare
RAEB-1
1–3 lineages
5–9%
RAEB-2
5–19%
Auer rods +/-
10–19%
MDS-U
1 lineage
BM = bone marrow; DysE = dyserythropoiesis; MDS-U = myelodysplastic syndrome, unclassified; N = neutropenia; pB = peripheral blood; RCMD = refractory cytopenia with multilineage dysplasia; RCUD = refractory cytopenia with unilineage dysplasia; RN = refractory neutropenia; RT = refractory thrombocytopenia; T = thrombocytopenia.
Swerdlow SH, et al., eds. WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. Lyon: IARC Press; 2008:

14. Survival of MDS patients according to transfusion dependency
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Transfusion-independent patients
Proportion surviving
Transfusion-dependent patients 20 40 60 80
100
120
140
Time (months)
Cazzola M, Malcovati L. N Engl J Med. 2005;352:536-8. 14

15. The WHO classification-based prognostic scoring system (WPSS) for MDS
Points 1 2 3
WHO subtype
RA, RARS, del(5q)
RCMD, RCMD-RS
RAEB-1
RAEB-2
Transfusion requirement
None
Regular –
Cytogenetic category
Good
Int.
Poor
Risk groups
Score
Median survival (months)
Very low
103
Low 1 72
Intermediate 2 40
High
3–4 21
Very high
5–6 12
Transfusion dependence is an independent indicator of severity of disease and has a significant effect on survival
Malcovati L, et al. J Clin Oncol. 2007;25: 15

16. Overall survival and AML risk assessments in MDS by WPSS
A. Overall survival at diagnosis (n=426)
B. Risk of AML at diagnosis (n=426)
C. Time-dependent overall survival (n=271)
D. Time-dependent risk of AML (n=271)
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
Cumulative probability of survival
Cumulative risk
Time (months)
Risk group
Very Low Low Intermediate
High
Very High
Malcovati L et al. J Clin Oncol 2007;25:3503–3510. 16

17. WHO prognosis scoring system allows time dependent prognosis scoring
IPSS
WPSS
Pros
More widely used and recognized
Allows time-dependent prognosis scoring and risk stratification
Takes into account individual patient transfusion need
Cons
Applies only at the time of diagnosis
Underestimates the impact of transfusion requirement and cytogenetics
Underestimates the impact of poor cytogenetics
Greenberg P, et al. Blood 1997;89:2079–2088. Malcovati L, et al. J Clin Oncol. 2007;25:3503–3510.
Schanz J, et al. Blood. 2007;110:[abstract 248]. Kantarjian H, et al. Cancer. 2008;113:
Garcia-Manero G, et al. Leukemia. 2008;22:

18. Practical guide to bone marrow aspirate analysis in MDS

19. Bone marrow biopsy How is it done:
Marrow aspirate and bone (trephine) biopsy are removed by physician in an outpatient procedure under local anesthesia
heparinized sample can be stored at room temperature for 24 hours
What tests are done?
assessment of cellularity, architecture and focal collection of blasts for hematopoietic dysplasia
smear staining examination
cytogenetic analysis
karyotype
FISH
What other tests might be done?
flow cytometry
cell counts
cell sorting
immunophenotyping
Hellström-Lindberg E. Myelodysplastic Syndromes. London: Remedica; Van de Loosdrecht, et al, Haematologica.2009; 94: Image from: Medline Plus. NIH/NLM. Accessed Jan, 2011.

20. Analysis of bone marrow smears
Bone marrow aspirate smears are prepared on a slide by a medical technician using:
Wright’s stain
Perl’s staining (for ringed sideroblasts)
May-Grünwald-Giemsa staining
Immunohistochemical stainings, i.e. CD34
A pathologist or hematologist then examines the slides for cell abnormalities under microscope:
at least 400 nucleated cells and 20 megakaryocytes should be examined for morphology
Hellström-Lindberg E. Myelodysplastic Syndromes. London: Remedica; 2008.

21. Analysis of bone marrow smears (cont.)
Refractory anaemia with excess blasts (RAEB)
Refractory anaemia (RA)
Abnormal large megakaryocyte (double arrow), abnormal hypo-granular and Pelger neutrophils (single arrows).
Erythroid cells with peri-nuclear iron accumulation Prussian blue staining (left); Perl’s stain showing ringed sideroblasts with peri-nuclear (mitochondrial) deposition of iron (right)
ASH Image Bank, used with permission, all rights reserved.
Courtesy of J. Goasguen, Université de Rennes, France.

22. Immunophenotyping by flow cytometry
Various lineages are labeled with antibodies that recognize specific haematopoeitic identifiers
Combination of no more than four labels recommended
Important for identification of blasts - CD34+/abnormal granularity/CD45dim
Well-correlated with other diagnostic techniques and prognostic systems
Van de Loosdrecht, et al. Haematologica.2009; 94:
Image from:

23. Cytogenetics of MDS in bone marrow aspirates

24. Importance of cytogenetic analysis in MDS
Nearly half of the patients with MDS present with cytogenetic abnormalities1
changes have a pathogenetic relevance (i.e. loss or gain of gene function)
Cytogenetic analysis is essential for the diagnosis and classification of MDS according to IPSS and WPSS2
Chromosomal aberrations have prognostic relevance for OS and for the time to leukaemic transformation, independent of other factors
Cytogenetic analysis forms the basis for therapeutic decisions
cytogenetics is indicative of response to therapy, i.e. lenalidomide in del(5q)3 and azacitidine in −7/del(7q)4
IPSS = International Prognostic Scoring System; OS = overall survival; WPSS = WHO classification-based Prognostic Scoring System.
1Haase D, et al. Blood. 2007;110: Greenberg P, et al. Blood. 1998;89: List AF, et al. N Engl J Med. 2006;355: Fenaux P, et al. Lancet Oncol. 2009;10: 24 24

25. Cytogenetic aberrations are frequent in patients with MDS9%
14%
29%
48%
Normal karyotype
One abnormality
Two abnormalities
Complex karyotype
N = 2,072 patients with MDS
Haase D, et al. Blood. 2007;110:

26. WHO 2008: Incidence of the most common cytogenetic aberrations in MDS (over 5%)
Unbalanced aberrations
De novo MDS (%)
Secondary MDS (%) +8 10
−7/del(7q) 50
−5/del(5q) 40
del(20q)
5–8 −Y 5
iso(17q)/t(17p)/del(17p)
3–5
Unbalanced aberrations with loss of genetic information (deletions or monosomies) are most common in MDS; balanced aberrations are rare
Swerdlow SH, et al. In: WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. 4th ed. Lyon: IARC; 2008:441.

27. When should cytogenetic testing be performed in patients with MDS: Diagnosis
WHO 2008 guidelines recommend a complete cytogenetic analysis of BM at initial diagnosis in all patients with MDS
Cytogenetic analysis is mandatory for
diagnosis of MDS associated with del(5q)
patients with refractory cytopenia(s) who lack MDS diagnostic features; these patients may be considered as having presumptive evidence of MDS if they have MDS-related cytogenetic abnormalities (slides 4 and 5)
rather than indicating abnormality, isolated loss of Y chromosome might be an age-related phenomenon and mosaicism with trisomy 8 might be a constitutional change. Therefore, they might not be sufficient to prove MDS
BM = bone marrow.
Swerdlow SH, et al. In: WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. 4th ed. Lyon: IARC; 2008:441. Valent P, Horny HP. Eur J Clin Invest. 2009;39: Vardiman JW, et al. Blood. 2009;114:

28. FAQs: Cytogenetic testing for diagnosis of patients with MDS
Is cytogenetic testing required for all patients?
Yes, cytogenetic testing should be performed whenever possible at initial diagnosis and every 6–12 months during follow-up since karyotype and prognosis might change during the course of the disease. There are a few exceptions that will have no therapeutic consequences, e.g. very frail and multi-morbid patients.
Are there disease presentations that correlate with specific cytogenetic abnormalities?
There is no correlation between specific abnormalities and disease presentation (with exception of the association between isolated del(5q) syndrome and RA, with typical dysplasia of megakaryocytes).
Questions and answers were prepared under the review of Dr. Haase, University of Göttingen, Germany.

29. FAQs: Cytogenetic testing during treatment in patients with MDS
Why is it important to perform cytogenetic testing during the treatment course?
Cytogenetic remissions represent a better quality of remission and are more reliable than those determined by blood films or cytomorphology from the BM. Furthermore, karyotype might change during the course of the disease affecting the prognosis and the treatment of the patient. First data show that a cytogenetic progression might be detectable several weeks before clinical manifestation.
Is cytogenetic testing important for all patients or is it recommended for specific focus groups?
All patients with clonal abnormalities identified before start of therapy should be followed up during therapy. Also, patients with initially normal karyotype might develop abnormalities during the course of disease and, therefore, require regular monitoring.
Questions and answers were prepared under the review of Dr. Haase, University of Göttingen, Germany.

30. FAQs: Cytogenetic testing during treatment in patients with MDS (cont
How often should cytogenetic testing be performed?
Cytogenetics from BM is recommended when possible at least once every 6 months during therapy. When FISH is performed using peripheral blood (i.e. CD34-FISH), testing should be conducted every 3rd month.
What is the definition of cytogenetic progression in MDS?
1) Occurrence of new cytogenetic abnormalities (first in patients with normal karyotype or additional for patients with abnormalities).
2) Significant increase (> 50%) of the size of the clone with certain cytogenetic abnormalities.
When should treatment be altered as a result of changes in the cytogenetic profile?
When a clear cytogenetic progression is seen, or when an abnormal clone is completely eliminated and karyotype turns normal and stays normal over time (at least 3 months); this depends on the type of therapy.
Questions and answers were prepared under the review of Dr. Haase, University of Göttingen, Germany.

31. Chromosome analysis in MDS: Karyotyping
Each cell in the body contains 46 chromosomes representing the normal human karyotype
MDS patients frequently have a clonal abnormality in the hematopoietic progenitor cells, where a proportion of these have an abnormal karyotype with altered number of chromosomes and/or large alterations in their structure
Changes in the number of the chromosomes is due to monosomies (loss of a chromosome) and/or polysomies (more then 2 copies of a chromosome)
Changes in the structure of the chromosomes are commonly noted as:
deletions, when part or entire chromatid is missing
insertions, when additional material is included in a chromosome
translocations, when genetic material is exchanged between chromosomes

32. How to perform cytogenetic testing in patients with MDS: Karyotyping
Sample
Collect at least 10–20 mL of heparinized BM aspirates
Storage
Samples should reach the lab within 24 hours after biopsy
Metaphase quality
To detect structural abnormalities, adequate chromosome banding is required (≥ 150–250 bands per karyogram)
Number of metaphases needed
Analyse 25 metaphases if possible, especially if the karyotype is normal, to exclude a small aberrant cell clone
Source of the BM aspirate photo:
Source of cytogenetics lab photo:
Source of metaphase quality photo: Dr D. Haase slides
Source of metaphase photo: 6 7 8 9 10
See presenter for references.

33. How to perform cytogenetic testing in patients with MDS: Karyotyping (cont.)
Medical technician prepares metaphase slides for karyotyping, by:
culturing bone marrow aspirate for hours, and then
exposing the cells to slightly hypotonic solution
synchronizing them in metaphase (e.g. using colchicine)
finally, staining them (e.g. DAPI staining) and fixing them on slides
A pathologist or hematologist then examines the slides for chromosomal abnormalities under microscope:
Samples are examined under microscope manually or with aid of analysis software (separating, enhancing banding pattern, chromosome pairing)
At least 25 metaphases should be examined, especially if the karyotype is normal, to exclude a small aberrant cell clone
Holland and Frei. Cancer Medicine 6. American Cancer Society; 2003.
Lucia Cytogenetics. Accessed Feb.2011.

34. FAQs: Karyotyping Can peripheral blood be used?
Peripheral blood is usually not an alternative. No BM available: attempt banding analysis from peripheral blood (CD34-FISH), especially when blasts are present. Metaphase yield from peripheral blood is generally worse than that from BM aspirates. CD34-FISH can be an option.1
What sample-related factors could influence the accuracy of the test?
Ex-vivo time over 24 hours: clotting; bacterial/fungal contamination; and low cellular content (e.g. hypocellular BM, or if several syringes are filled during biopsy and the last syringe is used for banding analysis).
What are the limitations of this method?
Need for dividing cells; cell clones < 10% of abnormal cells can be overlooked; submicroscopic abnormalities cannot be detected.
FISH = fluorescent in situ hybridization.
1Braulke F, et al. Leuk Res. 2010;34:
Questions and answers were prepared under the review of Dr. Haase, University of Göttingen, Germany.

35. Chromosome analysis in MDS: Fluorescence in situ hybridization (FISH)
Fluorescently labeled DNA probes recognize complementary sequences on the chromosomes
probes that recognize centromeres detect changes in the number of chromosomes
probes that recognize specific genes can detect changes in the chromosome sequence
Fluorescently labeled probes for bcr and abl
genes show exchange of DNA between
Chromosomes in chronic myelogenous leukemia
Images from: Accessed Feb.2011.

36. Preparation of the FISH sample
Metaphase slides for karyotyping could also use bone marrow smears and paraffin-embedded bone marrow biopsies)
Denature DNA (heat up the sample)
Hybridize with denatured (pre-heated) labeled probes
Wash to remove excess probe
DAPI stain for DNA
View with fluorescence microscope and take photographs
Preparation of the FISH could be done by trained medical technician or clinical geneticist. The analysis of the samples is carried by clinical geneticists and/or hematologists.
Image from: Accessed Feb. 2011
Protocol from: labs.mmg.pitt.edu/gjoerup/FISH%20protocol%20Vysis.doc. Accessed Feb

37. FISH: Selection of probes
MDS FISH panel for initial diagnosis detects the most common aberrations, and typically includes probes for 5q, 7q, #8, 11q, 12p, 13q, 17p, and 20q
Probes*
Manufacturer
Web site
Multiprobe MDS/AML panel
Cytocell
5/5q, 7/7q, 8cen, 20q
Genzyme Genetics
5p/q, 7q, 17p13, 20q13
Kreatech
5p/q, 7cen/q, 8cen, 17p13, 20q13, Ycen
Abbott Molecular
5/5q, 7/7q, 20q
Metasystems
Selection of the FISH probes is essential part of the analysis and is typically done by clinical geneticists in cooperation with hematologists
*Examples are not representative of the complete spectrum of probes available from each provider.
1Cherry AM, et al. Blood. 2010;116:[abstract 2922].

38. FAQs: FISH How is a probe selected?
Use the standard MDS FISH panel for initial diagnosis. When the aberration is known/suspected, use additional probes in the region. If disease morphology is suggestive of a certain genotype, one could directly use the respective probe – e.g. if RA with typical dysplasia of megakaryocytes occurs, then use probes for del(5q). Note, however, that one can miss other genetic changes with this approach.
How many probes are typically used in a panel?
A standard panel consists of 7–8 probes.1 An extended panel can include up to 12 probes.
1Cherry AM, et al. Blood. 2010;116:[abstract 2922].
Questions and answers were prepared under the review of Dr. Haase, University of Göttingen, Germany.

39. FAQs: FISH (cont.) What probes should be used for survival prognosis?
The available survival data are based on karyotyping (banding) studies. However, in addition to karyotyping, one should use a standard FISH panel: 5p/q, 7cen/q, #8cen, 17p13, 20q13, and Ycen (in males).
What are the limitations of FISH?
One sees/finds what one is looking for; therefore, one could overlook complex or rare abnormalities (e.g. finding an isolated del(5q) by FISH might give a false good prognosis if it is a part of a complex genotype that has been misidentified).
Questions and answers were prepared under the review of Dr. Haase, University of Göttingen, Germany.

40. Summary

41. Summary
WHO 2008 guidelines recommend complete cytogenetic analysis of BM at initial diagnosis of MDS
Chromosomal aberrations, among other factors, have prognostic relevance on overall survival and time to leukaemic transformation
IPSS was first to define cytogenetic risk groups and to show an association with the survival prognosis of the patient
improved understanding of the cytogenetic risk factors provides a better prognosis scoring for the patients with MDS
Approximately 50% of MDS patients have abnormal cytogenetics
in addition, it is supposed that many patients with “normal cytogenetics” actually have clonal abnormalities that remain undetected by metaphase cytogenetics

42. Summary (cont.)
Cytogenetic analysis is essential for making therapeutic decisions with regard to patients with MDS as it has shown associations with the response to hypomethylating and immunomodulating agents
Sequential cytogenetic analysis is recommended to improve clinical management in MDS

43. GLOSSARY OF TERMS

44. GLOSSARY AML = acute myeloid leukemia APFR = Atrialp peak filling rate
BA = basilar artery
ß-TM = Beta Thalassemia Major
ß-TI = Beta Thalassemia Intermedia
BM = bone marrow
BTM = bone marrow transplantation
BW = bandwidth
CFU = colony-forming unit
CMML = chronic myelomonocytic leukemia
CT2 = cardiac T2*.
DAPI = 4',6-diamidino-2-phenylindole
References
Kassab MY et al. J Am Board Fam Med 2007;20:65–71.
Krejza J et al. AJR Am J Roentgenol 2000;174:1297–1303.

45. GLOSSARY DFS = = disease-free survival. DysE = dyserythropoiesis
ECG = electrocardiography
EDV = end-diastolic velocity
EF = ejection fraction
EPFR = early peak filling rate
FatSat = fat saturation
FAQ = frequently asked questions
FDA = Food and Drug Administration
FISH = fluorescence in situ hybridization.
FOV = field of view
GBP = Currency, pound sterling (£)

46. GLOSSARY Hb = hemoglobin HbE = hemoglobin E HbF = fetal hemoglobin
HbS = sickle cell hemoglobin.
HbSS = sickle cell anemia.
HIC = hepatic iron concentration
HU = hydroxyurea
ICA = internal carotid artery.
ICT = iron chelation therapy
IDL = interface description language
IPSS = International Prognostic Scoring System
iso = isochromosome

47. GLOSSARY LIC = liver iron concentration
LVEF = left-ventricular ejection fraction
MCA = middle cerebral artery
MDS = Myelodysplastic syndromes
MDS-U = myelodysplastic syndrome, unclassified
MRA = magnetic resonance angiography
MRI = magnetic resonance imaging
MV = mean velocity.
N = neutropenia
NEX = number of excitations
NIH = National Institute of Health
OS = overall survival

48. GLOSSARY pB = peripheral blood PI = pulsatility index
PSV = peak systolic Velocity
RA =refractory anemia
RAEB = refractory anemia with excess blasts
RAEB -T = refractory anemia with excess blasts in transformation
RARS = refractory anemia with ringed sideroblasts
RBC = red blood cells
RF = radio-frequency
RCMD = refractory cytopenia with multilineage dysplasia
RCMD-RS = refractory cytopenia with multilineage dysplasia with ringed sideroblasts
RCUD = refractory cytopenia with unilineage dysplasia

49. GLOSSARY RN = refractory neutropenia ROI = region of interest
RT = refractory thrombocytopenia
SCD = sickle cell disease
SD = standard deviation
SI = signal intensity
SIR = signal intensity ratio
SF = serum ferritin
SNP-a = single-nucleotide polymorphism
SQUID = superconducting quantum interface device.
STOP = = Stroke Prevention Trial in Sickle Cell Anemia
STOP II = Optimizing Primary Stroke Prevention in Sickle Cell Anemia

50. GLOSSARY T = thrombocytopenia
TAMMV = time-averaged mean of the maximum velocity.
TCCS = transcranial colour-coded sonography
TCD = transcranial doppler ultrasonography
TCDI = duplex (imaging TCD)
TE = echo time
TR = repetition time
WHO = World Health Organization
WPSS = WHO classification-based Prognostic Scoring System