Acute leukaemia refers to acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL). AML is defined by a clonal expansion of myeloid blasts in the bone marrow, peripheral blood, or other tissues. ALL is defined by a clonal expansion of lymphoid precursor cells in the same areas. Both result from a proliferation and differentiation block. AML is diagnosed through cytology, cytochemistry, immunophenotyping, cytogenetics, and molecular biology tests. Response to treatment is assessed by degree of response including complete response, cytogenetic response, and molecular response.

1. MED-341:
Acute Leukaemia
Professor Abdulkareem Almomen, MD, FRCPC
(March 2011)

2. – Acute Myeloid Leukemia (AML)
– Acute Lymphoblastic Leukemia (ALL)
– Biphenotypic Acute Leukemia (BAL): My + Ly
Acute Leukaemia: main subtypes

3. • Clonal expansion of myeloid blasts in blood marrow
(BM), peripheral blood (PB) or other tissue
• Minimum threshold of blast cells for defining AML (BM):
– >20% blasts
AML: definition / concept
Proliferation + differentiation block / maturation arrest

4. Maturation arrest

5. Maturation arrest

6. Normal Bone Marrow: Cell Heterogeneity

7. BM in AML: Monomorphous Cell Appearance

8. AML5a
AML4-eos

9. • Incidence: 2 - 3 pts /100.000 inhab - year
• Overall: 1.2% (US)
• Lineal increase with age:
<35: < 1 /100.000 inhab - year
>65: >10 /100.000 inhab - year
• Median age: 60 - 70 year-old
• Not apparent increase during last years
AML: epidemiology

10. • Bone marrow failure
– Anemia
– Neutropenia
– Thrombocytopenia
• Extramedullary involvement (skin, gums, CNS, other)
• Proliferative symptoms
• Coagulopathy
• Leukostasis
• Metabolic disorders (tumor lysis syndrome)
AML: clinical presentation

11. AML: skin infiltration (granulocytic sarcoma)

12. AML: gums (gingival) infiltration

13. Acute Myeloid Leukemia (AML)

14. • Cytology
– PB
– BM (BM aspirate ± BM biopsy)
• Cytochemistry
– MPO (myeloperoxidase) & Sudan Black B (SBB) – Myeloid origin
– Non-specific esterase (NSE): -naphthyl acetate (ANA), -naphthyl
butyrate (ANB) – Monocytic origin
• Inmunophenotype
– Hematopoietic precursors: CD34, HLA-DR, CD45
– My Ag: CD13, CD33, CD15, MPO, CD117
– Megakaryoblastic Ag: CD41, CD61
• Cytogenetics
• Molecular biology
– Fusion transcripts (RT-PCR): PML/RAR-, AML1/ETO, CBF-/MYH11,
MLL/..., BCR/ABL, DEK/CAN)
– New mutations with prognostic impact: flt-3-ITD, CEBPalfa, NPM, …
AML - diagnosis:

16. AML – Auer rod

17. MPO
Naphtol-As-D-acetate esterase -naphthyl acetate esterase
AML : Cytochemistry

18. CD56
PE
100 101 102 103 104
CD2 FITC
10
0
10
1
10
2
10
3
10
4
NG2
PE
100 101 102 103 104
CD34 FITC
10
0
10
1
10
2
10
3
10
4
CD14
PE
100 101 102 103
104
CD123 FITC
10
0
10
1
10
2
10
3
10
4
AML : Flow cytometry

19. AML: Cytogenetics

20. Acute Promyelocytic Leukemia (APL, M3)
bcr1 bcr3
RT-PCR PML/RAR-alpha
FISH:
PML/RARA
fusion signal
Anti-PGM3 pattern staining

21. • Minimally differentiated (M0)
• AML w/o maturation (M1)
• AML with maturation (M2)
• Promyelocytic (M3)
• Myelomonocytic (M4)
• Monoblastic (M5a)
• Monocytic (M5b)
• Erythroleukemia (M6)
• Acute megakaryoblastic (M7)
FAB classification for AML:
lineage/differentiation- based
Granulocytic diff
Monocytic diff

23. I. AML with recurring genetic abnormalities
– AML with t(8;21)(q22;q22) & (AML1/ETO) rearrangement
– AML with abn BM eosinophils & inv(16)(p13q22)/t(16;16)(p13;q11) -
CBF/MYH11 rearrangement
– Acute promyelocytic leukemia associated to t(15;17)(q22;q11-12) &
PML/RAR- rearr
– AML with 11q23 (MLL) abn
II. AML with multilineage dysplasia
III. Therapy-related AML
IV. AML not otherwise categorized
WHO, 2001
WHO classification (AML): towards
molecularly-based categories

24. – Favorable: t(15;17), t(8;21), inv(16)
– Intermediate risk: normal karyotype
– Unfavorable: abn 5 (del/-5), abn 7 (del/-7),
inv(3q)/t(3;3), complex karyotype (≥5 abn),
abn 11q, t(6;9), del(17p)
AML: main cytogenetic abnormalities

25. AML (non-APL): standard approach
Intensification CT
Ara-C HD-based
Post-remission tx
AlloSCT AutoSCT CT
Induccion CT
Anthacycline + Ara-C /…
CR~75%
Long-term OS~35-40% (<60)
Salvage therapy
Refractory
Relapse

26. Acute Lymphoblastic Leukemia (ALL)

27. ALL: definition
– Clonal expansion of lymphoid (precursor
lymphoid cells) in blood marrow (BM),
peripheral blood (PB) or other tissue

28. ALL: main subtypes
– B-cell ALL / precursor B lymphoblastic leukemia
– T-cell ALL / precursor T lymphoblastic leukemia

29. • Incidence: 2/100.000 (inhab-year)
• 3/4 in children
• B-ALL:
– 80-85%
– Predominance in children
– 10% presenting without BM involvement
(B-cell lymphoblastic lymphoma)
• T-ALL:
– 15% of children ALL
– 25% of adult ALL
– Predominance in adolescent / young male pts
– Frequent presentation with exclusive extramedullary
involvement (T-cell lymphoblastic lymphoma)
ALL: epidemiology

30. • Extramedullary involvement
– CNS
– Mediastinal (T-ALL)
– Other (lymph node, testicular, ...)
• B symptoms
• Bone marrow failure
• Metabolic disorder
ALL: characteristic clinical features

31. T-ALL: mediastinal involvement

32. ALL – FAB1 subtype

33. ALL – FAB2 subtype

34. Common B-lineage antigens: HLA-DR, CD19, CD79a,CD22
• Pro-B (B-cell progenitor, B-I): Tdt+, CD10(-), cytIg(-), CD20(-)
• Common (early pre-B, B-II): TdT(+), CD10(+), cytIg(-)
• Pre-B (B-III): Tdt(+), cytIg(+)
• Mature B-ALL (B-IV): Tdt(-), sIg+, CD20(+)
B-ALL: immunological classification

35. T-ALL/Common Ag: Tdt, CD3cyt, CD7
– Early T-ALL: CD1(-),CD2(-),CD3s(-), CD5(-),CD4(-),
CD8(-)
– Thymic T-ALL: CD1a(+),CD2(+),CD5(+)
– Mature T-ALL: CD1a(-), CD2(+),CD5(+),CD3s(+)
T-ALL: immunological classification

36. – Favorable: t(12;21),
– Intermediate risk: normal karyotype, t(1;19)
– Unfavorable: t(9;22), 11q23 abn [t(4;11) & other],
hypoploid
ALL: main cytogenetic abnormalities

37. ALL: current therapeutic approach
Consolidation CT
Post-remission
AlloSCT AutoSCT CT (reinduction & maintenance)
CR:  83%
Induction Antr. / VCR / PDN
L-ASA, ARA-C, CFM
Surv*:  80% (children)
 35% (adults)

38. Imatinib: molecular-targeted therapy for
Ph-positive ALL
Goldman et al, Lancet 2000
Y = Tyrosine
P = Phosphate
Bcr-Abl
ATP
Substrate
P
P
P
P
Abl: a highly overexpressed
tyrosine kinase protein in CML
& Ph-pos ALL

39. Imatinib: molecular-targeted therapy for
Ph-positive ALL
Goldman et al, Lancet 2000
Bcr-Abl
Bcr-Abl
ATP
Substrate
P
P
P
P
Imatinib: blocks abl function by
interfering with ATP binding
Y = Tyrosine
P = Phosphate

40. Outcome
– Response criteria
• Complete response
• Cytogenetics response
• Molecular response
– Failure: primary refractory, relapse
– …

41. NCI criteria (Cheson et al, 1999)
1. <5% blasts in BM
2. Absence of extramedullary leukemia
3. Recovery of PB counts (ANC >1 & platelet >100x109/L)
4. Minimum 4-week duration
Definition of CR

42. CR (morphologic assessment) <5% of BM blast cells
Low sensitivity
Universally applicable
Cytogenetic CR Absence of abnormal metaphases
Low sensitivity
Only in cases with cytogenetic abn
(i.e., Ph-pos)
Molecular response Clearance of molecular marker
(bcr/abl, PML/RAR, AML1/ETO,...)
Only in AL with known molecular marker
High sensitivity (1 x 10-5)
Response assessment: types (degree) of response

43. Morphologic assessment of response
CR Non-CR