Module 2 Summary Flashcards
Acute Leukaemia Cytochemistry
Positive in AML:
Naphthol AS-D Chloroacetate esterase
Myeloperoxidase stain (MPO)
Sudan Black B stain (peroxidase dependent)
Acid phosphatase
Demonstration of esterases with Naphthyl acetate &
Naphthyl Butyrate
Acid alpha Naphthyl esterase
Positive in ALL:
Periodic Acid Schiff reaction (PAS) (Bind to the glycogen in leukaemia cells)
What were the principals of FAB classification?
- blast count > 30% (blast morphology was correlated to the myeloid/lymphoid
maturation sequence) - Morphology
- Cytochemistry: > 3% of blasts have to be positive either for MPO or SBB to qualify as myeloid blasts
- cases which appeared non myleoid, were classified as LL
What are the subtypes in AML FAB classification?
AML M0 - AML, MPO negative M1 - AML without maturation M2 - AML with maturation M3- APML M4- - Acute myelomonocytic leukaemia M5a - Acute monocblastic l M5b -Acute monocytic l M6 -Acute erythryoleukaemia M7 - Acute megakaryblastic l
What are the subtypes of ALL in FAB classification?
ALL
L1 - small monomorphic cells
L2 - large heterogeneous cells
L3 - burkitt’s
What advances led to WHO classification?
- Metaphase cytogenetics in 1960ies- interphase fluorescence in situ hybridisation (FISH) and polymerase chain reaction (PCR) came later
- Flowcytometrical phenotyping since mid 1970ies; examines DNA content and cell membrane expression of lineage associated membrane / cytoplasmic proteins
- the assignment to subtypes of acute leukaemias is important
- Improvement in standardisation
WHO AML classification?
AML with recurrent genetic abnormalities
AML with myelodysplasia related changes
Therapy-related myeloid neoplasm
AML, not otherwise specified
WHO ALL classification?
- Precursor lymphoblastic leukaemia
B – lymphoblastic leukaemia, not otherwise specified
B – lymphoblastic leukaemia, with recurrent genetic abnormalities
T – lymphoblastic leukaemia - Mature lymphoblastic leukaemia
Major concepts of WHO classification?
Stratification of acute leukaemias by major lineage (lymphoid, myeloid,
biphenotypic)
Cell of origin is suggested for each leukaemia
Lowers the blast count from 30% to 20% in blood or bone marrow
What does flow measure?
relative size
relative granularity
relative fluorescence intensity
What is flow made up of?
Fluidics system transporting particles to the laser beam
Optics system consisting of lasers to illuminate particles in the sample stream
Electronics system which converts the detected light signal into electric signals,
which are processed by a computer
What are fluidics?
Blood or bone marrow, or other cells in liquid suspension, are injected into a stream of sheath
fluid within the flow chamber:
- One cell at the time moves through the laser beam at any time
- The laser beam will then interact with the cell
How are fluorescent dyes used in flocyto?
Fluorescent dyes used in flow cytometry are conjugated to monoclonal antibodies, so that a particular antigen on a cell can be identified. (they are incubated with the sample from beforehand)
In a mixed population of cells, different fluorochromes can be used to distinguish separate subpopulations
What is the purpose of flo cyto? What can it be used for?
Blast identification
Lineage assignment
Classification
Myeloblast CD numbers
CD117 (myeloid/stem cell), CD34 (early precursor),
Myeloid: CD13, CD33, HLA-DR, -ve CD19
B lymphoid precursors CD
CD34 and TdT, CD19
T Lymphoid precursors CD
CD34, TdT, cyCD3
CLL lab findings
• Lymphocytosis between 5 and 300 x 109/l
• Smear cells
• Normocytic normochromic anaemia
• Thrombocytopenia
• Bone marrow: lymphocytic replacement of normal
marrow elements
CLL immunophenotyping + CLL score
•The main thing with mature CLL B cells is that they express CD5, which is usually exclusively expressed on T cells - normal mature B cells do not express it
• CLL is +ve for CD5, CD19, CD20, CD22, CD23, CD79b.
•The CLL score gives 1 point to CD5+. CD23+, FMC7 negative and weak expression of SmIg and negative/weak expression of CD79b.
A score of 5/5 = CLL likely
What cancers have Mature B cells CD5 +ve?
Mantle cell
Marginal zone NHL
B NHL unclassified
CLL
Other tests for CLL
•Other tests include antigolubulin test (coombs test), reticulocyte count, serum Ig, bone marrow aspirate/ LN biopsy
oSerum Ig - reduced concentrations/ immuneparesis (Hypogammaglobulinaemia)
oBM aspirate - lymphocytic replacement of normal cells
CLL Cytogenetics
Karyotpyping is impossible in CLL because cells are too slow diving - you need FISH
•Good prognosis - normal karyotype, del(13q), trisomy 12
•Worse prognosis - del 11q, del 17p
Role of NGS in CLL
Can identify other mutations such as:
NOTCH1- encodes tf that regulates MYC,
and SF3B1, which encodes a important part of the splicesome
CLL Poor prognostic mutations/factors
17p (TF53) deletion 11q (ATM) deletion in pnts under <55 ZAP70 and CD38 infer poor prognosis Unmutated IgH status High B2-microglobulin (Keating, 1995)
Why is unmutated IgH status a poor prog factor?
CLL with Mutated Ig heavy chain genes has a better survival than non-mutated. The principle behind this is that Ig somatic hyper-mutation is a normal process by which Ig’s transform to bind antigens better. Lack of mutation = worsenes B cell function
Good Prognostic factors for CLL
•Good prognosis - normal karyotype, del(13q), trisomy 12
Staging systems for CLL
Binet (A, B, C) A: <3 lymphoid areas are enlarged; B: >3; C: anaemia or thromboyctopenia are present
Rai (Stage 0-IV)
0 is lymphocytosis only
1 Lympho + enlarged LN
2 Lympho + enlarged spleen ± enlarged LN
3 Lympho + anaemia
4 Lympho + low plts + 1 enlarged (spleen/LN/liver)
CLL prognosis
HIGHLY variable!!
> Indolent disease 10-20 year course, never require treatment, death from unrelated cause (30% patients)
> Initially 5-10 years good health until progression to a 2-3 year terminal phase
> Rapid progression to death within 2-3 years
When do we begin treatment for CLL?
Watch and wait for all patients until they show an indication for intervention (5):
o Progressive BM failure
o Massive/progressive lymphadenopathy
o Progressive lymphocytosis defined as 50% increase of 2months and/or a doubling time less than 6 months
o >10% weight loss in 6months, fever >38 for >2weeks, fatigue, night sweats
o Autoimmune cytopenias
MBL?
Monoclonal B lymphocytosis (MBL) is defined as the presence of a clonal B-cell population in the peripheral blood with fewer than 5 × 10^9/L B-cells (>5 is the cut off for CLL) and no other signs of a lymphoproliferative disorder. The majority of cases of MBL have the immunophenotype and resemble CLL. MBL does not require treatment. 1% of cases become CLL per year.
What is the Mx in CLL?
o First line treatments - steroids, alkylating agent, purine analogues, anti CD20
o Second line - purine analogues, anthracyclines, allogeneic BMT
o Treatment of patients who are refractory - high dose steroids, anti-CD52
• Young patients may be cured by allogeneic SCT
• Supportive management for people who would not benefit from intensive chemo e.g. Prophylaxis/treatment of infections (infections account for 50% CLL deaths)
Why do 50% of pnts get recurrent infections in CLL?
Remember CLL is clonal proliferation of nonfunctional B cells!!!
Multifactorial:
Hypogammaglobulinaemia (due to b cells not working)
Impaired innate immunity
Neutropenia
Leukaemic infiltration of bone marrow
Therapy related
What increases in the incidence of infections in CLL?
Advanced age
Disease progression
Repeated therapies (Steroids, Cytotoxic chemotherapy reduces T and B cell number and function, B cell specific therapy worsens B cell function as affects CLL and residual normal B cells)
What complications in terms of infections can CLL pnts experience?
Rec sinopulmonary
CMV reactivation
Rec herpes zoster
Pneumocystis Jirovecii
CML pathogenesis
BCR-ABL fusion over-activates tyrosine kinase this activates signalling pathways: JAK STAT, Ras Mek, mtor, src kinases and PI3K/AKT. This leads to proliferation, survival and clonal expansion.
CML PC
Incidental finding Fatigue, night sweats, weight loss LUQ pain Splenomegaly Less frequent: bone pain, priapism, retinal haemorrhage, thrombosis, hepatomegaly
Accelerated phase definition
blasts in BM or PB 10-19% basophils >= 20% Persistent thrombocytopenia Ph+ on treatment Thrombocytosis unrelated to treatment Increasing spleen size and wcc unrelated to therapy
Blast phase definition
> 20% in PB or BM
Extramedullary blast proliferation, apart from spleen
Large foci or clusters of blast seen in the BM biopsy
CML diagnosis
- FBC + Blood film (mature leucocytosis with blasts <2% of nucleated cells in BM)
- FISH for BCR-ABL (24hr)
- RT-PCR for BCR - ABL (For monitoring)
- BM asp (morphology, flow, cytogen analysis) count blasts, ph+, rule out other cytogenetic abnormalities)
- BM trephine (histopathological confirmation + blast count)
Different scores for CML
bap bap bap bap to the top, CML and slide that rhythm
SOKAL (1984) - BAPS (blast % on pb, age, platelet count, spleen size)
HASFORD (1998) - BAPS + eo & basophil % on pb
EUTOS (2011) - Spleen size + basophil % on pb
Describe BM aspirate in CML
HYPERCELLULAR
o Megakaryocytes can increase in number and appear hypo-lobular
o The percentage of erythroid cells falls (increased myeloid:erythroid ratio)
o Increased deposition of reticulin fibres
o Pesudo Gaucher cells (macrophaged that have phagocytosed other cells) can be present
CML Mx
c - monitor white cell count, cytogenetics and molecular genetics.
m - imatinib is a useful treatment (interferons used to be used).
S - BM transplant is the only cure but it can not be used in all patients
What is the definition of MM?
Multiple myeloma is a cancer of transformed plasma cells, terminally differentiated B cells that secrete Ig and are the effector cells of the specific humoral immune response
MM pathogenesis
Transformation results from a range of numeric and structural genetic aberrations that accumulate from a pre-malignant condition (“MGUS”) to terminal progression
MM incidence + epidemiology
>4000 people every year in the UK incidence 5/100.000 per year 15% of blood cancers and 1% of cancers median age at diagnosis 65-70y 2x more frequent in blacks than in whites, less common in Asians
Prognosis of MM
Poor. Median survival 4-7years (age)