theme 2

hematopoiesis → what is it + what does it make + regulated by

• formation of blood cells from HSC in BM

• produces erythrocytes, leukocytes, platelets

• regulated by cytokines and growth factors → epo, tpo, g-csf

HSC = hematopoietic cell (character, act by?)

• self renewing, multipotent 

• activated by stress or injury

myeloid lineage → produces (4) + controlled by 

• produces:

  • erythrocytes

  • megakaryocytes → platelets

  • monocytes

  • granulocytes

• controlled by mainly cytokines → epo, tpo, gm-csf

lymphoid lineage produces (3) + controlled by 

• produces:

  • B cell

  • T cell

  • NK cell

• regulated by IL7 and antigenic stimulation in lymhoid organs

cytokines in hematopoiesis

• EPO: stimulates RBC production.

• TPO: regulates platelet production.

• G-CSF/GM-CSF: stimulate granulocyte/monocyte formation.

• IL-3, IL-6, SCF: early progenitor stimulation.

stress hematopoiesis (HT) (what happens, driven by, might do to compensate)

• enhanced HT activity during infection, bleeding or hypoxia

• driven by incr cytokine release

• may activate extramedullary HT (spleen, liver)

dysregulated HT

• disruption of normal diff/prolif of progenitors

• leads to cytopenia (underproduction) or cytosis (overproduction)

• seen in BM failure, leukemia or myeloproliferatative disorders

cytopenia (what is it + causes 4 + what to check 3)

• low blood cell count of one or more lineages

• causes → BM failure, infiltration, immune destruction, nutrient deficiency

• check CBC, reticulocytes, BM 

cytosis (what is it + causes)

• elevated cell count → erythrocytosis, leukocytosis, thrombocytosis

• causes

  • reactive → infection, inflamma

  • neoplastic → myeloproliferative

myeloproliferative neoplasms (MPN)

• clonal prolif of mature myeloid cells

myelodysplastic syndromes = MDS (what, dysplasia, can become?)

• ineffective HT → cytopenias despite hypercellular marrow

• dysplasia in 1 or more lineage

• can progress to AML

acute leukemia → what + kinds + symptoms + what is a hint

• rapid prolif of immature blast cells in BM

• 2 kinds

  • AML → myeloid blasts

  • ALL → lymphoid blasts

• symptoms → anemia, infections, bleeding, bone pain

  • cytopenia + leukocytosis → hint!

chronic leukemia → what + types

• accum of more mature but dysfunctional cells

• 2 types

  • CML → myeloid lineage, BCR-ABL fusion (philadelphia chr)

  • CLL → B cell accum, common in elderly

lymphoma

• malignancy of lymp tissue → nodes or extranodal

• two major types → hodgkin or non-hodgekin

• classified by

  • cell of origin → B or T cell

  • clinical behavior

approach to cytopenia

• confirm with repeat CRC

• evaluate BM morphology + cellularity

• assess for nutrional, autoimmune (AI), drug-induced or malignant cause

approach to cytosis (if persistent? evaluate what?)

• rule out reactive cause

• if persistent test for clonal markers → JAK2 or BCR-ABL1

• evaluate splenomegaly and thrombosis esp in MPN

lab tests for hematologic malignancies 4

• cytology/histology → morphology of blood and marrow cells

• immunophenotypin (FACS) → surface markers (CD antigens)

• cytogenetics/FISH → chromosomal abnormalities

• mol testing → mutation analysis, gene expression prolif

flow cytometry (FACS) → measures what, identifies what, for which diseases

• measures cell surface + intracellular markers w/ fluor antibodies

• identifies lineage (+ clonality) of blasts or lymphocytes 

  • mye vs lym

  • if lymp → B or T cells

• Essential for diagnosing leukemia and lymphoma.

Cytogenetic analysis (karyotyping) + examples

• Detects large chromosomal abnormalities and translocations.

• Examples

  • t(9;22) BCR-ABL in CML

  • t(15;17) PML-RARA in APL.

FISH (fluorescence in situ hybridization) in hematology

• Detects specific chromosomal rearrangements in interphase nuclei.

• Faster than conventional karyotyping.

• Used for confirming known fusions (BCR-ABL1, MYC, etc.).

Gene expression profiling

• Measures mRNA levels to classify malignancies by molecular subtype.

Connection hematologic malignancy and cell development → when does a mutation occur?

• mutations during specific diff atages determine disease type

  • early progenitor → acute leukemia

  • mature lymp cell → lymphoma

Leukemia vs lymphoma distinction

• leukemia → primarily in BM and blood

• lymphoma → primarily in lymph nodes or tissues

• Overlap exists (e.g., lymphoblastic leukemia/lymphoma).

chronic mye leukemia = CML (what?, causes what kind of prolif? how treated?)

• BCR-ABL1 fusion → constitutively active TK

• causes granulocytic prolif

• treated with imatinib = TKI

Acute Promyelocytic Leukemia = APL (what?, causes what? how treated?)

• t(15;17) → PML-RARA fusion

• blocks myeloid diff

• treated with ATRA + arsenic trioxide

Hodgkin lymphoma (HL) → what kind of cells

• reed-sternberg cells → cd15, cd30

• typically arises in one nodal region → contigouos spread

• often curable with combined chemo-radiotherapy

Non-Hodgkin lymphoma (NHL)

• diverse group of B/T cell malignancies

• examples

  • DLBCL

  • foll lymphoma

  • burkitt lymphoma

  • mantle cell lymphoma

Multiple myeloma (what, leads to, diagnosed by)

• plasma-cell malignancy producing monoclonal Ig (M protein)

• causes CRAB features → hypercalcemia, renal failure, anemia, bone lesions

• diagnosed by serum electrophoresis + BM biopsy 

burkitt lymphoma → gene, cell, what infection

• t(8;14) → MYC activation

• extremely fast-growing B cell lymphoma

• associated with EBV infection

treatment of hematologic malignancies

• chemo → backbone for most leukemias lymphomas

• targeted therapy

  • if CML → TKI

  • CLL → BTK inhibi

  • or anti-cd20 (rituximab)

• stem cell transplantation → for high risk or relapse

Autologous vs allogeneic stem-cell transplant

• auto → pt own stem cells

  • lower rejection

  • higher relapse risk

• allogeneic → donor

  • potential graft vs tumor effect, but risk of GVHD

Minimal residual disease (MRD)

• small number of malignant cells remaining after therapy

• detected by flow cytometry or mol methods (PCR/NGS)

Prognostic markers in hematologic malignancies

• cytogenix/mol abnormalities

• MRD status after therapy

environment in BM that protect HSC → stromal cells

• fibroblasts → produces ECM + growth factors

• fat cells → regulate metabolism + cytokine signaling

environment in BM that protect HSC → specialized cells

• CAR cells = CXCL12 (SDF1)abundant reticular cells

• -NES+ MSC = Nestin+ MSC

erythropoiesis (ery = RBC) → start + 3 phases

• hemocytoblast → pro-erythroblast

  • = stemcell → committed cell 

• phase 1 = ribosome synthesis → early erythroblast

• phase 2 = Hb accum → late eryblast → normoblast

• phase 3 = ejection of nucleus → normoblast → reticulocyte

thrombopoiesis

• platelet (=thrombocyte) formation from megakaryocytes in BM

coagulation

• damaged blood vessel → release of clotting factors (CF)

• CF makes prothrombin → thrombin 

left shift of neutrophil granulocytes

• presence of more immature forms of neutrophil in blood

• due to increased production 

  • eg = during infection 

hematopoietic growth factors + cytokines INFLUENCE

• HGF → directly influence → inhib/stim HSC or progenitor cells

• cytokines → indirectly influ → inhib/stim prod of hematopoietic GF

HGF (4 + IL’s)

• SCF → stem cell factor

• TPO → thrombopoietin

• EPO → erythopoietin

• G/M-CSF → gran/monocolony stim factor

• IL 2, 3, 7

TPO → what does it do and where is it made

• stim platelet production

• produced by liver

EPO (source + job)

• source → kidney

• stim prod of ery in BM

G/M-CSF (source (3) + job)

• G-CSF made by → endo cells, fibroblasts, macrohphages

• G-CSF incr granulocyte prod in BM → leukocytosis = WBC high

myeloperoxidase (MPO) staining 

• to distinguish AML from ALL 

• MPO + → myeloid origin → AML

• MPO - → lymphoid blasts → ALL

acute + myeloid

AML

chronic + myeloid

• MPN = myeloproliferative neoplasmata 

  • eg → CML

acute + lymp = 2

ALL/LBL

• acute lym leukemia 

• lymfoblastic lymphoma

chronic + lymfoid

lymphomas → B or T/NK cell

passenger mutations

• not harmful

• copied during cell division

driver mutations

• muta in genes that regulate prolif or diff 

• can cause clonal expansion

class I mutation in AML

• GF receptors → Flt3 or KIT

• signal transduction molecules → TK, NRAS

class II mutation in AML

• cell cycle → cyclin dependent kinase inhib

• gene transcription 

• gene splicing 

malignant lymphoma classification

• AgR - = TdT + → precursor neoplasia

• AgR + → mature neoplasia

proto-oncogene activation by VDJ recombination

• dna segments in B and T cell precursors are cut + joint → error prone process

• somtimes recom machinary mistakenly joins POG next to strong Ig or TCR promoter/enhancer 

  • results in overexpression of POG

follicular lymphoma → translocation, Ig, gene

• t14→18

• IgH - BCL2

mantle cell lymphoma → transloca, ig, gene

• t11 → 14

• IgH - CCND1

burkitt lymphoma which gene

• t8 → 14,8,22

• IgH/IgL → MYC

mantle cell lymphoma, follicuar, ALL/LBL, myeloma, hodgkin, CLL, burkitt, maginal zone, immunocytoma, diffuse large B cell lymphoma

1. ALL/LBL

2. CLL

3. mantle

4. burkitt

5. marginal

6. myeloma

7. hodgkin

8. immunocytoma

9. diffuse large b cell lymphoma

10. follicular lymphoma

extra nodal marginal zone lymphoma of MALT

• chronic ag stimulation like h. pylori → act T helper cells → cytokines that stimulate B cell prolif 

  • clonal B cell expansion → MALT lymphoma h pylori dependent

  • genetic changes →  MALT lymphoma h pylori independent 

follicular lymphoma → gene, when does mistake occur + leads to what

• derived from germinal center B cells

• VDJ + VJ recomb 

  • transloca IgM-BCL2 → anti-apop BCL2 gene under control of Ig 

  • overexpression of BCL2 → resistance to apoptosis 

  • B cell survives abnormally long

diffuse large B cell lymphoma → where, when mistake+ where mutation, which gene

• derived from (post)germinal center B cells

• SHM

  • act mutation in BCR → contstituve sig → prolif

  • BCL6 act → block diff + promotes survival

buffy coat

• platelets

• leukocytes

plasma apheresis

• donors blood processed by machine

• plasma is collected → non collected cells back to donor

when RBC transfusion (2)

• anemia

• blood loss

when platelet transfusion

thrombocytopenia

when plasma transfusion

coag factor deficiencies

classification anemia

• cell size → micro-, macro-, normocytic 

• Hb content → hypo-, hyper-, normochromic 

small cells = microcytes characteristics → what MCV + 4 reasons

• low MCV <80

• iron def

• thalassa

• anemia of chronic disease

• sideroblastic anemia

large cells = macrocytes → MCV, 2 kinds, 2/4 reasons

• high MCV > 96 

• megaloblastic

  • vit B12 or folate def

  • MDS

• normoblastic

  • alcohol

  • high reticulocytes → hemolysis, heamorrhage

  • liver disease

  • drug therapy

normal sized cells → how is MCV + 6 causes

• normal MCV

• acute blood loss

• anemia of chronic disease

• chronic kidney disease

• marrow infiltration/fibrosis 

• AI rheuma

• hemalytic anemias

inherited corpuscular hemolysis

• thalassemia = mi

• sickle cell disease = N

• combi of both = m 

thalass beta soorten = 3

• minor → carrier = trait

• intermedia → moderate anemia

• major → severe anemia = Cooley anemia

thalass alpha deletion of genes

• deletion of 1-4 alpha genes 

  • 1 gene → mild or no anemia = carrier 

  • 2 → mild anemia = minor

  • 3 → moderatley severe = int

  • 4 → hydrops fetalis = major/Hb Bart

mutation in thala → 0

• leads to absent production

mutation in thala → +

leads to reduced production

beta thalasemia major → what possible mut combi/what happens

• welke hemolyse

• hoezo geen beta thal → leidt tot en waarom

• b0/b0 of b+/b0

• normal erythroblast → insoluble alpha-globin aggregate → no beta-thal

• ineffective erythropoies → hypochromic RBC → extravascular hemolysis 

  • bc aggr-containing RBCs are destructed in spleen 

alpha thala (AT) inheritance → 4 and name disease

• auto rec disorder

• 3 normal copies = aa/a- → AT minima → asymp

• 2 normal copies = a-/a- OR aa/-- → trait → minimal anemia

• 1 normal copy = a-/-- → HbH disease → mod to severe

• 0 normal copies = --/-- → Hb Bart → incomp extra-ut life 

BT minor or trait

• b+/b OR b0/b

• usually asymp

BT intermedia

• b+/b+

• only reduced prod

• not dependent of transfusions

sickle cell disease = SCD → 4 kinds

• SC trait = HbS → inheri of 1 abnormal sickle 

• SC anemia = HbSS → inheri of 2 abnormal sickle genes 

• SCD = HbSC → inheri of 1 abnormal sickle gene + 2nd Hb variant of beta-chain that causes sickling

• sickle-thalassamia = BbSB0 → inheri of 1 abnormal SG and thala gene 

anemia through increased destruc of ery → hemolysis due to extracorp factors → 2 causes that have each 2 categories

• auto immune 

  • warm → IgG 

  • cold → IgM 

• alloimmune 

  • ABO

  • Rh 

AI IgG → what happens at temp, what does it, which test

• warm temperature → IgG attaches at RBC

• extravasc hemolysis → removal of IgG + complement coated ery

• Coombs detects C + IgG → strong positive 

AI IgM 

• cold temp → IgM attaches 

• intravas hemolysis → C acti by IgM bound to RBC

  • MAC

• coombs light positive 

spherocytosis

• loss of RBC membrane bc of scission

• scission = partial phagocytosis 

storage of filt RBC, thrombocytes and plasma → what temp and how long

• RBC → 2-6 graden → 35 dagen

• thrombocytes → 20 graden → 5-7 dagen

• plasma → -30 graden → 1 jaar