Haemopoiesis, blood malignancies, coagulation and platelet function defects

Dr H.M.D.MoratuwagamaDepartment of Pathology

Faculty of Medicine-Ragama

Haemopoiesis

Sites of Haemopoiesis

• Yolk sac

• Liver and spleen

• Bone marrow– Gradual replacement

of active (red) marrow by inactive (fatty) tissue

– Expansion can occur during increased need for cell production

Sites of Haemopoiesis

• Fetus- 2 months –Yolk sac 2-7 months-Liver/Spleen 5-9 months-BM• Infants-BM• Adult-Axial skeleton

Components of Haemopoiesis

• Cells • Bone marrow stroma• Growth factors

Cells

• Stem cells• Self renewal• Plasticity

• Progenitor cells• Developmentally-restricted cells

• Mature cells• Mature cell production takes place from the more

developmentally-restricted progenitors

Haemopoiesis

Common lymphoid progenitor cellCommon myeloid progenitor cell

BM

• Stromal cells-adipocytes,fibroblasts,osteoblasts,endothelial

cells ,macrophages• Microvascular network

Regulation of haemopoiesis

• Transcription factors-CEBP-Myeloid-GATA 1-Erythroid• Growth factors

Haemopoietic growth factors• Glycoprotein hormones• GM-CSF

• Granulocyte-Macrophage colony stimulating factor

• G-CSF Granulocyte colony stimulating factor

• M-CSF• Macrophage colony stimulating factor

• Erythropoietin(kidney)• Erythropoiesis stimulating hormone

(These factors have the capacity to stimulate the proliferation of their target progenitor cells when used as a sole source of stimulation)

• Thrombopoietin(liver)• Stimulates megakaryopoiesis

Haemopoietic growth factors cont.

• Cytokines• IL 1 (Interleukin 1)• IL 3• IL 5• IL 6• TNF• SCF (Stem cell factor, also known as kit-ligand)• TGF-β/IFN-γ-Negative effect

Role of growth factors in normal haemopoiesis

Erythropoiesis and erythrocytes

• Lifespan – 120 days

• Non nucleated

• Biconcave disc

• Production regulated by Epo

• Needs Fe, B12, folate & other elements for development

Granulopoiesis

• Granulocytes– Neutrophils

– Eosinophils

– Basophils

• Only mature cells are present in peripheral blood

E

N

B

Granulopoiesis• Neutrophil– 2-5 lobe nucleus– Primary or secondary

granules• Pink (azurophilic granules)• Grey-blue granules

– Life 10 hours

• Precursors– Myeloblast <4%– Pro myelocytes– Myelocytes– Metamyelocytes– Band form (stab form)

Monocytes

• Larger than lymphocyte

• Oval or indented nucleus

• Monocytes >>>>to macrophage

• Specific function depends on the tissue type

Lymphopoiesis

Thrombopoiesis

• Platelet play a major role in primary hemostasis

• Life span 7-10 days• Production,

fragmentation of cytoplasm

• Megakaryocytes undergoes endomitotic division

Summary

• Normal haemopoiesis is necessary for the survival

• It is under the control of multiple factors

• Normal bone marrow environment is necessary for normal haemopoiesis

• Decreased production results in cytopenias

Blood malignancies

Blood malignancies

LEUKAEMIA LYMPHOMA

Blood malignancies

Leukaemia Acute ChronicMyeloid Lymphoid Myeloid Lymphoid AML ALL CML CLL

Aetiology of haemopoietic malignancies

• Idiopathic• Inherited factors-Down’s syn.,Blooms

syn.,Fanconi’s anaemia• Chemicals-ex:Benzene• Drugs-Alkylating agents• Radiation• Infections-viruses-HTLV-1/EBV/HHV8 Bacteria-H pylori-MALT Lymphoma

Leukemia

• Acute leukemias: rapid onset, rapid death if treatment is not successful

• Chronic leukemias: natural history measured in years, even without initial treatment

differentiation block

enhancedproliferation

AcuteLeukemia+

Gain of function mutations of tyrosine kinases

eg. FLT3, c-KIT mutations N- and K-RAS mutations BCR-ABL TEL-PDGFbR

Loss of function of transcription factors needed for differentiation

eg. AML1-ETO CBFb-SMMHC PML-RARa

Two-hit model of leukemogenesis

Hematopoieticstem cell

Neutrophils

Eosinophils

Basophils

Monocytes

Platelets

Red cells

Myeloidprogenitor

Lymphoidprogenitor

B-lymphocytes

T-lymphocytes

Plasmacells

naïve

ALL

AML

Myeloid maturation

myeloblast promyelocyte myelocyte metamyelocyte band neutrophil

MATURATION

Adapted and modified from U Va website

Acute Leukemia

• accumulation of blasts in the PB/BM

AML

Auer rods in AML

ALL

Classification of acute leukemias

ALL• mainly children• curable in 85% of children• curable in minority of adults

AML• mainly adults

• curable in minority of adults

Clincal manifestations

• symptoms due to:– marrow failure– tissue infiltration– leukostasis– constitutional symptoms– Others- DIC (acute promyelocytic leukaemia)

• usually short duration of symptoms

Marrow failure

• Neutropenia: :infections, sepsis

• Anaemia : fatigue, pallor

• Thrombocytopenia: bleeding

Infiltration of tissues/organs

• enlargement of liver, spleen, lymph nodes

• gum hypertrophy

• bone pain

• other organs: CNS, skin, testis, any organ

Constitutional symptoms

• Fever • sweats • weight loss • LOA

Investigations

• FBC+BP• Bone marrow aspiration & trephine biopsy• Special stains-Sudan black/PAS• Flow cytometry• Cytogenetics-t(15,17)-Acute promyelocytic

leukaemia

Principles of treatment

• combination chemotherapy– first goal is complete remission– further Rx to prevent relapse

• supportive medical care– transfusions, antibiotics, nutrition

• psychosocial support– patient and family

CML

• Clonal disorder of pluripotent stem cell• Philadelphia chromasome t(9,22)• Enhanced thyrosine kinase activity(TK)• Clnical features: due to hypermetabolism,

splenomegaly,BMF,leukostasis Treatment-TKI

CLL

• Common in elderly/west

LymphomaClonal proliferation of lymphoid cells

Non Hodgkin HodgkinB cell T cell FollicularMantleDLBCL

Clinical presentation

• Lymphadenopathy• Bone marrow failure• Organ involvement• Constitutional symptoms(B symptoms)

Investigations

• FBC+BP• ESR• LDH• Radiology• Biopsy• Flow cytometry• Immunohistochemistry

Management

• Aggressive/indolent• Stage-early/advanced• Patient factors• Options-watch and wait Chemotherapy Radiotherapy Immunotherapy BMT

Haemostasis

HEMOSTASISDefinition

• Hemostasis: drives from the Greek meaning “The stoppage of blood flow”.

• Components involved in haemostasis *Blood vessel *Platelets *Coagulation factors *Coagulation inhibitors *Fibrinolysis

drmsaiem

Vessel wall, Blood flow & Coagulation Substances

drmsaiem

In Case if there is an Endothelial Injury(Bleeding must be prevented at site of injury)

HEMOSTASIS

Under normal conditions, the formation and dissolution of thrombi is maintained in a delicate balance.

Clotting cascade

Fibrinolysis

Tests used in coagulation disorders

Screening tests1.FBC+BP2.BT3.PT4.APTT5.TT6.FibrinogenOthers: Factor assays/VWF assays/platelet function

tests/D-dimer/PFA 100/TEG ect.

Abnormal bleeding

• Vascular disorders• Platelet disorders-Thrombocytopenia Platelet function defects• Defective coagulation

Platelet function disorders

Congenital• Glanzmann’s disease

/Thrombasthenia• Bernard- Soulier syndrome• Storage pool diseases

Acquired• Anti platelet drugs• Hyperglobulinaemia• MPD/MDS• Uraemia

Glanzmann’s disease /Thrombasthenia• Def. Gp 11b/111a• Platelet aggregation –only with ristocetinBernard-Soulier syndrome• Gp 1b def.• Large platelet• Thrombocytopenia• Platelet aggregation-not with ristocetin

Bernard-Soulier vs Glanzmann’s

Coagulation disorders

Congenital• Haemophilia A(F VIII)• Haemophilia B(F IX)• VWD• Fibrinogen,XI,X,V,II def

Acquired• Liver disease• DIC• Vit K def

THANK YOU