Blood, hemopoesis Dr. Ádám Ágota → Blood cells + plasma Hematocrit: percentage of cellular elements Dr. Ádám Ágota

Blood cells: Erythrocytes (RBC) Leukocytes(WBC) – blood as transporting medium - granulocytes: lobulated nuclei, many cytoplasmic granules - neutrophils - eosinphils - basophils - agranulocytes: single, non-lobulated nucleus, few cytoplazmic granules - lymphocytes - monocytes - Thrombocytes (platelets)

Blood smear Staining: May-Grünwald-Giemsa

Main categories describing blood cells: Quantity/percentage in blood Shape Size Microscopic appearance (what does it look like?) – GIEMSA staining Electronmicroscopic picture, subcellular organelles Movement? Function Life span Site (organ) of origin? Site of destruction? Main pathological alterations

The red blood cell: 4-5 million/mm3 ; lab code: RBC: 4-5 T/l (T=tera) Doughnut (thinner centre, thicker rim) 7 µm diameter Periphery: intense acidophilia, lightly stained central part No subcellular organelles! Characteristic membrane components, e.g.: cholesterol: decreased amounts lead to loss of membrane elasticity . No self-mobility; drifted by blood stream Transport of oxygen and carbon dioxide 120 days (with aging cholesterol ↓) Red bone marrow Red bone marrow, spleen

The red blood cell, cont.: 11. Sensitive to ionic concentration lower than isotonic ⇒ ‘Spherocyte’ (ball shape) higher than isotonic ⇒ ‘Echinocyte’ (thorny) Pathological increase of RBC: ERYTHROCYTOSIS Pathological decrease of RBC: ANAEMIA ANISOCYTOSIS: RBCs are of different shape

Sickle cell anaemia

The neutrophilic granulocyte (Neutrophil): a.k.a. Polymorphonuclear WBC („Poly”) Abundant; 60-70% of total WBC Regular, spherical → appears round in blood smear 10-15 µm diameter Segmented nucleus (usually 3 lobules); neutrophilic granules Featureless cytoplasm, fair amount of glycogen particles; primary (20%) and secondary (80%) granules with enzymes: peroxidase, acidic phosphatase, collagenase, alkaline phosphatase, ribonuclease, lysozime, etc… Motility; the fastest moving type of WBC (40 µm/min); amoeboid movement (with pseudopodia) Devouring of foreign bodies („microphage”), small particles, bacteria, followed by decomposition with the help of specific particles Very short-lived, ca. 1 day! Red bone marrow At the site of phagocytosis ⇒ pus („pus cells”) or the connective tissue Enhanced percentage: NEUTROPHILIA (bacterial infection or leukaemia) Decreased percentage: NEUTROPENIA (disfunction of red bone marrow); „RIGHT SHIFT” – hypersegmentation – alcoholism

Neutrophils Barr body: Only in females – inactive X chromosome

The eosinophilic granulocyte (Eosinophil): crystalloid The eosinophilic granulocyte (Eosinophil): 2-4 % of total WBC Regular, spherical → round in smear 10-15 µm diameter Bilobular nucleus; eosinophilic granules in cytoplasm Featureless cytoplasm, many granules: specific granules (peroxidase, ribonuklease, acidic phosphatase, histaminase) Motility (chemotactic signal: allergic reactions – histamine release; metabolic products of parasites) Endocytosis, attenuation of allergic responses, anti-parasitic 2-3 days Red bone marrow Site of discharge or anywhere in the connective tissue Enhanced percentage: EOSINOPHILIA (allergic reactions of parasitic infections) Decreased percentage: EOSINOPENIA (disfunction of red bone marrow)

Eosinophils

The basophilic granulocyte (Basophil): Scarce (less than 1 %) – invisible in smears Regular, spherical → round in smear 10 µm diameter Horseshoe-shaped, non-segmented nucleus; large cytoplasm full of basophilic granules (metachromasic with toluidine blue) Lysosomes do not occur; heterogeneous granules, containing histamine, serotonin, hyaluronidase, etc. Motility Transforms to mastocytes – allergic and inflammatory reactions 5-6 days Red bone marrow Anywhere in connective tissues Enhanced percentage: BASOPHILIA (initial symptom of allergic reactions)

Basophils

The lymphocyte: 20-30 % Regular, spherical → round in smear Heterogeny in size: small lymphocyte: 7-8 µm, medium sized: 10-12 µm, large: 15-20 µm Round nucleus; small lymphocyte (resting form) – rich in heterochromatin; large lymphocyte (active, lymphoblast) – rich in euchromatin; reduced and pale stained cytoplasm Abundant free ribosomes, little cytoplasm Fast and active movements; Ly’s tend to leave the circulatory system when stimulated by any foreign substance Generation of immune response Different life spans: few days – years (memory cells) Red bone marrow, followed by migration into primary lymphatic organs (thymus) Usually in lymphatic organs Enhanced percentage: LYMPHOCYTOSIS (foreign proteins) Decreased percentage: LYMPHOPENIA (destruction of lymphatic organs)

Lymphocytes (large, medium, small)

The monocyte: 2-8 % Regular, spherical→ round in smear; in tissue: irregular, with processes The largest WBC, 15-25 µm Bean shaped and eccentric nucleus; cytoplasm „greyish-blue” – discrete azurophilic granules (tiny) Abundant lysosomes, well developed microtubular system Active motility Large, phagocytic cells (MACROPHAGE); transient form in blood – migrating from bone marrow to tissues, transforming into macrophage Variable life span; 2-3 month Red bone marrow At the site of definitive formation Enhanced percentage: MONOCYTOSIS (protracted bacterial infections, mononucleosis); Decreased percentage: MONOCYTOPENIA (diseases of bone marrow)

Monocytes

The thrombocyte (platelet): 200.000 – 500.000/mm3 Ovoidal or elongated; multiple occurrence in smear (tends to aggregate) The smallest blood cell; 2-5 µm Only part of it is visible in smears (granulomer: central part, hyalomer: peripheral part – glassy, not stained) Specific components (α-granule, dense-core granule – blood clotting factors) No self-mobility; drifted by circulation Blood clotting (hemostasis) (degranulation – hemostatic factors released) 5-10 days Red bone marrow Spleen Enhanced percentage: THROMBOCYTOSIS (hypertrophy of bone marrow); Decreased percentage: THROMBOCYTOPENIA (may be related to side effects of certain medicines)

Thrombocytes Origin: Megakaryocyte (red bone marrow)

Haematopoesis Red bone marrow CFU cells (Colony forming unit) – pluripotent precursors of blood cells; all blood cells are differentiated from these

Erythropoiesis CFU-E cell Proerythroblast: - Large (20-25µm) - Euchromatic - Basophilic cytoplasm - Many ribosomes Basophilic erythroblast: - 16-18µm Heterochromat. - Basophilic cytoplasm Polychromatophilic erythroblast: - 10-15 µm -hemoglobin prod. - Mixed eosinophilic and basophilic cytoplasm: „greyish” Acidophilic erythroblast: - 8-10 µm -nucleus pressed onto periphery Reticulocyte Nucleus is being ejected Erythrocyte Normally, only this form is present in circulation In summary: cell size decreases, haemoglobin synthesis, ejection of nucleus.

Granulopoiesis (myelopoiesis) myelocyte metamyelocyte STAB form! Myeloblast (euchromatic nucl.; basophilic citopl., multiple ribosomes) Promyelocyte (large granules)

Thrombopoiesis Megakaryoblast (euchromatic nucleus; free ribosomes) Promegakaryocyte (2 nuclei) Basophilic megakaryocyte (4 nuclei) Acidophilic megakaryocyte 6 osztódás Thrombogenic megakaryocyte (64 nuclei!; gigantic cell) Cytoplasmic fragmentation Thrombocyte (remaining nuclei get phagocytosed by macrophages)

Normal blood smear

Acute myeloid leukemia Acute proliferation of abnormal myeloid precursors

Chronic myeloid leukemia

Acute lymphoid leukemia Acute proliferation of immature lymphoblasts

Thank you for your attention!