Blood and immune disorders Mgr. Veronika Borbélyová, PhD. [email protected] www.imbm.sk Blood • 4-6 L • Hematopoetic system • Formed blood elements, not cells!!! • Erythrocytes: transport of O2 and CO2 • Leukocytes: specific and nonspecific immune defenses • Thrombocytes (platelets) – hemostasis • pH 7.35-7.45 Plasma vs. Serum • Blood clot – Blood cells + fibrin Li Heparin K EDTA – yellow liquid = serum. 3 • Anticoagulants: heparin, citrate, EDTA (after centrifugation): – Erythrocytes – Leukocytes – Platelets – Plasma Plasma Albumin plasma osmotic pressure and the maintenance of blood volume serves as a carrier for certain substances Globulins • alpha globulins (transport of bilirubin and steroids) • beta globulins (transport iron and copper) • gamma globulins (constitute the antibodies of the immune system) Fibrinogen conversion to fibrin in the clotting process • Hematocrit (Hct): • ratio of blood cell volume to total blood volume (99% erythrocytes) muži 44±5%; ženy 39±4% Functions of the blood • Transport of various substances: – gases: O2, CO2 – nutrients – metabolic products – vitamins – hormones • Termoregulation - transport of heat (heating, cooling) • Immune response - defense against foreign materials and microorganisms • Hemostasis (prevention of water and nutrients lost) Formation of blood cells • The hematopoietic tissue: – adults: bone marrow – fetus: spleen and liver • pluripotent stem cells • → hematopoietic growth factors → – Myeloid precursor cells – Erythroid precursor cells – Lymphoid precursor cells • Lymphocytes - require further maturation (thymus, bone marrow) • later formed in the spleen and the lymph nodes (lymphopoiesis) • all other precursor cells proliferate and mature up to their final stage in the bone marrow (myelopoiesis) Erythropoietin Thrombopoietin Regulation of hematopoiesis • hormone-like growth factors = cytokines • production: • bone marrow stromal cells • liver and kidney Hematopoietic growth factors (colony-stimulating factors: CSF) 1. Erythropoietin → erythrocytes 2. Granulocyte-monocyte colony-stimulating factor (GM-CSF) → granulocytes, monocytes, erythrocytes and megakaryocytes; 3. Granulocyte colony-stimulating factor (G-CSF) → neutrophils 4. Macrophage colony-stimulating factor (M-CSF) → macrophages 5. Thrombopoietin → platelets. Hemoglobin (Hb) •an oxygen-transport protein •tetramer: -2 types of subunits (α and β) - heme (red color) - Fe2+ atom •oxygen-binding capacity: 1.34 mL O2/g Hb Hemoglobin A1: 2α and 2β subunits (α2β2) ~ 97%. Hemoglobin A2: 2α and 2δ (α2δ2) ~ 3% Hemoglobin F: α2 and γ2 (α2γ2) ~ 1% Concentration in blood: 130 – 160 g/l Anemia • a decrease in the total amount of red blood cells (RBCs) or Hb in the blood, or both • lowered ability of the blood to carry O2 • ♂: Hb < 130-140g/L (13 to 14 g/dL) • ♀: Hb < 120-130 g/L (12 to 13 g/dL) Anemic syndrome • Pallor • Fatigue • Dyspnoe • Tachykardia and palpitations • Headache, faintness, dim vision Causes of anemia The 3 main types of anemia are due to: 1. loss of blood (RBCs) – trauma, GIT bleeding 2. increased red blood cell breakdown – genetic conditions (sickle cell anemia, infections – malaria, autoimmune diseases) 3. decreased RBC production – iron deficiency, lack of vitamin B12 Classification according to the size of RBCs and amount of Hb: 1. Blood loss anemia • Iron or other components of RBCs are lost from the body • 2 forms: • Acute (rapid): • trauma or surgery • GIT bleeding – peptic ulcers • (normocytic, normochromic) • Chronic (slow): • Angiodysplasia • Gynecologic disturbances (menstruation, fibroids) • (microcytic, hypochromic) 2. Increased red blood cell breakdown Hemolytic anemia • Premature destruction of RBC • ↑ erythropoiesis • ↑ reticulocytes in the circulation • Mild jaundice • Mostly normocytic & normochromic • Hemolysis: o Intravascular (transfusion, mechanic injury, toxins) o Extravascular (spleen phagocytosis of abnormal RBS) Types of hemolytic anemia • Hereditary (inherited): a) Defects of RBCs membrane b) Enzyme defects c) Defects in hemoglobin production (hemoglobinopathies) • Acquired: • drugs, bacterial or other toxins, antibodies, trauma a) Inherited: Defects of RBCs membrane • Deficiency of membrane proteins like ankyrin and HEREDITARY SPHEROCYTOSIS spectrin → gradual loss of membrane surface → tight sphere instead of concave disk • RBC is susceptible to destruction when passes thorough the splenic circulation • Treatment: splenectomy (reduces red cell destruction) b) Inherited: Enzyme defects • G6PD deficiency • RBC more vulnerable to oxidants → direct oxidation of Hb to methemoglobin & denaturing of Hb → Heinz bodies c) Defects in Hb production Hemoglobinopathies THALASSSEMIA SICKLE CELL ANEMIA • Deficit in synthesis of α or β chains of Hb • Point mutation in the β- • β -thalassemia – restricted β- chain of Hb chains production → HbA1 • Causes: hemolytic anemia & deficiency vessel occlusion • Minor (Tt – few symptoms) vs • Treatment: BM major (tt - fatal) transplantation • α -thalassemia – rare (death of the fetus) Acquired hemolytic anemias • nonhereditary acute or chronic anemia • external factors leadingto hemolysis o direct membrane destruction – drugs, chemicals, toxic materials from plant and animal forms (snake venoms), infections 3. Anemias from deficient RBC production • Deficiency of nutrients for synthesis of Hb (iron) or DNA (folic acid, cobalamin) → decreased production of erythrocytes by the BM o Iron deficiency anemia o Megaloblastic anemias Iron-deficiency anemia o Dietary deficiency o Loss of iron through bleeding - Metrorrhagia - Menorrhagia - ↑ Requirement - pregnancy o Iron – a component of heme – iron deficiency → ↓ hemoglobin synthesis → impaired O2 delivery o Iron-deficiency : o ↓ hemoglobin + Hct + iron stores o RBCs = microcytic & hypochromic Megaloblastic anemia Cobalamin (B12) deficiency anemia • Impaired DNA synthesis • Vitamin B12 – essential for DNA synthesis, if there is a deficit nuclear maturation and cell division fail to occur o dietary deficiency o IF deficiency o Ileal resection o Inflammation of the ileum o Defective transcobalamine II (TCII) Megaloblastic anemia Folic acid deficiency • Impaired DNA synthesis o similar manifestation as in previous o malnutrition/dietary lack (elderly) o alcoholism – ↓FA in serum o pregnancy (increased requirement) Animal models of anemia • Chronic posthemorrhagic anemia in rats • Anemia of inflammation – Infectious Models – Intestinal Perforation – Pyogenic Bacterial Infections – Mycobacterial Infections – Parasitic Infections • Erythropoietin-deficiency anemia: – EpoKO/flox mice – homework Inflammation • Defense reaction of the organism • The aim is to repair or at least limit the damage caused by: • Microorganisms (bacteria, viruses, fungi, parasites) • Foreign bodies (pollen, asbestos) • Tissue destruction (mechanical damage, physical influences, chemicals, extremes of heat and cold) • Destroying, diluting or neutralizing the primary course • Damaged tissue is replaced by regeneration of parenchymal cells or by filling in the residual defects with fibrous scar tissue Acute inflammation • short duration - few minutes to several days. Chronic inflammation • longer duration – weeks to years Acute inflammation • Early response (few minutes – several days) • Nonspecific • Signs: Rubor (reddening) Calor (warmth) Tumor (swelling) Dolor (pain) Functio laesa (loss of function) Acute Inflammation • Vascular stage Acute inflammation • Cellular stage Granulocytes + monocytes Mastocytes + macrophages - cytokines Acute Inflammation Chronic inflammation • Self – perpetuating (weeks, months ... years) • Result of a recurrent or progressive acute inflammatory response or from low-grade smoldering responses that fail to awake acute response • Infiltration by mononuclear cells (macrophages) and lymphocytes • Proliferation of fibroblasts Causes: • talc, silica, asbestos, surgical suture materials, viruses, certain bacteria, fungi Local manifestation of inflammation A) Exudate – AIR • Serous - watery fluids low in protein content (plasma entering the inflammatory site) • Hemorrhagic - severe tissue injury, leakage of RBCs (damaged blood vessels) • Fibrinous - large amounts of fibrinogen • Purulent – pus - composed of degraded WBCs, proteins, and tissue debris B) Abscess - localized area of inflammation containing a purulent exudate + layer of neutrophils C) Ulcer - epithelial surface (skin or GIT epithelium) – necrotic and eroded + subepithelial inflammation (peptic ulcer) D) Edema - fluid in the interstitium located beneath the skin and in the cavities of the body Systemic manifestation of inflammation • inflammatory mediators are released to circulation • Acute phase response hours or days after inflammation CRP [mg/l] Meaning IL-1, IL-6, TNF-α up to 6 normal 6-35 Infection - virus 35 – 50 Uncertain range nad 50 Infection - bacteria [c] plasma proteins, ↑ ERY sedimentation rate fever, lethargy ↑ leukocytes Acute phase proteins ↑ CRP, fibrinogen Systemic manifestation of inflammation • SIRS = systemic inflammatory response syndrome - nonspecific • Multiple organ dysfunction SIRS: Temperature >38°C or <36°C Heart rate >90 beats per minute Respiratory rate >20 breaths per minute or PaCO2 <32 mm Hg (pH <4.3) WBC >12,000 cells/mm3, <4000 cells/mm3 Tissue repair • Tissue regeneration (replacement by the same cells) • Replacement by connective tissue (scar/fibrosis) • Cell migration, proliferation, and differentiation as well as interaction with the extracellular matrix Animal models • Plethora.. • LPS,