INFLAMMATION Inflammation. Inflammation. Causes of inflammation. Classical signs of inflammation. Acute local inflammation

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1 INFLAMMATION Marta Kalousová Institute of Medical Biochemistry and Laboratory Diagnostics First Faculty of Medicine, Charles University and General University Hospital Prague Reaction of the organism to any pathogenic insult Phylogenetically and ontogenetically the oldest defence mechanism Causes of inflammation Biological factors infection bacteria, viruses, fungi Chemical factors poisons, corrosive substances Physical factors burns Mechanic factors injury Tissue ischemia and necrosis pathogenic insult acute local inflammation systemic response reparation OR chronic inflammation Classical signs of inflammation Calor Rubor Tumor Dolor Functio laesa Acute local inflammation Release of mediators of inflammation First shortly vasoconstriction, then vasodilation, increase of vascular permeability, exsudation of fluids Migration of leukocytes, phagocytosis, respiratory burst of neutrophils, role of ROS (reactive oxygen species) Activation of complement, coagulation, fibrinolysis and kinine system Later: Involvement of specific immunity Ag-Ab, T- lymphocytes Aim to demarcate, destroy and eliminate the pathogenic agens, reparation of the damage 1

2 Chronic inflammation Possible persistence of foreign material Presence of lymphocytes, monocytes and plasmatic cells (x neutrophils in acute inflammation) Sustained production of mediators of inflammation Deposition of collagen and fibrinogen, fibrotisation (mediator TGFβ) - scarring Systemic inflammatory response (SIRS) Temperature >38 C OR <36 C Leukocyte count >12,000/µL OR <4,000/µL OR >10% of immatured formes Tachycardia >90/min Breath >20/min OR pco 2 <32 mm Hg Systemic inflammatory response (SIRS) Increase of acute phase reactants Release of glucocorticoids Sepsis = SIRS caused by infection Possible progression to septic shock Hypotension Hypoperfusion ( multiorgan damage) Mediators of inflammation Alarmins DAMPs Vasoactive amines histamin, serotonin Eicosanoids - derivatives of arachidonic acid prostaglandines, prostacyclin, tromboxanes, leukotrienes Cytokines Reactive oxygen and nitrogen species Complement, coagulation, fibrinolytic and kinine systems Alarmins Alarmins = DAMPs damage-associated molecular patterns released from damaged cells (necrotic not apoptotic) - HMGB1, EN-RAGE (S100A12), S100A8/S100A9, interleukins (IL-1α), HSP, nucleosomes, ATP PAMPs pathogen-associated molecular patterns - microbial structures dsrna and DNA, bacterial protein flagellin, fungal β-glukan and α-mannan cell wall components, lipopolysaccharide of G-, lipoteichoic acid (G+), peptidoglycan Alarmins PRRs pattern recognition receptors receptors for DAMPs and PAMPs regulation of the immune responce - or, cell death or differentiation Toll like receptors (TLR) NFκB production of cytokines e.g. IL1β... (synergistic action of DAMPs and PAMPs) RAGE receptor for advanced glycation end products Nod-like receptors (NLRs) - receptors in cytosol 2

3 Cytokines e.g. IL-1, IL-6, TNF-α etc. Produced mainly by activated macrophages and T- helpers after stimulation by immunocomplexes or microbial products Stimulation of hypothalamic thermoregulation center fever Influence on syntesis of acute phase reactants in the liver Activation of complement, opsonization Stimulation of myelopoesis and release of leukocytes from bone marrow Increased synthesis of heat shock proteins they function as chaperons (affect right configuation of newly synthetized proteins) Complement Part of innate immunity, alexine Complex of >25 proteins and their fragments Plasma proteins (mainly β globulins, some of them are proteases) Serosal proteins Cell membrane receptors Cascade activation amplification of the response, fast inactivation Activation of complement Classical pathway Lectin Alternative pathway pathway Ag + Ab (IgM, IgG) MBL mannose C3 is cleaved spontaneously binding lectin + C3b binds to microb. wall C1 C2, C4 C1qr 2 s 2 mannose on microb Factors B, D, P (properdin) C4b2b = C3 convertase C4b2b3b = C5 convertase of classical pathway opsonization C5 C3 C3b C3a C5b + C5a C5b C6 C7 C8 (C9)n MAC membrane attack complex C3bBb = C3 convertase PC3bBb3b = C5 convertase of alternative pathway anaphylatoxins chemotaxis Complement Presence of inhibitors C1 inhibitor (classical pathway) lack of C1 inhibitor hereditary angioedema Factors H and I (alternative pathway) mutation of factor H hemolytic uremic syndrome Role of complement in autoimmune diseases Cells involved in inflammation Neutrophils acute inflammation Monocytes macrophages phagocytosis Lymphocytes Ig, chronic inflammation Endothelial cells Eosinophils Mast cells Thrombocytes Phagocytosis Recognition of material Chemotaxis Adhesion opsonization co-operation between Ab and C Ingestion Intracellular decomposition of material Monocytes-macrophages (mononuclears), neutrophils and to a limited extend eosinophils (polymorfonuclears) 3

4 Bactericid activity intracellularly Content of lysosomes (lysozym, lactoferrin, collagenase, elastase, myeloperoxidase, further enzymes) phagolysosom Respiratory burst consumption of oxygen, oxidation of glucose (pentose cycle glucose-6-phosphate dehydrogenase), activation of NADPH oxidase, subsequently production of hydrogen peroxide and FR (free radicals) NADPH oxidase deficiency chronic granulomatous disease Respiratory burst Activation of NADPH oxidase NADPH + O 2 NADP + + O.- 2 H 2 O 2 Release of iron from storage - Fenton reaction formation of hydroxyl radical H 2 O 2 + Fe 2+ HO. + OH - + Fe 3+ Myeloperoxidase from phagolysosoms H 2 O 2 + Cl - HClO chloramines HClO + O.- 2 HO. + Cl - + O 2 Synthesis of NO. induction of NOS II (inos) via cytokines and microbs arginin citrulin + NO. OONO - (peroxynitrite) vasodilation, antimicrobial effects Acute phase reaction Physiological reaction to any insult or pathological state (cellular damage and reparation, metabolic activation of cells) inflammation local or systemic trauma (including surgery) presence of a tumor extreme physical activity, acute myocardial infarction, after labour Cells release mediators and signal molecules (e.g. cytokines) which affect synthesis of proteins in the liver acute phase reactants Positive acute phase reactants Early acute phase reactans Acute phase reactants with middle response Late acute phase reactants Negative acute phase reactants Acute phase reactants (APR) Increase Proteins Time of increase 100 fold CRP, SAA, procalcitonin 2-4 fold α-1-antitrypsin, α-1- antichymotrypsin, acidic α-1-glycoprotein (orosomukoid), haptoglobin, fibrinogen 6-10 hours hours 50 % ceruloplasmin, C3, C hours Decrease albumin, prealbumin, transferrin according to half-life Acute phase reactants Protease inhibitors (proteases released form leukocytes) α-1-at (elastase, collagenase), α-1-acht (cathepsin), haptoglobin (cathepsin), α-2-macroglobulin Scavangers haptoglobin (Hb), SAA (cholesterol), ceruloplasmin (free radicals) Immunoregulation CRP, orosomucoid Reparation of the damaged tissue orosomucoid ( fibroblast growth) Coagulation factors - fibrinogen C-reactive protein (CRP) MW: 135,000 Reference range (adults): <8 mg/l Electrophoresis: β-2 Half-life: 24 hours able to bind the cell wall C- polysaccharide of Streptococcus pnemoniae ( name C-reactive) binds polysaccharides and other compounds from microbes activation of complement 4

5 C-reactive protein (CRP) Procalcitonin Decrease Increase Acute phase reaction Bacterial infection Autoimmune diseases Surgery Acute myocardial infarction Tumor MW: 13,000 Structure: 116 amino acids Production: Physiologically produced by C cells of the thyroid gland, precursor of calcitonin In generalised bacterial infections produced also by other cells monocytes, macrophages and neuroendocrinne cells, not converted to calcitonin Procalcitonin Reference range: µg/l Half-life: 24 hours, increase within 2-3 hours Increased in generalized bacterial, mycotic and protozoal infections, slightly also in burns, after OP, in polytraumas Immunoglobulins - antibodies Synthesis: plasmatic cells Electrophoresis: β-γ Formed upon stimulation by antigen, capable to bind antigen against which is directed Binding of complement Binding neutrophil leukocytes and macrophages Activation of phagocytosis Immunoglobulins - antibodies 5 classes - IgA, IgD, IgE, IgG, IgM Structure: 2 heavy chains (α, δ, γ, ε, µ) 2 light chains (κ, λ) Immunoglobulins - IgA MW: 160,000, dimer Reference range (adults): g/l Electrophoresis: β-γ antibodies of mucous immunity increased in mucosal inflammation and liver diseases 5

6 Immunoglobulins - IgG MW: 150,000, monomer Reference range (adults): g/l Electrophoresis: γ late antibodies increased mainly in chronic inflammation Immunoglobulins - IgM MW: 900,000, pentamer Reference range (adults): g/l Electrophoresis: β-γ early antibodies increased in acute inflammation Electrophoresis of plasma proteins ELFO acute inflammation Fraction % g/l Albumin α 1 globulins α 2 globulins β globulins γ globulins ELFO chronic inflammation ELFO chronic active inflammation 6

7 Metabolic changes during inflammation Complex neuroendocrine response Role of cytokines and hormones katecholamines, ACTH steroids, ADH, STH, inzulin Independent on the character of the insult, but depends on its intensity Influenced by the status before the insult age, comorbidities etc. Stress starvation hypermetabolism hypercatabolism during systemic inflammatory response (anabolism in reconvalescence) Metabolic changes during inflammation Increased vascular permeability hypalbuminemia (extravascular leak) oedemas Proteolysis degradation of structural proteins AA for synthesis of acute phase reactants, cytokines, complement, Ab, reparation, gluconeogenesis Increased utilisation of glutamin by the immune system; arginin (precursor of NO); BCAA main substrate of muscles Gluconeogenesis hyperglycemia; insulin resistance Lipolysis FFA for gluconeogenesis ( insulin resistance), for synthesis of TAG ( liver steatosis) Physiological defence mechanism But can become pathological Chronic inflammation relationship to cancer Atherosclerosis a microinflammatory disease 7