Inflammation & Repair

Inflammation

Acute Inflammation

• Cardinal signs– Red (rubor)– Swelling (tumor)– Warm (calor)– Tender (dolor)– Loss of function (functio laesa)

NeutrophilsPolymorphonuclear Lekocytes (PMN)

• Margination– Pavementing

• Adhesion– Complementary adhesion molecules on

leukocytes and endothelial cells

Leukocyte-Endothelial Adhesion

Neutrophils Rolling

Emigration & Chemotaxis Mediators

• Bacterial products - LPS• Complement derivatives - C5a• Arachidonic acid derivatives

– leukotriene B4• Cytokines - IL-8

Emigration & Chemotaxis Mediators

Neutrophil Chemotaxis in vitro

Emigration & Chemotaxis Defects• WBC defects -

– Chediak-Higashi Syndrome– Diabetes mellitus

• Chemotactic factor defects – C5 or immunoglobulin deficiency

• Serum chemotaxis inhibitors – C5 inactivators - in cirrhosis, sarcoidosis,

and other diseases• WBC locomotion inhibitors

– Chloroquine, cancer and other chronic diseases

Phagocytosis & Degranulation

• Phagocytosis requires three distinct steps– Recognition– Attachment– Engulfment

Recognition & Attachment

• Opsoninzation• Opsonins

– Fc fragment of IgG– C3b– Mannose-binding protein (produced in the

liver)• Covers the surface of microorganisms and

is recognized by neutrophils and macrophages

Phagocytosis & Degranulation

Phagocytosis & Degranulation

Activation and Destruction (killing)• Oxygen dependent killing

– myeloperoxidase requires hydrogen peroxide and halide (e.g., Cl-) to produce HOCl

– Hydrogen peroxide and ferrous ion without myeloperoxidase will generate OH free radical

Chemical Mediators of Inflammation

Chemical Mediators of InflammationPreformed & Newly Synthesized

Arachidonic Acid System

Noninflammatory and Inflammatory Conditions

• Transudate - fluid with low protein content and a specific gravity <1.012

• Exudate - inflammatory extracellular fluid composed of plasma proteins, principally albumin, cells and cellular debris, and a specific gravity >1.020

Transudate - Pulmonary Edema

Pitting Edema

Laryngeal Edema

Pulmonary Edema

Ascites

Ascites

Noninflammatory and Inflammatory Conditions

• Anasarca - edema which is severe and generalized

• Abscess - localized collections of pus caused by suppuration buried in a tissue, organ, or confined space

• Cellulitis - spreading suppurations in subcutaneous tissue

Types of Exudates• Serous - blister in thermal burn• Fibrinous - uremic pericarditis,

viral/chemical pneumonitis, idiopathic• Purulent - meningococcal meningitis• Eosinophilic - IgE mediated - asthma &

parasitic infection• Hemorrhagic - rickettsial• Pseudomembranous - diptheria &

pseudomembranous enterocolitis

Serous Exudate - Blister

Serous Exudate - Blister

Fibrinous Exudate - Pericarditis

Fibrinous Pericarditis

Acute Inflammation - Purulent

Acute Inflammation - Purulent

Acute Inflammation - Purulent

Acute Inflammation - Purulent

Pseudomembranous ExudateDiphtheria

Pseudomembranous ExudateDiphtheria

Diphtheria

Outcomes of Acute Inflammation

Outcomes of Acute Inflammation

The End

Acute Inflammation