Inflammation I'

1
Inflammation I.

• Dr Madaras Lilla

2
Definition

• Inflammation is a complex protective response to
  injury that consists of vascular reaction,
  migration and activation of leukocytes and
  systemic reactions

3
Causes of inflammation

• Microbes (bacteria, viruses,fungi, protozoa,
  worms, insects)
• Toxic agents
• Mechanic agents ( trauma)
• Thermal injury ( burns, frostbite)
• Irradiation
• Foreign bodies
• Endogenous toxins (uraemia)
• Tumours
• Necrosis
• Immune reactions

4
Inflammation (general features)

• The goal of
• to eliminate injurious agent ( e.g. Bacteria,
  viruses, etc.)
• to resolve consequences of the injury (
  e.g. to remove necrotic cells,etc)
• Inflammation and repair are closely related !
• Both may be harmful ! ( e.g. hypersensitivity
  reactions, autoimmune diseases etc.)- normally
  anti-inflammatory mechanisms control the response
  and prevent damage to the host

5
Components of inflammation
6
Main symptoms of inflammation(CELSUS)

• Rubor
• Calor
• Dolor
• Tumor
• Functio laesa (Virchow)

7
Diapedesis of a leukocyte across the wall of a
small blood vessel ( Metchnikoff, 1892)
8
Subtypes

• Acute inflammation
• (Subacute inflammation)
• Chronic inflammation

9
Acute inflammation

• Rapid onset ( seconds, minutes)
• Short duration ( max. a few days)
• Exsudation of fluids and plasma proteins
• Characteristic cells neutrophil granulocytes
• Orchestered by chemical mediators

10
Chronic inflammation

• Longer duration
• Proliferation of blood vessels, necrosis,
  fibrosis
• Main cell types lymphocytes, macrophages

11
Acute inflammation

• Alteration in vascular caliber ?increased blood
  flow
• Leakage of the vessel wall ? Exudation escape of
  plasma proteins, fluid and leukocytes from the
  circulation to the interstitium and/or body
  cavities
• Emigration and activation of PMNs

12
Vascular changes

• 1.Vasodilation ( after a transient
  vasoconstriction) arterioles? opening
  capillaries? increased blood flow
• 2. Increased vascular permeability
• Plasma proteins escape? increased osmotic
  pressure in the interstitium
• Increased blood flow? increased hydrostatic
  pressure within vessels
• The net result is increased extravasated fluid
  !!!

13
Increased vascular permeability -theories
14
Cellular events PMNs role in inflammation

• Final goal PMNs activation (phagocytosis and
  elimination of the injurious substance)
• Steps Margination
• Rolling
• Adhesion to the endothelium
• Transmigration
• Migration ( chemotaxis)

15
Extravasation of PMNs
16
Further steps

• Chemotaxis
• Leukocyte activation
• Phagocytosis
• Recognition and attachment ( opsonization by IgG,
  complement, lectins etc.!)
• Engulfment
• Killing and degradation

17
Chemical mediators
18
Types of acute inflammation

• Serous inflammation inflammatio serosa
• Fibrinous inflammation inflammatio fibrinosa
• Purulent inflammation inflammatio purulenta
• Hemorrhagic inflammation inflammatio
  haemorrhagica
• Gangrenous inflammation inflammatio ichorosa
  seu gangraenosa

19
Serous inflammation

• Exudate thin fluid
• Examples Skin blisters
• Common cold
• Peritoneal, pleural, pericardial cavities

20
Blisters
From a burn
Herpes simplex type I
21
Fibrinous inflammation

• Exudate contains fibrin
• On mucosal and serosal membranes
• Examples Fibrinous pericarditis, pleuritis
  diphteria (Corynebacterium diphteriae)
• ileum typhus abdominalis (Salmonella typhi)
  colon dysentery (Shigella ),
  pseudomembranous
• colitis
• lobar pneumonia

22
diphteria
Fibrinous pericarditis
Pseudomembranous colitis
Fibrinous pleuritis
23
Lobar pneumonia- grey and red hepatization
24
Purulent inflammation

• Exudate pus
• Examples -infections with pyogenic bacteria
  (staphylo-, streptococci)
• -acute appendicitis
• -abscesses ( lung, brain)
• - phlegmone
• - empyema

25
Brain abscess
Staphylococcus abscess
H. influenzae meningitis
26
Hemorrhagic inflammation

• Exudate contains red blood cells
• Examples influenza virus pneumonia anthrax
  (Bacillus anthracis)
• variola vera ( hemorrhagic smallpox)
• plague (Yersinia pestis)

27
Influenza pneumonia
28
Anthrax- skin lesion
29
Smallpox- variola vera
30
Dr Beak from Rome, engraving 1656
31
Gangrenous inflammation

• Tissue necrosis predominates
• Examples aspiration
• perforation of the appendix
• perforation of the esophagus (gangrenous
  mediastinitis)
• tumor necrosis
• septic abortion

32
Dehiscent wound
Gangrenous appendicitis
33
Systemic manifestation of inflammation

• Lymphangitis, lymphadenitis (follicular
  hyperplasia, sinus histiocytosis)
• Fever ( IL-1, TNF, prostaglandins)
• Pain ( prostaglandins, bradykinin)
• Leukocytosis ( neutrophilia, eosinophilia,
  lymphocytosis)

34
Main symptoms of inflammation(CELSUS)

• Rubor
• Calor
• Dolor
• Tumor
• Functio laesa (Virchow)

35
OUTCOMES OF INFLAMMATION