Chronic Inflammation Flashcards
Can chronic inflammation occur without acute inflammation ?
Yes
What is organisation ?
Replacement of destroyed tissue by granulation tissue.
Which factors favour resolution ?
Rapid destruction of causal agent
Rapid removal of fluid and debris by good drainage
Minimal cell death
Occurrence in tissue or organ with regenerative capability
What factors favour organisation ?
Presence of large amounts of fibrin
Consequential necrosis
Exudata and debris cannot be drained away
Which cells are present to replaces inflammatory exudate in chronic inflammation ?
- Sprouting capillaries
- Proliferation of fibroblasts
- Infiltration of macrophages (rather than neutrophils as in acute inflammation)
- Deposition of collagen
- Presence of multinucleate giant cells and plasma cells
- Layer of lymphocyte around vessels where new capillaries sprouting
Why is the appearance of a skin bruise undergoing chronic inflammation red and moist ?
Redness due to sprouting capillaries
Moist due to exudate
Who is responsible for regulating organisation ?
Growth factors (e.g. Tumour Necrosis Factor, Epidermal Growth Factor)
What different kinds of chronic inflammation exist ?
Primary and Moving from Acute Inflammation
What are examples of situations in which it is primary chronic inflammation. Give examples of conditions for these situations.
- Resistance of infective agent to phagocytosis and intracellular killing (tuberculosis, leprosy, brucellosis, viral infections)
- Foreign body reactions to endogenous materials (gout, in which metabolism is not getting rid of uric acid causing it to deposit in joints, resulting in arthritis.
- Foreign body reactions to exogenous materials (asbestos)
- Some autoimmune diseases including R. arthritis
- Specific diseases of unknown aetiology (ulcerative colitis, causing damage to gut)
- Primary granulomatous diseases (sarcoidosis, where large amounts of typically macrophages accumulate in organ/tissue and outside)
Which factors favour the progression from acute to chronic inflammation ? Give an example of a condition for each factor.
- Indigestible substances
- Deep seated suppurative inflammation without inadequate drainage by vascular or lymphatic system (possible abscess wall, granulation tissue, organisation of pus, fibrous scar). E.g. Osteomyelitis, chronic abscess in bone
- Recurrent episodes of acute inflammation and healing E.g. chronic cholecystitis (wall replaced by fibrous tissue, macrophages and lymphocytes predominate over neutrophils)
What are diagnostic symptomatic features of chronic inflammation ? Give examples of each.
- Chronic ulcer (e.g. mucosa breached)
- Chronic abscess cavity (e.g. enpyema thoracic in pleural cavity)
- Thickening of wall of hollow viscus
- Granulomatous inflammation (e.g. tuberculosis)
- Fibrosis
Which cells are present in chronic inflammation ?
Sprouting capillaries
Fibroblasts
Collagen (granulation tissue resulting in fibrosis)
Macrophages and plasma cells and lymphocytes
What are the microscopic features of :
- Macrophages
- Lymphocytes
- Plasma cells ?
- Macrophages- Either appears to have single, or lobed or bilobed. Larger armount of cytoplasm that other two. Can fuse to form granuloma/multinucleate giant cells. In chronic inflammation, may find something cause the damage in the center of those multinucleate cells.
- Lymphocytes- Not activated (naive). Large nucleus and small cytoplasm. When activated, vastly increased cytoplasm (nucleus also a little larger) to allow for antibody production.
- Plasma cells- eccentric nucleus. Activated version of B lymphocyte.
What is an example of leukocytes communicating ? How do they achieve such communication ? Why is this important ?
Macrophages with T cells and B cells to
i. activate them, so they form antibody secreting cells and/or cytokine secreting T cells)
ii. inactivate them to limit damage
Do so through direct cell contact or secretion of agents
Important to modulate and down-regulate immune response
What is the function of macrophages ?
- Phagocytosis
- Producing cytokines
