Flashcards in MoD Session 3 Deck (108):
What is chronic inflammation?
Chronic response to injury w/associated fibrosis
How long can chronic inflammation last?
From hours to days
What does chronic inflammation overlap with?
Is chronic inflammation homogenous or heterogenous?
How does acute insult lead to chronic inflammation?
Acute insult --> acute inflammation --> more than slight damage --> chronic inflammation
What is the result of chronic insult and more than slight damage from acute insult?
Repair and scarring
How does chronic inflammation arise?
Take over form acute inflammation of damage cannot be resolved in a few days
Develop alongside acute inflammation in severe, persistent or repeated irritation
When does de novo chronic inflammation arise?
Some autoimmune conditions - RA
Some chronic infections - viral hepatitis
Chronic low level irritation (physical/microbiological)
What disease may cause chronic inflammation due to repeated irritation?
What is the most important characteristic of chronic inflammation?
Type of cell present
Describe the microscopic appearances in chronic inflammation.
Is chronic inflammation stereotyped?
Where are macrophages derived from?
What allows macrophages to be present in blood but not activated?
Various levels of activation
Which type of inflammation are macrophages important in?
Acute and chronic
What are the functions of macrophages?
Synthesis of cytokines, complement components, blood clotting factors and proteases
Control cells by cytokines release
Why do macrophages have a foamy appearance?
What type of pathogen is macrophage phagocytosis particularly useful for?
Difficult to kill bacteria e.g. mycobacteria
How does the lifespan and replication of macrophages compare to that of neutrophils?
Live for moths and can replicate unlike neutrophils
What effects do macrophages have in chronic inflammation?
Acute phase reaction
Hen are lymphocytes seen?
Normal component of many tissues but always present in chronic inflammation
What is needed in addition to lymphocyte presence to indicate chronic inflammation?
What is the function of B lymphocytes?
Mature in bone marrow to form plasma cells to release antibodies
What are the functions of T lymphocytes?
Secrete cytokines to influence inflammatory cells
Differentiate into NK cells which attack virus infected and some tumour cells
Where do T lymphocytes mature?
In the bone marrow
What do B lymphocytes and T lymphocytes provide together?
Coordinated immune response
How does the chromatin in a plasma cell appear after it has been phenotypically changed from a B lymphocyte?
'Clock face' - clear background w/blobs
Why do plasma cells have abundant cytoplasm?
For antibody production and secretion
What do the presence of plasma cells imply?
Chronicity as they take a longer time to develop
Describe the distribution of eosinophils.
Normally present but scattered, accumulate in certain circumstances
What circumstances cause accumulation of eosinophils?
What circumstance are eosinophils predominant in?
What do demotactic stimuli do?
Secreted by macrophages and other inflammatory cells to recruit fibroblasts and myofibroblasts
What do fibroblasts and myofibroblasts secrete?
Glucosaminglycans (fibroblasts only)
Why do myofibroblasts differentiate?
So they can contract
What are the three types of giant cells?
Foreign body type
How are small and large foreign bodies dealt with?
Small foreign bodies are engulfed
Giant cells stick to the surface of large foreign bodies
How are the nuclei arranged in foreign body type giant cells?
How are giant cells formed?
Fusion of macrophages
What appearance do Langhans giant cells have?
Foamy centre w/peripheral horseshoe shared nuclei
What disease are Langhans cells associated with?
What are Touton cells associated with?
What do Touton cells form in high lipid content?
What cells are seen with Touton cells?
Which type of cells form xanthomas?
How are the nuclei arranged in Touton cells?
Ring towards centre
What is 'frustrated phagocytosis'?
Formation of giant cells
How is the morphology of most chronic inflammatory reactions described?
Give the main cell types present in RA, chronic gastritis and Leishmaniasis.
RA = plasma cells
Chronic gastritis = lymphocytes
Leishmaniasis = macrophages
What cell type can be used in chronic inflammation to help diagnosis?
What is Leishmaniasis?
What are the effects of chronic inflammation?
Stimulation of immune response
How is fibrosis caused?
Cytokines stimulate fibroblasts to produce excess fibrous tissue
How is fibrosis initially helpful?
Walls off infected area
Scar needed for wound healing
How can fibrosis be problematic?
Can replace parenchymal tissue and impair organ function
What determines the consequences of fibrosis?
How does chronic cholecystitis causes fibrosis?
Repeated obstruction by gall stones --> repeat acute inflammation causing chronic inflammation --> fibrosis of gall bladder wall as the muscle thickens to try and push stone out
How do peptic ulcers appear?
Inflamed w/central acute inflammation causing the submucosa to be washed in acid causing pure acute inflammation
What can cause acute gastritis leading to peptic ulcers?
What can cause chronic peptic ulcers?
What is ulceration due to in peptic ulcers?
Imbalance of acid production and mucosal defence
What protects the gastric mucosa?
How can myofibroblasts cause further problems in chronic inflammation?
Can slowly contract
What disease is impaired function due to chronic inflammation seen in?
Chronic inflammatory bowel disease
Give three diseases in which fibrosis due to chronic inflammation is seen.
Give two examples of increased function caused by chronic inflammation.
Increased mucus secretion
Thyrotoxicosis in Grave's disease
Why is Crohn's said to have a 'cobblestone' appearance?
Characterised by islands of mucosa surrounded by inflammation
What do both Crohn's and Ulcerative Collitus result in?
Give two examples of sites of atrophy caused by chronic inflammation.
What happens in atrophy of gastric mucosa caused by chronic inflammation?
Thickness and density of gastric bands decrease due to lymphocyte degeneration
What interactions stimulate immune response in chronic inflammation?
What does stimulation of the immune response in chronic inflammation attack?
What leads to a disease process?
Stimulation of immune response by chronic inflammation
How do patients with idiopathic inflammatory disease affecting large and small bowel present?
What are the characteristics of Ulcerative Colitis?
More likely to cause acute problems than Crohn's
Causes diarrhoea and bleeding
What are the characteristics of Crohn's Disease?
Stricture and fistulae formation
Can be considered as 'regional enteritis'
What two effects of chronic inflammation is cirrhosis and example of?
What are common causes of cirrhosis?
Infection with HBV or HCV
Fatty liver disease
Drugs and toxins
How does chronic inflammation lead to cirrhosis?
Fibrosis --> disorganisation of architecture --> attempt regeneration --> abnormal collagen deposits --> nodules formed disrupting bile path giving green colour
What causes rheumatoid arthritis?
Autoimmune localised and systemic immune response causing joint destruction
What effects can rheumatoid arthritis have in organs?
Beta-pleated sheet deposited causing amyloidosis
What produces rheumatoid factor in RA?
Lots of lymphoid tissue
What shows lymphoid aggregates in RA?
Fronds of synovium
How can the link between chronic inflammation, immune response and immune disease sometimes be described?
Overlapped and circular
What is granulomatous inflammation?
Chronic inflammation w/granulomas
What is a granuloma?
Aggregate of active macrophages
What is a hypersensitivity reaction?
Immunological reaction that damages self
What are the cells present in a foreign body granuloma?
Foreign body cells
Epitheloid (tightly packed)
Some peripheral fibroblasts
Are lymphocytes present in foreign body granulomas?
Probably not - few if any
What are foreign body granulomas found around?
Not antigenic material e.g. Surgical thread causing persistent, low-grade stimulation
How does breakdown of an artificial joint cause fluorescence in polarised light?
Foreign material from breakdown of artificial joint --> giant cells form holes that shouldn't be in the joint --> foreign material fluoresces
What cells are present in a hypersensitivity/immune reaction?
What does central caseating necrosis in an immune reaction indicate?
How does caseating necrosis damage organs?
Forms around insoluble antigenic particles and occupy parenchymal space
What are two idiopathic causes of granulomatous inflammation via hypersensitivity reactions?
What can cause granulomatous inflammation via immune reaction?
Crohn's - seen in ~50% of cases
How are BCG and TB differentiated?
Look similar but BCG has no caseous necrosis
What does Wegener's granulomatosis affect?
How do sarcoids present?
Common in young adult women affecting lungs and lymph with non-caseating granulomas
How does TB spread from the lungs?
Arrest, fibrosis and scarring in lungs
Erosion --> bronchus causing bronchopneumonia and TB in GI tract
Erodes into bloodstream
Why does it take 6 weeks to receive a +/-ve result for TB?
M.tuberculosis difficult and slow to culture
Why can M. tuberculosis survive inside macrophages?
Has mycoside wall lipids
Does M. tuberculosis have toxins or lyric enzymes?
How does TB cause scarring in lungs?
Persistence and induction of cell-mediated immunity
What causes miliary TB?
Many M. tuberculosis present therefore affects multiple organs
What causes single organ TB?
Few M. tuberculosis present
In miliary TB what percentage of lung tissue is taken over by granulomas?