Lecture 5 - Chronic Inflammation Flashcards
What is the definition for Chronic Inflammation?
Prolonged inflammation with associated repair
Why is acute inflammation referred to as being stereotyped and chronic inflammation being modulated?
Acute stereotyped occurs rapidly and responds to any type of injury
Chronic modulated takes over if the injurious agent is not quickly removed
How does Chronic inflammation arise?
Takes over from acute Inflammation (if acute inflammation cant resolve)
Develops alongside acute inflammation (at same time, e.g ongoing bacterial infection)
Develops without preceding acute inflammation
Why might chronic inflammation arise without preceding acute inflammation?
Chronic infection like TB
Autoimmune conditions (Rheumatoid arthritis)
Prolonged exposure to toxic agents (silica)
What is the main cell involved in acute inflammation?
Neutrophil
What cells are involved in chronic inflammation?
Macrophages
Lymphocytes + Plasma cells
Eosinophils
Fibroblasts/Myofibroblasts
What is a monocyte?
A blood circulating phagocyte
What is a macrophage/histiocyte?
A monocyte which his migrated into tissues
What is the appearance of a macrophage?
Large
Abundant “foamy” cytoplasm
Slipper shaped nucleus
What causes the foamy cytoplasm look in a macrophage?
Abundant phagolysosomes
What is the function of the macrophages?
Remove pathogens (degrade)
Antigen presentation
Release mediator controlling inflammation
What is the appearance of a lymphocyte?
Small cell (like RBC)
Large spherical nucleus
Very thin rim of cytoplasm
What are the 2 types of lymphocyte?
T Cell
B Cell
What is the function of T Cells?
Helper T Cells assist other inflammatory cells
Cytotoxic T cells destroy pathogens
What is the function of B Cells?
Mature into plasma cells
These produce antibodies that neutralise pathogens
What is the appearance of a plasma cell?
Clumped chromatin
Eccentric non central nucleus
Paler peri-nuclear clearing
What causes the paler peri-nuclear region around the nucleus of a plasma cell?
The prominent Golgi bodies
What is the function of a plasma cell?
Produces antibodies
What is the appearance of an Eosinophil?
TOMATO WITH SUNGLASSES
Bi-lobed nucleus
Very granular so cytoplasm stains quite red
What is the function of Eosinophils?
Parasitic infections
Hypersensitivity reactions (allergies, asthma etc…)
Release variety of mediators
What is the general function of fibroblasts/myofibroblasts?
Lay down collagen to regenerate and repair
What are giant cells?
Multinucleated cells formed by the fusion of multiple macrophages
What is meant by frustrated phagocytosis?
When a phagocyte fails to engulf a pathogen and so fuses with other macrophages to form a giant cell to be able to engulf the pathogen
What are the 3 types of Giant cells?
Foreign body giant cell
Langhans giant cell
Touton giant cell
How are giant cells named/categorised?
Depending on the arrangement of the nuclei
What is the structure/appearance of a foreign body giant cell?
Randomly arranged nuclei
What is the appearance/structure of a Langhans giant cell?
Nuclei arranged in horseshoe in rim around cell
What is the appearance/structure of a Touton giant cell?
Central ring of nuclei
When a foreign body giant cells usually formed?
When body is responding to a foreign body present (like a suture)
When are Langhans Giant cells usually present?
Usually with TB
What type of giant cell can be seen in fat necrosis?
Touton giant cell
What is the importance of the proportions of cells present in chronic inflammation?
Can indicate a diagnosis
Which cells are predominantly present in Rheumatoid arthritis?
Mainly plasma cells
Which cells are mainly present in chronic gastritis?
Mainly lymphocytes
Which cell is mainly present in Whipple’s disease (bacterial infection of intestines and lymph nodes)?
Mainly macrophages
What are the effects of chronic inflammation?
Fibrosis
Impaired function
Atrophy
Stimulation of immune response
What is fibrosis and what is the effect of fibrosis on a tissue?
The deposition of collagen
Fibrosis impairs tissue function
Why is atrophy a negative effect of chronic inflammation?
Reduction in size of tissue (reduced amount of normal functioning tissue)
What is Chronic Cholethiasis?
Repeated obstruction of bile duct by gall stones
How does chronic inflammation occur with Chronic cholethiasis?
Blocking of common bile duct causes acute inflammation
Repeat blockage = repeat bouts of acute inflammation = chronic inflammation
Fibrosis of gall bladder wall (thickened and pale)
How does a patient with Chronic cholethiasis and chronic inflammation present?
Pain in RUQ
Fever
Raised neutrophils
Which 2 inflammatory bowel diseases are idiopathic?
Chron’s Disease
Ulcerative Colitis
What symptoms do patients present with when suffering with Crohn’s disease or Ulcerative Colitis?
Abdominal pain
Altered bowel motion
Weight loss
Rectal bleeding
Where does Ulcerative colitis affect and where can Crohn’s Disease affect?
Ulcerative Colitis = LARGE BOWEL ONLY
Crohn’s Disease can affect all of GI tract
Out of Crohn’s Disease and Ulcerative Colitis, which one is most likely to cause rectal bleeding and why?
Ulcerative colitis since it causes CONTINUOUS Inflammation
Crohn’s disease = discontinuous patchy inflammation
How is the bowel wall affected by inflammation in Crohn’s disease and ulcerative colitis?
Crohn’s disease = affects full thickness of wall
Ulcerative colitis = affects superficial wall only
Which inflammtory bowel disease (Crohns or ulcerative colitis) can granulomata be found?
Crohn’s disease
What are the nodules caused by in liver cirrhosis?
Hepatocytes regenerating
What does fibrosis look like on a liver?
Bands of collagen separating the nodules of regenerating Hepatocytes
What is Granulomatous inflammation?
Chronic inflammation + Granuloma
A specific type of chronic inflammation where at least 1 Granuloma is present
What is a Granuloma?
Collection of macrophages that look like epithelial cells that may be surrounded by lymphocytes
What is the name given to macrophages that look like epithelial cells?
Epithelioid Histiocytes
What is the difference between a giant cell and a Granuloma?
Granuloma = all distinct cells
Giant cell = 1 fused cell
Granulomas can contain giant cells
What are the 2 types of Granuloma?
Foreign body Granuloma
Immune Mediated Granuloma
How are Granulomas classified as either foreign body or immune mediated?
Depends on what they destroy
What is the role of a foreign body Granuloma and what is the relative levels of lymphocytes?
Destruction and removal of foreign material
Few lymphocytes
What is the role of Immune Mediated Granuloma and what are the relative levels of lymphocytes?
Destruction of pathogens (bacteria/fungi)
Can undergo central necrosis
Many lymphocytes
What can cause granulomatous inflammation?
Infections like:
Mycobacterium tuberculosis
Mycobacterium leprae (Leprosy)
Thick cell walls hard to destroy
What type of necrosis do mycobacterium Granulomas have?
Central necrosis usually caseous necrosis
How does caseous necrosis of a Granuloma appear on an image?
Pale pink centre of Granuloma (lacks any structure)
What type of granulomata does sarcoidosis cause?
Non-necrotising granulomata
What type of granulomata does Crohn’s disease cause?
Non-necrotising granulomata?
