Chronic Inflammation Flashcards
What is chronic inflammation?
Chronic response to injury with associated fibrosis
How does chronic inflammation arise?
1) It may ‘take over’ from acute inflammation if damage is too severe to be resolved within a few days
2) May arise de novo
3) May develop alongside acute inflammation in severe persistent/repeated irritation
In which situations can chronic inflammation arise de novo?
Some autoimmune conditions (such as rheumatoid arthritis)
Some chronic infections (eg viral hepatitis)
‘Chronic low-level irritation’
What is the most important characteristic of how chronic inflammation looks?
The type of cell present
What are the cells of chronic inflammation?
Macrophages, lymphocytes, plasma cells, eosinophils, fibroblasts
What are macrophages derived from?
Blood monocytes
What are the functions of macrophages?
1) Phagocytosis
2) Antigen presentation
3) Synthesis of cytokines, complement, blood clotting factors and proteases
4) Control of other cells by cytokines release
Which are the two types of lymphocytes?
B lymphocytes and T lymphocytes
What is the difference between T and B lymphocytes?
T = involved in control and some cytotoxic functions
Cell mediated
B = Differentiate to produce antibodies
Humoral
What is a feature of the appearance of plasma cells?
Open nucleus - can see cytoplasm, visible golgi
What is a feature of the appearance of eosinophils?
Stain pink, bilobe nucleus
What are plasma cells?
Differentiated antibody-producing B lymphocytes
What does the presence of plasma cells usually imply?
Considerable chronicity - usually lasted a while
In which situations are eosinophils usually involved?
Allergic reactions, parasite infestations, some tumours
How are fibroblasts involved in the chronic inflammatory response?
Recruited by macrophages, make collagen
What are giant cells?
Multinucleate cells made by fusion of macrophages
When are giant cells usually present?
Frustrated phagocytosis
What are 3 types of giant cells?
Langhans (TB)
Foreign Body Type
Touton (fat necrosis)
What is a feature of the appearance of langhans type giant cells?
Horseshoe nuclei
What is a feature of the appearance of foreign body type giant cells?
Multiple irregular aggregates of nuclei
Which cell type is usually present in rheumatoid arthritis?
Mainly plasma cells
Which cell type is usually present in chronic gastritis?
Mainly lymphocytes
Which cell type is usually present in leishmaniasis (a protozoan infection)?
Mainly macrophages
What are some effects of chronic inflammation?
Fibrosis, impaired function, atrophy, stimulation of immune response
What is an example of a condition where fibrosis is the effect of chronic inflammation?
Cirrhosis
What is an example of a condition in which impaired function is the effect of chronic inflammation?
Chronic inflammatory bowel disease
What is an example of a condition in which increased function is the effect of chronic inflammation?
Thyrotoxicosis
What is cholecystitis?
Inflammation of the gallbladder
What is one cause of fibrosis of gall bladder wall?
Chronic cholecystitis (Repeated obstruction by gall stones, repeated acute inflammation leading to chronic inflammation)
What is inflammatory bowel disease?
Idiopathic inflammatory disease affecting large and small bowel
What do patients with inflammatory bowel disease present with?
Diarrhoea, rectal bleeding (due to damaged mucosa, ulcers)
What is ulcerative colitis?
Ulcerative colitis is a long-term condition, where the colon and rectum become inflamed.
What is a fistula?
Abnormal connection between two epithelium-lined organs
True or False:
Ulcerative colitis is superficial thus causing diarrhoea and bleeding
True
True or False:
Crohn’s disease is transmural thus causing strictures and fistulae
True
What are some common causes of cirrhosis?
Alcohol Infection with HBV, HCV Immunological Fatty liver disease Drugs and toxins Obesity
What is thyrotoxicosis?
Hyperthyroidism - thyroid produces too much thyroid hormone
How do immune diseases cause pathology?
Chronic inflammation
What is granulomatous inflammation?
Chronic inflammation with granulomas
What is a granuloma?
A mass of granulation tissue, typically produced in response to infection, inflammation, or the presence of a foreign substance.
What do granulomas arise with?
Persistent, low grade antigenic stimulation and hypersensitivity
What are the main causes of granulomatous inflammation?
1) Mildly irritant foreign material
2) Infections (eg TB)
3) Sarcoid
4) Crohn’s disease
5) Wegener’s granulomatosis
Why are Myobacteria tuberculosis hard to phagocytose?
Contain wall lipids (mycosides) that are difficult for phagocytes to digest
How do Mycobacteria tuberculosis cause disease?
By persistence and induction of cell-mediated immunity (use body’s reaction to cause disease)
So produce no toxins or lytic enzymes
What is sarcoidosis?
Sarcoidosis is a rare condition that causes small patches of red and swollen tissue, called granulomas, to develop in the organs of the body. It usually affects the lungs and skin.
