Chronic Inflammation Flashcards
What are the functions of macrophages?
Phagocytosis and destruction of bacteria and debris
Processing and presenting antigens to the immune system
Synthesis of cytokines and complement proteins
Control and activation of cells by cytokine release
Name the cells involved in chronic inflammation
Macrophages Plasma cells Eosinophils Lymphocytes Fibroblasts/Myofibroblasts Giant cells
What do lymphocytes look like?
Large nucleus with barely any cytoplasm
Where are T lymphocytes produced and matured?
Produced in the bone marrow
Mature in the thymus
Where are B lymphocytes produced and matured?
Produced and matured in the bone marrow
What can B lymphocytes differentiate into?
Plasma cells or memory cells
What can T lymphocytes differentiate into?
T helper (CD4) T killer (CD8) Natural killer cells
Function of T lymphocytes?
Control
Cytotoxic functions
Can kill virally infected cells
What do plasma cells look like?
Have a clock face nucleus
Pinkish-blue cytoplasm
Pale halo around the nucleus which is the Golgi apparatus
What does the presence of plasma cells imply?
That the inflammation is chronic
What do plasma cells do?
Produce antibodies
In which situations are eosinophils found in?
Allergic reactions
Parasite infestations
Some tumours
How do fibroblasts get there and what do they do?
Recruited by macrophages
Secrete collagen
What are giant cells made up of?
Giant macrophages
What is the function of giant cells?
Frustrated phagocytosis
Phagocytose what macrophages can’t by themselves
What are the types of giant cells?
Langhans
Foreign body type
Touton
Which type of giant cell is normally seen in TB?
Langhans
Which type of giant cell is described as disorganised aggregates of multiple nuclei?
Foreign body type
Which type of giant cell is described as organised nuclei with foamy cytoplasm?
Touton
What type of giant cell forms in fat necrosis?
Touton
What is chronic inflammation?
Chronic response to injury with associated fibrosis
How does chronic inflammation arise?
Take over from acute inflammation if not resolved in a few days
De novo- when there has been no preceding chronic inflammation
Develop alongside acute inflammation in severe or repeated irritation
What can cause de novo chronic inflammation?
Autoimmune diseases eg rheumatoid arthritis
Chronic infections eg viral hepatitis
Chronic low level irritation eg foreign body in tissue
What are some possible complications of chronic inflammation?
Fibrosis
Impaired function and atrophy
Stimulation of immune response
Carcinoma
What are gall stones caused by?
Repeated obstruction to the cystic duct causing acute inflammation which leads to chronic inflammtion
What damage can gall stones cause?
Damage mucosa and damage gall bladder wall
Cause of acute gastritis?
Alcohol and drugs
Cause of chronic gastritis?
Helicobacter pylori
Why does gastric ulceration occur?
Ulceration due to an imbalance of acid production and mucosal defence
What can patients present with in IBS?
Diarrhoea, rectal bleeding and other symptoms
What are strictures?
Narrowing
What are fistulae?
Abnormal connections between two epithelium-lined organs
What complication can IBS lead to?
Impaired function
What complications can gall stones and gastric ulceration lead to?
Fibrosis
What complication cam cirrhosis lead to?
Fibrosis and impaired function
What complication can Grave’s disease lead to?
Increased function
Causes of cirrhosis?
Alcohol Hep A and B Immunological Fatty live disease Type 2 diabetes Drugs and toxins
What happens in cirrhosis?
Nodules of regenerating hepatocytes appear in the liver as it tries to repair itself
Surrounded by bands of collagen
What happens in Grave’s disease?
Auto-antibodies stimulate TSH receptors causing hyperthyroidism
How is Grave’s disease treated?
Carbimazole and sometimes surgery
Pathology of atrophic gastritis?
Lymphocytes and plasma cells produce auto-antibodies which destroy parietal cells
Leads to atrophy of gastric mucosa
What can you see in atrophic gastritis?
Lots of lymphocytes and fibrous tissue
Pathology of rheumatoid arthritis?
Local chronic inflammation leads to inflammation of synovial capsule ➡️ joint destruction
What is a granuloma?
An accumulation of epithelioid histiocytes (macrophages) and lymphocytes
What is granulomatous inflammation?
Inflammation with granulomas
What is granulomatous inflammation caused by?
Persistent, low grade irritation such as
- mildly irritant foreign material
- unknown causes such as sarcoidosis and Crohn’s disease
What is sarcoidosis?
An autoimmune disease where there is granulomatous inflammation in tissues
What can be seen in the middle of a granuloma?
Caseous necrosis
Why are mycobacterium tuberculosis difficult for the body to remove?
Their cell wall contains lipids and they can survive in the cytoplasm of macrophages
What type of necrosis is often seen in TB?
Caseous
How do Tb bacteria cause disease?
Their persistence in the body causing induction of cell meditated immunity. Don’t release any toxins or lytic enzymes.
Outcomes of TB?
Arrest - stopped by immune system
Progresses - erosion into bronchus. Can spread into GI tract
TB empyema - erodes through plural surface of lung
Erosion into blood
What is the difference between miliary TB and single organ TB?
Miliary - many bugs
Single organ - few bugs
