MoD - Chronic Inflammation Flashcards
What is the result of chronic inflammation?
What is the result of acute inflammation?
Repair and scarring
Resolution is possible
How does chronic inflammation arise?
May ‘take over’ from acute inflammation - if damage is too severe to be resolved within a few days
May arise de novo - some autoimmune conditions = RA
Chronic persistent infections - Viral hepatitis
Chronic low level irritation - reaction to foreign material
May develop alongside acute inflammation - in severe repeated or persistent irritation
Prolonged exposure to toxic agents
What does chronic inflammation look like?
Microscopic appearances are much more variable than acute inflammation
Most important characteristic = type of cell present
What types of cell are present in chronic inflammation?
Macrophages Lymphocytes - B (Plasma cell) and T type Eosinophils Fibroblasts/myofibroblasts
What are macrophages derived from?
What are their functions?
Blood monocytes
Phagocytosis and destruction of debris and bacteria
Processing and presentation of antigen to immune system
Synthesis of cytokines, complement components, blood clotting factors and proteases
Control of other cells by cytokine release
Stimulate angiogenesis - formation of new blood vessels
Induce fibrosis
Induce fever
What are the functions of lymphocytes?
What are the the two types and their functions?
Complex, mainly immunological Process antigens Secrete antibodies Secreting cytokines Killing cells
B lymphocytes = produce antibodies
T lymphocytes = control and some cytotoxic functions
What are plasma cells?
Differentiated antibody producing B lymphocytes
When are eosinophils present?
Allergic reactions
Parasite infestations
Some tumours e.g. Lymphomas
What is the function of fibroblasts/myofibroblasts?
Recruited by macrophages to make collagen
What are giant cells
What are the three types?
Where are they found?
Multinucleated cells made by fused macrophages
‘Frustrated phagocytosis’
Langhans - TB
Foreign Body Type - Foreign material
Tout on - Fat necrosis
What are the cell types in..
Rheumatoid arthritis
Chronic gastritis
Leishmaniasis (protozoan infection)
Mainly plasma cells
Mainly lymphocytes
Mainly macrophages
What may the presence of a giant cell type help with?
Help to diagnose
What are four effects of chronic inflammation?
Excessive fibrosis - e.g. Gall bladder, cirrhosis, ulcers
Impaired function - e.g inflammatory bowel diseases (rarely increases function)
Atrophy - gastric mucosa (loose cells that produce gastric acid)
Stimulation of immune response - macrophage, lymphocytes interactions
What is an example of fibrosis?
What happens in this condition?
Chronic Cholecystitis
Repeated obstruction by gall stones.
Gall stones and thickened fibrotic wall
Repeated attacks of acute inflammation –> chronic inflammation
Why would gastic ulceration occur?
What are the two types and what causes them?
Imbalance of acid production and mucosal deference
Acute - alcohol, drugs
Chronic - helicobacter pylori
What disease result in impaired function?
What are the two types?
What are the symptoms of this disease
What causes these?
Inflammatory bowel disease - affecting small and large bowel
Ulcerative colitis and Crohn’s
Rectal bleeding and diarrhoea
Idiopathic
What is the difference between ulcerative colitis and Crohn’s?
What is a fistula?
Ulcerative colitis is superficial - diarrhoea and bleeding
Crohn’s is trans mural - Strictures and fistula
Fistula - abnormal connection between two epithelium lined organs
What is the effect of chronic inflammation in cirrhosis?
What is the main cause of cirrhosis?
What shows on the histology?
Fibrosis and impaired function
Alcohol
Nodules - blue stained fibrous tissue, lots of collagen
Chronic inflammation with fibrosis –> cirrhosis
What is an example of increased function of chronic inflammation?
How does it increase the function?
Thyrotoxicosis - Graves’ Disease
Antibodies reduced by plasma cells, stimulate TSH receptor, thyroid epithelia produced thyroxin
What is rheumatoid arthritis?
Autoimmune disease
Localised and systemic immune response
Localised chronic inflammation –> joint destruction
Systemic immune response can affect other organs and cause amyloidosis
What is a granuloma?
What is granulomatous inflammation?
What are the two general types of granuloma?
What is granulomas inflammation a characteristic of?
Cohesive group of macrophages and other inflammatory cells
Chronic inflammation with granulomas
Foreign body granuloma
Hypersensivity
/immune type granuloma
Crohn’s disease
Why do granulomas arise?
Persistent, low grade antigenic stimulation
Hypersensitivity
What causes a granuloma?
Foreign material
Infections e.g. Mycobacteria - TB, lepropsy, syphilis
Unknown causes e.g. Sarcoidosis, Crohn’s disease
What causes TB?
Why is it difficult of diagnosis?
How does it cause disease?
What is characteristic about a TB granuloma?
What are the outcomes?
Mycobacteria especially M.tuberculosis
Difficult and slow to culture - takes 6 weeks growth in a lab
By persistence and induction of cell-mediated immunity
Produces no toxins or lytic enzymes
Caseous necrosis in the middle
Arrest, fibrosis, scarring
Erosion into bronchus
TB empyema - formation of pus in pleural cavity
Erosion into blood stream –> effects multiple organs
Name 2 granulomatous diseases of unknown cause
Describe
Sarcoidosis - non case acting granuloma, giant cells, involves lymph nodes and lung. Young adult women. Variable clinical manifestations.
Crohn’s disease - ‘patchy’ full thickness inflammation throughout bowel (regional enteritis)
Name Crohn’s distinguishing factors from ulcerative colitis?
Crohn's Discontinuous distribution Affect any part of the GI tract Deep inflammation Cobble stone appearance to bowel mucosa Granulomas often present Anal lesions common Bowel fistula more likely Can't surgically remove anything for Crohn's as it affects who GI tract
Ulcerative colitis
Tends only to affect rectum
Superficial disease - Inflammation limited to mucus on and sub mucosa
Crypt abscesses common and distorted crypt architecture
Significant Increased risk of colon cancer - due to cell turnover
Most severe in distal colon
Colectomy often indicated
Why is it very important to distinguish between TB and sarcoidosis?
Sarcoidosis would treat with steroids to reduce immune response but would not want to give that to someone with TB
Both granuloma disorders
Define chronic inflammation
A chronic response to injury with associated fibrosis
It is NOT rapid, NOT immediate and NOT shortlived (acute inflammation)
