chronic inflammation Flashcards
what is the time period for acute inflammation?
days (rapid)
what is the time period for chronic inflammation?
months often years
possibly forever
Causes of non specific chronic inflammation?
- failure to resolve acute inflammation
- persistent bouts of acute inflammation
- excessive suppuration
Causes of specific (primary) chronic inflammation?
- arises de novo
- persistant exposure to agent
give features of chronic granulomatous inflammation?
- subset of specific chronic inflammation
what are the 3 main classes of chronic inflammation?
- non specific chronic inflammation
- specific (primary) chronic inflammation
- chronic granulomatous inflammation
what characterises non-specific chronic inflammation?
characterised by a dynamic balance between tissue destruction and repair
what characterises specific (primary) chronic inflammation that is non-granulomatous?
excessively activated macrophages
how is specific (primary) chronic inflammation induced by non-immunological agents?
- foreign body reactions
- insert noxious material (silica and asbestos)
how is specific (primary) chronic inflammation induced by immunological agents?
- infective organisms that grow in cells
- hypersensitivity reactions
- autoimmune reactions
- infection by fungi, protozoa or parasites
what is an autoimmune disease?
unwanted response to body own cells and tissues or commensal bacteria
what do PAD enzymes do?
This enzyme citrullinates proteins – arginine conversion to citrulline
what produces PAD enzyme?
naturally produced by host cells such as neutrophils but also produced by Pgingivalis
how does chronic granulomatous inflammation differ from normal chronic inflammation?
predominant cell types are known as modified activated macrophages
what are epithelioid macrophages?
- mass of macrophages joined together
- giant cells (multinucleate: formed from fused epithelioid macrophages)
- b and T cells present in tissue
what is the immunological causes of chronic granulomatous inflammation?
delayed hypersensitivity reaction or invading pathogens
what is the non immunological cause of chronic granulomatous inflammation?
foreign body in tissue eg asbestos particles
what is the main aim of macrophages in chronic inflammation?
phagocytose and present antigen
which type of macrophage is tissue injury?
M1
which type of macrophages is tissue repair?
M2
what is tissue injury by M1 macrophages in chronic inflammation?
Toxic oxygen metabolites
Proteases
Neutrophil chemotactic factors
Coagulation factors
AA metabolites
Nitric oxide
what is tissue injury by M2 macrophages in chronic inflammation?
Process of fibrosis
Growth factors (PDGF,FGF,TGF beta)
Fibrogenic cytokines
Angiogenesis factors (FGF)
Remodelling collagenases
give an example of a chronic granulomatous inflammation?
Orofacial Granulomatosis
what is Orofacial Granulomatosis termed if a patient has intestinal crohns?
oral crohns
give an example of Specific (primary) chronic inflammation?
autoimmune disease
give an example of Non-specific chronic inflammation?
Periodontists
what is chronic periodontitis characterised by?
soft tissue (gingival tissue) and hard tissue (alveolar bone destruction)
what is the extracellular matrix remodelled by?
matrix metalloproteinases
what do Matrix metalloproteinases apart from remodel the extracellular matrix?
help cells migrate and angiogenesis
after how many years do we get a new skeleton?
10
what do osteoblasts do?
osteoblastogenesis = bone formation
what do osteoclasts do?
osteoclastogenesis = bone resorption
what do osteoblasts and osteoclasts differentiate from?
macrophages
what produces RANKL?
osteoblasts
what are RANK receptors found on?
osteoclasts
what is OPG?
osteoprotogerin
where does OPG come from?
secreted from osteoblasts
what does RANKL stand for?
Receptor Activator of Nuclear Factor Kappa-B Ligand
what does OPG do?
inhibits RANKL function - therefor controlling bone resorption
what is it important to control the ratio of RANKL to OPG?
balance between bone loss and resorption
what destroys soft tissue?
Matrix metalloproteinases