chronic inflammation and granulomas

Question 1

list 5 signs of inflammation

Answer 1

• redness (dilation of blood vessels)
• heat (increased blood flow)
• swelling
• pain
• lack of function

Question 2

what factors influence the development of chronic inflammation

Answer 2

Question 3

what is chronic inflammation

Answer 3

• can occur if there is no return to steady state conditions followinf acute inflammation
• often infectious cause, may be immune mediated
• granuloma may form
• granuloma may take long time to develop and is an example of delayed type hypersensitivity

Question 4

what disorders/causes lead to chronic inflammation

Answer 4

• autoimmune disorders
• exposure to toxins
• chronic exposure to irritant or foreign material
• auto-inflammatory
• infection
• trauma

Question 5

what disorders are associated with chronic inflammation

Answer 5

• osteoarthritis
• gingivitis
• hyper-inflammatory syndrome in the weimaraner
• diabetes

Question 6

what disorders cuase chronic inflammation with granuloma formation

Answer 6

• canine lick granuloma
• brucellosis
• tuberculosis
• johnes disease
• suture granuloma

Question 7

how do granulomas form

Answer 7

1. macrophages fail to clear foreign agent and become chronically infected
2. activated macrophages cponstantly secrete TNF alpha and pther pro-inflammatory cytokines which promote the influx of T cells and other cells, T cell activation and inhibit regulatory T cells and T cell apoptosis
3. T cells around the periphery secrete IFN gamma which os beleived to contribute to the chronic reactivity of macrophages (cycle of T cells telling macrophage to make more TNF-alpha)
4. stimulated macrophages can further mature into epitheloid cells that are elongated and resemble apithelial cells. epitheloid cells appear to lose their phagocytic function and shift to more secretory capacities
5. prolonged stimulation leads epitheloid cells to fuse together and form multinucleated giant cells (langhans cells) which are capable of phagocytosius and sytokine secretion
6. T cell and macrophages stimulate fibroblasts promotin fibrosis which can lead to organ damage

Question 8

what are the pros and cons of granuloma formation

Answer 8

• can form a focal killing point in which micro-organisms may eventually be killed
• prevent dissemination since it walls off micro-organisms
• break down of granuloma can have serious effects since the bacteria can disseminate
• may cause severe tissue necrosis hence effecting organ function
• can cause fibrosis and tissue thickeninf impairing organ function

Question 9

discuss johnes disease in cattle

Answer 9

• infection by mycobacterium avium subspecies paratuberculosis
• young animals infected through milk, via fecal ingestion and possibly intrauterine
• severe weight loss
• clinical signs may not be apparent until 2 or 3 years after infection
• granulomatous enteritis

Question 10

what are the 4 forms of chronic enterocolitis in dogs and cats and what immune cells are associated with each of them

Answer 10

• lymphocytic plasmocytic enteritis = increased lymphocyte and plasma cell infiltrate into the lamina propria (common and seen in middle aged)
• eosinophilic gastroenteritis = infiltrate predominantly eosinophils (chronic parasite infection/allergies)
• neutrophilic colitis = neutrophil infiltrate (cuase unknown)
• granulomatous colitis = macrophages (rare)

Question 11

why is hypereosinophilic syndrome in cats

Answer 11

a variant of eosinophilic enteritis
- overproduction of eosinophils in bone marrow
- widely disseminated eosinophilic infiltration of multiple organs
- organs commonly affected include bone marrow, small intestine, liver, spleen, mesenteric and peripheral lymph nodes, skin lesions

prognosis is poor