Chronic Inflammation and Granulomatous Inflammation

Question 1

Discuss three characteristics of chronic inflammation.

Answer 1

(1) Infiltration with mononuclear cells: This includes macrophages, lymphocytes and plasma cells.
(2) Tissue destruction: this is largely induced by the products of the inflammatory cells. The persistent presence of these cells and their secreted substances can lead to ongoing tissue damage.
(3) Repair: This involves new vessel proliferation (angiogenesis) and fibrosis. Fibrosis involves the formation of scar tissue to replace damaged tissue.

Question 2

State three causes of chronic inflammation.

Answer 2

(1) Persistent infections by microbes that are difficult to eradicate e.g. mycobacteria, treponema pallidum, and certain viruses and fungi, which tend to establish persistent infections and elicit a T lymphocyte-mediated immune response called delayed-type hypersensitivity.

(2) Immune-mediated inflammatory diseases (hypersensitivity diseases)

(3) Prolonged exposure to potentially toxic agents. Examples include non-degradable exogneous materials such as inhaled particulate silica.