Chapter 3: Chronic Inflammation

Question 1

What is all occurring during chronic inflammation?

Answer 1

inflammation, tissue injury, and attempts at repair coexist in varying combinations

Question 2

what are 3 different settings that chronic inflammation arises?

Answer 2

1) persistent infection by organisms that are difficult to eradicate 2) hypersensitivity diseases 3) prolonged exposure to potentially toxic agents (exogenous or endogenous) such as silica

Question 3

what is an example of a difficult organism to eradicate?

Answer 3

mycobacteria and parasitic infection where it can be associated with a granulomatous reaction

Question 4

what are three examples of hypersensitivity diseases?

Answer 4

1) immune reaction against self (multiple sclerosis) 2) unregulated immune responses against microbes (IBD) 3) immune responses against common environmental substances (asthma)

Question 5

what is the onset like of chronic inflammation?

Answer 5

slow: days

Question 6

what is the cellular infiltrate of chronic inflammation?

Answer 6

monocytes/macrophages and lymphocytes

Question 7

what is the cellular infiltrate of acute inflammation?

Answer 7

mainly neutrophils

Question 8

what is the tissue injury/ fibrosis like of chronic inflammation?

Answer 8

often severe and progressive

Question 9

are the local and systemic signs prominent or less in chronic inflammation?

Answer 9

less

Question 10

what are the dominant cells in most chronic inflammatory reactions? and how do they contribute to the reaction?

Answer 10

macrophages- which contribute to the reaction by secreting cytokines and growth factors that act on various cells, destroying foreign invaders and tissues, and activating other cells, notably T lymphocytes

Question 11

What exactly are macrophages?

Answer 11

tissue cells derived from hematopoietic stem cells in the bone marrow in postnatal life

Question 12

what are macrophages circulating in the blood called?

Answer 12

monocytes

Question 13

what are liver macrophages called?

Answer 13

kupffer cells

Question 14

what are spleen/lymph node macrophages called?

Answer 14

sinus histiocytes

Question 15

what are macrophages in the CNS called?

Answer 15

microglial cells

Question 16

what are macrophages in the lungs called?

Answer 16

alveolar macrophages

Question 17

what are macrophages in the skin called?

Answer 17

langerhans cells

Question 18

what is the half life of a blood monocyte?

Answer 18

about one day

Question 19

what is the lifespan of tissue macrophages?

Answer 19

may be several months or years

Question 20

Macrophages secrete mediators of inflammation such as cytokines. What are some of these cytokines? What else do macrophages secrete

Answer 20

TNF, IL-1, chemokines; eicosanoids

Question 21

where do macrophages display the antigen to?

Answer 21

to T lymphocytes

Question 22

what causes classically activated macrophages?

Answer 22

IFN-gamma (microbial products)

Question 23

what do classically activated macrophages secrete to cause microbicidal actions of phagocytosis and killing of many bacteria and fungi?

Answer 23

ROS, NO, lysosomal enzymes

Question 24

what do classically activated macrophages secrete to cause inflammation?

Answer 24

IL-1, IL-12, and IL-23

Question 25

what causes alternatively activated macrophages?

Answer 25

IL-13 and IL-4

Question 26

what do alternatively activated macrophages secrete to cause tissue repair and fibrosis?

Answer 26

growth factors and TGF-beta

Question 27

what do alternatively activated macrophages secrete to causes anti-inflammatory effects?

Answer 27

IL-10 and TGF-beta

Question 28

what amplifies and propagates chronic inflammation?

Answer 28

when microbes and other environmental antigens activate T and B lymphocytes

Question 29

what happens when T and B lymphocytes are involved in the inflammatory reaction?

Answer 29

the inflammation tends to be persistent and severe, in part because lymphocyte activation leads to the generation of long-lived memory cells

Question 30

In some chronic inflammatory reactions, the accumulated lymphocytes, antigen presenting cells, and plasma cells cluster together to form what?

Answer 30

lymphoid tissues resembling lymph nodes. These are called tertiary lymphoid organs or lymphoid aggregates

Question 31

when might eosinophils be abundant?

Answer 31

in immune reactions mediated by IgE and in parasitic infections (think eosinophil in the setting of hypersensitivity, allergy, and parasitic infection)

Question 32

what recruits eosinophils?

Answer 32

specific chemokines- eotaxin and IL-5

Question 33

what do the granules of eosinophils contain?

Answer 33

major basic protein, a highly cationic protein that is toxic to parasites but also causes lysis of mammalian epithelial cells

Question 34

what could be used to treat severe asthma?

Answer 34

a unique IL-5 inhibitor: Benralizumab

Question 35

what is granulomatous inflammation?

Answer 35

a form of chronic inflammation characterized by collections of activated macrophages, often with T lymphocytes and sometimes associated with central necrosis

Question 36

what is one example of a disease with granulomatous inflammation; what is the cause of this disease; and what is the tissue reaction?

Answer 36

Tuberculosis; mycobacterium tuberculosis; caseating granuloma

Question 37

what should always be excluded as the cause when granulomas are identified?

Answer 37

tuberculosis