Arthritis and Systemic Inflammation

Question 1

Which of the following substances are most likely to be recognized by toll-like receptors?

A. Antibodies

B. C5a

C. Chemokines

D. HIV gag peptide

E. Lipopolysaccharide

Answer 1

LPS

Question 2

Which of the following molecules is an acute phase reactant?

A. Antibody

B. C-reactive protein

C. IFN-I

D. NKG2D

E. TLR5

Answer 2

C reactice protein

• acute phase reactants are produced in the liver
• IFN-1 is a type I interferon where there is also IFN-1 alpha and IFN-1 beta

IFN-II is a type II interferon and there is only IFN-II-gamma

-all of the other answers are produced quickly, but only C-reactive protein is the acute phase reactant

Question 3

What would you expect of C-reactive protein and ESR during inflammation?

Answer 3

You would expect them to be elevated.

Question 4

What is ESR?

Answer 4

Erythrocyte Sedimentation Rate; Rate at which RBCs settle in a westergren tube (rate increased by acute phase reactants)

caution: rate can increase in patients with fewer RBCs (anemia)

Question 5

Compare the sensitivity/specificty of CRP and ESR in low-grade inflammation

Answer 5

ESR: Is more specific, less sensitive (longer term effect)

CRP: more sensitive, less specific (short term acute)

Question 6

Which test is suceptible to alteration in the size/shape/# of RBCs?

Answer 6

ESR, so it can monitor inflammation, but also anemias as well.

Question 7

Describe when in the inflammation process would ESR or CRP be the test of choice?

Answer 7

CRP up to 7 days, ESR after 7 days

Question 8

Release of which of the following molecules is most directly responsible for the continued low blood pressure?

A. ICAM-1

B. IFN-I

C. IL-1

D. IL-12

E. TNFα

Answer 8

TNFalpha working on the endothelial cells and causing them to vasodilate (IL-6 is also helps)

-IL-1 is mainly involved in traveling to the brain and affectng tempterautre regulation causing fever.

Question 9

In the example of the elderly woman with a hip replacement, what is the pathway of progression of her infection throughout her body?

Answer 9

Cold spread to the lungs, becomes systemic and spreads to the hip

Question 10

What are the danger signals produced by macrophages?

Answer 10

IL-1, IL-6, TNF alpha, also IL-12

IL-1 causes fever

TNF alpha casues vasodilation, proinflammatory

IL-6 goes to the liver and causes acute phase response

IL-12 coactivates Th1 pathway and induces IFN-gamma production

Question 11

What is the criteria for SIRS?

Answer 11

Temp under 36C of above 38C

HR above 90 beats/min

RR over 20 or arterail CO2 tension less than 32mm Hg

Abnormal WBC (high or low)

Hypotensive

Question 12

For sepsis, when is it appropriate to use steroids?

Answer 12

Only use them when vital organs are at risk, like in severe forms of sepsis.

-the risk is allowing the infection to worsen, but goal is to try and save organs by reducing inflammatory states.