Immunology Flashcards
What agents are typically used for induction (such as for a new transplant) and what are their mechanisms?
- Alemtuzumab: an anti-CD52 antibody that depletes lymphocytes (referred to as “liquid AIDS”)
- Corticosteroids: decrease T cell activation
- Thymoglobulin: anti-thymocyte antibody that attacks T cell production
What agents are typically used for maintenance of immunosuppression and what are their mechanisms?
- Calcineurin inhibitors that decrease T cell activation: cyclosporine and tacrolimus
- Mycophenolate mofetil that decrease lymphocyte proliferation
List the types of prophylaxis that organ-transplant patients need.
- CMV if they in a high-risk category (use Valcyte)
- Pneumocystis if they are on steroids (use Bactrim if not G6PD deficient, use dapsone or inhaled pentamidine if they are G6PD deficient)
- There is no ppx for EBV but it is good to be aware of their status (e.g., D+/R- or D-/R+) because they can have reactivation.
True or false: all organ-transplant patients require chronic prednisone.
False
Typically only those who have had confirmed or suspected rejection require long-term steroids.
The original name for rapamycin was _____________.
sirolimus
Review the management of allergic reaction and anaphylaxis.
- Always give an H1 and H2 blocker. These are safe medicines and have essentially no reason not to give them in an allergic reaction.
- Give epinephrine and steroids for anaphylaxis, which is more than one organ system involvement.
- Give albuterol if wheezing is present.
- Observe for at least four hours.
What is the weight cutoff for Epi Pen Jr?
< 30 kg
Review all the agents available for anaphylaxis.
Epinephrine
Antihistamines (H1 and H2 blockers)
Steroids
Glucagon (this works to increase adrenergic tone through the cAMP pathway, not the receptor-mediated pathway)
Review the mechanism of IgE mediated reaction.
Type I reactions happen when IgE binds to an antigen. Mast cells then bind to IgE and degranulate, releasing histamine and other vasoactive mediators.
Immune complex deposition is a type ______ immune reaction.
III
DRESS is a type ______ immune hypersensitivity reaction.
IV (T-cell mediated)
Which cells are responsible for acute and chronic transplant rejection?
Acute is CD8, chronic is CD4
What is the pediatric dose of epinephrine for anaphylaxis?
0.01 mg/kg IM up to a max of 0.3 mg
Example: a 12 kg toddler (like June) would need 0.12 mg IM. Her auvi-q is 0.1 mg.
What three classes of medications can induce angioedema?
ACEi
NSAIDs
tPA
How is the swelling of angioedema different from anaphylaxis?
Angioedema is well demarcated
Unlike urticaria, angioedema is usually __________.
non-pruritic
Why might you give anaphylaxis medicines to those with angioedema?
There are histamine-mediated forms of angioedema as well as angioedema-anaphylaxis overlap syndromes that respond to anaphylaxis treatment.
Why might you give FFP to someone having angioedema?
Although evidence is poor, FFP has ACE in it so can hypothetically relieve ACEi-induced angioedema. FFP also has bradykinin in it, though, so might worsen bradykinin-induced angioedema.
The three pathophysiologies of angioedema are what?
Histamine-mediated
Bradykinin-mediated
Idiopathic
Those with hereditary angioedema can receive what targeted therapies?
Concentrated C1 esterase inhibitor
Icatibant (bradykinin receptor antagonist)
Kallikrein inhibitors such as ecallantide
How can the history help you figure out which type of angioedema is present (i.e., histaminergic or bradykinin-mediated)?
- Medication-induced angioedema (such as ACEi, NSAIDs, or tPA) is typically bradykinin-mediated
- Envenomation is usually histaminergic
- Pruritis and urticaria are usually seen in histaminergic angioedema
What cause of angioedema do you need to consider in those with a first-time case of angioedema who are older than 40?
Malignancy (typically lymphoproliferative)
True or false: angioedema is usually non-pruritic.
True
In hereditary angioedema, what protein is missing?
C1 esterase inhibitor
