Autoimmunity I and II Flashcards
What is the difference between type II and type III HSR since they’re both antibody mediated?
Type II HSR - typically local/organ or tissue specific. Caused by antibodies attacking surface antigen
Type III HSR - typically systemic. Caused by antibodies forming immune complexes with free antigen
What kind of tissue distribution of the antibodies would you see with type II vs III hypersensitivity? (which one is which in the image below?)
(see image below)
Type II distribution - linear and smooth/localized, Type III distribution - all over (irregular)
Goodpasture syndrome arises from auto-antibodies against ___ in the glomerular basement membrane (and also alveolar basement membrane
Type IV collagen
Goodpasture syndrome can lead to pulmonary symptoms such as __, coughing and shortness of breath
Renal symptoms include hematuria/RBC casts and ___
hemoptysis (bloody sputum)
cough and shortness of breath
hematuria / RBC casts
rapidly progressive renal failure
What are two ways to diagnose Goodpasture’s? (hint: one’s in the tissue and the other is in circulation)
see below
How do you treat Goodpasture’s?
Plasmapheresis/plasma exchange
Decrease new auto-Ab formation: corticosteroids or cyclophosphamide (immune suppresant)
In Myasthenia Gravis, the ACh receptor can be blocked leading to 3 different outcomes, What are they?
Which of these outcomes plays the major role in mediating injury?
Complement activation leading to receptor destruction
Internalization of the receptor
Functional AChR block
Complement activation plays the major role in mediating injury
Symptoms of Myasthenia Gravis (ocular and muscular)
ptosis and diploplia, limited adduction
generalized proximal muscle weakness
(some pts also hav thymic hyperplasia and develop thymoma
How do you treat MG?
Thymectomy
Anticholinesterase agents (inhibit AChE) - accumulate more ACh to outcompete the antibody that’s blocking the receptor
What are some other ways to treat MG?
Steroids and immunesuppresants to lower formationof other antibodies
Removal of antibodies via plasmapheresis
IVIG
Graves disease results from auto-antibodies mimicking TSH and causing TH hormone secretion to be always on.
T/F: This happens only in the absence of TSH
Falsehood. You can also have TSH present and the antibody can still bind.
What are two classical symptoms of Graves disease?
In general, how would you classify hyperthyroidism symptoms?
Goiter and proptosis
Everything is too much (see image below)
Why is Hashimoto’s thyroiditis a mixed HSR?
Mixed because there’s a Type II response involving autoantibodies directed at thyroglobulin or thyroid peroxidase, and there’s also a Type IV response where CD4+ T cells recruit mononuclear cells and cause inflammation/tissue destruction etc
Describe the pathways involved in the pathogenesis of SLE
Loss of tolerance >> dysregulation of immune system >> end organ targeting
Where does the antigen that auto-antibodies bind to to form immune complexes in lupus come from?
What is the main contributor to the pathogenesis of SLE?
Cellular debri from apoptosis
Failure to clear the immune complexes that form from antibodies binding to cellular debri