Flashcards in Chp. 2 Lupus Deck (27):
In it's simplest definition, what is Systemic Lupus Erythematous
It is a chronic systemic autoimmune disease characterized by flares and remissions
What is the disease process for Lupus? What is damaged as a result of this pathology?
Ag/Ab complexes deposit in many tissues , thus damaging those tissues.
Poorly cleared apoptotic debris (i.e. from UV damage) activates self reactive lymphocytes. These lymphocytes then generate Abs twd the nuclear material (or nuclear Ag) of the apoptotic debris. These Abs are generated in LOW LEVELS.
The Ab/Ag complexes are then taken up by dendritic cells. Now here is where it gets started: The TLRs on the dendritic cells are activated by the DNA material from DNA Ags. Their activation amplifies the immune system (IFN-a) and now the auto reactive lymphocytes make Abs at a faster level.
These Ab/Ag complexes then deposit into tissues causing disease.
What HSR is lupus?
Type III (Immune Complex Deposition)
When the Ag/Ab complex deposits in tissues, what is activated?
Complement is now activated. B/c there are so many of these complexes, complement begins to be depleted. This is evident in the CH50 test.
What is a test you can use to detect a fall in complement?
The CH50 test. This test looks at C1-C9. In Lupus patients, C50 is low, C3 and C4.
People born with what deficiency are at risk for developing Lupus?
Those with Complement (most commonly C2) deficiencies. About half of these patients will develop lupus.
What opsonin does macrophages recognize?
C3b. If they see this, they phagocytose that material
What if the Ag/Ab complex is in the blood? Who recognizes it and how is it processed?
RBCs will see it. They have a CR1 receptor that can bind C3b. They then take the complex to the spleen where it is consumed.
Deficiency of what which complement proteins is associated with SLE?
C1q, C4, and C2. C2 is the most important.
What are the classic findings of SLE?
Almost tissue can be involved...this is a long list.
1. General non specific: fever, fatigue, weight loss, Reynaud
2. Malar rash or discoid rash esp when exposed to sun
3. Oral or nasal ulcers (painless)
4. Arthritis ( 2 or more joints, peripheral but no deformity)
5. Serositis (pleuritis and pericarditis)
6. Pyschosis or Seizures
7. Renal Damage
8. Anemia, Thrombocytopenia, Leukopenia (Type II HSR)
9. Liebmann Sacks Endocarditis
11. Anti-dsDNA or Anti-Sm Abs (highly specific)
Describe the renal findings of lupus. What are the two classifications?
1. NEPHRITIC SYNDROME...Diffuse proliferative glomerulonephritis is the MOST COMMON AND MOST SEVERE. You get severe HTN and Hematuria
2. NEPHROTIC SYNDROME...Membranous glomerulonephritis. You get proteinuria
Describe the cellular injury in Lupus. What kind of HSR is this?
Abs are generated against blood cells.
Leukopenia: Leukocytes (neutrophils & lymphocytes)
Basically these cells will begin to disappear.
This is a TYPE II HSR
How does lupus affect the heart? Which layer if affected has a particular disease name, and why is it so special?
Lupus can affect any layer of the heart but if it attacks the ENDOCARDIUM it is called LIEBMAN SACKS ENDOCARDITIS
It is so special because these are small vegetations ON BOTH SIDES OF THE MITRAL VALVE!!!
What is a non-specific Ab test for Lupus?
Antinuclear Ab (ANA)
This test is sensitive but not specific. tells you something is wrong, but doesn't tell you what?
If the ANA test is positive, then what test should be done next?
You could do either an Anti-dsDNA or Anti-Sm Ab test. These are both highly specific for lupus.
If the Anti-dsDNA is +, what does this mean?
A + anti-dsDNA Ab test means that there is active disease and renal nephritis. This test can be prognostic...if there is elevated titers, this means a relapse is here or imminent so treat.
If the Anti-Sm Ab is +, what does this mean?
This means that there are Abs against snRNPs. Though this test is specific, it is not prognostic.
What Ab is associates with 1/3 of Lupus patients?
Antiphospholipid Ab. It is an Ab directed against proteins bound to phospholipids.
What are the important antiphospholipid autoAbs?
Anti-B2 Glycoprotein I
What is a clinical consideration of Anticardiolipin?
This test can produce a FALSE + FOR SYPHILIS. When the VRDL and RPR tests done on a lupus patient will produce a + result, even if they don't have syphilis. To confirm a syphilis Dx, just run the more specific treponema test.
What is a clinical consideration of Lupus anticoagulant?
It will create a falsely elevated PTT. The lupus anticoagulant will interfere with the phospholipids within the test itself depleting them, making it seem that there are no proteins in the blood-->thin blood.
This is paradoxical bc this AutoAb induces a HYPERCOAGULABLE STATE.
What is Antiphospholipid Ab syndrome?
It is a syndrome characterized by a hypercoagulabe state due to antiphospholipid Abs, especially lupus anticoagulant.
What is the outcome of antiphospholipid syndrome? What do these patients require?
Arterial and venous thrombosis including:
Hepatic venous thrombosis (Bud Chiari, i think)
Placental (then pregnancy loss)
These patients require lifelong anti-coagulant therapy.
If a patient has drug induced lupus, what autoAb is present?
ANA is + by definition
What are the drugs responsible for inducing lupus? What can be done to overcome this?
Removal of drug results in remission usu.
How is Lupus treated?
Stay out the sun
Glucocorticoids (immune suppressant) for flares
Other immunosuppressives for severe refractory disease