Apheresis - Plasmapheresis Flashcards
What are the subtypes of Guillain-Barre Syndrome?
Classic is demyelinating (AIDP)
ASMAN/AMAN (axonal damage)
Miller-Fischer (ophthalmoplegia and ataxia)
What is the treatment of Guillain-Barre Syndrome?
Respiratory support, TPE and/or IVIG (equivalent). Steroids are not helpful.
What defines CIDP?
2+ months of chronic symptoms consistent with AIDP (motor/sensory loss).
What is the treatment of CIDP?
TPE is first-line if severe. IVIG is comparably good.
How is peripheral neuropathy with monoclonal gammopathy treated?
Because they are usually IgM-mediated, they should respond to plasma exchange. Exception: POEMS does not respond.
What serologies are seen in Myasthenia Gravis?
Most cases have an anti-AChR, some have anti-MuSK, and some are seronegative.
How is myasthenia gravis treated?
Symptomatic treatment (stigmines), immunosuppression, thymectomy (many a/w malignant thymoma), TPE or IVIG (equivalent)
How does LEMS compare to MG?
LEMS patients may often present with pain, but not diplopia/dysarthria. TPE is somewhat less effective.
What antibodies are implicated in LEMS?
Antibodies against presynaptic antigens, mostly P/Q/N voltage-gated calcium channels.
Stiff-person syndrome
Caused by antibody to Glutamic Acid Decarboxylase, maybe Gephyrin. Extremely poorly described.
MS/NMO
Not antibody-mediated, though NMO does have anti-aquaporin antibodies. NMO is better indication than MS, but reserve TPE for severe cases.
How do the microthrombi in TTP differ from those in DIC?
TTP microthrombi generally lack fibrin and inflammatory cells.
What are some causes of atypical hemolytic uremic syndrome?
Abnormalities of Factor H, Factor I, or CD46 (inborn deficiency vs acquired inihibitors)
What are some secondary causes of thrombotic microangiopathies?
Infection (incl. HIV), CVDs (SLE), drugs (ticlopidine, quinine), pregnancy…
What are the consequences of major incompatible ABO mismatched HSCT?
Hemolysis of red cells in product.
Delayed engraftment.
Pure red cell aplasia (destruction of normoblasts in product)
What are the consequences of minor incompatible ABO mismatched HSCT?
Hemolysis of patient red cells, passenger lymphocyte syndrome
How can apheresis be helpful pre-hSCT-transplant?
In major incompatibility, reduces isohemagglutinins. In minor incompatibility (RCX!), can “convert” patient’s type temporarily.
What is the role of TPE in aplastic anemia?
Basically no role (not even in ASFA), despite some cases being immune-mediated (others: drug, virus, acquired clonal)
What autoimmune hemolytic anemias should respond to TPE?
Cold hemolytic anemias moreso than warms, due to IgM more often than IgG (exception: PCH)
What is the role of TPE in ITP?
Not great; ancient and scant data. Would not recommend.
What is the role of TPE in hemophila?
Can reduce high-strength (>5 BU) inhibitors, but not really favored.
What are the three types of cryoglobulinemias?
Type I: IgG or IgM monoclonal
Type II: IgM (mono) or IgG (poly); HCV-assoc
Type III: Polyclonal, associated with infection
At what serum viscosity should patients become symptomatic?
Above 4-6x viscosity of water.
How should TPE be timed with rituximab?
Always done before rituximab, both to not remove antibody and because of temporary IgM worsening with rituximab infusion.
What is the recommended regimen for treatment of Goodpasture?
Exchange daily and at least partially with FFP.
What is the role of TPE in treating the rapidly progressive glomerulonephritides?
Maybe some benefit if concomitant pulmonary hemorrhage (PEXIVAS?). ASFA categories range from I-III.
How should myeloma cast nephropathies be treated?
Treat underlying myeloma. Mixed evidence for benefit of TPE. Standard dialysis will not remove free light chains.
What is the role of TPE in lupus?
May actually worsen disease due to antibody rebound; reserve for severe cases or secondary complications like TTP or antiphospholipid syndrome.
What is the role of TPE in scleroderma?
Mixed; ECP may be superior. Reserve for scleroderma renal crisis?
What is the role of TPE in GVHD?
Extremely limited, due to markedly better efficacy of extracorporeal photopheresis.
How can TPE be used in the pre- and post-transplant settings?
Pre: Reduce isohemagglutinins for ABO-incompatible transplants, reduce DSA/PRA pre-transplant.
Post: Reduce DSA, antibody-mediated rejection.
What isohemagglutinin titer is recommended for safe ABO-incompatible transplant?
16
How is recurrent FSGS treated?
TPE is first-line (as compared to primary FSGS, which is chronic and irreversible).
What is the role of TPE in heart, liver, and lung transplant?
Not popular; cellular rejection is more common and is treated with ECP. HLA tolerizing is not practical pre-transplant. ECP also treats AMR…
How does HUS present differently from TTP?
More renal manifestations, fewer neuro manifestations.
What is the normal viscosity of plasma? At what levels can symptoms set in?
1.4 - 1.8 centipoise
Symptomatic hyperviscosity above 4 centripoise.
At what plasma levels does each paraprotein isotype cause hyperviscosity?
IgM: 3 g/dL
IgG: 4 g/dL
IgA: 6 g/dL
