Question

In which of the following conditions is plasmapheresis useful?

• A. Wegener's granulomatosis
• B. HSP (Henoch-Schonlein purpura)
• C. Goodpasture syndrome
• D. Guillain-Barre syndrome

Hint:

Think of the disease where a circulating antibody against basement membrane is the direct cause.

Answer 1

The Correct Option is C

Step 1: Recall what plasmapheresis does.
Plasmapheresis (plasma exchange) removes the liquid part of blood, along with whatever harmful antibodies or immune complexes are floating in it, then returns the blood cells with replacement fluid. It works best in diseases where a circulating antibody is directly causing the damage.

Step 2: Look at Goodpasture syndrome closely.
Goodpasture syndrome is caused by antibodies against type IV collagen in the basement membrane of the kidney glomeruli and the lung alveoli, called anti glomerular basement membrane (anti-GBM) antibodies. Since the disease is driven directly by a circulating antibody, physically removing that antibody with plasmapheresis is a core part of treatment, given together with steroids and immunosuppressants.

Step 3: Compare the other options.
Wegener's granulomatosis (granulomatosis with polyangiitis) is driven by ANCA antibodies plus vessel inflammation, and is mainly treated with steroids and cyclophosphamide or rituximab; plasmapheresis is kept for severe cases with lung hemorrhage or advanced kidney failure, not as the standard first answer.
Henoch-Schonlein purpura (HSP) is an IgA mediated vasculitis in children that is usually self limiting and managed with supportive care and sometimes steroids; plasmapheresis is not a standard treatment for it.
Guillain-Barre syndrome does also respond to plasmapheresis, since it removes antibodies against peripheral nerve myelin, but among these four choices, the disease where plasma exchange is most directly tied to the disease mechanism is Goodpasture syndrome, since the antibody itself is the entire cause of the tissue damage.

Final Answer:
Plasmapheresis is useful in Goodpasture syndrome, where it directly removes the disease causing anti-GBM antibody. \[ \boxed{\text{Goodpasture syndrome}} \]