Re: 2 Difficult Questions

[Guest guest]

Ezra asked:

> 1. In light of recent posts regarding recurrence of PSC

> post-tranplantation, what do you think could cause this to

> happen in a new, foreign liver? ... what could be provoking

> the attack post-transplant?

My theory (pure speculation mind you) is that antibodies exist

that guide an attack against bile duct cells, keying off some

surface protein that is expressed only by bile ducts (probably a

protein that keeps the cell walls resistant to the effects of

bile). A small percentage of transplants express the same

protein, which causes the ducts in the new liver to be attacked.

The rest have a different alle for that protein and the attack

doesn't occur.

> 2. Is it theoretically possible that a mechanical/ artificial

> biliary tree composed entirely on inorganic matter could be

> developed -- one that could take the place of a PSC patient's

> own biliary system? What would the barriers to development of

> such a device?

I can envision growing hepatocytes (liver cells) on a substrait

of such a system (even then I don't think it is technically

feasible yet), but not of developing something that would be

able to be " inserted " into an existing organ.

The liver acts as a huge cross flow exchanger, there is blood

from the heart to provide fresh oxigenated blood, the portal

blood system with blood from the gut that needs to be processed

and the biliary system to carry off bile. All these networks

have to get within one or two cell widths of every cell in the

liver. Thats a lot of tubing - small tubing yes, but a lot.

Getting a bile duct system in place without completely

disrupting the two blood flow system, seems completely beyond

me.

Tim

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