Day +132

I am fine today. I would like to explain the differences between the Graft Versus Host Disease (GVHD) and rejection.

The new immune system that is established by “borrowing” my sister stem cell is called graft. If this graft discovers that my body’s (host’s) organs are not the same as my sister’s, it will launch an attack on the organs (喧宾夺主) resulting in GVHD. On the other hand, rejection happens on patients who undergo organ transplant. When the host (organ recipient) immune system discovers that the transplanted organ is not belonged to it, it will launch an attack on the new organ in an attempt to get rid of it, resulting in rejection.

In other words, GVHD is like you invited a new guy into your house as new owner (graft) and he tried to kick off somebody (host organs) from the house, while rejection is like you bring in somebody into the house and the owner of the house don’t like him and wanted to kick him off.

See the differences? If you still cannot see the differences. Just read the FAQ(Frequently Asked Questions) below.

1. Who is the bad guy? (A useful and good "bad guy")
GVHD: New immune system borrowed from someone. (different owner)
Rejection: Own immune system. (owner still the same)
2. What the bad guy attacks?
GVHD: Possibly more than one organ such as liver, kidney and skin.
Rejection: Only the transplanted organ.
3. Who might experience this?
GVHD: Allogeneic bone marrow or stem cell transplant patients.
Rejection: Organ transplant patients.

Now you understand the differences? If you still don’t understand, I can only say, “Alamak! How am I going to explain?”(天啊！如何解释？). Never mind-lah, just treat everything as rejection-lah; else you can come to my house bringing something delicious and I guarantee that I will make you understand the differences.

I told my wife I am so happy with this post because now I imagine a lot of people bringing delicious foods to me tomorrow :-)

See you next pots :-)