Actually it's quite common for transplant patients to have rejection within the first six month after transplant ::gasp, shock, horror::
I was one of those people who didn't think it'd happen to them. My transplant went well [not counting a few trivial mishaps] so I was home free. Or so I thought. Anyway rejection is quite normal for a transplant patient to have. Your body is still adjusting to the lungs, the medications, and various other stressors placed on your body. Honestly it's surprising that some people don't go through rejection. Mine was very easy to treat, just have me on i.v.'s for a week and change my medication around and there was no signs of rejection afterwards. That's the good thing about these clinics, they are so diligent they catch these things before they have a chance to become anything major.
Of course that was only describing acute rejection, which is the most common form of rejection.
There is another rejection which is 'chronic' rejection. This is the type of rejection that you can't get rid of. Now I'm taking this right out of my transplant notebook. 'Chronic rejection, also called "bronchiolitis obliterans", is different from the acute form in that it involves the airways more so than the tissue. The small airways of the lung become plugged with scar tissue resulting in decreased air flow. The cause is unknown at this time, and not well understood. This condition is irreversible with no adequate treatment except, perhaps, re-transplantation. As this conditioin progresses, more than likely you will become oxygen dependent and your exercise capacity will gradually decline.'
I've heared that chronic rejection is not common though.
Honestly if you were to expect anything I'd expect acute rejection. The signs of rejection fever, shortness of breath, cough, lethargy. I didn't have any symptoms but that was because my rejection was so slight it hardly registered. They caught it with a bronch and biopsy. So rejection is fairly easy to manage, or it was in my case, and I've never heard of anybody having chronic rejection though I know it happens. Anyway if you have any more questions feel free to ask.
I also agree with what Emily said.