Kitty, I don't know the statistics but I can tell you the liklihood of being a close match to someone you were not related too would be extremely rare. Not only would tissue have to match but so would blood types and organ size.
However, I know why you are asking so let me just share this bit of info...
In the past, the conventional wisdom was that close tissue typing was necessary for a successful donation, and close tissue typing implied blood relationships. But anti-rejection drugs are so powerful now that close tissue typing is less important. Consequently, unrelated living donation has increased dramatically over the last 10 years. You will still need to go through the normal evaluation of donors. Also be prepared to discuss your motives for donation and the impact it might have on your relationship with the recipient and family.
What are the odds my donated kidney will work...that it won't be rejected?
Excellent. In fact, living kidney donation has the best track record of all forms of donation. Statistics from United Network for Organ Sharing show that the kidney donated from living donors is still functioning in 97% cases after one year and 85% of cases after four years. Even so, you should be prepared mentally for the possibility of rejection.
What is the process for determining whether you can donate a kidney?
The short answer is you need to show three things: (1) you have blood and tissue types compatible to the recipient, (2) You are generally healthy, and (3) you have two healthy kidneys. You might also undergo psychological and financial assessments.
What are the long-term effects on me if I donate one of my kidneys?
Research has shown there are few, if any, long-term effects on a living kidney donor. There are small possibilities of high blood pressure and elevated levels of protein in the urine.
I'm ready to donate. Who pays?
The transplant recipient's medical insurance covers the cost of the donor's testing, surgery, and recovery in the hospital. You are on your own as far as lost wages if you miss work, but most enlightened employers cover this time off with sick leave and vacation pay. Alternatively, you might qualify for unpaid leave. U.S. employees may qualify for special leave under the Family and Medical Leave Act (FMLA) Some progressive employers, such as United Network for Organ Sharing and some state governments, have arranged for paid leave specifically for living donors. Talk to your employer about the types of time-off benefits available to you.
source:
livingdonorsonline.org