Today, a growing number of people find themselves potentially in the position to be a living organ donor. They include:

• Living Related Donors. These consist of relatives by birth -- a parent, a child, a sibling, a half-sibling, or in some cases a more distant blood relative.
• Living Unrelated Donors. These include spouses, adopted children and parents, and increasingly, close friends and co-workers.
• Paired Donors. These are donors whose blood type makes them ineligible to donate directly to their loved one, so the prospective donor and recipient are then "paired" with another couple in the same position.
• Samaritan Donors. This is a term used to describe the growing number of persons expressing a desire to donate an organ anonymously to a total stranger.

Regardless of which category you fall into, there are some basic criteria you must meet to be a living donor. As with everything, there are exceptions -- so be sure to check with your transplant center. But here are some guidelines.

Age: Approximately two-thirds of living donations come from donors between the ages of 18 and 49. Living donations from adolescents below the age of 18 are considered only in extremely rare cases, and fewer than a dozen are approved each year. Donations from persons aged 50 to 65 are increasing and now account for more than 15 percent of living donor kidney transplants, but only a handful of living donor liver transplants. Donations from persons over the age of 65 are considered in unusual cases, but account for fewer than one percent of living donor kidney transplants and no living donor liver transplants.

Blood Group: To qualify as a living donor of a kidney or part of your liver, your blood group must be the same as that of the recipient, unless you have group O, in which case you are a "universal" donor. Otherwise, the chart on the right applies. (Some centers seek to avoid performing liver transplants using a group O living donor for a group A or B recipient, or a group A or B living donor for a group AB recipient, because of the possibility of graft vs host disease.)

Tissue Typing : Historically, kidney transplants (but not liver transplants) have been the most successful when the six (major) human leukocyte antigens (HLA) of the donor matched the six of the recipient. Since a person inherits a set of three of these antigens from each parent, most children and parents parent start with at least a three-antigen match, although the match could be fortuitously better. There is a 25 percent chance that siblings will be totally identical. Most centers still believe the best results come when a donor is a good HLA match for the recipient. But with the development of more effective anti-rejection drugs, many centers now place less importance on HLA matching, and may consider a donor even when there is a low or no match.

Crossmatch Testing : In a further test of antigen compatibility for kidney transplants (but not liver transplants), white blood cells are mixed with serum from the intended recipient. If the white blood cells from the potential donor are attacked and die, the recipient has antibodies to some of the donor's antigens -- meaning the recipient's immune system would most likely rapidly reject the donated organ, even on the operating table. If the white blood cells for the potential donor are not attacked, it is described as a "negative crossmatch" -- meaning you are a suitable donor for the intended recipient.

General Health Guidelines: These additional general health guidelines will help you quickly determine whether you might be eligible to be a living donor.

To be a living kidney donor, you should:

• Have two kidneys that are functioning normally.
• Not suffer from diabetes.
• Not suffer from heart disease.
• Have blood pressure that is less than 150 over 90.
• Have been cancer and infection free for at least five years.
• Be negative for Hepatitis B and C, and for HIV.
• Not consume alcohol to excess.
• Not exceed the normal bodyweight for your height by more than 15 percent.
• Not be undergoing psychiatric treatment for severe depression or other mental disorders.

To be a living liver donor, you should:

• Have no liver problems or abnormalities.
• Have no kidney problems.
• Not suffer from diabetes.
• Not suffer from heart disease.
• Have blood pressure that is less than 150 over 90.
• Have been cancer and infection free for at least five years.
• Be negative for Hepatitis B and C, and for HIV.
• Not consume alcohol to excess.
• Not exceed the normal bodyweight for your height by more than 15 percent.
• Not be undergoing psychiatric treatment for severe depression or other mental disorders.

All information provided in this site is offered for educational purposes only, and it is not intended nor implied to be a substitute for professional medical advice. Always consult your own physician or healthcare provider with any questions you may have regarding a medical condition.