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Transplant rejection is caused by the body’s immune response to foreign material. The body naturally tends to attempt to destroy encountered foreign matter. As a result, those who receive transplants are given transplant rejection medications that reduce the body’s immune response.
In most cases, the white cells of the blood, called leukocytes, serve our bodies very well. They identify viruses and bacteria that have entered our bloodstream and begin to assiduously eliminate them. Leukocytes help us recover from illnesses and also keep us from getting some illnesses because we have already become immune to them from previous white blood cell action.
However, when someone receives a transplant, leukocytes work against the new organ. They immediately recognize the organ as foreign, and set about to destroy it. More leukocytes are produced to rid the body of the organ, setting up a battle between the new organ and the white blood cells.
When the white blood cells are effective, this causes transplant rejection. Usually transplanted organs are tested for the presence of leukocytes to gauge amount of rejection. The answer to this problem is problematic itself. The leukocytes have to be reduced in order to allow the new organ to do its job.
As such, those who receive an organ take immunosuppressant medications that can prevent transplant rejection. This results in a weakened immune system, because leukocytes are not available to fight off the normal diseases one might encounter. Those receiving a transplant are then more vulnerable to both viruses and infections. In addition to transplant rejection medications, most who receive a transplant frequently must take antibiotics, or are on consistent doses of prophylactic antibiotics to prevent infections.
The long-term use of antibiotics creates another issue. Germs tend to become resistant to antibiotics over time, thus fighting bacteria means switching to newer and stronger antibiotics. As well, patients can be allergic to certain classes of antibiotics, limiting the kinds of medications patients can take. A stronger antibiotic also translates to more side effects like frequent fungal or yeast infections, stomach upset, and skin rashes.
Thus, attempting to avoid transplant rejection requires a very delicate pharmaceutical balance. One must have eliminated enough leukocytes to avoid transplant rejection, but not so many that viruses will claim the life of the patient. Antibiotics must be given to stop infection; yet antibiotics must not be so strong that the patient will die from antibiotic resistant illnesses.
With anti-rejection medications, transplant rejection is now reduced to about 10-15%. Closely matching blood types and blood factors help, but the body still “knows” the organ is not of the body. Only transplants from identical twins, and cornea transplants seem to go unrecognized by leukocytes. As well, valves for the heart taken from pigs, cows and from cadavers seem not to be considered “foreign.” Often transplant rejection is not the cause of death in patients with transplants. Fighting transplant rejection is. Complications from transplants are more likely to cause death than transplant rejection.
The field of transplant technology is, however, continually evolving. At one time, almost all transplants were rejected. Now, continual research into anti-rejection medications is turning the tide on transplant rejection and complications from transplant medications.
The goal of transplant specialists is to reduce rejection, and also to create medications that will not cause those receiving a transplant to suffer life-threatening complications. When this goal is reached, the medical field can certainly claim victory.