by Josephine Varnier
The Medical College of Virginia, a part of the Virginia Commonwealth of University’s Health System, began its Clinical Transplant Program as one of the first in the nation and continues to be one of the leading Transplant Centers in 1956.
With procedures specializing in the pancreas, liver and kidney that were once considered risky, the Hume-Lee Transplant Center now performs them with a 90% success rate.
New studies, however, are always on the rise and are detrimental in finding new and safer ways to transfer organs from donor to patient.
Dr. Robert A. Fisher is serving as the principal investigator in a study on the tolerance of organ transplants in rats.
The animal model for kidney transplants was created at the HLTC and Fisher has been analyzing functional, kidney histological and cytokine data since 1991.
Cytokines, imperative for cellular communication, have been understood to affect the tolerance of kidney transplants. The levels in the cells of the test rats are measured as a main focus.
“Similar to the way bees communicate via pheromones,” Fisher says, the cytokines deliver a positive or negative response to the stimulus created by the foreign object, or in these cases, the new kidney.
The T-cells mediate a response against the stimulus and are therefore provide the detrimental information needed to compare the studies to the responses made by human patients.
“Of course they are. You can’t make direct comparisons, but you can learn about the physiology and the process,” Fisher says.
The two different rats tested in the study have specific and dissimilar antigens, similar to the different antigens of different human beings. In studying the tolerance of transplanted organs, a kidney is removed from an ACI, or small black rat, and then is planted into a Lewis rat, or a big white rat.
In their separate families the rats serve as perfect clones, but in order to create the study so advancement in human transplantations can occur, organs must be taken from one family to another.
The ACI rats are euthanized after a kidney is removed. The normal life of a rat in a lab is 360 to 370 days.
“Our life spans are increasing and for the rat, it’s the same,” Fisher says, also stating that 60% operated on turn out more physically healed than the other percentage that show scarring or damage.
The amount of physical disfigurement after the transplantation occurs is the main way in which the cytokine communication can be determined.
Other animals had been used in the history of the studies within the HLTC, such as Hanover mini pigs for bell transplantation, dogs, and primates.
“I got too attached to them,” Fisher says of the prior test animals. “We still treat them [the rats] with respect and consider their lives to be respected and valued.”
When asked about the possibility of animal’s rights activists opposing any of the transplantation studies, Fisher replies, “I think that they worry about that. Some places have had whole experiments and labs destroyed. We’ve never had it happen.”
The drugs tested on the animals after their transplants are those already approved for humans, and therefore the need to move to primates after two successful rat trials is unnecessary.
Humans or animals accepting an organ without an immunant suppressant drug afterwards has not yet occurred within the tolerance study.
“We have never achieved it- not yet,” Fisher says of the need for bodies to have a boost at this time. “90 to 110 days is the definite time period where cytokines would decide whether the kidney would act normally.”
The skills needed to even complete a transplant are those only possessed by a few.
“Only two out of ten can complete a kidney transplant,” Fisher says of the students who graduate and complete the surgical courses needed to help in the study. “The less skilled can do transplants easier with bigger animals, but regular PhDs would not be able to do it.”
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