Genetic variations in cell surface proteins are able to predict kidney transplant success, shows Austrian research, serving as a potential screening tool for improving future transplants.
Many kidney transplants fail over time because the patient’s immune system rejects the organ. This rejection happens because the immune system recognizes that particular proteins on the cell surface, such as immune ‘ID’ proteins called histocompatibility antigens, are foreign to the body.
Although transplant programmes often select organs that have similar immune ID proteins to the patient, transplants still have a high long-term failure rate.
“Even transplants with identical histocompatibility antigens fail at a rate of roughly 5% per year,” Rainer Oberbauer, from the Medical University of Vienna, and the lead researcher in the study, told me. In fact, up to 50% of kidneys are rejected within 15 years of transplantation.
In research published in The Lancet, Oberbauer’s team investigated whether part of this failure rate could be due to the immune system recognizing foreign cell surface proteins that aren’t histocompatibility antigens. The researchers took 477 pairs of transplant organs and recipients, and measured how similar the genes of cell surface proteins were between the donor and patient.
The researchers found that organs transplanted into patients with a similar genetic makeup to the organ donor were more successful than those with more genetic mismatches. If experts could screen for this similarity in future, they could have more success in selecting the right kidney for the right patient.
In addition, this tool could improve transplant cases where it’s hard to find organs with the same histocompatibility antigens as the patient.
This study adds to many efforts across Europe to improve the success rate of organ transplants. The Spanish biotech Biohope focuses on personalizing immunosuppression drug therapies for patients, which could help to restrain the immune system from attacking the transplant. Hansa Medical also has a promising treatment in the clinic that destroys antibodies targeting the transplant.
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