MAY 03, 2017 3:09 PM PDT

Reducing the Risk of Rejection During High-Risk Heart Transplants

WRITTEN BY: Kara Marker

Waiting for the perfect heart can be a long and unsuccessful process, made necessary by specific antigens and antibodies in human organs that can target each other and lead to the rejection of a transplanted organ. However, a new technique provides an opportunity of reducing the risk of heart transplant rejection by “soothing” patient antibodies prior to the procedure, through desensitization.

Credit: Plus100Years

Measurement of a factor called anti-human leukocyte antigen (HLA) antibodies tells doctors when a patient is at risk of organ rejection. Anti-HLA can bind donor HLA antigens like the immune system binds antigens from a pathogen, and binding causes rejection of the organ as if it were recognized as a dangerous, foreign invader.

When a person waiting for a heart transplant has anti-HLA antibodies specific to the donor tissue’s HLA antigens, the person’s antibodies are called “donor specific” anti-HLA antibodies, or DSA. Because of the high risk of rejection in the case of a person with DSAs, the transplant is usually cancelled, and the person has to wait for a different donor with different HLA antigens.

"Most centers do not perform heart transplantation in patients with a high DSA level,” explained lead author Guillaume Coutance. According to the Gift of Life Donor Program, the average median wait time for heart transplants is four months, with the availability of local hearts providing the potential to speed up the process. Regardless, many heart failure patients don’t have any time to waste.

To save precious time for those waiting, Coutance’s new study investigated the possibility of using drugs to prevent the immune system from rejecting transplanted organs even in the most risk DSA situations. Depending on whether patients had low DSA or high DSA, essentially a distinction between how at risk they were of organ rejection, Coutance used a different “cocktail” of desensitization drugs:

  • Anti-thymocyte globulins

  • Conventional immunosuppressive therapy

  • Intravenous immunoglobulins

  • Pre- and post-op plasmapheresis

A study of just over five hundred participants followed for about four years after the procedure helped Coutance and his team visualize the effectiveness of the new sensitization approach. Diversity among the participants enabled the researchers to compare outcomes between patients with no DSA, low DSA, and high DSA. After controlling for several potentially confounding variables, they saw that survival times were very similar among the three groups.

“By desensitising patient's antibodies, those with high immunological risk experience similar survival to patients without DSA,” Coutance explained. “Pre- and post-operative plasmapheresis results in a dramatic drop in DSA levels, which reduces the risk of hyper-acute rejections and early antibody-mediated rejections. Intravenous immunoglobulins will neutralise DSA for weeks."

With positive results on the table, Coutance anticipates the new desensitization approach to benefit many people in the future, especially those patients with not a lot of time to wait for a 100 percent perfect organ match: "This desensitisation programme could shorten waiting times and increase access to transplantation for patients at high immunological risk.”

Sources: European Society of Cardiology, Gift of Life Donor Program

About the Author
I am a scientific journalist and enthusiast, especially in the realm of biomedicine. I am passionate about conveying the truth in scientific phenomena and subsequently improving health and public awareness. Sometimes scientific research needs a translator to effectively communicate the scientific jargon present in significant findings. I plan to be that translating communicator, and I hope to decrease the spread of misrepresented scientific phenomena! Check out my science blog: ScienceKara.com.
You May Also Like
APR 06, 2022
Cardiology
Are Leadless Pacemakers the Future?
APR 06, 2022
Are Leadless Pacemakers the Future?
The human heart rate is under the influence of various hormonal and neural control mechanisms. Normally, conduction of a ...
MAY 10, 2022
Cardiology
Screen Time is Linked to Heart Disease and Cancer
MAY 10, 2022
Screen Time is Linked to Heart Disease and Cancer
Spending too much time in front of the TV or computer can lead to major health risks.
JUL 05, 2022
Cardiology
Certain Gut Bacteria Make Blood Pressure Drugs Less Effective
JUL 05, 2022
Certain Gut Bacteria Make Blood Pressure Drugs Less Effective
A new study has shown that gut bacteria reduce the effectiveness of some blood pressure medications.
JUN 25, 2022
Health & Medicine
Excess Sitting Is Bad for Your Health but Exercise Can Help with That
JUN 25, 2022
Excess Sitting Is Bad for Your Health but Exercise Can Help with That
Winston Churchill said, "Never stand up when you can sit down." Nowadays, sitting down is an unavoidable part ...
SEP 07, 2022
Health & Medicine
Weather Fluctuations Shown to Increase Risk of Heart Attack in the Tropics
SEP 07, 2022
Weather Fluctuations Shown to Increase Risk of Heart Attack in the Tropics
Changes in temperature have predictable effects on human physiology. Exposure to hot temperatures changes heart rate and ...
SEP 18, 2022
Cardiology
Adult ADHD Could Lead to Increased Chances of Cardiovascular Diseases
SEP 18, 2022
Adult ADHD Could Lead to Increased Chances of Cardiovascular Diseases
In a recent study published in World Psychiatry, an international team of researchers suggests that people with attentio ...
Loading Comments...