For successful transplants, rein in those raging hormones

Harvard scientists have discovered how drugs that suppress the production of sex hormones could help boost tolerance for organ transplants.

And we’re not talking about the raging hormones of teenagers… the study focuses on changes caused by the hormonal differences in older adults.

The immune systems of elderly patients often respond poorly to organ transplants, and researchers blame this failure partly on the shrinking of the thymus (pictured) – the main manufacturer of immune T cells.

Thymus shrinkage begins around the same time as puberty, when sex hormone levels start to change… dramatically.

So Shaoping Deng and colleagues from Harvard Medical School investigated the reversal of thymus atrophy and the effects it would have on transplant tolerance.

1. They surgically castrated aged mice. Specifically 'elderly' 12-month-old male mice struggling to develop tolerance to cardiac transplants.
2. The surgical castration modified their sex hormone levels, leading to long-term acceptance of grafts and the restoration of their thymuses.
3. Then, to confirm their findings with a more (human) patient-friendly procedure, the team chemically manipulated the sex hormones using a chemotherapy drug called Lupron Depot. Made by Abbott Laboratories, the drug temporarily disrupts testes function in men and is used to treat prostate cancer.
4. What they saw were similar transplant tolerance-inducing effects after injecting Lupron Depot into the mice.

It's difficult to translate mouse years into human years, but… the results do point to a new hormone-based therapy to help ensure successful transplants in the elderly.

The study was published today in Science Translational Medicine.

Image of thymus from Gray’s Anatomy via Wikimedia

Related on SmartPlanet:

• Stem cell setback: mice reject their own reprogrammed cells
• Can reprogrammed cells nix the need for liver transplants?
• Looking for DNA debris: blood test detects organ transplant rejection
• Inaugural transplant of a bioengineered voicebox
• Replacement human organs, thanks to a 3-D printer

This post was originally published on Smartplanet.com