T+50 (GVHD)

Most people are familiar with the concept of organ rejection as a key concern with organ transplants. This rejection is caused by the immune system of the recipient treating the donor organ as a foreign body and attacking it. Consequently, most organ transplant recipients end up taking immunosuppressant drugs for the rest of their lives to prevent organ rejection.

In the case of a bone marrow stem cell transplant like I had, the donor’s immune system replaces the recipient’s immune system (which was purposely destroyed through chemotherapy). Hence, my organs are now the foreign bodies and are subject to attack by my new immune system. This attack is known as Graft vs. Host Disease (GVHD).

There are two forms of GVHD:

• Acute. Generally occurs within the first 100 days post transfer of stem cells from the donor to the recipient. Organs most often affected are the skin, gastrointestinal tract, and liver. While the impact can range from mild to severe, the duration is finite. Estimates vary but somewhere between 30% and 70% of recipients develop acute GVHD.
• Chronic. Can occur at any time but generally manifests at least 100 days post transfer of stem cells from the donor to the recipient. In addition to the organs affected by Acute GVHD, Chronic GVHD can also affect eyes, mouth, nails, scalp and body hair, lungs, muscles and joints, and genitals and sex organs. As with Acute GVHD, the impact can range from mild to life threatening. Unlike Acute, GVHD, the duration is measured in years and can even persist for the remainder of the recipient’s lifetime. Approximately 40% to 50% of recipients develop chronic GVHD.

While GVHD is generally to be avoided, there is a potential benefit to developing a non-life threatening acute GVHD reaction. In addition to attacking the recipient’s organs, the new immune system can also attack any remaining cancer cells. This effect is called a Graft vs. Leukemia reaction.

My medical team is trying to induce an acute GVHD reaction in the hopes that it will also induce a Graft vs. Leukemia reaction. They have taken several steps to do so including taking me off my immunosuppressants earlier (at T+60 days) than the normally would (at T+100 days).

I had an acute GVHD reaction with my first stem transplant in the form of a rash that covered my entire body. I was treated with an oral steroid (prednisone) and the rash subsided after several months. I had no chronic GVHD reactions.

So far, with the second stem cell transplant, I have experienced very mild skin irritation. While there are few signs of a rash, I am itchy from my upper torso to the top of head. So far, this reaction has been successfully treated with a topical cream.

I will confess that when I started this journey I worried most about three outcomes:

• A severe or life threatening GVHD reaction. Given that the liver is apparently a favoured target, I worry a lot about dealing with some form of liver disease and possible resulting liver damage.
• A chronic GVHD reaction that necessitates lifelong treatment. 
• Recurrence of the leukemia. The likelihood of a third transplant is very small. The probability of dying within 5 years, on the other hand, after a second failed stem cell transplant is very high.

As I have mentioned in early blog posts, the stem cell transplant process is a long one with many twists and turns. Successful engraftment, while a significant milestone, is one I have achieved before. My objective this time is to beat cancer without too many lasting effects. It will be close to two years before I can start to breathe a little easier. Until then, every morning I will wake up wondering “what new symptoms am I experiencing?” and I will anxiously await the results of every blood test.

Thanks for listening,

Mike