Allogeneic stem cell transplant (or bone marrow transplant with donor cells) can potentially cure some blood cancers, but it comes with a risk of serious complications. Graft-versus-host disease (GVHD) is a common complication of a stem cell transplant using cells from another person. Symptoms of GVHD can range from mild to life-threatening, and early diagnosis and treatment are key to a good outcome.

Whether you or a loved one has had an allogeneic stem cell transplant or you’re still weighing your blood cancer treatment options, it’s helpful to learn more about GVHD.

1. GVHD Develops When Donated Cells Attack Your Body

An allogeneic stem cell transplant may be a treatment option for some people with lymphoma, leukemia, or other types of blood disorders. This procedure involves taking immature blood cells from a healthy donor and transplanting them into another person. These donated immune cells (the graft) form a new immune system for the transplant recipient (the host). The donated cells can help cure some blood cancers by finding and attacking cancer cells.

In GVHD, the donor transplant cells begin to identify the healthy cells of the host’s body as harmful invaders and attack them too, causing damage to tissues and organs.

Read more about what causes GVHD.

2. There Are Four Types of GVHD

GVHD can develop at any time after a stem cell transplant. In the past, the types of GVHD were determined by how soon it developed after the transplant:

• Acute GVHD — Most often develops in the first 100 days after the transplant
• Chronic GVHD — Most often develops more than 100 days after the transplant
• Overlap syndrome — Has features of both acute and chronic GVHD at the same time
• Late acute GVHD — Happens when acute GVHD persists past 100 days, returns after a period of getting better, or appears after a change in immunosuppressive medication

However, the National Institutes of Health has updated the guidelines to consider what symptoms are involved and how severe they are.

Read more about the types of GVHD.

3. GVHD Is Common, and Certain Factors Raise Your Risk

About 50 percent of people who have had an allogeneic stem cell transplant develop some type of GVHD. It’s estimated that between 30 percent and 70 percent of people develop acute GVHD after a transplant. Between 40 percent and 50 percent of people may develop chronic GVHD.

According to the Leukemia & Lymphoma Society, you’re more likely to develop GVHD if any of these risk factors apply:

• You had a mismatched or unrelated donor.
• You or your donor are older adults.
• You’re a male who received donated cells from a female.
• The donor was a female who had previously been pregnant.
• The donated cells came from peripheral (circulating) blood instead of from bone marrow or umbilical cord blood.

4. There Are Ways To Lower the Risk of GVHD

Donors are chosen carefully to lower the risk of GVHD. Receiving donor stem cells from a closely matched donor decreases the risk of developing GVHD. For many people, siblings are more likely to be a close match. However, closer matches can also come from someone unrelated who is on a donor registry.

In addition to finding a closely matched donor, you’ll likely take medication to suppress or dampen the immune response before and after the stem cell transplant. Talk to your healthcare team about the best prevention regimen for you.

5. GVHD Symptoms Depend on Which Organs Are Affected

GVHD can affect any organ in the body. However, some parts of the body are more likely to be affected based on whether you have acute or chronic GVHD.

Acute GVHD Symptoms

In acute GVHD, the most common symptoms are:

• Rash on the skin — This can range from mild discoloration to severe blistering.
• Liver problems —These can include changes in liver blood tests and jaundice (yellowing of the skin and whites of the eyes).
• Gastrointestinal (digestive tract) problems — These can involve abdominal pain and diarrhea, which can be severe.

Your healthcare team will determine the severity of your acute graft-versus-host disease based on how many organs are affected and how severe the symptoms are. This is known as grading.

Read more about how GVHD symptoms are graded.

Chronic GVHD Symptoms

Chronic GVHD can affect just one or several organs. The most common organs affected by chronic GVHD include:

• Skin
• Eyes
• Mouth
• Liver

In some people, the symptoms can be mild, while in others, chronic GVHD can be life-threatening. Your healthcare team will determine if chronic GVHD is mild, moderate, or severe based on the number of affected organs and the severity of your symptoms.

Read more about GVHD symptoms.

6. Diagnosing GVHD May Require Multiple Tests

If you start to develop symptoms that could be GVHD, you’ll need tests to make sure there isn’t another cause. An infection or the serious side effects of some medications can look like acute or chronic GVHD.

You’ll likely be referred to a doctor who specializes in diagnosing problems in the affected organ. For example, a dermatologist would look into any skin issues you’re having. Tests to diagnose GVHD may include blood tests, imaging tests, and biopsies (taking a small sample of tissue for testing).

Read more about how GVHD is diagnosed.

7. Corticosteroids Are the First Treatment for GVHD

Corticosteroids (often simply called steroids) are a type of immunosuppressant medication. Immunosuppressants work by weakening the immune system and decreasing inflammation.

If you have mild GVHD symptoms, you may only need steroid treatment in the affected area. For example, if you have a mild rash caused by acute or chronic GVHD, you may only need a topical (on the skin) steroid cream.

If you have more severe symptoms, or symptoms in several organs, you may need systemic (whole-body) treatment. This involves taking steroids such as prednisone by mouth or intravenously (by IV).

GVHD treatment with steroids usually continues until your symptoms improve and stabilize. At that point, your healthcare team can begin to decrease your steroid dose over time.

8. GVHD May Stop Responding to Steroids

When GVHD symptoms don’t improve with steroid treatment, it’s called steroid-refractory GVHD. First-line steroid treatment will be all that is needed for between 40 percent and 60 percent of people with acute GVHD. Others will need additional therapies.

For those with chronic GVHD, research shows between 50 percent and 60 percent of people develop steroid-refractory GVHD within two years of starting treatment.

If you develop steroid-refractory GVHD, you’ll need other treatments, referred to as second-line therapies. Several second-line medications have been approved by the U.S. Food and Drug Administration (FDA) to treat steroid-refractory GVHD. Researchers are also exploring new treatments in clinical trials.

A procedure called extracorporeal photopheresis may also be helpful for people with acute or chronic GVHD who don’t respond to steroids. This treatment involves treating white blood cells called lymphocytes with ultraviolet light to alter the immune system’s activity.

Read more about treatment options for GVHD.

9. Early Treatment May Improve Your Outlook

Your prognosis (outlook) with GVHD depends on the type of GVHD you have, the severity of the damage, and how you respond to treatment. Getting a GVHD diagnosis and beginning treatment early may improve your outlook and quality of life.

Talk to your healthcare team to learn more about your outlook with GVHD.

Talk With Others Who Understand

On myGVHDteam, the site for those with GVHD and their loved ones, people come together to ask questions, give advice, and share their stories with others who understand life with GVHD.

Have you or a loved one been diagnosed with GVHD? What questions do you have about GVHD? Share your experience in the comments below.