Graft Versus Host Disease in Haematopoietic Stem Cell Transplantation & Cellular Therapy

After you receive stem cells from another person (donor), the donor’s stem cells will grow and function as your new immune system. The new immune system (graft) may see your own body (host) as foreign and attack your body tissues and organs, resulting in diarrhea, liver injury, lung injury and severe skin reactions, which may be difficult to manage and life-threatening.

Anti-rejection medicines or immunosuppressants such as cyclosporine, tacrolimus and mycophenolate may be given to reduce the activation of new immune cells, and thus preventing them from attacking your body tissues and organs or may be given to treat GVHD. Immunosuppressants can start as early as 3 days before stem cell infusion and continue for several months after the transplant. The choice of medicine, dosage and duration of immunosuppressants will depend on the type of transplant as well as the severity and duration of GVHD.

Initially you may be given immunosuppressants via injections. Subsequently, they will be changed to oral medicines when you can eat and drink normally. Inform your doctor and pharmacist if you have difficulty swallowing these medicines, do not cut, crush or chew the tablet, or open the capsule.

Try to take your medicine at the same time each day. If you miss a dose and remember it within 6 hours, for example Cyclosporine and Tacrolimus, take the missed dose as soon as you remember. However, if it is almost time for the next dose, skip the missed dose, go back to your regular dosing schedule, and inform your doctor during your next appointment. Do not stop taking this medicine or change the amount that you are taking without informing your doctor.

Infection risk 

Immunosuppressants can make you fall sick more easily. Thus, it is important to take the medicines for preventing infections as advised by your doctor. You should see a doctor immediately if you are feeling unwell due to an infection. Also, you should not receive any other vaccinations without checking with your doctor because immunosuppressants can weaken your immune system, so the vaccination may not be effective and there is a risk of infection with “live vaccines”.

Refer to the document on “Preventing Infections in Haematopoietic Stem Cell Transplantation & Cellular Therapy” for more information. 

Potential side effects 

While immunosuppressants are important in preventing Graft Versus Host Disease, they too have their potential side effects that you would need to look out for. 

1.    Liver injury, which can appear as yellowing of skin and whites of the eyes, bruising, easy bleeding, pale stool, confusion and dark urine etc.

2.    Kidney injury which can appear as less urine output, swelling of feet, ankles and hands, shortness of breath, confusion etc.

3.    Cyclosporine and Tacrolimus can affect magnesium and potassium level in your body.

4.    Cyclosporine and Tacrolimus can cause high blood pressure, high blood sugar and high cholesterol.

5.    Allergic reactions such as itching, rashes or swelling of eyes. Stop the medicine and see a doctor immediately. 

Inform your doctor of these side effects and see a doctor as soon as possible if you feel that the side effect is serious. It is important for you to attend follow-up appointments, take blood tests (for example Cyclosporine or Tacrolimus drug level) as advised and follow the doctor’s advice on how to take your medicines to reduce the risk of with these potential side effects.

On the day of blood test to check Cyclosporine or Tacrolimus levels, do not take the medicine in the morning before the blood test. This is because the doctor wants to check the medicine level in your blood so that they can adjust the dose of Cyclosporine or Tacrolimus, for the drug to be effective and safe. You may bring the medicine to the hospital to take after the blood has been taken. It is important to come for your medical appointments and take your medicines as per doctor’s advice.

Some medicines, supplements and food can increase or decrease the effect of immunosuppressants. As such, it is important to inform your doctor and pharmacist about all your medicines and supplements and check with them before you start any new medicines and supplements or make any change in your diet. Avoid taking grapefruit, pomelo, pomegranate, Seville oranges and starfruit as well as their juices, as these fruits can affect the medicine level in your body.