The haploidentical donors are those donors whose (Human leukocyte antigen) HLA matches with the patient. HLA is a protein that is found on all cells of our body. This protein in our immune system tells the difference between our own cells and foreign cells. The closer the HLA match between a donor and recipient, the higher are the chances of a successful transplant. If the HLA match is not close enough, the donor’s immune system, which contains the donated stem cells, recognizes the mismatch in HLA and thus tries to attack the recipient’s tissues. This process is known as graft versus host disease (GVHD). A haploidentical related donor is usually a 50% match to the patient and it can be his/her parents, sibling or child. The most common advantage of getting a haploidentical transplant is that it increases the chances of finding a donor as nearly everyone has at least one haploidentical relative present in the family. The donor can usually be asked to donate stem cells much more quickly and at any time because after the transplant the recipient may require more of the HLA proteins from the donor and in case the donor lives in another state or country he must donate in advance, so that the transplant can be done in a more timely way. Such transplant involves a higher risk than when done with a 100% match with a relative.
Matched Unrelated Donors (MUD)
A matched unrelated donor is a donor who is not a blood relative of the recipient but has a complete human leukocyte antigens (HLA) match to the patient. The process involved here is same as the haploidentical donors, the only major difference here is that the donor is not a family member of the recipient. A matched unrelated donor has a higher percentage of matches of HLA proteins with the recipient but these types of donors are very hard to find. The cost of the operations also increases due to the factor that the donor is not related to the patient. Several tests are conducted with different persons for finding the right match and there is also a high risk involved with the matched unrelated donor. The long term side effects include increased risk of infection, fatigue and graft versus host disease (GvHD)
Graft Versus Host Disease (GVHD)
Graft versus host disease (GVHD) is an immune-related disease resulting from a complex interaction between the donor and recipient’s immunity. It is divided into two parts depending upon its duration: Acute and Chronic.
Acute GVHD describes a different syndrome of dermatitis, hepatitis, and enteritis developing within 100 days after the (Human leukocyte antigen) HLA transplantation. Chronic GVHD describes a more contrasting syndrome developing after 100 days of the transplant. In addition to (Human leukocyte antigen) HLA, procedures associated with high risk of GVHD include transplantation of organs in human body and blood transfusions from an external donor.
Acute GvHD might occur once the donor’s cells have been transferred in the recipient. It might develop in your skin, liver, eyes, or gastrointestinal tract, and symptoms might appear within weeks after your transplant
Signs and symptoms of Acute GVHD
An itching or painful rash (5-47 days)
Diarrhea, intestinal bleeding, cramping abdominal pain, and ileus
It may or may not be an extension of acute GVHD. It may also occur in patients who never have clinical evidence of acute GVHD, due to no regular checkups or it may emerge after a short interval after acute GVHD resolves.
Signs and symptoms of Chronic GVHD
Burning, irritation, photophobia, and pain from lack of tear secretion
Mouth dryness, sensitivity to acidic or spicy foods, dysphagia, odynophagia, and insidious weight loss
Obstructive lung disease, with symptoms of wheezing, dyspnea, and chronic cough
Generalized or focal weakness, neuropathic pain, vision loss, muscle cramps, myalgia
Joints – Arthralgia, arthritis
Your BMT doctor can make the diagnosis of a GvHD during a physical exam by observing certain symptoms and/or by evaluating the results of site biopsies and lab values.
In the case of chronic graft versus host disease (cGvHD), some symptoms might be very vague, which might make the diagnosis possible only after other causes are treated.