Guest: Dr. Michelle Hudspeth
Host: Dr. Linda Austin
Dr. Linda Austin: I am Dr. Linda Austin. I am interviewing Dr. Michelle Hudspeth who is director of the Pediatric Blood and Marrow Transplant program here at the Medical University of South Carolina in the Children’s Hospital. Dr. Hudspeth, I know one of your areas of great interest is bone marrow transplant. Can you begin to describe, if you could, just what is a bone marrow transplant?
Dr. Michelle Hudspeth: Of course and we are very happy to be here at MUSC, to be able to offer this therapy to patients in South Carolina. We are the only pediatric transplant program in the state. We take care of patients, actually, from all over the Southeast. So, we are happy that children in South Carolina do not have to travel out of state to receive excellent care when they need it. So, bone marrow transplant is sort of a catchall word that we also generally say to also mean cord blood transplantation, stem cell transplantation. All of those names relatively mean the same thing.
This is a way of replacing the blood cells in a patient’s body and this can be done for a number of reasons. Stem cell transplantation or bone marrow transplantation can be done to treat certain types of cancer, most commonly cancers of the blood stream like leukemia. It can also be used to treat solid cancers, tumors of the body. It can also be used to treat non-cancerous conditions, so, children with sickle cell disease, children with metabolic disorders such as adrenal leukodystrophy, severe immunodeficiencies, or aplastic anemia. So, we take care of a number of patients who have both cancer and non-cancer conditions.
Dr. Linda Austin: Let’s walk through the procedure and lets start with whichever of those numerous procedures is the most common. Which one do you do the most of?
Dr. Michelle Hudspeth: We do the most of something called an autologous transplant. This is a fancy word that just means that we give you cells back from your own body. So, auto means self. This is commonly used for a cancer that is not in the blood stream. This is what we typically treat high risk cancers that are solid tumors, such as neuroblastoma, brain tumors, other solid tumors of childhood. What this really allows us to do is, ahead of time we collect stem cells from the patients and we freeze those.
Dr. Linda Austin. Just to back up, those stem cells now are in the bone marrow? Is that right?
Dr. Michelle Hudspeth: They typically do live in the bone marrow. But, we actually have ways of administering a medication and collecting those, that actually we do not even have to go into the patient’s bone marrow. The patients have a special type of IV catheter placed and are hooked up to a special machine that processes their blood and is able to separate out the stem cells from the other components of the blood. So, it actually overall is a very painless procedure for the patient. Then, we store those cells for use at a future time.
What that allows us to do is, typically, we are limited in the doses of chemotherapy we can give to someone because there are toxicities related to the chemotherapy, side effects. The most common side effects of chemotherapies are that we make the blood counts go down. There are three, sort of, main blood cells. We have white blood cells that help you fight infection, red blood cells that give you energy, and platelets that help you clot. In general, because chemotherapy is attacking rapidly dividing cells, those are rapidly dividing cells, so, chemotherapy makes us go down. At the doses we usually administer to people, after a period of time, those counts will come back up. That obviously limits the doses of chemotherapy we can normally give.
What advantage we have by storing a patient’s cells, this allows us to escalate and increase those doses of chemotherapy and give them what we call high-dose therapy, therapy that if we did not have these cells to give back, we would not expect their bone marrow to recover and they would not be able to make cells again. But, because we have these cells stored, we administer these to the patient and their blood counts will recover. So, it basically is a way of getting around the dose limitations of chemotherapy and giving high doses of chemotherapy to the patients and ultimately improving their outcome.
Dr. Linda Austin: How long does that process take?
Dr. Michelle Hudspeth: It is variable. Depending on the disease, we give different combinations of this high-dose chemotherapy. It is generally given over about a week’s time. The actual infusion of these frozen cells is actually very easy. If you walked in the room, you would simply think a patient was getting a blood transfusion. A lot of times people have the misconception that we are putting needles into the hip bones and directly injecting the cells into the bone marrows and that is not so. The cells are actually just administered through an IV line. What is quite nice is these stem cells, I like to call them sort of like they have their own GPS devices, and we do not have to put them back in the bone marrow. The cells know how to get back to where they belong, and they go there and they grow and divide and repopulate the bone marrow. So, typically, that process of going from wiping out the bone marrow then starting to see recovery takes anywhere from one to two weeks, when a patient is getting her own cells back. In general, most patients are in the hospital for a total of three to four weeks during that time of recovering from intense chemotherapy and having some recovery of their cells.
Dr. Linda Austin: I understand they have to be in isolation during that time because they are susceptible to infection. Am I right about that?
Dr. Michelle Hudspeth: They are susceptible to infection, for sure. We are very blessed here at MUSC on our oncology unit. We have a bank of seven brand new bone marrow transplantation rooms that are specially made just for transplant patients. These rooms are hepa filtered and positive pressure, meaning that they blow air out of the rooms so that anything that might be in the hallways is not allowed to come into the patient. The hepa filters help filter out particles in the air that can contribute to infection. Other than that, there is often a misconception about this too. Other than that, a lot of it is just plain old common sense, very strict hand washing, we do not allow any sick folks to visit the patients while they are in the hospital. But, it is not routine practice, you know, for us to gown and glove to go in and see these patients because it has actually been shown that does not make a difference. So, very strict hand washing is very important and then being in these special rooms during that time.
Dr. Linda Austin: What is the age range of the children who get this procedure?
Dr. Michelle Hudspeth: We have treated patients all the way from infancy up to age 21, and then the adults pick up from there.
Dr. Linda Austin: Dr. Hudspeth, thank you so much for talking with us today.
Dr. Michelle Hudspeth: Thank you very much.
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