Listen to Byung-soo Kim, Professor of Hematology at Eunpyeong St. Mary’s Hospital, The Catholic University of Korea
Blood disease refers to a disease in which abnormal cells grow excessively in the factory that makes blood (bone marrow), the components that make up blood (leukocytes, red blood cells, platelets) or the lymphatic system that makes up the immune system. There are more than 100 types of cancer, including leukemia, malignant lymphoma, and multiple myeloma.
Hematopoietic stem cells, meaning ‘mother cells that produce blood’, are produced in the bone marrow. Hematopoietic stem cells generated from bone marrow make various immune cells including red blood cells, white blood cells, and platelets through growth and proliferation. If there is a problem with this process, anemia (decrease in red blood cells), bleeding (decrease in platelets), infection (decrease in white blood cells), etc. evidence appears.
◇ What is hematopoietic stem cell transplantation?
Hematopoietic stem cells are removed from the body and healthy cells are transplanted. In blood disease treatment, in general, the induction of remission, which removes cancer cells in the body, is first performed through chemotherapy or radiation therapy.
Afterwards, hematopoietic stem cells are additionally transplanted for the purpose of increasing the cure rate or preventing recurrence when the patient has improved. Hematopoietic stem cell transplantation is the last step toward a cure for blood diseases that are considered incurable.
Hematopoietic stem cell transplantation is largely divided into autologous transplantation, in which the patient’s own cells are transplanted, and allogeneic transplantation, in which hematopoietic stem cells are transplanted from others. The time and method of transplantation are different for each disease. Patients under the age of 70 who have maintained adequate physical strength and physical function are the first priority for transplantation because they have to go through difficult processes such as cell collection and administration of strong anticancer drugs in the preparation process for transplantation.
Diseases subject to autologous transplantation include △multiple myeloma and T-cell lymphoma (if improved after first-line anticancer treatment, relapsed and improved with second-line anticancer therapy) △B-cell lymphoma (stage 3-4 at diagnosis, after first-line anticancer treatment) In case of improvement, in case of recurrence and improvement after 2nd chemotherapy) △Hodgkin’s lymphoma (in case of recurrence and improvement after 2nd chemotherapy), acute leukemia is determined by medical staff according to the patient’s condition.
Autologous hematopoietic stem cell transplantation consists of △mobilization of hematopoietic stem cells △collection △processing/freezing/storage △pre-patient treatment therapy (administration of anticancer drugs) △hematopoietic stem cell transplantation △engraftment.
Hematopoietic stem cells in the bone marrow are transferred to the blood by administering medicine to the patient, collected, frozen, and transplanted back to the patient who has undergone chemotherapy. While the patient is undergoing chemotherapy, hematopoietic stem cells are stored in liquid nitrogen at minus 196 degrees Celsius and thawed next to the patient on the day of transplantation.
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* Hematopoietic stem cell mobilization: The process of preparing for collection by transferring hematopoietic stem cells from the patient’s bone marrow to peripheral blood using anticancer drugs and promoters. It takes 7 to 14 days depending on the underlying disease.
*Collection: After inserting a catheter above the patient’s clavicle, connect the catheter and collection equipment to isolate only hematopoietic stem cells. Collect cells for about 4 hours a day, and if it is not enough, do it for 2 to 3 days. Discharge the patient after completion of collection.
*Processing∙Freezing∙Storage: Remove unnecessary components, freeze hematopoietic stem cells, and store in liquid nitrogen until the day of transplantation.
* Pre-patient treatment regimen: Patients who take a break for a certain period of time after collection are hospitalized again. Administering strong anticancer drugs to remove residual cancer cells.
Since autologous hematopoietic stem cell transplantation originally transplants one’s own cells, side effects are not significant. However, during the engraftment process, nausea, mucositis, and diarrhea may occur for 1 to 2 weeks, and antibiotics and blood transfusions are necessary because they are vulnerable to infection and bleeding due to a decrease in white blood cells and platelets.
Usually, 10 to 17 days after transplantation, the patient enters a recovery period due to cell engraftment, and can be discharged when symptoms such as fever, diarrhea, and nausea improve. If you have symptoms such as unexplained pain, fever, or bleeding after discharge, you should visit the hospital quickly.
In addition, it takes a long time to fully recover, so regular life, steady exercise, and balanced nutrition are essential.
Allogeneic transplantation, in which other people’s cells are transplanted, has subdivided transplant types and procedures, and life management after transplantation is more difficult. This is because there is a high probability of immune complications such as transplant rejection as transplantation of hematopoietic stem cells from others after completely removing one’s own hematopoietic and immune systems. However, it has the advantage of having a low recurrence rate in terms of completely regenerating the immune system.
First of all, allotransplantation is possible for patients who have a blood or unrelated donor with a matching transgene, a family donor with a half-match (50%) transgene, or a patient who has available umbilical cord blood for transplantation.
When it is determined that allogeneic hematopoietic stem cell transplantation is necessary, the first thing to check is whether there is a patient’s siblings who have the same transplant gene, because hematopoietic stem cell transplantation between siblings shows the best treatment results.
Recently, due to the rapid development of transplant technology, semi-congruent transplants between siblings are being actively performed depending on the patient’s condition.
Diseases eligible for allogeneic transplantation include △newly diagnosed acute leukemia (completely improved hematologically) △recurrent acute leukemia (improved after 2nd chemotherapy) △high-risk myelodysplastic syndrome △severe aplastic anemia and recurrent malignancy Lymphoma and multiple myeloma can be considered according to the judgment of the medical staff.
Provided by Eunpyeong St. Mary’s Hospital
If an allogeneic transplant donor is secured, preparations begin in earnest. The donor is tested one month before the transplant. Donors limit unnecessary medications while preparing for transplant.
In the case of patients, cancer cells are removed with chemotherapy or radiation therapy. In addition, it is important to implement sufficient immunosuppression so that hematopoietic stem cells to be transplanted can grow well without rejection.
Hematopoietic stem cell collection in allogeneic transplantation is divided into a method of collecting hematopoietic stem cells from blood and a method of collecting bone marrow from pelvic bones. The period from transplantation to engraftment is 13 to 30 days for blood collection, 17 to 24 days for bone marrow collection, and 21 to 28 days for cord blood transplantation.
Hematopoietic stem cells collected for allogeneic transplantation are not frozen, unlike autologous transplantation, and are directly transplanted to the patient after undergoing a slight processing step.
The three most common complications after allogeneic hematopoietic stem cell transplantation are infection, graft-versus-host disease, and visceral organ damage. Since it takes a considerable amount of time for the patient to recover immunity after transplantation, the patient becomes vulnerable to various infections.
Bacterial and fungal infections before engraftment, and viral infections after engraftment become a problem. This is why you should pay attention to maintaining a clean living environment after transplantation and pay special attention to hygiene management when eating food.
Since the immune system formed in the patient after transplantation belongs to another person, it can recognize the patient’s normal cells as that of another person and trigger an immune response. Graft-versus-host disease is when this response is not well controlled and normal tissue is damaged.
The heart, lungs, liver, and kidneys may be damaged due to high-dose anticancer drugs, whole-body radiation therapy, and immunosuppressive drugs experienced in the process of preparing for transplantation.
Therefore, it is important to visit the hospital every week or every other week for up to 100 days after allogeneic transplantation and carefully observe the occurrence of complications. Immunosuppressant doses should be adjusted according to signs of graft-versus-host disease. After that, regular inspections are conducted every 2 to 4 weeks for up to one year.
If there are no signs of complications, some outdoor activity is possible, but it is better to avoid long-distance travel. If you have plans to return to work, it’s a good idea to talk to your health care provider to make a plan.
In addition, proper nutrition management is essential for recovery, so if you continue to lose weight or find it difficult to recover your food intake, you need professional nutrition counseling.
Byung-Soo Kim Professor of Hematology at Eunpyeong St. Mary’s Hospital, The Catholic University of Korea
Daeik Kwon medical journalist dkwon@hankookilbo.com
