A total of 232 autologous and allogeneic stem cell transplants of adults and children were performed at the Center for Translational Medicine and Cell Therapy at "St. Marina" University hospital in Varna.
The transplantation program for stem cells for children and adults at "St. Marina" University Hospital in Varna is unique for Bulgaria, as it provides a high level of multidisciplinary patient care and technological support. The medical staff of physicians, nurses, orderlies, health assistants and psychologists provide high-quality medical service with excellent results. Transplantation physicians have proven experience gained from their specializations in Europe and the USA. Nurses have received specialized training to work with transplant patients. The high level of expertise, modern diagnostic (laboratory and imaging) methods and innovative thinking define the transplant department at "St. Marina" University hospital as preferred by patients from all over the country.
A personalized, multidisciplinary approach is used in preparation for, during and after transplantation, ensuring continuity of care for transplant patients. We talk about the possibilities for patients with stem cell transplantation with Dr. Yavor Petrov, assistant physician at Medical University of Varna and head of the transplantation department at the Clinic for Hematology at "St. Marina" University hospital in Varna.
What are stem cells?
Stem cells are a unique population of cells that reside in the bone marrow, have the ability to divide and transform into different types of cells (white blood cells, red blood cells and platelets), thus maintaining a balance in proper functioning of the human organism. Currently, stem cell transplantation is the only option for a complete cure for patients with hematological, oncological and autoimmune diseases, in which standard treatment does not show good results.
What are the sources of stem cells?
Sources of stem cells can be peripheral blood, bone marrow and umbilical cord/placenta. On a global scale, the extraction of stem cells from the blood of patients and healthy donors is the most widely advocated, due to the faster recovery of blood parameters after transplantation, the faster recovery of the immune system and the relatively lower rate of complications related to transplantation technology. Extracting the stem cells from the blood is done through a procedure called apheresis or cytapheresis. The patient/healthy donor is pre-stimulated with drugs (growth factors) that help the stem cells to become abundant in the bone marrow and be released into the circulation (usually it takes about 5 days) and then, through a special apparatus, they are collected, processed and frozen or transfused immediately (in cases where stem cells are used for allogeneic transplantation).
However, in some cases, the preferred source of stem cells is the bone marrow (e.g. in children, certain diseases such as aplastic anemia, etc.) because, in addition to stem cells, other cells necessary for the proper functioning of the immune system are transfused . Harvesting bone marrow stem cells is done in an operating room, under general anesthesia, and the bone marrow is extracted using a trocar, a special needle through which punctures and aspirations are made in the pelvic bone area. The amount required to perform the transplant depends on the type of disease, the immunological compatibility between the donor and the recipient (in cases where an allogeneic transplant is performed), the body weight of the donor and the recipient. After the collection procedure, the bone marrow is fully restored within a few weeks.
The umbilical cord and placenta after birth contain a large amount of stem cells that could be used for transplantation. After obtaining consent from the parents, immediately after birth, medical professionals extract the stem cells, freeze them and store them in so-called "umbilical cord stem cell banks" for a long period of time. Umbilical cord/placental stem cells are a preferred choice for transplantation in very young children or in adult patients with very low body weight.
How many types of stem cell transplants are there?
There are two types of stem cell transplantation: autologous and allogeneic.
In autologous transplantation, own stem cells are used after their preliminary collection. It is suitable for patients with non-Hodgkin's lymphomas, Hodgkin's disease, multiple myeloma, oncological diseases such as neuroblastoma, germ cell tumors, sarcomas, neurological diseases such as multiple sclerosis, gastro-intestinal diseases such as Crohn's disease and ulcerative colitis.
Before the transplant, patients undergo aggressive chemotherapy, which destroys the bone marrow and residual cancer cells in the patients, after which the stem cells, which were previously collected and frozen, are thawed and transfused. In this way, a faster recovery of patients after the received high dose of chemotherapy is ensured.
In an allogeneic transplant, stem cells are used from a donor, which can be a related, unrelated, or partially compatible related donor. Allogeneic transplantation is suitable for the treatment of patients with various types of leukemia, some lymphomas, and congenital and acquired immunodeficiency syndromes. Before the transplant, patients undergo high-dose chemotherapy, which provides a place for the donor cells to take hold and reduces the risk of their rejection. After their transfusion, the stem cells from the peripheral blood enter the bone marrow of the recipients, where they settle and begin to perform their biological functions. When some of the transplanted stem cells become lymphocytes (a type of white blood cell, donor T-lymphocytes), they recognize the cancer cells and destroy them – a graft-versus-tumor/leukemia effect. This is done with the help of the human leukocyte system (HLA - the system), through which the recognition between "own" and "foreign" takes place. The whole transplantation philosophy of organs, tissues and cells is based on the identity between the HLA antigens between donor and recipient. In the context of stem cell transplantation, the greater the compatibility between donor and recipient, the fewer complications that can occur.
What is a stem cell transplantation?
Stem cell transplantation is a multi-step process that takes into account the individual characteristics of patients suitable for this type of treatment (eg type of disease, age of the patient, co-morbidities, type of donor, etc.). Before entering the transplant department, patients undergo thorough examinations by various medical specialists who check how the various organs and systems of the recipients are functioning, blood group tests and virological tests are performed to determine the risk of complications in the early period after the transplant. Due to the fact that the compatibility between the donor and the recipient can never be perfect, it is necessary to prepare the recipients in advance so that the graft can be accepted in the best conditions.
This is another implemented large-scale project of the Varna University Hospital, thanks to which millions of Bulgarian levs are saved for the Bulgarian taxpayer and it is not necessary for the patient to collect funds for treatment abroad.
More information can be found at the following links:
www.svetamarina.com - official website of "St. Marina" University hospital in Varna;
www.svetamarina.com/index.php?go=c&id=32 - Clinic of Hematology
www.svetamarina.com/index.php?go=c&id=42 - Clinic of pediatric clinical hematology and oncology.
