WHAT IS STEM CELL?
Being the progenitors of all body cells and having the capacity for rapid regeneration, stem cells instill hope in treatment of many diseases, including certain cancers. The platelets that coagulate the blood, the red blood cells that transport oxygen throughout the body and the white blood cells that undertake the body defense are produced in the bone marrow – the tissue located in flat bones of the human body, especially in pelvic bone and sternum– throughout the life span. The blood stem cells found in the bone marrow are not fully mature; they differentiate into white blood cells, red blood cells and platelets based on various stimulations depending on the need of the body.
- Red blood cells distribute oxygen to the entire body.
- White blood cells combat infection.
- Platelets stop bleeding.
The stem cells used for the bone marrow transplantation are harvested in two ways. In the first approach, the bone marrow is aspirated from the hip bone under anesthesia in the operating theater. Depending on the amount collected, the blood counts may temporarily decreased, but they restore to normal ranges within 1 to 2 weeks and they are not irreversible.
In the second method, the donor will be given a certain drug in the morning and at night in order to stimulate movement of the stem cells from the bone marrow into the bloodstream and they are collected from a vessel using a specific device without administering anesthesia. No adverse effect of this stem cell mobilization drug on the donor can be demonstrated to date.
No irreversible postoperative harm occurred in donors following thousands of transplantations, wherein these medicines have been globally used for approximately 20 years. White cell count increases while the medicine is administered and for several days after the procedure is completed, but they are restored to normal ranges thereafter. Bone ache can develop on the days the medicines are administered, but it can be managed with simple pain killers.
Blood type compatibility is not required for the bone marrow donor. If the blood type does not match, the product is treated in certain processes before it is infused to the patient. Following a successful transplantation, the blood type of the recipient will transform into the blood type of the donor.
Full tissue match between the recipient and the donor is a desirable factor for the bone marrow transplantation. For the transplantation, the primary hematologist informs the patient and obtains consent before the stem cells are transplanted from a non-full matching donor. Although there are inter-patient variations in terms of risks and expected benefits, it is possible to transplant the bone marrow of a non-full matching donor.
