Urszula Jaworska Foundation

Jacek Toporski: Bone marrow liquid fills the cavities of bones. This is a factory that produces blood. Bone marrow is the soft, spongy material found in the center of bones. Its principal function is the formation of blood cells, mainly red blood cells, white blood cells and platelets. When withdrawn from the bone cavity, it looks like blood. Circulating red blood cells (RBCs, erythrocytes) carry oxygen from the lungs to all tissues. White blood cells (WBCs, leukocytes) are part of the immune system are responsible for fighting infections. Platelets (thrombocytes) are cells that help prevent bleeding.

Jacek Toporski: You must be between the ages of 18 and 60 and in general good health. And you must be ready for marrow donation. In general the qualification for marrow donation is the same like for the blood donation. If you fulfill such a criteria you are asked to contact The Bone Marrow Donor Registry-Urszula Jaworska Foundation. You will be given additional information. Once the blood tests will be completed your data will be recorded in the Registry database. When a patient matching your data will be identified you will be asked for the donation. The transplantation of your marrow may save someone's life.

Jacek Toporski: Hematopoietic cells are responsible for production of erythrocytes, leukocytes and platelets. Apart from blood production they have unique ability of self-renewal. In fact, bone marrow transplantation means the transplantation of hematopoietic cells. The bone marrow is the standard source of hematopoietic cells for transplantation. It was shown that those cells are also present in the peripheral blood. This observation made possible the transplantation of hematopoietic cells collected from peripheral blood.

Bone marrow is harvested under general or regional anesthesia. The marrow is removed with a single use bone marrow aspiration needle from the back of pelvic bone. Usually, 3 to 4 incisions are made in the pelvic area on both sides. Total volume of harvested marrow depends upon situation, particularly recipient's body weight is important. However, donor body weight and marrow cellularity should be considered. The procedure lasts between 60 and 90 minutes. Usually, 1000 ml of marrow should be harvested (with a range from 500 to 1500 ml). The marrow is injected into a special bag containing anticoagulant. After completion of harvesting the marrow is filtered. Finally additional processing could be performed if necessary.
It is standard procedure that 10 -14 days before scheduled bone marrow donation the donor is admitted to the blood bank. It is necessary to collect donor's own blood, which will be retransfused directly after bone marrow harvesting.
Marrow is regenerating and is replaced within several weeks after donation.

Collection of hematopoietic cells from peripheral blood

In that case so called mobilization of hematopoietic cells into peripheral blood is necessary. For this purpose the donor receives one or two injections of Filgrastim (Neupogen) per day for four to five days. The hematopoietic cells are harvested from the blood through a process called apheresis with the use of cell separator. This is performed in a specialized center. During apheresis, blood is removed through a needle placed in a vein in one arm mixed with anticoagulant solution and passed through an apheresis machine that separates out the hematopoietic cells. The remaining blood, without hematopoietic cells, is returned back through a needle placed in a vein in the other arm. This is a procedure technically similar to a standard collection of platelets, routinely performed in blood banks. The difference is what cells are kept in the cell separator. Usually it is necessary to perform tow aphereses during two consecutive days.

Is the donation of hematopoietic cells a safe procedure, and what are the possible complications?

a)Bone marrow collection
The possible risk of bone marrow donation results from general anesthesia, infection at or near the aspiration site, and bone/nerve/ tissue damage at the aspiration site. The most common side effects resulting from the marrow collection are localized pain and general fatigue. Side effects from anesthesia include sore throat, nausea, vomiting and headaches. Bone/nerve/tissue damage could result from the procedure itself. Most complications are related to pain/numbness and/or swelling (typically originating near the marrow aspiration site), but there may also be temporary cardiovascular complications, temporary excessive fatigue/weakness or temporary urinary retention. There is an approximately 2% chance that there would be a serious (intense or prolonged) complication, and a less than 1% chance that the complication would last longer than 3 months. No donor (National Marrow Donor Program report) has ever died. Approximately 8000 bone marrow collections have been recorded by the NMDP since 1987. Most donors feel back to normal in about two to three weeks.

b)Collection of hematopoietic cells from the peripheral blood.
- A growth factor medication called Filgrastim (Neupogen) is administered to increase the number of circulating hematopoietic cells. It is usually given subcutaneously once or twice daily for 4-6 consecutive days. As the result of Filgrastim administration a substantially higher number of white blood cells is observed. Bone pain, muscle pain, nausea, insomnia and fatigue while receiving Filgrastim may be experienced. Bone pain and headaches have been the most frequently reported symptoms. These symptoms disappear shortly after the stem cell collection is completed or could be easily controlled pharmacologically, if necessary. Filgrastim is widely used when patients underwent chemo/radiotherapy to increase the number of granulocytes. Hematopoietic cell collection is similar to a routine platelet collection at a blood bank, a well known standard procedure. Several studies evaluated donors of hematopoietic cells from peripheral blood one to five years after donation and revealed no adverse effects.
- During the apheresis some donors experience a tingling feeling caused by the anticoagulant used to prevent cells from clotting. These symptoms are caused by the low blood calcium concentration resulting from anticoagulant administration and are easily controlled by calcium substitution. Platelet counts may also be lowered temporarily.

What volume of the bone marrow should be harvested?

Jacek Toporski: Usually, 15 to 25 ml of the marrow calculated per donor body weight is harvested. The final volume of the marrow depends on the donor body weight, calculated optimal number of hematopoietic cells, which should be transplanted and the need of further bone marrow processing.
i) The optimal number of hematopoietic cells is estimated at 300000000 bone marrow cells per kg of recipient body weight. The actual number of collected cells is checked during bone marrow harvesting. The final bone marrow volume to be harvested depends upon its cellularity and recipients body weight.
i) On the other hand it is not allowed to harvest more than 25 ml of the bone marrow per donor's body weight. This is the upper limit.
ii) When additional bone marrow processing is necessary (e.g. in the case of blood group incompatibility) it is advised to harvest more marrow, but never more than 25 ml per kg of donor's body weight.

The collection of hematopoietic cells from the peripheral blood may be considered when the donor is small and recipient is big or when blood group incompatibility is present. Using the peripheral blood as hematopoietic cells source it is easy to collect sufficient number of cells. Usually, one or two aphereses have to be performed.

How donor after hematopoietic cells donation regenerate?

Jacek Toporski: The donor is usually admitted to the hospital in the morning on the procedure day and sometimes spends the night there. Most donors are back to their usual routine within a few days. Some may take two or three weeks before they feel completely recovered. Donors receive usually general anesthesia. The typical donation procedure lasts from 60-90 minutes. The marrow constantly regenerates itself, and the donor's system will replace the extracted marrow within 2-3 weeks.
The collection of hematopoietic cells is usually performed in the outpatient clinic. The typical apheresis lasts from 3-4 hours. Within few days the number of white blood cells (elevated after Filgrastim administration) will normalize. Also platelet number, which is low after apheresis will reach the normal value within few days.

Does the donation of hematopoietic cells influence donor's normal activity?

Jacek Toporski: Usually, the donor should be monitored several times after the donation in terms of hemoglobin level, white blood cell count and platelet count. Enteral preparation of iron and vitamins might be indicated. There are no particular limitations of donor's activity.