All about stem cells

What are stem cells?
Adult stem cells are unspecialized cells that can renew themselves through cell division. When stem cells divide the new cells may either remain stem cells or they may become other blood cells, such as red and white blood cells or platelets.

The stem cells can be found in the bone marrow, especially in the iliac crest, the breast bone and the ribs. There they mature. The mature cells leave the bone marrow and pass over into the bloodstream, where they fulfill their tasks. The blood cells have a limited life span. They die after few days (platelets) or few months (red blood cells). Therefore these blood cells are constantly being reproduced in the needed amount.

This reproduction process may be malfunctioning: Mostly immature cells form and are incapable of fulfilling their tasks. This is referred to as leukemia or cancer of the blood.

Fighting leukemia with transplantation
The malignant disease causes the defective development of blood cells in the hollow bones. In such severe diseases the transplantation of healthy stem cells of an unrelated donor is often the only chance of survival for the patient.

During the transplantation the patient receives new full functioning stem cells. The blood cells and the immune system of the recipient can develop out of these stem cells.

Stem cell sources
There are two methods to donate stem cells. The stem cells my either be collected from the bone marrow or from the peripheral blood.

When the stem cell are collected from the peripheral blood the administration of G-CSF ( a natural protein) causes the reproduction of great quantities of stem cells, which pass over into the bloodstream. Once the cells pass over into the bloodstream the stem cell product can be collected with a so-called cell separator.

How to donate peripheral blood stem cells (PBSC)
Stem cells can be collected from the donor’s peripheral blood.

The donor is given small injections of a natural protein G-CSF (a natural protein) under the skin. The administration takes place every morning and evening for several days, a hospital stay is not necessary. This medication causes the overproduction of stem cells in the bone marrow and the release of the stem cells into the circulating blood. The amount of white blood cells is elevated for a short term. This can cause side effects such as headache and body aches, similar to those usually associated with the flu. These effects disappear shortly after collection. After 5 days the stem cells will be „washed out“(centrifuged) of the blood by Leukapheresis. The donation process takes approximately four-five hours. The blood is removed through a needle from the donor’s arm and is passed through the cell separator which collects the needed blood-forming cells. The remaining blood is returned to the donor through a needle in the other arm. A hospital stay is unnecessary, but in some cases a second collection may take place on the following day. The donor’s stem cell count is back to normal within four to six weeks.