BIOPHYLAXIS
Glossary
Acknowledged International Organizations for the control and setting standards
FACT-NETCORD
Fact (Foundation for the Accreditation of Cellular Therapy) was founded in 1996 with the scope to establish and promote standard quality for medical and laboratory practices in the transplantation of prodroma haematopoetic stells and other cellular therapies.

Netcord is an Institution with member cord blood stem cell banks, established as the worldwide network for request of cord blood stem cell transplants. It develops and establishes the worldwide standards and is also a quality control system in the field of cord blood. The Fact-Netcord standards cover all the stages from the collection, processing, storage and release of cord blood stem cells.

What is AABB?
AABB (American Association of Blood Banks) is an international association which represents individuals and institutions which deal with activities related to transplants and cell therapies. Since 1974, it is an association which deals with the creation of very high standards, accreditation, education, etc.

What is GVHD (Graft versus Host Disease)?
This is also called "Reaction to Transplant against the Recipient" and is the most common complication which develops from transplants. It is related to the recognition of the transplant as a foreign body by the active cells of the immune system which "attack" the transplant and as a result, reject it.

What is HLA (Human Leukocyte Antigen) compatibility antigen and how does it affect transplants?
HLA is the critical compatibility of the human body or differently, the systemic leukocyte antigens of the human body. The immune system uses the antigens in order to recognize if something is foreign to the human body. In the case where a body and or cell is recognized as foreign, it is considered an intruder and the autoimmune system is activated in order to reject it.

As a result, these antigens set the compatibility (ability to accept a transplant) between donor and recipient of the transplant. For transplants, 6 primary genetic types are of interest: HLA-A, HLA-B and HLA-C, DR, DQ, and DP.

Ideally, the compatibility should be 100% (6 out of 6) so that the risk of rejection is eliminated. This is necessary in autologous transplants and in transplants between identical twins.

What is cell expansion?
Cell expansion is the process by which we can increase the number of cells without activating other biological processes as for example, differentiation. Despite the fact that the worldwide scientific community is especially optimistic for this possible future possibility, today expansion of stem cells is not yet clinically accepted.

What is cell vitality?
In a cell population in which cells are isolated not all cells are "alive". Viability shows us the percentage of live cells in the total cell population. This number is especially important as it in effect shows us the percentage of "active cells." The higher the percentage of viability, the better it is.

What is the difference between autologous and heterologous transplant?
Autologous transplant is when the donor and recipient of the transplant is the same person. Heterologous transplant is when the donor and recipient are different individuals.

Embryonic Development and Differentiation
With conception, when the egg is fertilized by the sperm, the result is zugotis, the first cell which developes in the developing organism. The zygotis is divided into 2, 4, and 8 cells (multipotent cells) up to the stage of the blastocyte (70-100 cells). At the blastocyte stage, there is the first differentiation of the cells into two categories, the embryoblast and the trophoblast. The cells of the embryoblast are the embryonic stem cells (pluripotent). The next stage of embryonic development, the gastridio, there is the differentiation of cells into three layers, the ectoderm, the mesoderm, and the endoderm. The cells of these layers are multipotent.

Διαφοροποίηση των κυττάρων

What are multipotent, pluripotent and omnipotent Stem cells?
Omnipotent stem cells are those that have the capability to create an entire organism.

Pluripotent stem cells are those that have the ability to differentiate into every type of cell of the organism.

Multipotent stem cells are those that have the ability to differentiate towards a number of types of cells.

What are CD34+ cells?
These are the haematopoetic stem cells of cord blood.

What do we mean with the term differentiation?
Differentiation is the biological process by which a non-specialized cell is transformed into a specific type of cell, for example muscle cell.