Hematopoietic Stem Cells:
These are a type of stem cells which consists of blood and its progenitors. In particular they give raise to specialized cells such as red blood cells which carry oxygen to different tissues in our body, white blood cells which are our bodies immune cells for defence against pathogens and any foreign agents, platelets for blood clotting, macrophages and lymphocytes which are also a part of immune defence.
All the types of blood cells are short lived and need to be replaced continuously. Each day of our life, billions and billions of new blood cells needs to be synthesized in our body which is done by hematopoietic stem cells. The process of formation of new blood cells (creation, development and differentiation) is known as Haematopoiesis.
Haematopoiesis mainly occurs in yolk sack during the prenatal stage which is latter taken care by the Liver and then finally in the bone marrow. In a healthy individual, this process occurs in the bone marrow and lymphatic tissues to maintain the steady state levels. Haematopoietic stem cells are not only found in bone marrow but are also found in femur, pelvis, sternum umbilical cord and the blood from the placenta.
Hematopoietic stem cells (HSC’s) are widely used in many medical conditions such as leukaemia and lymphoma. These are transplanted in different ways such as: autologous (from same patient), Synergic (from identical twins) or allogenic (from an unrelated donor). HSC’s are harvested from bone marrow from the posterior iliac crest under either epidural or general anaesthesia. Iliac crest or sternum is one of the richest sources of HSC’s.
HSC’s are usually collected with the help of long bore needle in a heparinized syringes. These can be either used immediately or can be stored at 4oC for 72hours without any loss of cell viability. Also under controlled conditions in liquid nitrogen which has a temperature of about -196oC stem cells can be preserved for many years which allows the use of stem cells as and when required.
There are many national and international studies and clinical studies which has proven beyond any doubt the safety and efficacy for use of HSC’s clinically. US FDA has also approved the use of HSC’s clinically for many conditions.