This process is carried out using a specialized machine that separates the different blood elements—plasma, platelets, red blood cells and white blood cells—allowing the desired component to be selected and collected in accordance with the clinical indication.
Applications of apheresis: donation and therapeutic use
There are two main applications of apheresis: donation and therapeutic use In the context of donation, apheresis makes it possible to obtain particular components from volunteers, such as platelets (plateletpheresis), red blood cells (erthyrocytapheresis) and plasma (plasmapheresis). Unlike whole blood donation, this method is more efficient, as larger volumes of the desired component can be collected, and the donor can donate again in shorter periods of time, as only a fraction of the blood elements are lost.
The plasma obtained from voluntary donors is essential for the subsequent production of plasma derivatives such as albumin, immunoglobulins and coagulation factors, which are necessary for treating various types of patient. Every year, some 30,000 apheresis donations are made in Catalonia, mainly of plasma and platelets. Haematopoietic progenitor cells are also collected by apheresis and used for transplants, and lymphocytes, which are used as the starting materials in the new CAR T-cell therapies.
Apheresis as a treatment
Therapeutic apheresis, on the other hand, is used to treat people with specific diseases. In this case, the aim is to remove pathological components or toxic substances circulating in the blood. For example, in plasma exchange, plasma containing harmful antibodies is removed and replaced with substitute fluids, helping to treat autoimmune diseases, neurological diseases, transplant rejections, and certain intoxications. It is also performed on patients with leukaemia, to reduce an excess of white blood cells or platelets. In Catalonia, some 6,000 therapeutic apheresis procedures are carried out each year.
Apheresis, both in its donation and therapeutic forms, is fundamental to the advancement of medicine and the treatment of various diseases. This procedure is safe, controlled and performed under strict medical parameters, contributing significantly to the treatment of patients requiring specific blood components or blood purifying treatments.
In 2019, the American Society for Apheresis began to celebrate Apheresis Awareness Day annually on the third Tuesday of September, to raise awareness about this type of procedure and recognize the contribution of the donors who help save lives with their donations, the patients who receive the treatment, and the professionals who perform it.
