The COBE Spectra Apheresis System:

This machine can separate and collect blood components from both donors and patients.  From donors blood products can be collected for transfusion to patients.  If  desired, plasma can be collected concurrently with platelets but this has been dropped in the UK because of the minute risk of the transmission of CJD.  Collected plasma is available for use as plasma or fresh frozen plasma.  Alternatively, it may be used as source plasma for further processing into Factor XII and Factor IX concentrates (clotting factors).  The machine can be programmed to collect platelets in a pure form, i.e. virtually free of white cells(to minimise the risk of disease transmission) for transfusion to patients with thrombocytopaenia (lack of platelets)

For patients undergoing therapeutic procedures, the system can be used to exchange or deplete blood components.  In addition it can be used for the collection of plasma or platelets form patients who will later require transfusion of those blood products and particularly want their own products only.

The system can be used to perform therapeutic plasma exchange on patients with autoimmune diseases (antibodies which attack own tissue or platelets) or for patients about to undergo a transplant operation.  It can be used to perform red blood cell exchange on patients with haematological disorders such as sickle cell anaemia and thalassemia (where red cells contain the wrong type of haemoglobin), for which red blood cells would be typically used as the replacement fluid, and on patients with polycythaemia (too many red cells) or hamochromatosis (too much iron), for which salt solution or albumin would typically be used as the replacement fluid.  The system can also be used to perform therapeutic platelet depletions from patients with thrombocytosis (too many platelets).

Finally the system can be used to harvest peripheral blood stem cells (immature blood cells which can be used in bone marrow transplants in patients with leukaemia) after their mobilisation into the general circulation with some plasma so the product can be frozen for future use.  It can also be used for white cells harvests from normal donors (for transfusion to individuals with overwhelming infection or lack of white cells after chemotherapy) or simply to remove excess white cells (in people with leukaemia).  

This explanation has beeb kindly written for us by Dr Verjee.

THE GROUP MEMBERS ARE NOT MEDICAL PROFESSIONALS. YOU MUST SEEK MEDICAL ADVICE IF YOU HAVE ANY CONCERNS REGARDING TTP.