Cytapheresis is medical procedure to separate cells from a patient’s blood after it has been withdrawn. The purpose of this technique is to remove abnormalities from the blood. A centrifuge machine is used to separate out the cells. The remaining plasma is returned to the body while the separated cells are retained. Once the defective blood cells are removed, the blood is then transfused back into the patient.
There are a number of reasons for this procedure. A patient suffering from acute leukemia will often have cytapheresis performed to lessen the potential of thrombocytosis or leukocytosis, conditions that occur when the white blood cell and platelet counts are raised. Cytapheresis can also be employed to collect blood stem cells for operations involving bone marrow reconstitution. This is when the bone marrow is restructured, as opposed to straight transplantation of marrow.
The process of cytapheresis includes erythrocytapheresis, which is a separation of the red blood cells, most commonly in patients with sickle-cell anemia and severe malaria. During the centrifuge process the red blood cells are separated from the other cells. A further washing step is performed to purify the cells. Once the infected cells are removed, the normal blood cells are transfused back into the patient. Very often the blood is drawn and returned by a method called continuous flow centrifugation, which is where the blood is collected, spun and returned at the same time.
Leukapheresis is a method whereby the white blood cells are separated from the blood sample. This method of cytapheresis can be used to lower the white cell count in patients suffering from acute leukemia. The white blood cells are often removed as a means of protecting the cells in patients who are receiving high doses of chemotherapy. Leukapheresis can also be employed when attempting to stimulate a patient’s immune system during the process of eradicating prostate cancer cells.
Another type of cytapheresis is plateletpheresis. This is where platelets are separated from the blood. Platelets are the cells that aid in clot forming and help to control bleeding. Patients suffering from cancer or leukemia can benefit from this procedure as the disease, as well as the therapy, can compromise the body's ability to produce platelets. Plateletpheresis may also be beneficial for patients undergoing open heart surgery.
There are a number of complications that could occur when cytapheresis is performed. These include circulatory disturbances and sodium citrate reactions. Sodium citrate is an agent that prevents blood clotting. The probability of negative reactions usually depends on the frequency of the sessions and amount of blood that is exchanged.