Hemapheresis refers to the selective removal of certain component(s) of the blood via machine, designed specifically for this purpose. The blood component may require removal due to a disease or excess. Therapeutic Hemapheresis can be defined by 4 general types of treatment:
(a) Plasma Exchange: The plasma may contain harmful, disease-causing components which must be removed and replaced by an isotonic albumin solution. For certain diseases, fresh frozen plasma (provided by the Blood Bank) is used as a replacement fluid. Plasma exchange is beneficial for a number of neurological diseases (Myasthenia Gravis, Guillian-Barre Syndrome, etc.) and hematological diseases, such as TTP.
(b) Cytapheresis: In certain hematological disorders, the white blood count or platelet count is dangerously high, and these components can be selectively removed using leukapheresis or platelet-apheresis.
(c) LDL Apheresis: In this procedure, the patient's blood is filtered through a unique type of membrane which selectively removes the harmful plasma lipid components, leaving behind the beneficial lipids and all other healthy plasma constituents.
As of 2002, we have two types of machines to perform LDL apheresis. One is a DALI, acquired by Hadassah in March 2000. The DALI performs whole blood filtration using a special affinity column. The other machine separates the plasma and precipitates the LDL using altered pH and heparin (HELP). Two separate systems are needed to meet the specific requirements of all of our patients. We are at present one of 2 centers in Israel which provide this service.
LDL apheresis is a lifesaving procedure. It prevents or reverses atherosclerosis of individuals with hypercholesterolemia who for various reasons, are not able to be treated by medical therapy using cholesterol-lowering drugs. These patients are referred to and followed closely by Professor Eran Leitersdorf, of the Internal Medicine "B" Department, a renowned specialist in lipid disorders.
(d) Extracorporeal Photopheresis: this is innovative type of therapy, which has only been developed within the last decade. The treatment was initially designed for patients with skin lymphomas who had malignant cells circulating in their blood as well as being present in the skin.
Since these diseases were often not responsive to systemic chemotherapy, a unique therapy was thus developed in which the patient's white blood cells (including the malignant cells) could be radiated outside the body of the patient. First the white blood cells are removed from the body by leukocytapheresis, and then a special photosensitizing medication (8-hydroxy-MOP) is injected into the blood collection bag. This medication renders the cells highly sensitive to ultraviolet irradiation.
The addition of the medication directly to the collection bag of white blood cells means that only a small dose of medication to be used, greatly reducing the possibility of any side effects. The bag of cells is then placed in a special machine which delivers a specific amount of ultraviolet radiation over a short period of time, about a half an hour. This causes damage to the malignant cells, which ultimately leads to their destruction. The last step in the treatment is retransfusing the radiated cells into the body of the patient, where they are removed by action of the immune system of the patient. This also stimulates the body to destroy the other malignant cells which were not removed and radiated, such as those located in the skin.
The therapy is often effective in treating the cutaneous lymphomas, which may be refractory to regular medical therapy. Aside from this type of direct cytotoxic application, there are many other potential uses for extracorporeal photopheresis. An important application of this therapy is in the treatment of patients who have received organ or bone marrow transplants. This therapy has been found to prolong the survival of transplanted solid organs, such as cardiac transplants, by preventing rejection. The treatment can also be used to successfully treat severe graft versus host disease after allogeneic bone marrow transplantation.
This promising form of Extracorporeal Photochemotherapy has many therapeutic applications. We are proud that Hadassah Ein Kerem was the first hospital in Israel to administer this treatment and we have successfully administered more of these treatments than any other center in Israel.
Our Unit
The Hemapheresis Unit is headed by Prof. Deborah Rund. Mrs. Tova Schaap is the senior technician, and they both have nearly 2 decades of experience in this field. Mrs. Schaap is works exclusively with hemapheresis patients, and frequently travels abroad to stay up-to-date with the research and newest developments in this rapidly changing field. This has enabled Hadassah to remain at the forefront of apheresis treatment not only in Israel but in the world. The technician staff consists of professionally trained medical technicians who undergo an extensive period of supervised training in the techniques of these various apheresis procedures. Two of our technicians are experienced cardiac intensive care nurses. They are indispensable for treating our cardiac patients who undergo LDL apheresis.