Apheresis donor safety ‐ changes in humoral and cellular immunity

Abstract

Modern techniques of mechanical hemapheresis have made it possible to selectively remove vast quantities of lymphocytes and plasma immunoglobulins, and the concentration of these substances in donor blood can fall below the normal range. It is feared that this may lead to immunosuppression; a condition associated in some clinical settings with infections, malignancy and autoimmune diseases. Using primary immunodeficiency diseases and induced immunodeficiency states (for example, therapeutic lymphocytapheresis, chronic thoracic duct drainage and intestinal lymphangiectasia) as models to judge competency of the immune system, it can be predicted that body defense mechanisms can become defective when serum IgG levels are less than 200 mg/dl or the blood lymphocyte count is less than 1000/microliter. However, impaired immunologic function can occur in the presence of normal quantities of these substances in the blood stream; conditions that may be related either to imbalances of immune regulatory factors or to qualitative (rather than quantitative) abnormalities of the immune system. A number of investigators have documented the losses of lymphocytes and plasma immunoglobulins incurred by donors experiencing mechanical hemapheresis. In addition, both the immediate and long-term decreases in the concentration of these substances in donor blood have been reported. In summary, the immediate decreases in blood lymphocyte counts and serum immunoglobulin concentrations are of slight to moderate degree and are without known adverse effects. Less information is available regarding long-term alterations of the immune system, and little data have been collected from prospective studies in which large numbers of donors have been thoroughly evaluated by modern techniques. In general, results of many laboratory studies have been altered. However, these abnormalities have been transient for the most part, and it has been difficult to document clinically significant adverse effects. Thus, the quantities of blood lymphocytes and plasma immunoglobulins that can be removed from healthy donors without causing significant immediate or long-term harm is unknown. Bearing these limitations in mind, the following recommendations are suggested regarding the frequency of repeated mechanical plasma-and-cytapheresis. 1) The usual requirements for whole blood donation must be met if the frequency of mechanical hemapheresis does not exceed once every eight weeks.(ABSTRACT TRUNCATED AT 400 WORDS)

Effects of plasmapheresis on peripheral blood mononuclear cell populations from patients with macroglobulinemia

“…This finding is not unexpected since there have been reports of statistically significant changes in immune system parameters in hemapheresis donors [ 14,151 and in patients with other diseases who undergo therapeutic plasmapheresis [ 16,171. Plasmapheresis has been employed in the treatment of various immunological disorders [18][19][20]. Its effectiveness has been attributed to the removal of humoral factors such as immunoglobulin, immune complexes, coagulation, and other factors that lead to improved immune system function.…”

Recovery of white blood cells and platelets from leukoreduction system chambers of Trima Accel and COBE Spectra plateletpheresis devices

“…In comparison, the same number of plateletpheresis procedures with the COBE Spectra LRSCs would remove only 3.2 × 10 7 WBCs per donation or a total of 7.7 × 10 8 WBCs for 24 collections per year. Strauss 4 reported high losses of lymphocytes per PLT donation with previous plateletpheresis methods. This observation of immediate and long‐term decreases in donors' lymphocyte counts lead to limits on the frequency of plateletpheresis.…”

A Two-Year Flow-Cytometric Immune Surveillance of Plateletpheresis Donors

“…Predominantly, this limitation was introduced because, before 1984, the platelet concentrates produced with an apheresis machine contained a very high number of contaminating leukocytes. Sometimes more than 10 × 10 9 leukocytes per product were found, and as the consequence the authors noted a substantial loss of lymphocytes in the donor's peripheral blood [11]. In addition, at that time it was not clear whether this loss may have detrimental consequences for the donor's immune system.…”

“…For this reason we regard the possibility of immunodeficiency induced by apheresis as improbable. The reduction of lymphocytes would not be clinically relevant until a constant cell count under 500 lymphocytes/µl is reached or a loss of more than 1 × 10 11 lymphocytes occurs over a short period of time [5,11,23].…”