Douglas W. Huestis

Use of Hydroxyethyl Starch To Improve Granulocyte Collection in the Latham Blood Processor

This report describes a practical, relatively inexpensive system of leukapheresis and plateletpheresis, utilizing the Haemonetics blood processor. The results of 236 phereses of normal donors are reported, with particular attention to an evaluation of five different anticoagulant mixtures: ACD, 2 per cent citrate in saline, and three different combinations of citrate and hydroxyethyl starch (HES). These mixtures were compared with respect to their effectiveness in the harvesting of granulocytes and platelets, respectively. The best harvest of granulocytes (3.5 × 109 cells per liter of blood processed) was with 6 per cent HES anticoagulated with trisodium citrate. All solutions gave about the same platelet yields (a mean of 1.6 × 109 per liter of blood processed). Because of its higher citrate content, ACD caused three times as many donor reactions as the other solutions. The use of HES thus permits this widely available plateletpheresis system to be used for leukapheresis with only minimal procedural modification.

The neutrophil in transfusion medicine

NEUTROPHILIC WHITE CELLS (granulocytes) play a checkered role in transfusion medicine. They exist throughout the body and form an essential part of its defenses against bacterial infections. They are an unnoticed and usually undesired presence in most cellular blood components, in which setting they can cause transfusion reactions. Concentrates of neutrophils can be collected as a transfusion medium for infected neutropenic patients. Once collected for this purpose, the cells must be transfused within hours, as they cannot be stored effectively. When too many neutrophils and their precursors are present in certain leukemias, the excess may have to be removed with a blood cell separator to treat or prevent blood leukostasis. Like other blood cells, neutrophils possess intrinsic immunogenetic systems of antigens that can cause alloimmunization. This article will discuss the varied pathophysiologic roles of the neutrophil, with particular emphasis on the way its presence or absence and function or malfunction affect transfusion practice. We decided to use the word “neutrophil” rather than “granulocyte.” The latter is more commonly used nowadays, but it is less accurate because it includes eosinophils and basophils, which do not play a role in transfusion and will not be discussed in this review. Neutrophil is not only more specific but also a syllable shorter and more euphonic.

Citrate anticoagulants for plateletpheresis

In 112 plateletphereses done by the Haemonetics blood processor, the comparative effectiveness of ACD formula A, ACD formula B, and 2 per cent citrate in saline was evaluated. With respect to yields of platelets and white blood cells (e.g., lymphocytes), ACD‐B was significantly better than the other two. Both ACD‐B and 2 per cent citrate gave a much lower incidence of citrate reactions in the donors than were encountered with ACD‐A.

Adverse clinical effects of immune sorption with staphylococcal protein A columns

S TAPHYLOCOCCAL Protein A (SPA) is a major constituent of the cell wall of certain strains of Staphylococcus aureus (eg, Cowan strain 1), which has a great affinity for mammalian immunoglobulin. Analogous immunoglobulin binding sites exist in some other bacteria3 SPA has five immunoglobulin binding regions at the N-terminus. Its one C-terminal nonimmunoglobulinbinding site serves to attach the protein to the cell wail. SPA binds avidly to the Fc portions of human immunoglobulin G (IgG) of types 1, 2, and 4, less reliably to type 3, weakly or variably to IgM, and IgA. 2-4 The binding is nonimmune. The affinity of SPA for IgG seems to be even greater (fivefold) when an antigen is bound to the IgG as an antigen-antibody complex. SPA is physically and chemically stable, and can be attached to various support matrices firmly enough to defy leaching, but without appreciable loss of its immunoglobulin-binding characteristic. Thus, it is possible to develop systems in which SPA, attached to an inert matrix in a column, can extract IgG and immune complexes from serum or plasma. In theory, it seems simple. In fact, the mechanism of action of SPA is complex, involving much more than removal of IgG and immune complexes. That is not the topic of this review, although it has a bearing on the types of reactions encountered. Suffice it to say that SPA affects the immune system in a variety of ways, activating complement, apparently by the alternative pathway, ~ reducing circulating immune complexes, possibly altering antigen-antibody ratios, and other forms of immune modulation. 5 In some clinical applications, such as with a fixed amount of plasma passing once through the sorbent, there seems to be little or no relationship between the quantity of plasma treated or of SPA used, 6 and the observed

The significance of pulmonary infiltrates developing in patients receiving granulocyte transfusions

Summary. We reviewed a series of 109 patients given granulocyte transfusions between 1974 and 1978, to determine if pulmonary infiltrates developing during granulocyte transfusion therapy carried any specific prognostic significance. Eighteen patients developed new infiltrates while receiving granulocytes. Six of these patients died during the acute episode, an overall mortality rate no different from patients not developing new infiltrates. However, the subgroup with pulmonary infiltrates who died had some special features including: infiltrates that developed between 7 and 21 d after transfusions were begun; infiltrates that progressed or persisted during the period of transfusion; and infiltrates that were local rather than diffuse. Autopsies on five of the six patients who died revealed disseminated fungal infection in three, pulmonary haemorrhage in one, and alveolar hyaline membranes in association with Pseudomonas sepsis in one. Besides this high‐risk group specific aetiologies could rarely be assigned for other more diffuse or earlier/later developing infiltrates, despite usual diagnostic studies.

Modified fluid gelatin: An alternative macromolecular agent for centrifugal leukapheresis

We studied a French modified fluid gelatin (MFG), substituting it for hydroxyethyl starch (HES) in leukapheresis procedures using three currently available blood cell separators, and observing its effects on the function of platelets and granulocytes. As a cell‐collecting agent, we found MFG to be as effective as HES with intermittent flow centrifugation (Haemonetics), and slightly less so with one continuous flow device (IBM 2997). MFG was clearly less effective than HES with the Fenwal CS‐3000 continuous flow separator, although we have reason to believe it would be possible to improve efficiency with this machine by changing the operating variables. Tests of platelet and granulocyte function showed negligible alteration with either agent and no difference between them. MFG disappears much more rapidly from the circulation than HES (after a single injection, it is undetectable by the third day). Reaction frequency with MFG was about the same as that of HES, with perhaps somewhat more frequent allergic manifestations.

Characteristics of stored granulocytes collected from donors stimulated with dexamethasone.

Two hours after normal donors were given intravenous dexamethasone, their leukocytes were collected by intermittent flow centrifugation. Neutrophils were tested immediately after collection and following storage at 4 to 6 C for 24, 48, 72 and 96 hours. Tests included total leukocyte and absolute neutrophil counts, plasma glucose concentrations, the percentage of phagocytic neutrophils, the ability of phagocytes to accumulate particles, can‐didacidal activity, bactericidal capacity and chemotaxis. Total leukocyte and absolute neutrophil counts in the stored suspensions were decreased after 48 hours (p = .005). Plasma glucose levels in the suspensions declined at first, then stabilized at 48 hours of storage probably because of loss of cellular integrity. Chemotaxis, candidacidal activity, phagocytosis and dye exclusion showed statistically significant decreases at 24 hours. Chemotaxis deteriorated rapidly, with a mean 63 per cent functional loss at 48 hours. We conclude that treatment of donors with dexamethasone does not extend the storage limits of granulocyte concentrates used for clinical transfusions. Based on these and our previous observations, unless the storage changes should be shown to be reversible, granulocyte concentrates should probably not be stored more than 24 hours before transfusion.

Modified fluid gelatin in leukapheresis accumulation and persistence in the body

Current methods for centrifuged granulocyte procurement involve the use of an agent to produce red cell rouleaux and enhance separation of leukocytes. Hydroxyethyl starch (HES), the agent most frequently used, has the disadvantage of causing progressive volume expansion and persisting in the circulation for long periods. We therefore assessed modified fluid gelatin (MFG) as a possible replacement for HES during granulocyte collection. We found that MFG is cleared more rapidly from the circulation with no traces remaining 7 days after multiple exposure, as determined by hydroxyproline measurement. However, after four consecutive daily infusions, we measured 0.60 liters plasma expansion in four individuals tested, somewhat lower than the 0.85 liters previously reported for HES. Modified fluid gelatin causes no impairment of coagulation with normal prothrombin time (PT), partial thromboplastin time (PTT), and platelet function.

Albumin: The Need versus the Demand

This discussion will include normal serum albumin, ofwhich the protein content is approximately 96% albumin, and plasma protein fraction (PPF), about 88% albumin, as essentially interchangeable fractions in clinical use. Both are generally available in 4 or 5% solutions. Albumin is also provided in a more concentrated form, usually 25%. Countless litres of plasma are used every year in the preparation ofthese two fractions by commercial and non-commercial institutions, and in either case, by the time they are purified for clinical use, both albumin and PPF are costly. Consequently, it is of the utmost importance to follow strict clinical indications for their use, as with any other expensive form of therapy. Most reviews of the clinical users of albumin acknowledge that a great deal of it is wasted, or at least given in clinical situations where its use is not scientifically established [I-31. The demand for it thus tends to exceed the real need by a considerable extent. In addition, for most uses ofalbumin in comparatively small amounts, i.e. less than the patient’s own plasma volume, synthetic oncotic media may be substituted. These include various dextran and gelatin preparations, and hydroxyethyl starch. Certainly, greater use of these plasma substitutes would reduce the clinical demand for albumin.

A Review of HLA Techniques for Blood Bankers

This small book is intended to supplement an earlier (1982) book from the same publisher on Theoretical Aspects of HLA. Originally, both books were manuals to be given out to participants in workshops held by the American Association of Blood Banks, and were intended to present the ins and outs of HLA to blood bankers who were not already experts in the field.