Ingestion of hydroxyethyl starch by human leukocytes

Following infusion into animals, hydroxyethyl starch (HES) can be found in nearly all tissues, including phagocytic leukocytes (WBCs) of the reticuloendothelial system (RES). Conceivably, the ingestion of HES molecules by these cells might lead to RES blockade. We studied the ability of WBCs obtained from human blood (neutrophils, mononuclear leukocytes, and mixtures of these cells) and from the RES (alveolar macrophages) to interact with radioactive HES in vitro in the presence of normal serum. In general, 14C-HES failed to associate with blood WBCs (i.e., the cells did not acquire significant amounts of radioactivity). Generally, less than 0.1 percent of radioactivity available in the reaction mixtures became cell associated. Moreover, when used as a phagocytic stimulus, HES elicited practically no superoxide anion production from blood WBCs. Alveolar macrophages acquired significant amounts of 14C-HES (presumably by ingestion). However, only tiny quantities (0.09%) of the total amount of radioactivity available in the reaction mixture became cell associated. Despite this slight interaction with alveolar macrophages, it seems unlikely that the internalization of HES by WBCs will lead to phagocytic dysfunction (such as RES blockade) in humans since human WBCs seem quite limited in their ability to interact with this drug.

Evaluation of flatbed reciprocal motion agitators for resuspension of stored platelet concentrates

We studied the storage characteristics of platelet concentrates prepared in polyolefin (PL-732) and thin-film polyvinyl chloride (CLX) plastic bags and stored on a newly designed flatbed reciprocal motion agitator with a 1.5 inch (3.8 cm) lateral movement and an oscillation frequency of 70 cycles/min. We also studied the ability of this device to resuspend the platelet button formed after preparative centrifugation. Results showed that platelet concentrates stored on the 1.5-inch shaker had storage characteristics equivalent to those reported for the conventional 70 cycles/min, 1-inch (2.5-cm) lateral movement flatbed shaker. Due to a more rapid acceleration and deceleration rate, however, the 1.5-inch shaker resuspended the platelet button formed after preparative centrifugation much more efficiently than did the less dynamic 1-inch shaker. Furthermore, with either agitator, platelet aggregates in the CLX bag were more readily resuspended than were aggregates in the PL-732 bag due in part to differences in plastic bag wall elasticity.

Extended storage of platelets in a new plastic container. II. In vivo response to infusion of platelets stored for 5 days

A new blood container material (PL 1240 plastic) made of polyvinyl chloride containing a tri(2-ethylhexyl) trimellitate plasticizer was evaluated in three laboratories. When platelet concentrates (50-60 ml) were stored on a variety of agitators for 7 days at 22 +/- 2 degrees C, poststorage pH (mean +/- SD) ranged from 7.29 +/- 0.05 (6 rpm elliptical rotator) to 6.87 +/- 0.8 (70 cycles per minute flatbed agitator). The platelet counts ranged from 1.51 +/- 0.12 to 0.95 +/- 0.36 X 10(6) per microliter. Morphology scores and hypotonic shock response values of platelets stored 7 days in PL 1240 plastic containers were better than those noted following 3-day storage of control platelets in PL 146 plastic containers. The percent discharge of lactic dehydrogenase from platelets stored 7 days in PL 1240 plastic containers for 3 days (p less than 0.05). Mean platelet recoveries of 44 +/- 15 percent (n = 11; 111Indium) and 39 +/- 8 percent (n = 29; 51Chromium) were seen when autologous platelets were infused following 5-day storage in PL 1240 plastic bags. Platelet half-lives of 3.6 +/- 0.4 (n = 9) 4.1 +/- 0.4 (n = 20) days were reported in the two laboratories which used 51Cr labeling, while survival values of 7.0 +/- 1.0, 2.8 +/- 0.8, and 5.4 +/- 1.9 days were seen when data from the 111Indium studies (n = 11) were analyzed using linear, exponential, and multiple hit programs, respectively. Platelets stored for 5 days also were administered to 13 thrombocytopenic oncology patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Uptake of extracellular calcium by neonatal neutrophils

Neutrophils from human neonates exhibit abnormalities of plasma membrane and cytoskeletal dependent functions such as chemotaxis, deformability, and lectin capping. The uptake of extracellular calcium by neutrophils is a key early event in neutrophil activation and in the optimal performance of these functions. We found that neonatal and control neutrophils acquire extracellular radioactive calcium comparably under most experimental conditions. No differences (P greater than 0.05) were seen between neonatal and control neutrophils following stimulation with soluble sodium fluoride, N-formyl-methionyl-L-leucyl-L-phenylalanine, dimethylsulfoxide, and opsonized zymosan particles. However, the uptake of calcium by resting (unstimulated) neutrophils was significantly less (P less than 0.0001) by neonatal cells. The kinetics of calcium uptake by neonatal and control neutrophils were similar both at rest and following stimulation for 15 min with sodium fluoride. Although additional studies will be necessary to completely define the ionic events involved in the chemotaxis of neonatal neutrophils, it seems unlikely that the abnormal mobility of these cells is due simply to an inability of neonatal neutrophils to acquire extracellular calcium in response to cellular stimulation.

Use of an electromechanical infusion pump for transfusion of platelet concentrates

To determine whether platelet concentrates can be administered safely through electromechanical infusion devices, we studied stored platelet concentrates passed through one pump system (Abbott). We measured in vitro changes in platelet count and lactic dehydrogenase (LDH) and beta-thromboglobulin (beta-TG) release which occurred after passing the concentrates through the pump system. To compare in vivo survival, five normal volunteers were given an injection of autologous Indium-111-labeled platelet concentrates at two different times, once using platelets which had been passed through the pump system (test group) and once using platelet concentrates which had not (control group). In vitro studies showed no significant changes (p greater than 0.05) in platelet count, or in LDH or beta-TG release after passage through the pump system. In vivo platelet recovery at 2 hours was 39.8 +/- 4.7 percent (mean +/- 1 SD) for the control platelets and 40.7 +/- 9.3 percent for the platelets passed through the pump system (p greater than 0.05; n = 5). There was no significant difference in platelet survival measured in days between the control group and the test group using a linear (8.0 +/- 0.9 vs. 7.2 +/- 0.3), exponential (3.7 +/- 0.7 vs. 3.1 +/- 0.5), or multiple hit (5.4 +/- 2.3 vs. 4.8 +/- 1.0) (p greater than 0.05; n = 5) model. We conclude that this pump system is acceptable for use in clinical practice when control over volume and rate of platelet transfusion is important.

Fibronectin in liquid and frozen stored blood components

To quantitate the concentration of fibronectin in blood components to determine if the fibronectin present in liquid and frozen stored blood products deteriorates in vitro, we measured the concentration of this opsonic protein at the beginning and at the end of storage. In addition, electroblotting studies were performed to ascertain if aggregation or degradation of fibronectin occurred during component preparation or storage. Results showed that fibronectin concentration was stable in whole blood, single donor plasma, platelet concentrates, fresh-frozen plasma, and cryoprecipitate. By electroblotting, aggregated or degraded fibronectin was found in some components, especially cryoprecipitate. Most of the fibronectin, however, appeared to be unaffected by component preparation or storage.

Chemotactic peptide binding by intact neutrophils from human neonates

Binding of the chemotactic peptide N-formyl-methionyl-L-leucyl-L-phenylalanine (FMLP) by neutrophils from neonates was measured to investigate whether an abnormality of this event that initiates chemotaxis could explain the decreased chemotaxis of neonatal neutrophils. No differences of FMLP binding by neonatal and control neutrophils were found at 4 and 22 degrees C when specific binding was assessed by analysis of binding isotherms and Scatchard plots. At 4 degrees C (n = 6) the average number of FMLP molecules bound per neutrophil was 13,854 (neonates) and 17,368 (controls); affinity expressed as Kd was 32 nM (neonates) and 34 nM (controls). At 22 degrees C (n = 5) the respective values were 22,587 FMLP molecules per neutrophil (neonates) and 21,082 (controls); Kd was 29 nM (neonates) and 23 nM (controls). Based on these data, we suggest that mechanisms responsible for decreased chemotaxis of neonatal neutrophils must involve events subsequent to initial FMLP-receptor interaction.

5-day storage of platelet concentrates in CLX containers: effect of type of agitation

To determine the degree of platelet damage produced by different modes of agitation during storage of concentrates for 5 days in CLX blood bags, we studied pH, platelet counts, release of LDH and beta thromboglobulin, morphology and osmotic recovery. Platelets were maintained at 20-24 degrees C on elliptical, 6-rpm circular, 2-rpm circular and flat bed agitators. At 72-120 h platelet concentrates stored on the flat bed shaker had significantly lower pH values than units stored on the elliptical or on either of the circular rotators (p less than 0.05). The percent LDH discharged was highest for the units stored on the elliptical rotator (p less than 0.05). Remaining tests of platelet function were not significantly different for concentrates stored on any of the four agitators. Flat bed shakers were unable to resuspend the platelet 'button' which formed after the final preparative centrifugation. Based on our in vitro studies, we conclude that due to problems with low pH values, flat bed shakers may not be optimal for storing platelet concentrates in CLX blood bags and that some other form of agitation should be used.

Plasma fibronectin level and clinical status in cardiac surgery patients

To determine whether changes in plasma fibronectin concentration were related to the development of postoperative complications, we studied both plasma fibronectin concentration and the postoperative clinical course for 41 patients undergoing elective cardiopulmonary bypass surgery. Patients were divided retrospectively into three groups based on their hospital course. Group I (n = 21) had mild complications, group II (n = 15) had moderate complications, and group III (n = 5) had severe complications. Fibronectin was monitored preoperatively, intraoperatively, and postoperatively until discharge. Although fibronectin levels were unaffected by induction of anesthesia, a decrease in fibronectin concentration was seen after bypass in all patients. This decline was transient, however, and fibronectin concentration rose within 4 to 5 hr after the end of surgery. A subsequent fall to a level below the lower limit of normal (less than 180 micrograms/ml) was consistently seen only in critically ill (group III) patients and coincided with adverse changes in their clinical status.

Activation of complement by blood transfusion filters

Fresh blood, stored blood and granulocyte concentrates were passed through 170-micron and microaggregate blood filters to determine the degree of complement activation that occurs during transfusion of citrated blood products. Complement activation was assessed by measurement of C3 conversion using crossed immunoelectrophoresis and by assessment of C5a using a leukocyte aggregation functional assay. Prefiltration, fresh or stored blood products showed 0-1% C3 activation. Postfiltration, the degree of C3 conversion did not change for fresh blood or granulocyte concentrates. For stored whole blood, the degree of C3 conversion increased slightly to 2-3%. Prefiltration results for all samples showed a low level of C5a which did not change after passage through any filter. Serum incubated with filter material at 37 degrees C showed 2-10% C3 conversion. In contrast, results with citrated plasma showed less than 3% conversion of C3. We conclude that although some filter materials may activate complement in serum, filtration of citrated blood products through microaggregate blood filters induces little complement activation.

Effect of mode of agitation on storage of platelet concentrates in PL-732 containers for 5 days

To determine the degree of damage induced by different modes of agitation during storage of platelets for 5 days in polyolefin (PL-732), we studied pH, platelet count, release of lactic dehydrogenase (LDH) and beta-thromboglobulin (beta-TG), morphology and osmotic recovery. Platelets were maintained at 20-24 degrees C on elliptical, 6 rpm circular, 2 rpm circular and flat bed agitators. Results showed that the most and least effective modes of agitation were the 2 rpm circular and the elliptical rotators, respectively. Elliptical rotators exhibited excessive release of LDH (46%) and beta-TG (51%) while the 2 rpm circular model produced significantly less discharge of these proteins (LDH 13%; beta-TG 30%; p less than 0.05). With elliptical units, by 120 h of storage, pH was often very alkaline (pH greater than 7.5) when platelet counts were under 1 x 10(9)/ml. Flat bed shakers and 6 rpm circular agitators were acceptable but flat bed units were unable to resuspend the platelet 'button' which forms after the final preparative centrifugation. The 2 rpm circular rotator showed significantly less LDH and beta-TG release than did the 6 rpm version (p less than 0.05) and permitted smooth resuspension of the platelet 'button'. Based on our in vitro studies, we conclude that elliptical rotators may not be suitable for storing PL-732 platelet concentrates and that some other form of agitation should be used.

Stability of red cell antigens during prolonged storage in citrate-phosphate-dextrose and a new preservative solution

Red cells anticoagulated with citrate-phosphate-dextrose (CPD) or a commercial preservative solution containing adenine, sodium chloride, and mannitol (ADSOL) and stored in heat-sealed segments of plastic tubing were tested for antigen stability after refrigeration at 4 degrees C for up to 56 days. Reactivity of the A, B, c, D, K, Lea, Fya, M, and P1 antigens was maintained adequately during the storage period in both solutions. Heat-sealed segments containing red cells suspended in either CPD or ADSOL preservation solutions for up to 56 days appear acceptable for use in compatibility testing.

Stability of red cell antigens and plasma coagulation factors stored in new formulation plastic blood containers

The stability of red blood cell antigens and plasma coagulation factors stored in new plastic blood packs containing either citrate-phosphate-dextrose (CPD) or citrate-phosphate-dextrose-adenine (CPDA-2) was studied. The containers were made of either polyolefin (PL 732TM) plastic without a plasticizer, or polyvinyl chloride with a non-diethylhexyl phthalate (non-DEHP) plasticizer (PL 1240). All studies were done in parallel using standard polyvinyl chloride (PL 146) bags containing DEPH plasticizer as controls. Red blood cell antigen scoring was performed for the A, B, c, D, K, Fya, Lea, Jka, M, and P antigens using cells obtained from both the blood container and tubing segments. Units of fresh frozen plasma and cryoprecipitate were prepared, and age and donor-matched sets of each of these blood components were stored in both test and control plastic containers. The red blood cell antigens showed no decrease in reactivity over 21 (CPD) or 35 (CPDA-2) days of storage in either test plastic compared with controls. For fresh frozen plasma (factors V, VIII, IX) and cryoprecipitate (factor VIII) the factor activity found for the test plastics ranged from 94 to 115 percent of that recorded for the age and donor-matched control plastic. The concentration of fibronectin found in cryoprecipitate stored in the test plastics averaged 90 to 99 percent of the activity found in PL 146 plastic. We conclude that the red blood cell antigens and coagulation factors tested remain stable in the plastic-anticoagulant combinations studied.

Glutathione in neutrophils from human infants

The concentration of total glutathione (GSH + GSSG) and its depletion during oxidant stress were studied in neutrophils obtained from human neonates, their mothers and adult controls to determine if the previously reported increased susceptibility of infant neutrophils to oxidant damage could be related to glutathione deficiency. We found the basal level of glutathione to be lower and the oxidant-induced depletion of glutathione to be greater in infant neutrophils than in cells obtained from the blood of the infants' mothers and adult controls. In studies reported earlier, neutrophils from infants were found to be deficient in the oxidant protective enzymes glutathione peroxidase and catalase. These abnormalities, in a fashion similar to that observed for patients with congenital defects of glutathione and catalase metabolism, may render infant neutrophils prone to oxidant damage and consequent dysfunction.

Effect of microaggregate blood filtration on granulocyte concentrates in vitro

To determine the effect of transfusing granulocyte concentrates through microaggregate blood filters, granulocytes prepared with a cell processor were passed through screen and depth microaggregate filters. Pre- and postfiltration evaluations were made of total granulocyte count, levels of muramidase, granulocyte viability, motility, phagocytosis, bactericidal activity, and hydrogen peroxide-forming capacity. Compared to prefiltration levels, a significant (p less than 0.05) decrease in postfiltration granulocyte counts was seen for all the depth filters studied but not for the standard 170 microns (control) or the 40 microns screen filter. For the various tests of granulocyte function evaluated prefiltration, no significant postfiltration differences (p greater than 0.05) were seen for any of the filters studied. Screen microaggregate filters retained only 1 to 3 percent of granulocytes contained in the concentrates, and thus appear satisfactory for use in clinical transfusions. The large percentage of neutrophils retained by the depth filters (20-62%), however, precludes their use for transfusion of granulocyte concentrates.

Microaggregate blood filtration in patients with compromised pulmonary function

To determine the effect of microaggregate blood filtration on patients with compromised pulmonary function, we divided 50 patients having elective coronary bypass surgery into two groups. One group received all blood transfusions via a 170-micron standard filter (SF). The other group received blood through a 20-micron microaggregate blood filter (MF). Patients were monitored pre- and postoperatively for changes in arterial blood gases and cardiopulmonary function. Mean transfusion volume was seven units (SF) and six units (MF). Preoperatively, patients in both groups showed abnormal lung function with elevated intrapulmonary shunting (Qs/Qt) and alveolar-arterial gradients (A-aO2). Postoperatively, no significant differences (p greater than 0.05) were found between the groups for any of the tests of cardiopulmonary function evaluated. Posttransfusion, none of the patients in either group showed clinical signs of respiratory distress. We conclude that even for patients with some degree of pretransfusion pulmonary dysfunction, use of a microaggregate blood filter for six- to seven- unit transfusions does not provide significant clinical benefit.

Occurrence of the release reaction during preparation and storage of platelet concentrates

To determine the degree of damage occurring during preparation and storage of platelet concentrates, the percent release of B-thromboglobulin (BTG) and percent leakage of the cytosolic protein lactic dehydrogenase was determined sequentially from phlebotomy to the end of storage for 72 h at 20-24 degrees C. The effect of storage temperature, pH, and radiation was also evaluated. The results showed that during preparation of platelet concentrate a large degree of release was found after resuspension of the platelet button formed after the high-speed centrifugation. During storage the percent BTG release increased from 18.1 to 40.2% (p less than 0.05). The percent release seen during storage at 4 degrees C (72 h) was 19.2%, while that seen for platelets subjected to temperature cycling at 4-37 degrees C was 24.9%. Both of these values were significantly less (p less than 0.05) than that seen for concentrates stored at room temperature. A negative correlation between pH and BTG release was found (r = -0.64). Irradiation to 10,000 rad did not induce the release reaction or lactic dehydrogenase leakage. We conclude that the degree of in vitro platelet release is dependent on the preparative manipulations, and gentler protocols for preparation and storage of platelets should be investigated.

Platelet collection and transfusion using the fenwal CS-3000 cell separator

A prototype model of the Fenwal CS-3000 Blood Cell Separator (Deerfield, IL) was studied for plateletpheresis in 63 donors and 5 transfusions in patients. Donor effects were consistent with platelet removal and mild hemodilution. The incidence of reactions (9 of 63) was low and all were mild "citrate" type. A two-hour collection yielded 4.0 +/- 0.72 x 10(11) platelets at an efficiency of 45 +/- 6.9 per cent. The product had little contamination with leukocytes (0.26 +/- 1.2 x 10(9) and red blood cells (hematocrit less than 1%). Morphology and pH were well preserved during 24 hours of storage. Four patients with uncomplicated aregenerative thrombocytopenia were transfused on five occasions, with a mean of 4.5 +/- 0.87 x 10(11) platelets resulting in a mean platelet count increment of 55,000/microliter and dramatic reduction in template bleeding times.

Effect of blood transfusion on in vivo levels of plasma fibronectin

Fibronectin, an opsonic glycoprotein, is known to bind fibrinogen and fibrin. Microaggregate debris contained in stored bank blood is composed of degenerating platelets, leukocytes, and fibrin strands. The debris ranges in size from 10 to 160 micrometers. This study examined the effect of transfusion of 2 units of stored red blood cells, containing varying amounts of macroaggregate debris, on in vivo levels of fibronectin. Anemic outpatients were selected at random to receive blood transfusion through either a 170 micrometer standard blood filter or one of four microaggregate filters. A sixth group received saline-washed red blood cells. Results showed that the greatest drop in posttransfusion levels of fibronectin (39 microgram/ml) were found in the group that received blood through a 170 micrometer standard filter and thus received the greatest amount of microaggregate debris (p less than 0.05; N = 50). The patients who received the least microaggregate debris, those receiving washed red cells, showed the smallest decrease in posttransfusion levels of fibronectin (9 microgram/ml); this decrease was not significant (p greater than 0.05; N = 50). Patients receiving blood through 20 to 25 micrometer microaggregate blood filters showed a fall in posttransfusion levels of fibronectin (10 to 15 microgram/ml) intermediate between that found for the two groups described above; this decrease was not significant (p greater than 0.05; N = 35). The decrease in posttransfusion levels of fibronectin found after administration of blood through a 40 micrometer microaggregate screen filter (31 microgram/ml) was significantly different from pretransfusion levels (p less than 0.05; N = 20). Data obtained from this study suggest that transfusion of the microaggregate debris contained in 2 units of stored bank blood can lower in vivo levels of fibronectin. We conclude that if maintaining high levels of fibronectin is shown to be of value in the treatment of critically ill patients, removal of microaggregate debris from any blood transfusions required by these patients would be warranted.