Occurrence of cold activation of transfusion plasma during storage at +4 degrees C.

BACKGROUND AND OBJECTIVES: The storage of transfusion plasma at +4 degrees C sometimes leads to the activation of several proteolytic systems. In this study the frequency of cold activation was investigated, as well as whether cold activation of plasma is an individually recurrent property of the donor. MATERIALS AND METHODS: Plasma units prepared from whole blood obtained from 100 male donors were stored at +2 degrees to +5 degrees C, in bags for 28 days and in cryotubes for up to 42 days. Samples from plasma units, collected by apheresis from 100 male donors, were stored in cryotubes for up to 42 days. Cold activation was measured weekly as kallikrein-like activity of plasma. Samples from repeat apheresis plasma units from 32 donors were measured 12-20 months later. The effects of storage on the contact, coagulation and fibrinolytic systems were determined. RESULTS: The cumulative frequency of cold-activated plasma units stored in bags was 5% on day 7 and 18% on day 28. After 42 days in cryotubes, 49% of the plasma units were cold activated. Large intraindividual differences in the onset-day of cold activation were observed in plasma samples of some donors. During cold activation, an increase in kallikrein-like activity was accompanied by a decrease in C1 esterase inhibitor activity and an increase in the concentrations of activated factor VII and fibrinopeptide A. The functional plasminogen level was unchanged, while a minor decrease in plasmin inhibitor activity was combined with a corresponding increase in the concentration of plasmin-plasmin inhibitor complex. CONCLUSIONS: The cumulative frequency of cold-activated plasma units increased in a time-dependent manner during storage at +2 degrees to +5 degrees C for 42 days. The intraindividual onset-day of cold activation varied widely between plasma samples of some donors. Cold activation was associated with a high degree of activation of the contact and coagulation systems. The fibrinolytic system was scarcely affected.

Local vs. systemic immune and haemostatic response to hip arthroplasty.

Local and systemic immune and haemostatic responses were studied in 10 patients, aged 57-78 years, undergoing elective hip arthroplasty. Cytokines, soluble cytokine receptors, interleukin-1 receptor antagonist, soluble adhesion molecules, antithrombin, fibrin, soluble and fibrin D-dimer were analysed in wound drainage blood and in blood taken from the systemic circulation for up to 24 h post-operatively. Wound drainage blood concentrations of cytokines, interleukin-1 receptor antagonist and soluble cytokine receptors were increased compared with those in the systemic circulation except for the soluble interleukin-6 receptor. In wound drainage blood, soluble tumour necrosis factor receptors (P < 0.05), interleukin-1 receptor antagonist (P < 0.05) and interleukin-6 (P < 0.05-< 0.01) increased during the study period. In blood from the systemic circulation interleukin-6 increased (P < 0.05) while the soluble interleukin-6 receptor decreased (P < 0.05) compared with pre-operative values. Concentrations of soluble adhesion molecules did not change. Wound drainage blood showed marked hypercoagulation. After hip arthroplasty pro-inflammatory cytokines and their inhibitors were mainly confined to the local trauma site. A predominance for inhibitors was noted.

Local wound and systemic coagulation/fibrinolysis responses in hip arthroplasty. Influence of allogeneic and autologous blood transfusion.

22 patients undergoing elective hip arthroplasty were studied. In 12 patients, a closed-loop autotransfusion system, without anticoagulant, was used and 10 had an ordinary wound drainage allowing repeated blood sampling from the wound. Plasma concentrations of antithrombin (AT), fibrin, soluble (SF) and fibrin D-dimer were determined preoperatively, 3, 8, and 24 hours after starting surgery. Wound drainage blood had increased concentrations of SF and fibrin D-dimer and decreased concentrations of AT compared to reference values and systemic concentrations in patients. Plasma concentrations of SF, fibrin D-dimer and AT did not differ between patients receiving retrieved blood and those receiving stored red blood cell concentrates (RBCs). Patients receiving blood transfusions had lower AT concentrations at 8 hours after starting surgery than those not receiving such a transfusion.

Stability of blood coagulation factors and inhibitors in blood drawn into half-strength citrate anticoagulant.

Drawing of blood into a citrate-phosphate-dextrose (CPD) solution with a reduced citrate concentration has been shown to improve the maintenance of coagulation factor VIII (F VIII) in plasma and to give possibilities to improve erythrocyte preservation. We studied the quality of plasma obtained from whole blood drawn under continuous mixing into CPD in which the citrate concentration was reduced by 50% (0.5CPD). The blood was stored at room temperature for 8 h before component preparation. We confirmed improved stability of F VIII by 0.5CPD. We found no clinically significant changes in inhibitors to the coagulation and kallikrein systems, and no signs of activation of these systems, during the 8-hour holding time. In control blood drawn into CPD, F VIII and coagulation factor IX decreased by 0.09 IU/ml (8%) and 0.07 U/ml (7%), respectively, otherwise we found no significant differences between 0.5CPD plasma and CPD plasma.

Cytokine and coagulation characteristics of retrieved blood after arthroplasty.

OBJECTIVES: To investigate cytokine and coagulation/fibrinolysis characteristics in blood retrieved from wounds using an autotransfusion system, and to compare the cytokine pattern in the retrieved blood with those in the systemic circulation and in the initial portion of drainage blood from the wound. DESIGN: Prospective controlled clinical study. SETTING: The postoperative ward of a University hospital. PATIENTS AND PARTICIPANTS: Blood retrieval was performed over a period of 4-6 h on patients who had just undergone arthroplasty (nine hips, one knee). In five other cases involving hip arthroplasties, the initial portion of drainage blood was studied. MEASUREMENTS AND RESULTS: Coagulation/fibrinolysis parameters were analyzed in blood retrieved using the Stryker Consta Vac system. Concentrations of tumor necrosis factor alpha (TNF), interleukin-1 beta (IL-1) and interleukin-6 (IL-6) were analyzed in the retrieved blood, in the systemic circulation of the patients at the beginning and at the end of blood retrieval and in the initial portion of drainage blood from the surgical area. In the retrieved blood, the activities of thrombin, kallikrein and plasmin were increased, antithrombin and free protein S were decreased, and in all samples IL-6 was >1000 pg/ml. Postoperative plasma concentrations of IL-6 rose from a median value of 0 to 116 pg/ml (p <0.01). Four patients had circulating TNF concentrations (range: <15-50 pg/ml). Plasma IL-1 was not detected. TNF and IL-1 were detected in all samples of initial blood from the surgical area and IL-6 in one sample. CONCLUSION: Hypercoagulability and high concentrations of IL-6 were present in the retrieved blood. The cytokine pattern in the initial portion of blood from the surgical area differed from those in the retrieved blood and in the systemic circulation.

Coagulation factor VII mass and activity in young men with myocardial infarction at a young age. Role of plasma lipoproteins and factor VII genotype.

Factor VII (FVII) coagulant activity has been proven to be associated with the risk of future fatal coronary heart disease (CHD) in middle-aged men. Recent studies have emphasized the role of triglyceride-rich lipoproteins and FVII genotype in determining plasma levels of FVII protein and activity. The present study was undertaken to examine whether FVII activity state and protein concentration in fasting plasma are altered in young men with proven myocardial infarction (MI) and examined the relations of FVII to subfractions of apo B-containing lipoproteins and the Arg-->Gln polymorphism in the FVII gene. Activated FVII (FVIIa) was determined by a clotting assay using soluble, recombinant, truncated tissue factor. A total of 94 men with a first MI before the age of 45 (mean age +/- SD, 39.6 +/- 4.5 years) were included in the study along with 99 population-based, age-matched control subjects. In addition to FVIIa and FVII antigen (FVII:Ag), a panel of FVII activity assays were included for comparison with previous work in this field. The plasma level of FVII:Ag was higher in patients than in control subjects when the entire groups were compared (537 +/- 128 versus 479 +/- 93 ng/mL, P < .001), the differences being accounted for by patients with hypertriglyceridemic lipoprotein phenotypes. In contrast, FVIIa was similar in patients and control subjects (4.6 +/- 1.4 versus 4.3 +/- 1.3 ng/mL, NS), which means that the proportion of FVIIa molecules was unaltered or even lower in the patients. As expected, the Arg-->Gln polymorphism significantly influenced both FVII mass and activity levels. In addition, presence of the Gln allele appeared to be associated with a lower proportion of fully active FVII molecules. The polymorphism also affected the relation between the plasma concentration of VLDL and FVII:Ag. The triglyceride content and particle number of all VLDL subfractions, irrespective of particle size, correlated fairly strongly with FVII mass determinations but not at all with FVIIa. HDL cholesterol concentration, on the other hand, presumably reflecting the efficiency of lipoprotein lipase-mediated lipolysis of VLDL, related significantly to the FVIIa level. The Arg-->Gln polymorphism, independent of lipoprotein effects, explained 5% to 10% of the variation in FVII mass and activity. In conclusion, the present findings speak against a role of FVII as a risk factor for CHD, because a significantly increased potential for activation of coagulation (ie, raised basal concentration of FVIIa) was not observed among young postinfarction patients.(ABSTRACT TRUNCATED AT 400 WORDS)

Limited metabolic effect of mononuclear cells in platelet storage.

Platelet concentrates (PC) were prepared by platelet apheresis to obtain a low (< 0.1 x 10(9)/l, PC A) and high (2-9 x 10(9)/l, PC B) concentration of white cells from the same donor. The mean platelet count (+/- SD) of the PC were 1000 +/- 50 x 10(9)/l. During storage 71-96% of the white cells were mononuclear. A portion of red cells from each donor was also stored under the same conditions. The results of the PC were corrected for the influence of contaminating erythrocytes. During the whole storage period pO2 was significantly lower in PC with high white cell count, p < 0.05 and the concentration of ATP significantly higher, p < 0.01 on day 0, 3 and 5, p < 0.05 on day 1 and 7. There were no significant differences in pH, pCO2, production of lactate or consumption of glucose. In another 17 apheresis PC leukocyte viability was assessed by exclusion of 0.05% trypan blue on days 5 and 7; 90 +/- 3 and 88 +/- 4% respectively of the leukocytes remained viable; 87 and 96% respectively were mononuclear cells. In a third series of PC prepared with extra high white cell count (0.4-1.6 x 10(9)/unit) was oxidative phosphorylation maintained and pH remained between 6.80 and 7.16 in 12 of 16 PC after 5 days of storage. The presence of mononuclear cells in PC does not impair the maintenance of platelet ATP production and oxidative phosphorylation unless the platelet concentration is high enough almost to exceed the oxygen diffusion capacity of the bag. If so, the white cells significantly contributed to the oxygen deficit and pH and ATP rapidly decreased due to anaerobic metabolism. We conclude that mononuclear cells can be stored in plasma together with platelets at aerobic conditions for 7 days with maintained concentration of platelet ATP.

Freezing technique and quality of fresh-frozen plasma.

Cell-poor plasma was prepared by apheresis from 10 donors. From each donor, an amount of 200 ml was frozen rapidly to -40 degrees C in standard blood bags, and a further 200 ml was frozen slowly to -20 degrees C. Before freezing and after thawing, plasma samples were collected and frozen to -70 degrees C pending analysis. Coagulation factor VIII activity was reduced to 90% by rapid freezing and to 80% by slow freezing. Factor V was not influenced by rapid freezing, but slow freezing reduced the levels to 92% of the pre-freezing levels. In some of the plasma bags a slight increase in fibrinopeptide A occurred. However, soluble fibrin, thrombin-antithrombin complexes and spontaneous proteolytic activity were not altered by freezing. The beta-thromboglobulin increased slightly with slow freezing. Moreover, in a separate experiment, evaluating the possible effects of refreezing plasma samples, an increase in beta-thromboglobulin was also recorded, while the levels of factors VIII and V and von Willebrand factor were not affected. The changes in some variables, which were recorded in the cell-poor plasma, frozen soon after the blood donation at a slow freezing rate, must be regarded as insignificant in most clinical situations.

Proteolytic activity during storage of platelets in plasma.

Proteolytic activity was studied in platelet concentrates (PC) stored in plasma at 22 degrees C. In experiment 1, two PC with a higher (A) and a lower (B) white cell concentration were prepared from each of nine donors by centrifugation. Aliquots of the cell-free plasma, PPP, were stored as a control. Samples for the assay of fibrinopeptide A (FPA), elastase, spontaneous proteolytic activity (SPA), kallikrein-inhibiting activity, thrombin-antithrombin complexes (TAT) and D-dimers were collected initially and on days 1, 3, 5 and 7 of storage. Consumption of glucose, pH and concentrations of lactate dehydrogenase (LDH) and ATP were determined to investigate the metabolic status of the PC. The decrease in pH correlated to the leucocyte count, r = -0.74, P < 0.001 and to the increase in LDH, r = -0.74, P < 0.01. The levels of elastase and the SPA were consistently low in the PPP bags. In the PC elastase had increased by day 5 and the SPA by day 3; the levels in PC A were significantly higher than in PC B, P < 0.01. The leucocyte count correlated with the elastase activity, r = 0.71, P < 0.01, and with the SPA, r = 0.65, P < 0.01. A minor increase in FPA was demonstrated while no TAT and D-dimers could be detected. The cause of the formation of FPA was studied in experiment 2; three bags of PC and four of PPP were prepared from each of 16 donors. To the PC and three of the PPP bags either hirudin, aprotinin or no enzyme inhibitor (control) was added.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood component processing technique and plasma quality.

To maintain a closed system during the preparation of blood components, including the removal of buffy coat, many centers use a quadruple blood bag additive solution system which in this study has been reduced to a cheaper triple bag system. The buffy coat and plasma were after centrifugation transferred to the first satellite bag and, after a second spin, the plasma separated from the buffy coat was transferred to the second satellite bag and stored for a fortnight at 4 degrees C. This resulted in a statistically significant increase in platelet factor 4 and elastase activity levels. No significant changes were found in the levels of C1-esterase inhibitor and kallikrein inhibiting activity, thrombin-antithrombin complexes, soluble fibrin, fibrinopeptide A and spontaneous proteolytic activity. The changes observed must be regarded as clinically insignificant. The platelet count is low enough to meet the requirements for platelet poor plasma. Using this blood component separation technique, one can reduce the CPD/additive solution 4-pack blood bag system to a less expensive 3-pack blood bag system.