ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1994.34494233573.x

出版商:Blackwell Science Ltd    

年代:1994

数据来源: WILEY

摘要:

Background: For persons newly infected with the human immunodeficiency virus type 1 (HIV‐1), the time from the onset of infectivity to the development of detectable HIV‐1 antibody is unknown. Persons who donate blood during this period account for nearly all instances of HIV‐1 transmission from HIV‐1 antibody‐screened blood transfusions.Study Design and Methods: To estimate the window period from infectivity to HIV‐1 antibody positivity, 701 HIV‐1‐seropositive blood donors who made a previous seronegative donation at 40 United States blood centers were studied. The HIV‐1 antibody status was determined for at least one recipient of blood from the seronegative donation preceding the seropositive donation made by 182 of the 701 donors.Results: There were 39 seropositive recipients of blood from these 182 donors. Three donors were excluded from further analysis because the seropositive recipients of their blood had other HIV‐1 risk factors or had HIV‐1 infection before transfusion. The final study population comprised the remaining 179 donors, of whom 36 (20%) transmitted HIV‐1 infection to recipients. When the interval between the seropositive donation and the preceding seronegative donation was less than 180 days, 46 percent of the donors transmitted HIV‐1. In contrast, when that interval exceeded 540 days, only 2 percent transmitted HIV‐1. A mathematical model was developed to explain the relationship between the probability that the previous seronegative donation occurred during the donor's window period of infectiousness, and hence transmitted HIV‐1, as a function of both the window period and the duration between the seropositive and previous seronegative donations. This model indicated that the transmission data were most consistent with an average window period of 45 days. Assuming a log‐normal window period distribution, it was estimated with 95 percent certainty that at least 90 percent of persons had a window period of less than 141 days.Conclusion: The window period averages 45 days, with few, if any, donors remaining infectious and serone

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1994.34494233574.x

出版商:Blackwell Science Ltd    

年代:1994

数据来源: WILEY

摘要:

Background: Inappropriate transfusion in cardiac surgery may, in part, be due to empiric transfusion therapy instituted in the absence of timely laboratory data. Therefore, the effect of a transfusion decision algorithm based on intraoperative coagulation monitoring of physicians' transfusion practice and the transfusion outcome was evaluated.Study Design and Methods: In a randomized, controlled trial, cardiac surgical patients determined to have microvascular bleeding at the cessation of cardiopulmonary bypass were assigned to algorithm (A) or standard (S) therapy. Group A was treated with plasma and platelet therapy according to a transfusion algorithm based on on‐site coagulation data available within 4 minutes. For Group S, the use of laboratory‐based data and the decision to transfuse blood components were at physician discretion.Results: Sixty‐six patients were entered into the study (Group A, n = 30; Group S, n = 36). Other than the fact that there were significantly more female patients in Group S than in Group A, no differences between cohorts in regard to perioperative risk factors for blood transfusion needs were identified. Therefore, gender was factored in as a covariate in the statistical analysis. Group A patients received fewer hemostatic blood component units (p = 0.008) and had fewer total donor exposures (p = 0.007) during the entire hospitalization period. Linear regression analysis of the differences in slopes in Groups A and S for the relationships between the red cell volume lost and the red cell volume transfused (p<0.03), non‐red cell units transfused (p<0.0001), and total number of blood components transfused (p<0.0001) demonstrated that physicians' transfusion practice was significantly altered by the use of a transfusion algorithm with on‐site coagulation data, independent of surgical blood losses.Conclusion: The use of algorithms by transfusion decision makers can serve as an effective physician education int

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1994.34494233575.x

出版商:Blackwell Science Ltd    

年代:1994

数据来源: WILEY

摘要:

Background: Recently, proinflammatory cytokines including interleukin 1 (IL‐1) have been implicated in the pathophysiology of immune‐mediated hemolysis. Little is known, however, about the mechanisms by which inflammatory events in these reactions may be downregulated. IL‐1 receptor antagonist (IL‐1ra) inhibits the actions of IL‐1 by competition for cellular receptors, and thus it may regulate the biologic actions of IL‐1 during immune‐mediated hemolysis. The production of IL‐1ra by peripheral blood mononuclear cells (PBMNCs) in response to IgG‐coated red cells in vitro was investigated.Study Design and Methods: Fresh PBMNCs were obtained by density gradient separation of heparinized whole blood. PBMNCs were cultured in the presence of anti‐D‐coated, Rh‐positive red cells or uncoated Rh‐ negative red cells under nonadherent conditions. IL‐1ra concentrations in the culture media were measured by enzyme‐linked immunosorbent assay.IL‐1raandIL‐1β gene expression was assessed by Northern blot analysis of PBMNC mRNA.Results: IL‐1ra production was evident 4 hours after stimulation with IgG‐coated red cells and increased progressively over 24 hours. Gene expression of IL‐1ra was first detected at 2 hours, lagging behind that of IL‐1β.IL‐1ragene expression was not inhibited by neutralizing polyclonal antibodies to IL‐1. Immunocytochemical staining to determine the cellular source localized IL‐1ra production to monocytes engaged in erythrophagocytosis. IL‐1ra production was inhibited by dexamethasone (10−7M).Conclusion: These results suggest that IL‐1ra production may partly account for the variable pathophysiologic events seen in IgG‐ mediated autoimmune hemolysis and hemolytic transfusion reactions. Steroid treatment may also downregulate

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1994.34494233576.x

出版商:Blackwell Science Ltd    

年代:1994

数据来源: WILEY

摘要:

Background: Sepsis and death subsequent to the transfusion of blood containingYersinia enterocoliticais an increasing problem. The organisms probably originate from bacteremia in the donor and can subsequently multiply at low temperature.Study Design and Methods: Reported here are experiments with a strain ofY. enterocoliticaassociated with a case of transfusion‐associated bacteremia.Results: It was found that the rapid early killing ofY. enterocoliticainjected into donated blood does not require viable phagocytes and can be explained by complement‐mediated killing. Complement resistance inY. enterocoliticais known to be plasmid‐coded. It is expressed at 37°C, but not at 20°C, and is favored by calcium‐deficient culture media.Y. enterocoliticaorganisms induced to express complement resistance were still killed in donated blood, though the initial rate was slower. Such organisms multiplied in plasma at 37°C, but were killed after 6 hours of incubation at 20°C, presumably because complement resistance genes are switched off at this temperature.Conclusion: This experiment is thought to reflect the natural history of Y.enterocoliticacontamination of blood, in which complement‐resistant organisms in the donor blood encounter lower temperatures after donation. These observations suggest that the practice of plasma depletion may have contributed to the increased incidence of mortality due to Y.enterocoliticacontamination of

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1994.34494233577.x

出版商:Blackwell Science Ltd    

年代:1994

数据来源: WILEY

摘要:

Background: Posttransfusion complications can be prevented by pretransfusion removal of donor white cells from platelet concentrate. The filtration used for this removal seems to have little effect on platelet function and activation, but more information is needed on its effect on function during subsequent long‐term storage of concentrate.Study Design and Methods: The effect of prestorage filtration of buffy coat‐prepared platelet concentrates (PCs) on platelet function, metabolism, and activation was investigated. A pool of three PCs, each made of four buffy coats, was split into three equal volumes; two were filtered over two different filters and the third served as a control. Variables monitored immediately after filtration and during the subsequent 8‐day storage period at 22°C included aggregation upon stimulation with collagen and/or ADP, platelet adhesion capacity to collagen and fibrinogen in flowing blood, nucleotide content of and nucleobase release by the platelets, expression of activation‐dependent antigens, and β‐thromboglobulin release by the platelets.Results: No differences were observed between the PCs filtered over two different filters and the nonfiltered control PCs immediately after filtration and during storage, except for a selective removal (20%) of β‐thromboglobulin by one filter.Conclusion: PCs prepared from a pool of four buffy coats can be filtered and subsequently stored for 8 days (starting +/− 24 hours after whole blood collection) without detriment to platelet function, metabolis

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1994.34494233578.x

出版商:Blackwell Science Ltd    

年代:1994

数据来源: WILEY

摘要:

Background: When platelet concentrates (PCs) are shipped over long distances, it is not always possible to ensure that their temperature is maintained at 20 to 24°C. In addition, PCs are not agitated as during routine storage.Study Design and Methods: Studies have been conducted to evaluate how exposure to temperatures below 20°C in the absence of agitation influences properties of platelets. In initial studies, exposure to 4°C for 3 or 5 hours or to 12°C for 5 or 17 hours on Day 2 of a 5‐ to 6‐day storage period was associated with a loss of discoid shape. This was reflected by slightly lower but statistically different morphology scores after storage compared to those observed with control platelets that were stored only at 20 to 24°C. In addition, a qualitative difference in morphology was noted in controls and PCs held at 16°C for 17 hours. In more detailed studies, both the in vivo viability and in vitro properties of platelets exposed between Day 1 and Day 2 to either 12°C or 16°C for 17 hours were evaluated. The protocol involved a paired study design (n = 4 for each exposure temperature) with the simultaneous storage of two identical PCs, one exposed to 12 or 16°C and the other one maintained at 20 to 24°C throughout the 5‐day storage.Results: Exposure to 12°C significantly reduced (p<0.05 by paired t test) the in vivo recovery to 37.6 ± 13.8 percent (mean ± 1 SD) from 47.8 ± 11.5 percent and the survival time to 2.0 ± 0.3 days from 6.5 ± 1.4 days. On exposure to 16°C, the differences in viability from those of control units were much less but still significant. The in vivo recovery was 42.7 ± 3.8 percent compared to 49.2 ± 3.0 percent and the survival time was 3.5 ± 1.2 days compared to 6.6 ± 0.3 days. The loss of in vivo viability of the test platelets was associated with a loss of discoid shape, as reflected by morphology scores, extent of shape change, and mean platelet volume. In addition, platelet metabolism also appeared to be affected, as suggested by increased lactate production. All of the in vitro properties except for total ATP and residual glucose that were statistically different from those of controls on exposure to 12°C were also significantly different on exposure to 16°C.Conclusion: These findings demonstrate that platelets undergo substantial changes in in vivo viability and in vitro properties when they are exposed to temperatures

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1994.34494233579.x

出版商:Blackwell Science Ltd    

年代:1994

数据来源: WILEY

摘要:

Background: The purpose of this study was to evaluate an iodine‐based method of activating potentially harmful viruses that might be found in normal human plasma.Study Design and Methods: A procedure has been developed for inactivating lipid‐enveloped and non‐lipid‐enveloped model viruses in normal human plasma by using iodine complexed to crosslinked potato starch. The established conditions are an iodine concentration of 1.05 mg per mL and 60 minutes' incubation.Results: Under these conditions, inactivation of more than 9 log10of vesicular stomatitis virus, a lipid‐enveloped virus, and more than 7 log10of encephalomyocarditis virus, a non‐lipid‐enveloped virus, was achieved, with minimal losses of biologic activity of selected plasma proteins. Under these conditions, 70 percent of factor VIII activity, 77 percent of factor IX activity, and 100 percent of protein C activity in the plasma were retained.Conclusion: Crosslinked starch‐iodine may be useful in the inactivation of viruses in single‐donor plasma units and in pooled human plasma bef

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1994.34494233580.x

出版商:Blackwell Science Ltd    

年代:1994

数据来源: WILEY

摘要:

Background: During aging of red cells they undergo a multitude of physical and chemical changes.Study Design and Methods: Age‐dependent changes in the expression of ABH major blood group antigens on red cells were studied in a two‐variable flow cytometric analysis. The expression of the antigens was measured after staining with fluorescence antibodies (for A and B) or lectin (for H). Cell age was related to size as measured by forward light scattering. Aging senescent cells are smaller and have low forward light scattering properties.Results: The results indicated that, within a given population, the A and/or B and H antigens decreased with the decrease in forward light scattering (i.e., increase in age), but A and B antigen expression decreased to a greater extent than did H.Conclusion: During aging, red cells lose the antigens of the major blood groups, but the degree of this loss is related to the fact that these antigens are located on the cell surf

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1994.34494233581.x

出版商:Blackwell Science Ltd    

年代:1994

数据来源: WILEY

摘要:

Background: Monoclonal antibody 148 is a murine monoclonal anti‐ glycophorin B that preferentially reacts with S+ human red cells.Study Design and Methods: Serologic and immunochemical studies were performed using red cells with various phenotypes.Results: These studies reveal that this monoclonal antibody is unusual in that it fails to agglutinate S+ TSEN+ red cells and agglutinates S‐ St(a+) and S‐ Dantu+ red cells.Conclusion: These results allow the prediction of the glycophorin composition of GP.Hop (Mi.IV) red

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1994.34494233582.x

出版商:Blackwell Science Ltd    

年代:1994

数据来源: WILEY