摘要:

AbstractThe fibrinogen clotting time (FCT) is a measure of thrombin activity, and is used to evaluate the potential thrombogenicity of prothrombin complex concentrates (PCC). We have defined end points for clot formation in this test which allow the measurement in PCC of thrombin concentrations as low as 0.001 IU/ml. The FCT of thrombin and PCC samples which did not contain antithrombin III (ATIII) were the same when measured at 20°C or 37°C. In the presence of ATIII (0.05 or 0.25 IU/ml), samples of PCC which were known to contain thrombin showed shorter FCT at 20°C than at 37°C. Inclusion of both ATIII (0.25 IU/ml) and heparin (4 IU/ml) in PCC ensured the complete inactivation of endogenous throm

ISSN:0042-9007    

DOI:10.1111/j.1423-0410.1994.tb00268.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractAn enzyme‐linked immunosorbent assay (Elisa) method was developed in order to examine prevalence and titer of antibodies directed against the factor VIII coagulant protein (F.VIII:C) in hemophilia A and nonhemophilia A patients. Highly purified F.VIII:C was used as immunosorbent on microtiter plates with a peroxidase‐conjugated goat anti human IgG antibody for F.VIII:C antibody detection. Results determined by Elisa were compared with measurements according to the Bethesda method. Initially 24 plasma samples containing an F.VIII:C inhibitory activity ranging from 0 to 7,700 Bethesda units (BU) were analysed. At plasma dilutions of 1:128 the optical density determined by our Elisa measurement and the corresponding BU showed a logarithmic correlation. The coefficient of correlation was r=0.92 with a standard deviation of 0.002 from the regression curve. Plasma samples were analysed from 53 hemophilia A patients, from 21 nonhemophilia patients with acquired F.VIII:C antibodies and from 460 randomly selected nonhemophilia patients presenting for routine preoperative coagulation examination. F.VIII:C antibody‐positive Elisa results and positive BU were found in 7 hemophilia A patients and the 2 patients with a history of acquired F.VIII:C antibodies. Positive Elisa results and negative BU were found in 1 hemophilia A patient and 25 out of 460 nonhemophilia A patients (5.43%) suggesting F.VIII:C antibodies without inhibitory potency on F.VIII:C in these cases. The Elisa method proved to be suitable for F.VIII:C antibody screening in hemophilia and nonhemophilia patients. The Elisa protocol is easy to repr

ISSN:0042-9007    

DOI:10.1111/j.1423-0410.1994.tb00269.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractThe effect of the prestorage removal of leukocytes from platelet concentrates (PC) on the cytokine levels during its storage was studied. Two methods for leukocyte removal were examined: filtration and preparation of the PC by the buffy coat method. Cytokine levels were measured at various storage times. Highly increased levels of tumor necrosis factor‐α (TNF‐α; 120±131 ng/l) and interleukin 6 (IL‐6; 988±494 ng/l) were found after a 5‐day storage in the control group, whereas no increased levels were found in filtered PC (TNF‐α 14±4 ng/1, IL‐6<4 ng/l) or in buffy coat PC (TNF‐α 8±2 ng/l, IL‐6<4 ng/l). Furthermore an effect of the pooling of buffy coats or PC on the cytokine levels was not found. Transfusion of PC containing high levels of IL‐6 and TNF‐α has been associated with febrile transfusion reactions in the recipient and therefore the prestorage leukocyte removal might prevent these febrile transfusion reactions. The preparation of buffy coat PC, through its simplicity, seem

ISSN:0042-9007    

DOI:10.1111/j.1423-0410.1994.tb00270.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractPlatelet concentrates (PC) were stored for 6 days in either polyolefin (PO) or polyvinylchloride/di‐(2‐ethylhexyl)phtalate (PVC/DEHP) bags in 100% plasma or in a synthetic medium with 35 or 10% plasma. For all conditions studied the usual in vitro parameters were well maintained, with a pH above 6.8. In both bag types platelets can be satisfactorily stored for 6 days in a synthetic medium with minimal amounts of residual plasma. For this medium, the PO bag offers a slight advantage with respect to the preservation of platelet ATP content (>80 versus>70% in the PVC bags) and aggregation and adhesion capacity. The adhesion capacity increased in the PO bags, while it decreased in the PVC b

ISSN:0042-9007    

DOI:10.1111/j.1423-0410.1994.tb00271.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractTwo wet workshops were conducted involving 20 laboratories to determine optimum methods for counting residual white blood cells (WBC) in leukocyte‐depleted red blood cells (RBC). In both studies, calibration samples containing known concentrations of WBC were prepared by diluting 1‐day‐old EDTA blood in RBC virtually free of WBC. Study No. 1 was aimed at determining the lower limit of detection and at examining advantages and disadvantages of two methods based on flow cytometry (FC) and on the Nageotte chamber (NC), respectively. This study showed that the lower detection limits for FC and NC were 0.1 and 1WBC/μl, respectively. Methods based on FC showed less variability at 0.1–1 WBC/μl but were equal in performance to counting procedures based on the NC above 1WBC/μl. We then designed study No. 2 to evaluate three different protocols using the NC. In protocol 1, samples were diluted 1:10 with Plaxan and with Türk's solution; in protocol 2 a mixture of Türk's solution and Zap‐oglobin, a reagent used in manual hemoglobin determinations, was used to dilute the samples 1:5; and protocol 3 involved initial 1:10 dilution of a 1‐ml sample with Plaxan followed by WBC concentration into the original 1‐ml volume by centrifugation. In each participating laboratory, two technologists independently processed the samples and read the results with an NC. Plaxan and Türk's solution gave comparable results. Interobserver variability was not critical to the results. All three NC methods were valid for counting at concentrations of 1 WBC/μl. Protocol 3 showed the greatest precision, allowing the measurement of WBC at concentrations of 0.1–1/μl (30,000–300,000 WBC in a 300‐ml RBC unit) with a coefficient of variation of approximately 50% or less. Based on these results the Biomedical Excellence for Safer Transfusion (BEST) Working Party considers all three NC protocols adequate for the routine evaluation of current leukocyte removal filters, i.e. at levels ≥1 WBC/μl. The evaluation of new and more effective filters and validation of filter performance may require techniques with a greater precision at counts below 1 WBC/μl, such as protocol 3. For the latter purposes FC is also applicable. Because the counting techniques were not validated using stored blood, these conclusions only apply to samples obtai

ISSN:0042-9007    

DOI:10.1111/j.1423-0410.1994.tb00272.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractThe 2nd‐generation anti‐HCV test system was applied to a Saudi Arabian multi‐ethnic donor population. When donors were stratified according to first‐time donations versus repeat donations, the latter having been screened previously by a 1st‐generation set of tests, it was found that in Saudi Arabian and Middle East nationals, the 2nd‐generation tests (EIA and RIBA), identified close to double the number of anti‐HCV‐positive donors, compared to an earlier study using the 1st‐generation tests. Part of this finding was due to a 38% higher rate of RIBA‐confirmable repeat‐positive EIA results. In groups of donors, previously screened by the 1st‐generation system, some additional cases of anti‐HCV reactivity were identified, most prominently in Middle East nationals. It is assumed that some of these represented recent seroconversions, while others were cases of serologic subtypes of HCV, not reacting in the 1st‐generation tests. The current test system identifies 0.66% of Saudi‐Arabian, and 2.87% of other Middle East donors as putative carriers of hepatitis C virus. The study lends support to the opinion that donors who return regularly over the years have a lower prevalence of disease markers, thereby being a safer source of

ISSN:0042-9007    

DOI:10.1111/j.1423-0410.1994.tb00273.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractWe reported recently that anti‐Fab autoantibodies of the IgG isotype are associated with the decrease of helper/inducer (CD4+) lymphocytes in human immunodeficiency virus‐infected (HIV+) hemophilia patients with acquired immunodeficiency syndrome (AIDS) or AIDS‐related complex (ARC). In the present study we investigated the subclass distribution of IgG‐anti‐Fab autoantibodies, and whether anti‐Fab antibodies of the IgA and IgM isotypes also are associated with the development of AIDS. Sera of HIV+ patients with AIDS had significantly higher IgA‐anti‐Fab activity than HIV+ patients with ARC (p<0.02), HIV+ patients without AIDS/ARC (p<0.0001), HIV‐negative (HIV‐) patients (p<0.001), or healthy controls (p<0.0001). An inverse association was found between IgA‐anti‐Fab activity and CD4+ cell counts (r = ‐0.396, p<10‐6). In contrast, no association of CD4+ cell counts was observed with IgM‐anti‐Fab. However, IgM‐anti‐Fab was significantly increased in patients with thrombocytopenia. We found a significant association between IgA‐anti‐Fab activity and serum neopterin concentrations (r = 0.310, p<10‐5). IgG‐anti‐Fab activity was detected mainly in the IgG3 fraction, although in HIV+ patients with AIDS/ARC various IgG subclasses were present. Affinity‐purified anti‐Fab antibodies isolated from sera of AIDS patients bound to rgp120‐preincubated CD4+ cells of a healthy individual, supporting our hypothesis that anti‐Fab antibodies and free circulating gp120 molecules are involved in the elimination of uninfected CD4+ cells. Removal of anti‐Fab autoantibodies from the circulation by immune adsorba

ISSN:0042-9007    

DOI:10.1111/j.1423-0410.1994.tb00274.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractWe report a case of clinically significant hemolytic disease of the newborn due to Kpballoimmunisation requiring obstetric intervention. This case and a review of the literature are in contrast to reviews of hemolytic disease of the newborn that either ascribe no significance to the Kpbantigen or suggest that it causes only rare or mild disease. Analysis of our Kpb‐negative donor pool suggests that prior transfusion greatly increases the chance of alloimmunisation. The role of frozen rare donor registry cells as a public resource is emphasise

ISSN:0042-9007    

DOI:10.1111/j.1423-0410.1994.tb00275.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractPure anti‐Doastimulated by pregnancy was detected in 2 non‐transfused females during routine antenatal screening. Anti‐Doaoccurs rarely and has generally been reported in combination with other antibodies. The first, and only report to date, of pure anti‐Doawas also stimulated by pregancy. We believe these instances to be only the second and third reported cases of pure a

ISSN:0042-9007    

DOI:10.1111/j.1423-0410.1994.tb00276.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractA human‐mouse heterohybridoma (HMR0921) secreting human monoclonal IgG3, Λ antibody was produced from peripheral blood lymphocytes of a healthy blood donor with serum antibody to Jra, by EBV transformation and hybridization with mouse myeloma cell line P3X63Ag8.653. The reactivity of HMR0921 antibody was assessed by antiglobulin test with a panel of red cells including 14 different rare blood types. Only Jr(a‐) red cells were negative. The strict specificity of this antibody to Jraantigen was further confirmed by absorption test with fluorescence flow cytometry. On screening of 28,744 blood donor samples by HMR0921 antibody, we detected 19 agglutination‐negative samples, which were confirmed as Jr(a‐) by conventional anti‐Jraantisera. Therefore, our HMR0921 antibody is extremely useful for detecting rare Jr

ISSN:0042-9007    

DOI:10.1111/j.1423-0410.1994.tb00277.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY