Risk of infection from blood and blood products in the context of the AIDS scandal in Germany.
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Acquired Immunodeficiency Syndrome↗
Biomedical subjects
V Kretschmer
Publications and source records attributed to V Kretschmer.
Determination of bleeding risk in thrombocytopenic patients with platelet transfusion therapy.
In a clinical study (50 thrombocytopenic patients) we determined the bleeding risk and the platelet transfusion efficacy by a special modification of the in vitro bleeding test (IVBT, Thrombostat 4000). Additionally, cell count, hematocrit, body temperature, platelet volume and distribution width, Simplate bleeding time and a bleeding score were investigated. The use of the modified IVBT proved to be promising to find a clearer indication of platelet transfusion and to estimate its efficacy.
Bleeding Time↗
Protocol and preliminary results of a clinical study for comparison of solvent/detergent-inactivated plasma VIP versus FFP with special consideration of the balance of hemostasis.
Solvent/detergent virus-inactivated plasma (VIP) contains markedly reduced protein S (PS) and alpha 2-antiplasmin (APL) beside other slightly decreased inhibitors. This could possibly be critical for the balance of hemostasis in diseases in which plasma inhibitors are reduced. A heterogeneous group of 14 patients with 18 plasma transfusions (12 FFP/24 VIP, 2 units per transfusion) was investigated. The patients suffered from dilution coagulopathy, liver disease, disseminated intravascular coagulation (DIC), hyperfibrinolysis, or received massive transfusions. Prothrombin fragment 1 + 2, fibrin monomers, D-Dimers, thrombin-AT III complexes, antiplasmin-plasmin complexes and fibrinogen degradation products as markers of activated coagulation (MAC) were measured. Blood samples were taken before and after plasma replacement. Significant differences between VIP and FFP should be recognized by comparing the ratio of MAC after/MAC before plasma transfusion. Patients showed an average inhibitor plasma level of AT III 51%, protein C 44%, PS 63%, and APL 52%. Only the F 1 + 2 ratio was obviously higher in the VIP group but not significantly. So the remaining MAC ratios did not show any significant difference. Our preliminary data showed no indication for a higher state of activation of coagulation in patients receiving VIP in comparison with those receiving FFP, if the VIP had the quality required. Solvent/detergent (SD) inactivation of transfusion-relevant viruses in plasma was successfully performed by Horowitz et al. [1]. The procedure leads to a partial reduction of the activity of clotting factors [2]. PS and APL are more severely affected. Therefore, treatment with VIP might activate or at least increase the activation of coagulation, especially in patients with reduced plasma inhibitors. To clarify this problem, the following disorders with the indication for plasma replacement were included in a prospective randomized study of FFP vs. VIP: massive transfusion; dilution coagulopathy; disturbance in liver synthesis; disseminated intravascular coagulation (DIC); primary hyperfibrinolysis. Low PS levels could induce hypercoagulability by reduced F VIII and FV inhibition, and low APL could induce hyperfibrinolysis by reduced plasmin inhibition.
Blood Coagulation Disorders↗
[Component removal from whole blood by means of gravity sedimentation].
Our aim was to establish a new method for the separation of long-term storable blood components (red blood cells in additive solution and frozen plasma) from whole blood by a gravity sedimentation technique with hydroxyethyl starch. This investigation should offer a cheap and technically simple method of blood separation as an alternative to whole blood storage, valuable for autologous blood to extend the presurgical donation period. Although the separation of 8 whole blood units was successful, this method cannot be recommended for routine application. It is still too complicated, difficult to standardize and too time-consuming. Additionally, the cell contamination of the plasma is too high.
Blood Donors↗
[ID and Bio Vue systems--comparison of two systems for the typing of erythrocyte antibodies].
The gel centrifugation test ID Microtyping was compared with the column agglutination test BioVue for antibody (AB) screening by testing serum samples of 3,000 patients under controlled conditions: enzyme test (ET; Bromelin) and LISS indirect antiglobulin test (IAT), both incubated for 15 min at 37 degrees C. From a total of 64 ABs, more relevant or possibly relevant ABs were detected by ID than by the BioVue system (63 vs. 56). ABs only detected in ID were: anti-D 3, -Jk(a), E 1, -Le(b)1, -e 1, -C 1, -E,S 1. One anti-Le(b) was only detected by BioVue. The calculated sensitivity was 98.4% for ID and 87.5% for BioVue. Furthermore, this study showed a lower frequency of unspecific reactions or reactions due to irrelevant cold ABs in the ID system (ID: 2.3%, BioVue: 4.0%, specificity 97.7 vs. 96.2%).
ABO Blood-Group System↗
[Value of positive auto controls in the gel centrifugation method].
We studied 97 samples of patients being positive in the autocontrol of the indirect antiglobulin test (IAT) in the gel system (DiaMed). In 83.2%, retesting with monospecific anti-IgG serum gave also positive results, due to a specific phenomenon caused, for example, by drug-specific antibodies (AB), warm auto-AB or allo-AB. In contrast, only 52.9% of the samples retested by the standard tube technique with polyspecific antiglobulin serum reacted positive. Only in 6 patients slightly increased cold agglutinins could be detected. None of the investigated patients showed any clinical or laboratory signs of hemolysis except one with pernicious anemia. We conclude that positive results of the autocontrol in the gel IAT should be confirmed by an additional DAT in the tube technique. If this second test shows a negative result, transfusions can take place without any restrictions.
ABO Blood-Group System↗
[Vacuum ether elution--a modification of the Rubin ether elution method].
The time-consuming ether elution of Rubin can be shortened by vacuum evaporation of the ether (< 10 min). The modification developed by us was compared with the conventional method investigating 103 blood samples with a positive direct antiglobulin test or a possible immunohemolysis. No significantly different results could be obtained with the two different elution methods.
Autoantibodies↗
[Effect of HPA-1a(PLA1) and HLA antibodies on platelet function, measured with the in vitro bleeding test].
The influence of platelet-specific and HLA antibodies on primary hemostasis was investigated by the in vitro bleeding test (IVBT). Seven of 12 plasmas with HPA-1a (PLA1) antibodies and two with antibodies against glycoprotein Ib/IX significantly inhibited the IVBT of normal cross-match-positive donor blood. This correlated with an increase of GMP-140 on the platelets determined by flow cytometry. Therefore the inhibition of the IVBT was interpreted to be due to rapid platelet activation by platelet-specific antibodies followed by an irreversible loss of function. In contrast, with HLA antibodies neither activation nor inhibition of the platelet function could be proven.
Antigens, Human Platelet↗
[Second multicenter study of thrombocytapheresis using the Fresenius AS104 blood cell separator and ring study for quality control of cell counts. Members of the Preparative and Therapeutic Hemapheresis Section of DGTI].
The aim of the 2nd Multicenter study was to evaluate the separation protocol software version V 4.61 of the Fresenius AS 104 cell separator, for separation efficiency, WBC contamination and yield's deviation from prediction. Plateletpheresis data from 12 hemapheresis centers, using identical apheresis protocols and cell counting methods, were registered and statistically analyzed. Additionally, the counting methods of the centers were controlled by a ring study with biweekly cell counts. To get a comparison the apheresis data, which were dependent of the center effects, were corrected by the systematical deviation found in the quality control from the ring study. The results of 935 runs are 47.3 +/- 8.1% for the separation effectivity. 7.2% median deviation from predicted yield, whereby 90% of all runs deviated less than +/- 22% from predicted yields. 50% of products had a WBC contamination below 6 x 10(6), 99% below 5 x 10(7).
Blood Component Removal↗
[Preliminary results of a prospective randomized clinical study on the comparison of solvent- and detergent-inactivated plasma (SDP-TNBT/Triton X-100) and untreated fresh-frozen plasma].
We report on preliminary results of a randomised clinical study comparing solvent/detergent-inactivated plasma to untreated FFP. Factors V, VII, VIII:C and protein S in the plasma units and in 14 patients were determined. Additionally, we measured prothrombin fragments 1,2, fibrin monomers, D-dimers, thrombin-antithrombin III, plasmin-antiplasmin complexes and fibrinogen degradation products as markers of activated coagulation (MAC), and calculated ratios of MACpost/ MACpre. One batch of SD plasma (SDP 797) with very high FVII and very low protein S seemed to produce significant changes in vivo without any clinical relevance. The bad quality of this batch could be due to virus inactivation in the early phase of large-scale routine production from a plasma pool that was too small.
Blood Coagulation Factors↗
[Shortening of acetylsalicylic acid-prolonged bleeding time by means of desmopressin].
The pathomechanism of desmopressin (DDAVP)-dependent shortening of the bleeding time prolonged by acetylsalicylic acid (ASA) was investigated by the Ivy bleeding time (BT) and the in vitro bleeding test (IVBT). Additionally, platelet aggregation and von Willebrand factor (vWF) were determined. The possible effect on plasma or platelets was examined by blood compositions containing citrated whole blood after ingestion of ASA plus either plasma or platelets after application of DDAVP (control: plasma or platelets after ASA). Excellent correlations were found between BT and IVBT as well as vWF (r2 = 0.97-0.99). In contrast, platelet aggregation decreased after administration of DDAVP. Experiments with blood compositions showed an effect of plasma and platelets as well in the IVBT after DDAVP administration. The results demonstrate the superiority of the IVBT to describe the in vivo function of platelets in comparison with the platelet aggregation test.
Aspirin↗
[Risk assessment and diminution in preoperative autologous blood donation].
Preoperative autologous blood donation is only indicated if a positive balance between benefit and risk can be struck. In this contribution the different aspects to be considered are described and valued. By a mathematical formula we try to correlate the different aspects somewhat more objectively. In addition, we define 4 risk groups by the state of health of the patients which allow to estimate the risk of the patient by blood donation more easily and help to reduce it by selection of the appropriate donation procedure.
Blood Donors↗
[Comparison of thrombocyte concentrates from buffy coats after 3 and 16 hours of storage].
Since extended storage of the buffy coat (BC) might be disadvantageous for the platelet function because of granulocyte proteases we investigated platelet concentrates (PC) prepared from BC which rested either for 3 h (n = 18) or 16 h (n = 41) before further preparation. We found significant differences especially in the morphology score, pH and lactate in favour of the PC from 3-hour-BC. The differences decreased during the 5-day storage. PC of unacceptable quality (n = 4) only derived from 16-hour-BC. Therefore, the use of PC from BC stored for more than 4 h at least requires an adequate quality control before delivery.
Blood Platelets↗
[Evaluation of a noninvasive method for storage control of platelet concentrates].
We evaluated a system for storage of platelet concentrates (PC) which is thought to monitor the platelet function during storage by measuring the light transmission (Plateguard). Platelet function, morphology and metabolism altered during storage as usually. But the alterations did not correlate to light transmission. Only PC with very strong changes and final pH lower than 6.0 (4 of 59) showed different light transmission (exponential curves). Nevertheless the Plateguard can detect these unsuitable PCs if the software would be modified as proposed. In addition, several technical improvements are necessary before routine use.
Blood Platelets↗
Improvement of separation efficiency and concentrate purity of the Fresenius cell separator AS 104: results of a multicenter study. Haemapheresis Scientific Workshop Group of DGTI.
The aim of this multicenter study, initiated by the Haemapheresis Scientific Workshop Group of the DGTI was to evaluate separation protocols for the cell separator AS 104, marketed by Fresenius, using modified software and parameters which were believed to allow a more effective platelet collection with a significantly lower leukocyte contamination of the concentrates. Plateletpheresis data from 950 runs in ten hemapheresis centers, using virtually the same equipment, identical pheresis protocols, and cell counting methods were registered and statistically analyzed for each center and machine-related differences. Additionally, the counting methods of the centers were controlled by bi-weekly external cell count trials, and the plateletpheresis data were corrected using the results of these cell count trials, to obtain a comparison of the two versions of the protocol independent of the center effect. For protocol (or software version) 4.1, 610 runs were registered. The results of cell countings (chamber) are (given as means+/-standard deviations) 3.452x10 11+/-1.009x10 11 for the platelet yield (or thrombocyte yield), 9x10 6+/-23x10 8 for leukocyte contamination, and 17x10 6+/-70x10 6 for the erythrocyte contamination, and 53%+/-13.5% for the extraction efficiency, respectively. For software version 4.4 with 340 runs, the results are 3.642x10 11+/-0.974x10 11 for the platelet yield, 15x10 6+/-74x10 8 for leukocyte contamination, 20x10 6+/-44x10 6 for erythrocyte contamination, and 59%+/-12.4% for the extraction efficiency, respectively. For the leukocyte and erythrocyte contaminations, the means and standard deviations must be interpreted carefully since the statistical distribution showed a considerable skewing of the data. From the automatic counts, marginally smaller means were found. The data were corrected by the values from the ring study; and for these mathematically corrected data, statistical tests showed a significant improvement in the extraction efficiency from software version 4.1 to 4.4. At the same time, the leukocyte contamination was significantly lower with version 4.4.
Blood Component Removal↗
Multicenter study of standardization of cell counting. Haemapheresis Scientific Workshop Group of DGTI.
Multicenter studies on cell separators give valid data (which can be compared between the different centers) only if the cell counting methods are uniform. This has to be demonstrated by ring studies or multicenter counting studies. Twelve apheresis centers involved in a multicenter study for the evaluation of the Fresenius AS 104 cell separator participated in such a ring study from July 1990 to July 1991. The twelve participating centers split into three significantly different groups according to the platelet counts in the platelet concentrates and a calculated pseudo extraction efficiency. No differences could be found in the white and red blood cell counts. No mailing effect--or time effect--and no personal effect could be found in the reference center.
Blood Component Removal↗
[Indications and risks of autologous blood donation in pregnancy].
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Adult↗
[Autologous blood transfusion as whole blood or blood components?].
Modern haemotherapy is equivalent to restrictive use of blood components. Therefore, transfusion of whole blood in homologous transfusion generally cannot be accepted. In autologous blood transfusion blood components also are preferable if they can be separated appropriately. In order to have broad application of preoperative autologous blood deposits, close cooperation to transfusion services should be established guaranteeing optimal production of blood components. If this cooperation is impossible there are no objections against the use of autologous whole blood as long as the expected blood consumption is less than 3 red cell units. Additionally, in this case storage of more than 3 weeks mostly is not necessary. The fact that whole blood is not further part of the 'Monographien' of the Federal Health Administration (BGA) does not forbid the use of autologous whole blood since the 'Monographien' only concern generally available homologous blood components.
Blood Component Transfusion↗