The preparation of platelet concentrates by automated apheresis started in the early 1970s. Originally intended to increase the amount of platelets from selected (HLA compatible) donors to supply HLA-immunized patients, plateletpheresis has permanently expanded. Further development of plateletpheresis is described. Considering medical and economical perspectives, actual trends and possible future developments of plateletpheresis are discussed. Copyright 2000 S. Karger GmbH, Freiburg
Background: Phagocytosis represents a cornerstone in defence against infection as well as in wound healing process. Several reports are describing a negative influence on phagocytosis by hydroxyethyl starch (HAES). The aim of our study was to examine the effect of red blood cell packs (RCP), fresh frozen plasma (FFP) and HAES on leukocyte phagocytosis in human whole blood by an in vitro model. Materials and Methods: Heparinized blood samples of 20 healthy probands were incubated with probes of FFP, RCP and HAES for 30 min. Afterwards phagocytic activity in whole blood was measured with opsonized fluorescent Escherichia coli. A flow cytometer (FACScan) with an excitation wavelength of 488 nm was used. Human leukocytes were separated by live gating at 630 nm red fluorescence. For phagocytosis assay, FITC fluorescence was measured at 530 nm. Phagocytic activity was determined for monocytes and granulocytes separately. Results: In healthy persons there was no significant influence on phagocytosis in vitro neither by FFP and RCP nor by HAES incubation. However, after incubation with HAES and FFP there was a greater deviation from the whole blood sample than in the samples incubated with RCP.
Objective: Varying regimens of volume replacement are available. In today’s climate of cost consciousness and cost contain-ment it appears to be of interest to assess effective costs associated with the different fluid therapies. Design: Prospective, randomized study. Setting: Single-institutional, clinical investigation in an urban, university-affiliated hospital. Patients and Methods: 150 patients undergoing major abdominal surgery were divided into three groups. Perioperatively and until the first postoperative day, patient group 1 (n = 50) received 6% low-molecular weight hydroxyethyl starch (HES) (mean molecular weight (MW) 70 kDa, degree of substitution (DS) 0.5; HES 70/0.5), patient group 2 (n = 50) 6% medium-molecular weight HES (MW 200 kDa, DS 0.5; HES 200/0.5), and patient group 3 (n = 50) 3% modified fluid gelatin (MW 35 kDa) to keep mean arterial blood pressure (MAP) >70 mm Hg and central venous pressure (CVP) between 10 and 14 mm Hg. Results: The patients did not differ with regard to biometrics, type of surgery, and postoperative care. Hemodynamics (MAP, CVP), degree of hemodilution (hemoglobin), kidney (creatinine plasma level), liver (cholinesterase), and pulmonary function (paO2/FIO2) were without significant differences within the study. No differences were seen concerning blood loss, use of packed red blood cells (PRBC) and fresh frozen plasma (FFP). Significantly more gelatin (2,590 ± 500 ml) than HES 70/0.5 (2,130 ± 460 ml) and HES 200/0.5 (1,680 ± 430 ml) was given during the study period. Entire costs for volume replacement (in EUR and in USD) were significantly highest in the HES 70/0.5 group (118.25 EUR/patient, 134.45 USD/patient), whereas costs in the HES 200/0.5 (99.66 EUR/patient, 113.35 USD/patient) and the gelatin group (98.57 EUR/patient, 112.06 USD/patient) did not differ. Conclusions: Maintaining quality of patients’ care and simultaneously lowering costs represents a challenge. The type of fluid used for volume replacement continues to be debated. From the economic point of view, the use of gelatin offers no advantage compared to the use of HES 200/0.5. Only using HES 70/0.5 for volume therapy may result in some increases in costs.
Background: Reduced levels of protein S (PS) and alpha(2)-antiplasmin alpha(2)-AP) in solvent/detergent virus-inactivated plasma (S/D-VIP) might induce an imbalance of plasma coagulation factors and inhibitors in patients transfused. We investigated 40 patients (23 fresh frozen plasma (FFP), 17 S/D-VIP, random distribution by a list calculated by statisticians) who suffered from dilution coagulopathy, liver disease, disseminated intravascular coagulation (DIC), polytrauma or were connected to extracorporeal circulation. Study Design and Methods: The following markers of activated coagulation (MAC) were measured: Prothrombin fragment F1+2 (F1+2), fibrin monomers (FM), D-dimers (DD), thrombin-antithrombin (TAT) and plasmin-antiplasmin (PAP) complexes as well as fibrinogen degradation products (FgDP), and additionally antithrombin III (antithrombin), protein C (PC), PS and alpha(2)-AP. Blood was taken only just before and 1 h after the first plasma replacement (2 units). No additional blood products were transfused before the second blood withdrawal. Pre- and posttransfusion (pre/post) values of all parameters measured were compared within the same group and between both groups. Statistical evaluation of the data was done by Wilcoxon's paired test for data in the same plasma group and by the test of Mann and Whitney for data comparison between both plasma groups. Results: Average pretransfusion values of all inhibitors for both plasma groups were in the same range and increased after transfusion, except for PS in both groups. Whereas the pre/post values did not differ significantly in the FFP group, antithrombin (p = 0.02), PC (p = 0.0005), and alpha(2)-AP (p = 0.02) showed a significantly higher increase in the S/D-VIP group. Considering the pre/post differences between both plasma groups, there were no significant differences. The same was true for MAC measured pre- and posttransfusion. Conclusion: Data showed no significant difference between both plasma groups, indicating that S/D-VIP plasma behaves as FFP under the study conditions employed. Copyright 2000 S. Karger GmbH, Freiburg
Of all human herpesviruses, human cytomegalovirus (HCMV) is the most significant cause of transfusion-associated (TA) morbidity and mortality. The problem of TA HCMV infection differs from that of other transfusion-transmitted infections in that only certain groups of patients require HCMV-free blood or blood components, i.e. seronegative pregnant women, premature infants of low birth weight who are born to seronegative mothers, seronegative recipients of allogeneic bone marrow transplants from seronegative donors, seronegative AIDS patients, and seronegative immunosuppressed patients in general. HCMV is strictly cell-associated, and transmission appears to be due to reactivation of latent virus in white blood cells. TA HCMV infec-tion in risk groups can be minimized by selection of HCMV-seronegative donors. Since transmission of HCMV from seropositive donors by blood components containing fewer than 10 7 leukocytes per unit is unlikely, leukodepletion of transfusion products by filtration is an effective alternative to the use of seronegative blood products. Other human herpesviruses causing TA infections are Epstein-Barr virus (EBV) and the human herpesviruses 6 and 7 (HHV-6, HHV-7), whereas transmissions of herpes simplex viruses (HSV-1, HSV-2) and varicella-zoster virus (VZV) by blood transfusion - if occurring at all - are extremely rare events. Frequency and clinical significance of TA infections with the human herpesvirus 8 (HHV-8) have not yet been fully elucidated. Despite the low seroprevalence of HHV-8 in Germany, its oncogenic potential merits attention, and strategies to prevent transmission and spread of HHV-8 by blood and blood products should be discussed. Copyright 2000 S. Karger GmbH, Freiburg
In order to improve the process control of bedside filtration, a multisampling procedure was evaluated. Serial samples of postfiltration blood were collected, and white blood cells (WBCs) were counted by a microdroplet fluorochromatic assay. The kinetics of the bedside filter efficiency was shown to be nonlinear, with a saturation-like pattern owing to leukocyte escaping mostly during the second half of the filtration procedure. Multisample procedure allows the computation of the actual amount of filter-escaping leukocytes, while evaluation of filter-escaping leukocytes computed on the basis of a single-point sample (postfiltration terminal segment) may give misleading results and an overestimation of the number of filter-escaping WBCs.
Forthcoming shortfall of blood products and persisting concerns about viral transmission and immunosuppressive side effects of allogeneic blood transfusion have reinforced the studies with alternative oxygen carriers in the last years. Modern perfluorochemicals and cell-free hemoglobin solutions can be applied without prior cross-matching and are now available as stable formulations with long shelf life. Both groups of oxygen carriers have shown their effectivity and tolerability in numerous animal studies. An emulsion of perflubron which has a 60% weight/volume relation is actually undergoing phase III studies with respect to its effectivity in augmented acute normovolemic hemodilution since it has been shown to reverse hemodynamic transfusion triggers. While clinical studies with human cross-linked hemoglobin (DCLHb) have been stopped last year because of the results of two clinical trials showing an increased mortality in patients with stroke and multiple injury shock being treated with DCLHb in comparison with saline, a phase III study with polymerized bovine hemoglobin HBOC-201 is actually being performed in noncardiac patients with perioperative bleeding. The objective of this multicenter study is to show that treatment with HBOC-201 can reduce or avoid allogeneic RBC transfusion. Besides its use in clinical transfusion protocols, artificial oxygen carriers have a unique potential to deliver oxygen to the tissues by plasmatic transport due to its different physiology of oxygenation when compared with conventional oxygenation provided by red blood cells. Future studies must show if these modern oxygen carriers are able to improve outcome of patients with impaired perfusion and organ oxygenation. Copyright 2000 S. Karger GmbH, Freiburg
Background: The clinical relevance of antibodies directed against members of the Gerbich (GE) family of antigens is not invariably clear. Given the scarcity of serologically compatible red blood cells (RBC), various methods may have to be applied to assess the safety of transfusing serologically incompatible RBC. Patient and Methods: The serum of a 57-year-old male Caucasian admitted to hospital for gastrectomy was found to contain a highly reactive anti-GE2 antibody (IgG(1)). In addition to a monocyte monolayer assay, 50 ml of GE2-positive RBC were transfused, and blood samples were taken before and 1 and 24 h after transfusion for flow-cytometric determination of transfused cells. Results: Both tests showed no increased destruction of GE2-positive RBC. The transfusion of 4 units of GE2-positive RBC was well tolerated, and hemoglobin increased adequately. Conclusion: This case may extend the information available not only on antibodies directed against members of the GE family of antigens but also on methods to estimate the survival of transfused RBC. Copyright 2000 S. Karger GmbH, Freiburg
Background: The diminishing risks of allogeneic transfusion such as substantial reduction in transfusion-associated infections or prevention of immunosuppression and the recognition of limited financial resources for health care measures cast doubt on the value of preoperative autologous blood donation (PABD) for public health. Material and Methods: The epidemiological concept of efficacy, effectiveness, and efficiency has been applied to PABD. The results of hitherto published studies are summarized and commented. Measures to further improve the cost-effectiveness of PABD are presented and evaluated. They comprise limiting of serological screening or renunciation of component preparation of autologous units in appropriate cases. Results: With regard to the reduction of allogeneic transfusions, the efficacy of PABD appears to be proven in colorectal cancer surgery, knee and hip arthroplasty, and liver resect ion. PABD is possibly efficacious in most other elective surgical interventions with significant, anticipated blood loss. PABD is effective, i.e. it extends quality-adjusted life expectancy in these cases if there is no significant risk attributable to donation ora high statistical or individual risk of allogeneic transfusion. PABD is probably efficient, i.e. cost-effective, in case of low patient age, low production costs of the autologous deposit, high transfusion probability, and low donation risk. Conclusions: Published studies do not reflect the current situation. The safety of allogeneic blood has improved significantly, with regard to transfusion-transmissible infections owing to intensified resting and with regard to immunosuppression owing to leukocyte depletion methods. On the other hand, not all feasible cost containment measures have been applied to PABD. Thus, the cost-effectiveness of PABD is still at issue. Further carefully controlled studies are needed.
Patients with epilepsy are usually excluded from autologous blood donation due to the assumption that blood donation may provoke a convulsive attack. In this study we present the data of 26 unselected patients (age between 10 and 61 years) with epilepsy who donated autologous blood. A total of 50 blood donations were done (1–3 donations per patient). The patients were carefully observed during and following the procedure of blood donation. Autologous blood donation did not lead to epileptic attacks in any case.
Background: Sera with high-titer cold agglutinins (CAs) of unclear or even of apparently definite specificity may contain mixtures of CAs with different specificities. The combination of anti-I plus anti-Sia-b1 CAs in sera of patients with Mycoplasma pneumoniae infections is well documented. No systematic studies on CA mixtures in sera of patients with other diagnoses are available. Material and Methods: Sera of 322 patients with high-titer CAs were exhaustively absorbed with sialidase-treated red blood cells (RBCs). By absorption, CAs against the sialidase-resistant I/i antigens are removed. If CAs reacting with untreated RBCs are left after absorption, they are directed against the sialidase- and protease-sensitive Pr(1,2,3) antigens or against the sialidase-labile but protease-resistant antigens of the Sia-I/b/Ib complex. If CA mixtures were found, specificities and isotypes of the CAs obtained by cold adsorption and warm elution were determined. Results: Three patients had mixtures of anti-i plus anti-Pr CAs, 2 patients had mixtures of anti-I plus anti-Pr CAs. Conclusion: The occurrence of CAs directed against biochemically different antigens in individual sera proves two autoimmune processes against the same cells (erythrocytes) in the same patient. One explanation for this constellation would be a postinfection cold agglutination in a patient with chronic CA disease. Copyright 2000 S. Karger GmbH, Freiburg
The Guidelines for Blood Grouping and Blood Transfusion (Haemotherapy) of donors with exposure to malaria are at present restrictive and are being updated. In this study we would like to investigate whether these guidelines could be loosened due to safe serological test methods and made compatible with the recommendations of the European Council, without the risk of endangering blood recipients. Sources: The guidelines for blood grouping and blood transfusion (Haemotherapy), recommendations of the European Council and the WHO regarding blood and blood products, standards for blood banks and transfusion services of the American Association of Blood Banks, and screening of the malaria-relevant publications in tropical medicine und serological diagnosis in recent years. Results: A 6-month ban for immigrants from malaria-endemic areas without history of malaria infection and a 5-year ban after malaria disease seem to be sufficient if the indirect immunofluorecent test is negative after that time. A 12-month ban is recommended for returnees from endemic areas if immunological tests cannot be performed.
Objective: To determine the true platelet count in blood salvaged and processed for autotransfusion. Design: Prospective, randomized study. Setting: Department of anesthesiology and orthopedic clinic of a university hospital. Patients: 60 patients who were scheduled for elective hip surgery and included in routine intra- and postoperative blood salvage and autotransfusion programs. Interventions: Patients were randomly divided into 2 groups. In group I (n = 30) autotransfusion was performed using the Continuous Autotransfusion System(R) (Fresenius), in group II (n = 30) the Cell Saver 5(R) (Haemonetics) was used. In both groups samples were taken from the collection reservoir and the washed red cells. Platelet counts were performed with an automated cell analyzer and by flow-cytometric analysis using the monoclonal antibody CD42a. Results: The platelet counts obtained by the automated analyzer were 5 to 21 times higher than those obtained by flow-cytometric analysis. This appears to be due to the contamination of the samples with cell debris of about the same size as platelets. The platelet counts stated in literature should be reconsidered. Conclusions: Automatic cell-counting devices are inadequate to determine the platelet count of blood salvaged and processed for autotransfusion.
Background: Multiple sclerosis (MS) is an autoimmune disorder characterized by inflammatory, demyelinating lesions in the central nervous system. Open studies and experimental evidence suggest beneficial effects of intravenous immunoglobulin (IVIG) by immunomodulating mechanisms and induction of remyelination. Patients and Methods:In this randomized, double-blind, placebo-controlled multicenter trial we tested the efficacy of monthly IVIG in 150 patients with relapsing MS. Primary outcome measures were the effect on clinical disability as measured by the Expanded Disability Status Scale (EDSS), and the proportion of patients with improved, stable or worsened clinical disability (change by ≧?1.0 EDSS point) in each treatment group. Secondary outcome measures included the annual relapse rate and the proportion of relapse-free patients. IVIG was given over 2 years in a monthly dosage of 0.15–0.2 g/kg body weight. Results:As shown by intent-to-treat analysis, the EDSS significantly decreased in the IVIG-treated patients (–0.23 ??0.89) and increased in the placebo-treated patients (+0.12 ??1.07). The difference between both groups was statistically significant (p = 0.008). In the IVIG group 31% of the patients showed improved, 51% stable, and 16% worsened clinical disability. In the placebo group this distribution was 14%, 63% and 23%, respectively (p = 0.041). Annual relapse rates were 0.52 ??0.85 in the IVIG and 1.26 ??2.2 in the placebo group (p = 0.0037). The proportion of relapse-free patients receiving IVIG was 53% vs. 36% of patients in the placebo group (p=0.03). Adverse events occurred in 4% of patients in the IVIG group and in 5% of patients receiving placebo and did not appear to be directly related to the medication. Conclusion:This study demonstrates that monthly IVIG at a dosage of 0.15–0.2 g/kg body weight improves clinical disability and reduces the frequency of relapses without major side effects in relapsing MS.
In interventional cardiology major technical advances have been accomplished in the last 20 years. Especially, the introduction of endovascular prostheses (stents) was an important step forward. With the implantation of stents in coronary arteries by Sigwart and colleagues over 10 years ago to manage acute occlusion and restenosis after PTCA, the problems of thrombogenicity and biocompatibility were evident. Strict anticoagulation had reduced the risk of in-stent thrombus formation. The problem of late neointimal proliferation with development of restenosis is still not resolved. Many different designs, materials, and coatings were proposed to reduce thrombogenicity and optimize biocompatibility. Stent structure can influence flow conditions, surface charge can attract platelets or coagulation factors, and corrosion with diffusing ions may induce proliferation of surrounding tissues. Stent surface treatment, several metal alloys, and drug-eluting or drug-stable coatings are under investigation to improve the short-term and long-term results. In the mid 1990s the introduction of an extended antiplatelet therapy and a new implantation technique with high-pressure stent deployment have improved the results. However, the optimal stent still does not exist. This article describes possible reasons and some new promising versions.
Background: The efficiency of prestorage leukodepletion of whole blood on the production of proinflammatory cytokines (IL-β, IL-6, IL-8 and TNF-α) was compared in two groups of nonfiltered and filtered whole blood. Material and Methods:Ten experiments were performed. In each experiment we took two whole blood units drawn from a pool. In one group the units were immediately filtered by the new inline filter Biofil integral on NPBI Compoflex system while in the second group they were maintained without leukodepletion at +4 °C. Results:The filter showed a mean log10 depletion of 3.86 ± 0.08 (CV 2.1%) with a mean absolute number of leukocytes in the postfiltration units of 0.29 ± 0.049 × 106 and a RBC recovery of 92.5 ± 1.1%. IL-6 and TNF-α remained at concentrations less than 1 pg/ml in the samples during the storage period both in the control and filtered units. IL-β was not significantly higher on days 0 and 35 in the two groups while IL-8 was observed to be increased at day 35 in 2 out of the 10 experiments (620 and 415 pg/ml, respectively). Conclusions:The inline filter Biofil in combination with an NPBI Compoflex system has a high performance in the leukodepletion of whole blood. Proinflammatory cytokines have a concentration in whole blood less than described in platelet concentrates, and prestorage leukodepletion seems to prevent cytokine accumulation.
Numerous assays have been developed to measure the residual concentration of leukocytes in leukoreduced blood components. The performance characteristics of these assays are critical for process control of leukoreduction, evaluation of new devices, and clinical investigation. Not all assays are equally robust, however, and users should evaluate assays based on standard principles of performance. Five major performance characteristics of counting assays include: accuracy and bias, linearity, limit of detection, precision or reproducibility, and portability. In particular, the lower limit of detection has been used with various meanings in the literature. Laboratories considering using a particular counting assay can use the enclosed guidelines to evaluate the performance of the technique. In the future, the use of automated counting methods for counting very low levels of residual donor leukocytes is likely to become more widespread.
