Infusionstherapie und Transfusionsmedizin最新文献

Background: Intravenous immunoglobulins (IvIg) contain not only the declared antibodies against pathogenic microorganisms, but also all the other antibodies of the blood donors, e.g. against erythrocytic antigens.

Materials and methods: We tested 14 IvIg from 7 manufacturers (a total of 40 charges) for isoantibodies and irregular antibodies. To improve the reading of our tests we used the gel centrifugation method (ID-Microtyping-System, Fa. Diamed, Bensheim, Germany).

Results: The highest isoantibody titers were (in 8 charges) 1:32 or 1:64 in the Liss-Coombs test. Irregular antibodies were found in 5 IvIg (maximal titer 1:8).

Conclusions: Isoantibodies in the IvIg can influence blood group serologic tests. With an example of a newborn who had received IvIg we point to the potential danger of misinterpretation of a positive direct antiglobulin test after administration of IvIg. Therefore we recommend to carry out the direct antiglobulin test before administration of IvIg and to examine all eluates after a positive direct Coombs test not only with 0 RBCs but also with A or B RBCs of the AB0 blood group of the patient.

Objective: To determine the effect of transfusion therapy with leukocyte-depleted platelet concentrates in comparison to transfusion support with standard platelet concentrates on the frequency of HLA alloimmunization in hematologic-oncologic patients.

Design: Prospective randomized study.

Setting: Institute for Transfusion Medicine and Immunohematology at a University Hospital.

Patients: 52 hematologic-oncologic patients randomized in 2 groups.

Interventions: Exclusive substitution with leukocyte-depleted blood components (platelet concentrates and packed red cells, filter group) or with standard platelet concentrates and leukocyte-depleted packed red cells (control group). Determination of the development of HLA antibodies.

Results: 27% of the patients in the control group (4 out of 15) developed HLA antibodies in contrast to zero patients (0 out of 22) in the filter group (p < 0.02).

Conclusions: The results of this comparative clinical study show that the consequent and exclusive support with leukocyte-depleted blood components is an effective approach for prevention of HLA alloimmunization in long-term substituted patients.

Background: Hepatitis C virus (HCV) is responsible for the majority of post-transfusion hepatitis cases. We compared the correlation and reproducibility of different screening and confirmatory tests.

Material and methods: 1,406 samples of voluntary blood donors were tested in parallel using 3 enzyme-linked immuno sorbent assays (ELISA) for HCV antibodies. Those samples that were positive in at least 1 of the 3 tests were additionally tested in a 3rd-generation ELISA as well as in 3 different confirmatory tests.

Results: 13 samples (0.92%) were repeat reactive in at least 1 of the ELISAs with different results in the confirmatory tests. Only 3 samples (0.21%) with high sample/cutoff ratios in the ELISAs were positive in all 3 confirmatory tests.

Conclusions: The reproducibility of the tested ELISAs and the correlation with confirmatory tests were good only in samples with a high signal to cutoff ratio. Two different high-positive ELISA results can be regarded as confirmation.

Objective: To review recent reports on the interaction of cold agglutinins with the complement system and its relevance to cold agglutinin disease.

Data sources: Review articles and original papers have been selected for this contribution.

Selection criteria: The report focuses on experimental data available from in vitro studies as well as clinical findings regarding the mechanisms of cold agglutinin-induced complement activation.

Results: Despite the observation that only few cold agglutinins (almost exclusively IgM molecules with anti-I specificity) induce in vitro hemolysis of human red blood cells with human serum (homologous system), the vast majority of these autoantibodies are able to initiate the classical pathway sequence with the fixation of C1 and to a lesser degree of C4. The ability of IgM cold agglutinins to activate, in principle, complement is demonstrated by their hemolytic efficiency in the presence of animal serum as a source of heterologous complement. In addition to the thermal amplitude of cold agglutinin binding, a possible interference with membrane regulatory proteins may render certain cold agglutinins hemolytically active in a homologous system.

Conclusion: Despite a hemolytic inefficiency, cold agglutinin-induced fixation of early complement components up to C3 leads to an accelerated clearance of red cells from the circulation by hepatic sequestration. However, it is not yet clear, to what degree these cells are eliminated by the reticuloendothelial system or whether they return to the circulation. Dependent on the amount of membrane-bound C3 fragments these cells may even be protected against further cold agglutinin-induced complement attack.

Objective: 'Look-back' investigations can reveal and confirm transfusion-transmitted infectious diseases and provide data for risk calculations of blood transfusions.

Design: In 1993 we distributed a questionnaire to all governmental and communal blood transfusion services in Germany. The questionnaire comprised questions about the methods, numbers and results of look-back investigations in case of HIV-1/2-positive blood donors with previous donations and in case of HIV-1/2-positive recipients of blood transfusions. The questionnaire was returned by almost all blood transfusion services (n = 75). One additional institution briefly informed us by telephone.

Setting: All governmental and communal blood transfusion services in Germany.

Patients: All recipients of blood or blood products in the years from 1985 till the end of 1992 who were treated in hospitals supplied by the transfusion services defined above.

Interventions: None.

Results: All blood transfusion services included have performed look-back studies since 1985. The methods used varied considerably. The interval of looking back mostly was sufficient. A main problem was the poor documentation in the medical records. The incidence of HIV-1/2-positive blood donations decreased from 11.6/100,000 in 1985 to 3.4/100,000 in 1992. Only 7 of 73 transfusion-transmitted HIV infections derived from transfusions after the introduction of HIV testing (October 1985). Since then the risk of transfusion-transmitted HIV infection can be calculated as 1/800,000 whole-blood donations of governmental and communal blood transfusion services.

Conclusions: Since the introduction of HIV testing the risk of transfusion-transmitted HIV infection in Germany has been very low, at a rather stable rate of 1/800,000. The data from the look-back studies confirm the previous estimations of the risk of transfusion-transmitted HIV infections, which was calculated by the HIV incidence in the donor population. Nevertheless there is a need for standardization of look-back investigations.

Background: Disturbances of microcirculation and accompanying alterations of oxygen supply are central pathophysiological events in trauma and sepsis. There is evidence that omega-3 fatty acids can modulate prostaglandin formation and thereby regional blood flow. The aim of the study was to determine the effects of chemically defined structured lipids (SL) with omega-3 fatty acids in position sn-2 (MFM) compared to SL with omega-6 fatty acids in position sn-2 (MLM) on cardiac output (CO) and splanchnic blood flow in a low-dose endotoxin (E, 1 mg.kgBW-1.day-1) rat model.

Materials and methods: 24 male Sprague Dawley rats, divided in 4 groups (n = 6; MLM, MLM+E, MFM, MFM+E) received for 48 h a total parenteral nutrition. CO and regional blood flow were measured with 85strontium-labelled microspheres (16.5 +/- 0.1 microns).

Results: There was a slight rise in CO in the E groups compared to the control groups. Application of E resulted in a marked decrease of intestinal perfusion in the MLM-fed animals, whereas the MFM-fed animals showed only a minimal reduction. This decrease of portal blood flow to the liver was accompanied by an elevation of arterial blood flow to the liver. This compensatory increase in arterial liver blood flow was more pronounced in the MFM-fed animals, resulting in a total liver blood flow which was not different from the control group.

Conclusions: The results of this study implicate that 48 h of intravenous feeding with chemically defined SL with an omega-3 fatty acid in position sn-2 can significantly influence splanchnic bed perfusion in a low-dose endotoxin rat model. The better splanchnic perfusion may be mediated by a shift in prostaglandin production.

Objective: It was tried to retrospectively identify HIV infections in recipients of transfusions from donors who were tested HIV positive at a subsequent donation. These lookback data were traced back to answer the following questions: 1. How many transfusion recipients were infected before the start of the routine HIV testing in 1985? 2. How great is the risk of HIV infections from infected but not yet HIV antibody-positive donors? 3. Furthermore, the transfusion of HIV-infected transfusion recipients was traced back to the involved donor to establish causality.

Design: Retrospective ('lookback') study.

Setting: HIV Study Group of the Red Cross Blood Banks of the Federal Republic of Germany.

Participants: Preceding donations of HIV antibody-positive repeat donors were traced back to the transfusion recipients in order to establish their HIV antibody status. In a second lookback study, HIV-infected transfusion recipients and their corresponding donors were investigated after they had been reported to the blood bank as infected by transfusion-associated HIV.

Interventions: None.

Results: Recipients of 156 respectively 133 transfusions from repeat donors found to be Western blot-positive were investigated from 1985 to 1987 and from 1987 to 1992, respectively. About 50% of the recipients had died. About 40% of the recipients could not be examined, because they either were not available for testing or refused to be tested or because it was impossible to clarify the fate of the blood products. 25 HIV recipients were identified from 1981 to 1985, when routine HIV testing began. Nine transfusion-associated HIV infections were identified from 1985 to 1992. 25 million units of blood were prepared during this period.

Conclusions: The risk of HIV transmission by tested transfusions is extremely rare (in the order of 1:1 million). The second lookback study suggests that in more than 50% of the blood recipients in whom HIV infection was attributed to transfusion, a causal relationship to an infected donor could not be established.

Background: The allelic diversity of HLA-DPB1 antigens can be determined at the DNA level after PCR amplification. The pattern of polymorphism at the DPB1 locus makes it difficult to unambiguously assign all genotypes in a typing system using one single pair of generic primers.

Materials and methods: We apply here a simple technique based on the reverse dot blot analysis to the typing of HLA-DPB1 alleles. In order to increase its resolution, a group-specific amplification based on sequence variations of the polymorphic region F was used subdividing the HLA-DPB1 alleles in 2 nonoverlapping families. A separate analysis was then performed within each group of alleles.

Results: Using these 2 primer pairs, 21 group 1 and 30 group 2 alleles were separately amplified. From 1,378 possible allele combinations for DPB1*0101-5301 only 33 gave ambiguous typing results compared to 61 using a single pair of generic primers.

Conclusions: This procedure provides a rapid and simple HLA-DPB1 genotyping. Especially in heterozygotes the hybridization patterns were easier to interpret. The utilization of group-specific amplification substantially reduced ambiguous typing results.