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Biomedical subjects

M U Heim

Publications and source records attributed to M U Heim.

At least 37 records · Page 2Linked to original sources
PubMed1992

Intravenous anti-D gammaglobulin for the prevention of rhesus isoimmunization caused by platelet transfusions in patients with malignant diseases.

Previous studies of sensitization to RhD by RhD-positive platelet transfusions in RhD-negative cancer patients have shown different frequencies of alloimmunization (max. 19%). We studied 37 RhD-negative patients who received RhD-incompatible platelet transfusions and simultaneously anti-D-immune globulin. We provide evidence that in this setting RhD-prophylaxis is highly effective in preventing alloimmunization due to RhD antigen, since none of the patients studied developed anti-D. Detection of other red blood cell antibodies than anti-D proves the possibility of immunization in these patients. Prevention of isoimmunization in patients with malignant diseases is recommended especially in young females, since an increasing number of patients are having successful pregnancies, despite prior or even during cytotoxic therapy.

Adult↗
PubMed1992

[Graft versus host disease with fatal outcome after administration of filtered erythrocyte concentrates].

Transfusion-associated graft-versus-host disease (TA-GVHD) resulting from the engraftment of competent lymphocytes contained in blood products has been well described in immunocompromised patients and more recently in immunocompetent patients. Prophylactic irradiation of blood products prior to transfusion is the most efficient way to prevent TA-GVHD. Standard blood bank measures to reduce mononuclear cell contamination in red blood cell units, such as freezing, washing and filtration, may reduce the number of viable lymphocytes to prevent immunizations. However, it is unknown whether the depletion of leukocytes with these techniques would decrease the risk of TA-GVHD. In this report we describe the first case of TA-GVHD following transfusion of filtrated red blood cells given to a patient receiving cytotoxic therapy for Hodgkin's disease.

Adult↗
PubMed1992

[Combination of a simple hollow fiber system with leukocyte filter for production of leukocyte depleted erythrocyte concentrates and plasma].

Leukocyte-depleted red cell concentrate (RCC) and plasma were separated by a hollow fiber filter system combined with a leukocyte filter without any additional devices. The RCC with 100 ml additive solution had a weight of 329 g; hematocrit was 0.55, free hemoglobin 16 mg/dl; leukocytes were (0.6 +/- 0.6) x 10(9)/l. The plasma (268 g) contained 5.4 g/dl of total protein, and only a few blood cells; clotting factor VIII activity 75%, all satisfying the guidelines.

Blood Component Removal↗
PubMed1992

[Strong and weak histocompatibility antigens and immune response].

In blood samples of 88 healthy donors various red cell, HLA-A, -B, -Cw and -Dr antigens were determined by standard methods. Lymphocyte reactivity was measured by 3H-thymidine uptake into DNA of lymphoblastic cells stimulated by 14 different mitogens and antigens. Cluster analysis confirmed by t test and F test defined 3 distinct clusters of lymphocyte reactivity. Cluster 1 in 70% [relative risk (r.r.) 109, p < 0.001] and cluster 3 in 92% (r.r. 33, p < 0.01) showed significantly different cumulations of 3 or more increased characteristic red cell and HLA antigens. Our data suggest that the patterns of both red cell and HLA antigens play a major role in defining immunoreactivity.

HLA Antigens↗
PubMed1992

[Incidence of the detection of erythrocyte antibodies in relation to screening test cells].

A variety of antibody screening tests are available to detect immunization in patients' sera. However, antibodies can be observed only if corresponding antigens are present on test cells used by an antibody screen. By comparing available test cell kits of different manufacturers we revealed various specificities of antigens present or absent on these cells. Using by an antibody screen Wr(a+), Co(b+) and Kp(a+) test cells additionally to available test cells, we detected in 1000 sera of patients 13 anti-Wr(a) and 1 anti-Co(b) besides 17 antibodies with different specificities.

Autoantibodies↗
PubMed1991

White cell depletion of single-donor platelet preparations by a new adsorption filter.

A newly developed adsorption filter has been evaluated for the removal of white cells (WBCs) from platelet concentrates. It consists of surface-modified polyester fibers and can be used at the patient's bedside. WBC mean removal rate was 98.8 +/- 0.9 percent, and platelet recovery was 99.0 +/- 0.7 percent. The aggregation curves (ADP, collagen) and hypotonic shock response of platelets were not influenced by the filtration, and the plasma electrolyte and lactate dehydrogenase concentrations were unaffected. Transmission and scanning electron micrographs showed no difference in platelet ultrastructure before and after filtration. Determination of posttransfusion platelet recovery did not reveal any significant difference from that of nonfiltered platelets. The tested filter seems to be a suitable device for WBC depletion of single-donor platelet concentrates at the bedside.

Adenosine Diphosphate↗
PubMed1991

[Pregnancy with an extremely rare P blood group with anti-PP1Pk].

The authors report on a successful pregnancy in a young Turkish patient with p and anti-PP1Pk-antibodies. Anti-PP1Pk is considered to cause haemolytic diseases in the newborn and habitual abortions. The patient was treated via plasma exchange and substitution with intravenous immunoglobulin. At 31 weeks of gestation the patient underwent Caesarean section due to growth retardation and pathological signs in the fetal CTG. The child has developed well up to two years after the delivery. Based on our data and a review of the literature, the effectiveness of therapy by plasmapheresis and/or immunoglobulin is discussed.

Abortion, Habitual↗
PubMed1991

Presence of T-antigen on the vascular endothelium.

Bacterial neuraminidase plays an important role in the pathogenesis of some haemolytic anaemias. It divides neuraminic acid from the red cell surface to expose a hidden antigen (Thomsen-Friedenreich antigen, T). A physiologically circulating antibody can then react with the uncovered T and cause a rapid haemolysis. This study demonstrates the presence of T on human vascular endothelium. Similar to red cells it is exposed by the action of bacterial neuraminidase. The subsequent reaction with the physiological antibody could be involved in the pathogenesis of vascular damage observed in severe cases of bacterial septicaemia.

Animals↗
PubMed1991

[The need for thorough infection screening in donors of autologous blood].

To avoid the risk of diseases transmitted by homologous blood, predeposited autologous blood is useful for elective surgical patients. World-wide, there is disagreement over whether complete donor testing should or should not be done on autologous collections. There are a variety of testing concerns which have evolved into reasons for testing all autologous units for the presence of infections disease markers. One of the reasons is the risk of giving the wrong (untested) blood to the wrong patient and transmitting HIV (and thus AIDS) or viral hepatitis. Another stated concern is the risk of creating additional problems in the laboratory by treating some units differently than other units. The argument continues that without this testing, blood bank and hospital personnel may be unnecessarily exposed to blood that has the potential to cause illness. Another justification for testing is given when the blood bank participates in crossover (transfusing blood to recipients other than the autologous donor/patient).

Blood Component Transfusion↗
PubMed1991

[Storage of thrombocyte concentrates: ultrastructural and functional changes].

Optimal storage of platelet concentrates is still an unsolved problem. The present paper demonstrates changes in morphology and function of stored platelets. Transmission microscopy reveals a loss of organelles as well as a progredient destruction of cell membranes during storage. At the same time in vitro aggregability is clearly diminished. Therefore, further investigations seem to be necessary to improve storage conditions of platelets.

Blood Component Transfusion↗
PubMed1990

Preparation of white cell-depleted blood. Comparison of two bedside filter systems.

Numerous techniques have been established for preparing white cell-poor blood, such as centrifugation, sedimentation, freezing, and filtration. All of these methods have disadvantages that restrict their practical use: they are time-consuming, they require the facilities of a blood bank, and the white cell-poor units cannot be stored. Therefore tests have been performed on two filter systems that make possible the depletion of white cells directly at the bedside. Both filters have a high white cell-removal rate. The number of residual white cells in 1 unit of packed red cells was calculated as 1.08 +/- 0.53 x 10(7) in one system and 1.54 +/- 0.71 x 10(7) in the other. The filters do not affect the filtered red cells. Pressure filtration is performed without significant loss of efficiency. One of the systems can filter 2 units via one filter; however, handling the filters is tedious, and both filters are characterized by a low red cell recovery. Despite these disadvantages, the tested filter systems provide an effective device for preparing white cell-poor blood at the bedside. They are a suitable alternative to the conventional methods.

Blood Platelets↗
PubMed1990

Possibility to improve preservation of whole blood by leukocyte-depletion before storage.

In order to evaluate the influence of leukocytes in whole blood on the standard blood bank conditions for storage, we compared several parameters of red cells, leukocytes and platelets in leukocyte-rich and leukocyte-poor whole blood over a storage period of 5 weeks. The leukocyte-depleted units were prepared by filtration with a leukocyte trapping filter (Sepacell R500A). Our data indicate improved storage conditions, made evident by significantly lower cell damage: smaller increases of elastase, beta-thromboglobulin and lactate dehydrogenase in leukocyte-depleted blood. This improvement was achieved in a simple two-bag system using only filtration, without addition of rejuvenating solutions. In addition, this procedure allows greater flexibility in the use of filtrated blood for transfusions.

Adenosine Triphosphate↗
PubMed1990

[Production of leukocyte-poor thrombocyte concentrates: results with a new kind of filter system].

A newly developed filter-system (Sepacell PL) for the removal of leukocytes from single donor platelet concentrates was tested. It removes contaminating leukocytes by 99.9%, the platelet loss was calculated as less than 1%. Platelet ultrastructure and function do not seem to be altered by the filtration. Therefore, the tested filter system seems to be a suitable device for leukocyte depletion of single donor platelet concentrates. Further clinical studies, however, are necessary to prove the efficiency of the filter system in preventing alloimmunization in vivo.

Blood Transfusion↗
PubMed1990

[Thrombocyte crossmatching: clinical experience with the Capture P-test].

A commercially available solid phase red cell adherence test (Capture P) for platelet crossmatching was tested. The specificity of the test is 94.8%, the sensitivity 47.9%. Whereas the predictive value for negative results is low (52.9%), the predictive value for positive results was calculated as 93.8%. Therefore, the Capture P test seems to be useful for the exclusion of incompatible single donor platelet concentrates from transfusion. When negative results are obtained, however, no precise prediction of the transfusion success can be made.

Blood Grouping and Crossmatching↗
PubMed1990

[Plasmapheresis and/or intermediate high dosage immunoglobulin therapy--effective measures in threatened premature labor and intrauterine hemolysis in anti-PP1Pk (-Tja)?].

Anti-PP1Pk developed by women has been associated with abortion early in pregnancy and hemolytic disease of the newborn. The case of a 19-year-old woman who had had 2 spontaneous abortions in the first trimester is presented. When treated with plasma exchange and substituted with 5% albumin and intravenous immunoglobulin begun at six weeks' gestation and continued until the 30th week, she delivered a viable female infant without anemia. According to our data and review of literature, the effectiveness of therapy by plasmapheresis and/or immunoglobulin is discussed.

Combined Modality Therapy↗
PubMed1990

[3 new antibody detection tests. A comparative study].

Erythrocyte antibodies are of clinical importance since they may cause decreased red cell survival as the result of hemolytic transfusion reactions, hemolytic disease of the newborn or autoimmune hemolytic anemia. A variety of in vitro antibody screening tests are employed to detect their presence in donor and patient sera. Three new methods now available for pretransfusion testing--two solid phase antiglobulin tests and a gel centrifugation test--are compared in parallel with a conventional tube test.

Blood Group Incompatibility↗
PubMed1990

[Use of fresh frozen plasma in surgery with special reference to autologous fresh frozen plasma].

The use of FFP has increased dramatically in the last few years. In the majority of cases FFP is transfused in order to provide coagulation factors. Many physicians expect to get "better" blood parameters from concomitant FFP and red blood cell (RBC) transfusions. To avoid the risk of diseases transmitted by homologous blood predeposited autologous blood is useful for elective surgical patients. Intraoperative autotransfusion by blood salvage using a Cell Saver only provides autologous RBC without plasma, so predeposited autologous plasma seems to be a necessary supplement. However, according to the literature most patients receiving RBC units do not require concomitant FFP. Guidelines for the use of FFP based on controlled clinical trials are necessary.

Blood Transfusion, Autologous↗