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Biomedical subjects

W Ouwehand

Publications and source records attributed to W Ouwehand.

4 recordsLinked to original sources

Guidelines for platelet transfusions. British Committee for Standards in Haematology, Working Party of the Blood Transfusion Task Force.

Recommendations for the optimal transfusion support of patients likely to receive repeated platelet transfusions. 1. Determine policy for prophylactic platelet support, and select the platelet count below which platelet transfusions will be used. 2. Consider using leucocyte depletion of red cell and platelet concentrates to prevent HLA alloimmunization from the outset. 3. Type patients for HLA-A and B antigens at an early stage. 4. Use random donor platelet concentrates for initial platelet support (either single or multiple donor, depending on availability). 5. If refractoriness occurs, determine whether clinical factors, which may be associated with non-immune consumption of platelets, are present and test the patient's serum for HLA antibodies. 6. Use HLA-matched platelet transfusions if HLA alloimmunization is the most likely cause of refractoriness. 7. If there is no improvement with HLA-matched transfusions, platelet crossmatching may identify the cause of the problem and help with the selection of compatible donors. 8. Discontinue prophylactic platelet support if a compatible donor cannot be found. Use platelet transfusions from random donors to control bleeding and increase the dose, if necessary.

Blood Coagulation Disorders

Reticuloendothelial Fc receptor function in SLE patients. I. Primary HLA linked defect or acquired dysfunction secondary to disease activity?

Reticuloendothelial system (RES) Fc receptor-mediated immune clearance was measured in 18 patients with systemic lupus erythematosus (SLE). Only two patients, with major disease activity, had a prolonged T 1/2 of the blood disappearance curve of injected IgG coated red cells in comparison to 22 healthy controls. Circulating immune complexes (CIC) were studied with three methods: PEG precipitation, C1q-ELISA and the indirect granulocyte phagocytosis test (IGFT). The T 1/2 of the blood disappearance curve related significantly to the IGFT (r = 0.55, P less than 0.05) and not to the PEG and C1q-ELISA test. Although HLA-DR3 phenotype frequency was significantly increased in our SLE population (P less than 0.05), it was not related to Fc receptor function. Similarly, HLA-DR2 phenotype was not related to RES Fc receptor function. These data do not support the concept that a genetic HLA linked defect in reticuloendothelial Fc receptor function is a primary cause of SLE, predisposing the inflicted individual to immune complex deposition. However, Fc receptor-mediated immune clearance seems to be related to disease activity itself and to levels of CIC.

Adolescent

Reticuloendothelial Fc receptor function in SLE patients. II. Associations with humoral immune response parameters in vivo and in vitro.

We studied the relationship between reticuloendothelial Fc receptor function and some parameters of the humoral immune response in vivo and in vitro in 18 SLE patients. Fc receptor-mediated immune clearance correlated remarkably well with (a) a decrease of antigen specific IgG after immunization with a primary test antigen (alpha-Helix pomatia haemocyanin) (P less than 0.01) and (b) the spontaneous IgG release in vitro of B cells obtained from peripheral blood (P less than 0.01). These two parameters were significantly interrelated. Reticuloendothelial Fc receptor function was not related to serum IgG levels. The study provides evidence for an association between polyclonal B cell activation and Fc receptor-mediated immune clearance in SLE patients. The possible nature of this association is discussed.

Adult