ABSTRACT
The substitution of thrombocytes is on principle indicated only when a disturbance of the formation is present. The prophylactic application, i.e. before the occurrence of a haemorrhage, which is sometimes life-limiting, is to be preferred, however, on account of the danger of sensitization it is bound to particular conditions: temporarily limited need of substitution, decreased immune reagibility of the recipient (basic disease, therapy), medico-therapeutically induced thrombocytopenia (cytostatic drugs); example: haemoblastoses. Prerequisites are subtile control of clinical effectiveness and formation of antibodies. In planned bone marrow transplantation only preparation of individual donors (not related!) with HLA-A/B match are to be used. The same is applied to already alloimmunized patients, in which case a negative lymphocytotox cross test must still be present. Patients without option to transplantation or without HLA-antibodies may receive also random preparations of individual donors or mixed preparations. AB0-minor-incompatibilities are without significance, AB0-major-incompatibilities are not permissible. The introduction of thrombocyte-specific testings is urgently to be aspired to.--Exclusively therapeutic substitution of thrombocytes, i.e. in manifest haemorrhage, is performed in a primarily not limited period of substitution, in a completely immune competent recipient with regularly low values of thrombocytes without cytoreductive therapy (example: aplastic anaemia). In these cases on account of high danger of sensitization only preparations of individual donors with HLA-A/B-match should be used. In cases of exception in thrombocytopenic, life-threatening haemorrhages on account of metabolic disturbances (immune thrombocytopenia, massive transfusions) the substitution with thrombocytic mixed concentrates is satisfied.--The substitution of thrombocytes is a common task of clinic and blood donation service, which opens new possibilities of therapy (e.g. transplantation of bone marrow).
