[Determination of HLA antigens in serum and thrombocytes using microneutralization and microabsorption tests].

The microneutralization and microabsorption test is described for identifying HLA-antigens in the serum and on thrombocytes. The incubation time for neutralization and absorption amounts to 3 hours at 20-25 degrees C. Absorption is made by platelet suspension at a concentration of 300 000 to 500,000 thrombocytes per mm3. In the majority of cases satisfactory results can be achieved by a neutralizing ratio (absorption ratio) of 1: 1. Some HLA sera show a deviating ability of neutralization with those HLA-antigens contained in sera and absorption with appropriate platelets; this behaviour is not connected with the titre of HLA-cytotoxins. Depending on the case there will be a varying content of HLA-antigens in sera and on thrombocytes of individuals. Moreover there is no regular conformity concerning the content of HLA-antigens in the serum and on the thrombocytes of a single person.