Association between HLA and red cell antigens. IV. Further studies of haemagglutinins in cytotoxic HLA antisera

Cytotoxic HLA antisera of various specificities were examined on the AutoAnalyzer against red blood cells (RBC) from a great number of HLA-typed donors. HLA-associated haemagglutinins of different specificities were demonstrated. In cytotoxic anti-HLA-A9 and anti-HLA-A10, as well as in anti-HLA-B12, anti-HLA-Bw15 and anti-HLA-B17 sera, haemagglutinins of apparently corresponding specificities were found. This indicates that several HAL antigens may be present on RBC, but they are demonstrable only on RBC from a limited number of donors who possess the corresponding antigens on their white cells. Some antigens, like HLA-A28 and HLA-B7, are relatively strong RBC antigens, whereas others, like HLA-B12 or HLA-Bw15 seem to be much weaker. In cytotoxic anti-HLA-A1 and anti-HLA-B13 sera, no corresponding haemagglutinins were demonstrated. However, haemagglutinins of anti-HLA-B7 specificity were shown to be present in two cytotoxic anti HLA-A1 and three anti-HLA-B13 sera. No cytotoxic anti-HLA-B7 was found in these sera. Cross-reacting antibodies also seem to be frequent amoung HLA associated haemagglutinins.

An evaluation of some factors affecting the detection of blood group antibodies by automated methods

Some factors affecting the sensitivity of the automated methods for blood group antibody detection have been evaluated. The experiments revealed influencing differences between various albumin preparations. In the BMC method, one lot of albumin permitted no significant antibody detection. In the LISP technique, a plateau of maximum Polybrene activity was found. The beginning of this plateau depended on both the albumin preparation and the Polybrene lot. In the BMC method, methyl cellulose gave optimal sensitivity within a concentration range of 0.3 to 0.5 per cent. The stability of test cells stored in ACD at 4 C was studied. All test cells could be used safely up to two weeks. Cells from different donors showed variable reactivity after three weeks.

Preparation and Decay of 72Zn

A radiochemical method for separation of essentially carrier free zinc from uranium or thorium and their fission products has been worked out and applied to the study of the decay of 72Zn. Gamma transitions of energies 15, 42, 46, 78, 103, 112, 144, and 190 keV are found.