[Experiences with artificial immunization for the production of anti-HL-A sera].

In 17 cases positive cytotoxic anti-HL-A antibodies were gained from 26 immunizated pairs. On the whole this corresponds to the data to be found in literature [10, 17]. The antibodies against the antigens of the I. locus will appear more rapidly, younger persons will form antibodies more easily. The difference in one single antigen results in favourable findings when the pairs are composed; in spite of that, however, cross-reacting antibodies may frequently be obtained, particularly when boostered to produce sera with a high titre. No side effects were detected in the immunizated group; yet there is a certain reason to suppose that the production of anti-HL-A sera by artificial immunization cannot be compared with the usual production of AB0 sera. The immunopathological significance of the HL-A-system is still elucidated insufficiently; by no means it is confined to histocompatibility. Only those institutes should be concerned with artificial immunization which are able to perform the necessary immunological controls exactly in each case.