The Sixth Histocompatibility Workshop

The Sixth Histocompatibility Workshop, organized by F. Kissmeyer-Nielsen and held in Arhus, Denmark in June-July of 1975, had as its main objectives an investigation of the determinants and genetics of the MLR (subsequently termed the HLA-D locus) and the better identification and characterization of specificities belonging to the three previously-defined HL-A loci (subsequently termed HLA-A, B and C). This workshop was the first to include the use of D region homozygous typing cells (HTC) to study determinants of the HLA-D locus. A total of 62 HTC and 178 selected antisera were exchanged between participating laboratories. On the basis of workshop results, the WHO nomenclature committee named the first six HLA-D determinants. The first five HLA-C antigens were also named. At the Workshop Conference, numerous reports were made of HLA antigens that were expressed on B cells but not on T cells. These antigens were termed “Ia-like” or​_ “D region associated B cell antigens”, and their description paved the way for the future description and characterization of the HLA-DR locus and the DR series of leukocyte antigens. A total of 15 new HLA specificities were given WHO designations following the workshop, including the first antigens defined at the HLA-C locus (Cw1-Cw5).

Reference: Histocompatibility Testing 1975. Kissmeyer-Nielsen F, ed. Copenhagen: Munksgaard, 1975.