Human Leukocyte Differentiation Antigen workshop Ⅶ / HLDA7

The Human Leukocyte Differentiation Antigen workshop (HLDA7) took place in 2000 in Harrogate, United Kingdom, and the proceedings of the meeting (Leucocyte Typing VII1) have recently been published. Antibodies to the most immunogenic molecules had already been produced, and fewer laboratories than in the early days were prepared to devote resources to raising new antibodies, since the probability of finding novel reagents becomes ever less likely. In consequence many antibodies in the sixth workshop were reagents that proved to be of known specificity.

With these considerations in mind, HLDA7 adopted a different approach. Instead of screening poorly characterized antibodies, reagents were selected for which at least some molecular data were already available. A substantial number of monoclonal antibodies reactive with leukocyte-associated molecules exist that do not meet the traditional criterion for establishing a new CD specificity. Consequently, it is now considered appropriate to establish a CD designation for a molecule if its gene has been cloned and at least one specific monoclonal antibody has been studied in the workshop. Four new domains were introduced in HLDA7 to add to the traditional list from past meetings: Dendritic Cells, Stem/Progenitor Cells, Erythroid Cells, and Carbohydrate Structures.

HLDA7 were added over 80 new molecules to the list of CD antigens. This compares favorably with previous workshops (an average of fewer than 30 CD specificities per workshop), and it also largely avoided the laborious screening in multiple laboratories of antibodies that often prove to be directed against known CD molecules.