Monoclonal antibody 1994-01 (also known as ALVA 42) reported to recognize type II IL-1 receptor is specific for HLA-DR alpha and beta chains.

Monoclonal antibody (MAb) 1994-01 has been reported to bind to the human type II Interleukin 1 (IL-1) receptor and in so doing block IL-1 binding in vitro and certain IL-1 mediated responses in vivo. While this antibody binds to a type II IL-1 receptor positive cell line, it can be shown that it does not bind to the type II IL-1 receptor. By direct expression cloning, we have identified two gene products, both of which are required for binding of this antibody. The two proteins are the alpha and beta subunits of the MHC class II antigen HLA-DR.