Monoclonal antibody that specifically binds the interleukin 1 receptor type 1 (IL-lRAcP), or an antigen binding fragment thereof, comprising: a) a heavy chain variable region (VH) comprising CDR1H, CDR2H and/or CDR3H, wherein the CDR1H region comprises an amino acid sequence selected from the group of SEQ ID NO: 155 - 231, wherein the CDR2H region comprises an amino acid sequence selected from the group of SEQ ID NO: 232 - 308, and wherein the CDR3H region comprises an amino acid sequence selected from the group of SEQ ID NO: 309 - 385； and b) a light chain variable region (VL) comprising CDR1L, CDR2L and/or CDR3L, wherein the CDR1L region comprises an amino acid sequence selected from the group of SEQ ID NO: 386 - 462, wherein the CDRL2 region comprises an amino acid sequence selected from the group of SEQ ID NO: 463 - 539, and wherein the CDR3L region comprises an amino acid sequence selected from the group of SEQ ID NO: 540 - 616 The monoclonal antibody is characterized in that it inhibits IL-lRAcP induced NFkB activity, useful in treatment of IL-lRAcP related diseases.
