Pathogenicity of ACA
As the name implies, CENPs are intracellular, nuclear proteins involved in the assembly of
the kinetochore during cell division [99]. CENPs specify the mitotic behavior of chromosomes,
and thus are essential for mitotic progression and chromosome segregation [100]. The presence
of ACA in the sera of SSc patients suggests that CENPs come in contact with the immune system
so as to trigger an autoimmune response. The IgG isotype of ACA [101,102] suggests that these
patients have a persistent T cell-mediated immune response influenced by certain HLA allotypes,
namely HLA-DR1, -DR4, -DR8 and -DQB1 [103,104]. These findings are typical of most
antigen-driven immune responses.