SAA1 and neuromyelitis optica: We expected IL-6 inhibition therapies to be effective in SSM as well, given the similarities in the etiologies of NMO and SSM.[6] SAA proteins are small (104 amino acids) and have a striking relationship with the acute phase response, with serum levels rising as much as 1000-fold in 24 hours.[14] SAA is not merely an acute phase protein, but activates immunocomponent cells such as monocytes, neutrophils, and lymphocytes, and induces inflammatory molecules including pro-inflammatory cytokines and matrix metalloproteinases.