SSB and systemic lupus erythematosus: SLE is a multisystemic disease marked by a polyclonal B cell activation, with plasma cells producing ANA towards a broad range of autoantigens, including double stranded DNA, histones, and a number of ribonucleoprotein particles (RNPs), such as the Smith antigen (i.e., the common core proteins of spliceosomal small nuclear RNPs), and the SS-A/Ro and SS-B/La antigens.