SSB and systemic lupus erythematosus: Assuming that the molecular target of the autoantibodies contained in the rat-IHC positive sera could be represented by autoantibodies known for their association with NPSLE and SLE (anti-dsDNA, -Ro/SSA, -La/SSB, -RNP, -Sm, -Rib-P, and -DWEYS) their distribution was investigated.