Sohrabian A, Parodis I, Carlströmer-Berthén N, et al. - During a 24-month follow-up, a C1q-binding-eluting technique was used to clean immune complexes from 55 belimumab-treated systemic lupus erythematosus individuals in order to assess whether quantification of autoantibodies in immune complexes (IC) gave additional data in terms of disease activity and treatment response in comparison with conventional serum autoantibody measurements. In contrast with serum levels in belimumab-treated SLE individuals, immune complex levels of autoantibodies against double-stranded DNA and the Sjögren syndrome antigen (SS) A/SSB complex exhibited more precise relationships with treatment outcomes. Moreover, in circulating immune complexes, characterization of autoantibody content could prove beneficial in treatment assessment in SLE and other immune complex-associated diseases.