Presentation: Antibody Microarray-Based Serum Protein Profiling of Systemic Lupus Erythematosus and Systemic Sclerosis (2007)

814 Antibody Microarray-Based Serum Protein Profiling of Systemic Lupus Erythematosus and Systemic Sclerosis

OBJECTIVE: To improve the clinical understanding of systemic lupus erythematosus (SLE) and systemic sclerosis (SSc) by performing differential protein expression profiling of serum samples using recombinant antibody-based microarrays.
METHODS: In-house developed antibody microarrays, based on 129 human recombinant single-chain Fv (scFv) antibodies targeting 60 protein analytes (e.g. cytokines and complement proteins) of mainly immunoregulatory nature were fabricated using black polymer Maxisorb slides. Crude serum samples were directly biotinylated, added to the chips, and bound analytes were visualized using Alexa-647 labelled streptavidin. In total, 65 serum samples were analysed from 30 patients with active SLE, 20 patients with SSc and 15 healthy controls. The SLE group included 10 patients with skin and musculoskeletal involvement (SLE1); 10 patients with more severe manifestations such as serositis, systemic vasculitis but not kidney involvement (SLE2); and 10 patients with SLE glomerulonephritis (SLE3). The SSc group had a disease duration of less than 5 years from onset of skin thickening and included 10 patients with limited cutaneous SSc and 10 patients with diffuse cutaneous SSc. The antibody microarray data were compared with clinical parameters of the patients, e.g. SLE disease activity index (SLEDAI).
RESULTS: A preliminary disease specific serum protein signature based on 58 antibodies has been identified that discriminated SLE patients from healthy controls and displayed an area under the curve (ROC) value of 0.75. Targeting the three individual subgroups of SLE revealed that the signature of SLE1 was most similar to the one of the healthy controls (ROC value of 0.53), whereas the observed differences in protein expression patterns increased with severity of the SLE symptoms. The protein signature of patients with SLE glomerulonephritis (SLE3) showed the most significant difference compared to healthy controls (ROC value of 0.99). Of note, the three subgroups of SLE could also be distinguished based on a multiplexed serum protein expression signature. The expression patterns of already known SLE associated analytes, correlated well with data reported in other studies and with the SLEDAI. The protein signatures of SLE2 and SLE3 were found to differ significantly from the ones of SSc. No differences in biomarker signatures could be identified between SSc and healthy controls.
CONCLUSION: The recombinant antibody-based microarray is a powerful, multiplexed and non-invasive proteomic technology for serum protein profiling of autoimmune diseases in a highly specific and sensitive manner. Preliminary disease specific serum protein profiles discriminating patients and subgroups thereof from healthy individuals have been identified.

 D.M. Wuttge, None; A. Carlsson, None; J. Ingvarsson, None; A.A. Bengtsson, None; R. Hesselstrand, None; G. Sturfelt, None; C.A. Borrebaeck, None; C. Wingren, None.