Characterization of binding and quantification of human autoantibodies to PDGFRα using a biosensor-based approach.

Systemic sclerosis (SSc) is a chronic autoimmune disease of the connective tissue. The variety and clinical relevance of autoantibodies in SSc patients have been extensively studied, eventually identifying agonistic autoantibodies targeting the platelet-derived growth factor receptor alpha (PDGFRα), and representing potential biomarkers for SSc. We used a resonant mirror biosensor to characterize the binding between surface-blocked PDGFRα and PDGFRα-specific recombinant human monoclonal autoantibodies (mAbs) produced by SSc B cells, and detect/quantify serum autoimmune IgG with binding characteristics similar to the mAbs.