title: Biosensor for total antinuclear antibody determination at the point-of-care.
abstract: Antinuclear antibodies (ANA) are important in diagnosis and follow-up of patients with autoimmune conditions. The current increase in ANA requests is driven by broadening the use of ANA from a test for lupus to a test for diverse autoimmune diseases, but the standard method is protracted, cumbersome and prone to error. We describe an electrochemical method for quantifying total ANA for use as a point-of-care diagnostic aid. In this technology the target autoantigens are derived from a protein/nucleoprotein mixture prepared from an inexpensive source and adsorbed to a porous membrane with high protein binding capacity. Serum is slowly drawn through the membrane comprising the high density autoantigen mixture to induce rapid binding of patient autoantibodies. After rinsing, peroxidase-conjugated anti-IgG is drawn through the membrane followed by rinsing, insertion of an electrode assembly, and addition of the enzyme substrate. Substrate peroxidation is measured by microamperage-level current accompanying electrochemical reduction of the intermediate product. Values are comparable to a standard ANA test but require a total processing time of ~20min. This method has the promise to greatly expand ANA testing in clinical settings for initial patient assessment of autoimmune disease.
authors.affiliation: Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA. Electronic address: rlrubin@salud.unm.edu.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Rubin
authors.affiliation: Department of Internal Medicine, Division of Rheumatology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA.
authors.forename: Konstantin N
authors.initials: KN
authors.lastname: Konstantinov
mesh_terms: D000974:Antibodies, Antinuclear / Q000097:blood*; D015374:Biosensing Techniques / Q000379:methods*; D055664:Electrochemical Techniques / Q000379:methods*; D006801:Humans; D057230:Limit of Detection; D019095:Point-of-Care Systems
chemical_list: D000974:Antibodies, Antinuclear
keywords: Anti-nuclear autoantibody (ANA); Electrochemical flow-through biosensor; Human serum