Evaluating the utility of autoantibodies for disease activity and relapse in giant cell arteritis

Abstract

In patients with giant cell arteritis (GCA), autoantibodies against cytoskeletal elements, cardiolipin, neutrophil cytoplasmic antigens, ferritin, endothelial and smooth muscle cells have been reported, however no updated reviews are available evaluating their clinical utility. Methodology of detection is important, especially for quantitative assays, e.g. enzyme-linked immunoassays and multiplex beadbased immunoassays, while semiquantitative assays contribute valuable data on isoforms, epitope mapping and cellular localization. Most studies to date reporting on antiphospholipid antibodies in GCA have focused on anti-cardiolipin antibodies (aCL), while the highest prevalence of autoantibodies in GCA patients was reported for the anti-N-terminal peptides of the ferritin heavy chain (92%). Antineutrophil cytoplasmic antibodies were shown to be present in only a small percentage of GCA patients, decreasing after therapy, however in combination with aCL and antibodies against peptides of N-terminal ferritin heavy chain, they could represent an added value in detecting relapse in GCA patients.