Sjögren's Syndrome: autoantigens and autoantibodies

Karl Albert Brokstad 1)
Elisabeth Nginamau 1)
Johan G. Brun 2)
Roald Omdal 3)
Roland Jonsson 1)

1) Broegelmann Research Laboratory, The Gade Institute, University of Bergen
2) Department of Rheumatology, Haukeland University Hospital, Bergen
3) Department of Internal Medicine, Rogaland Central Hospital, Stavanger

  SS is a disease, which mainly effects women (clinical signs often starts at the age of 40-50 years) with a female to male ratio of about 9:1. The prevalence is in the region of 0.5%, but has been difficult to assess due to complex diagnostic criteria and clinical signs. The number of SS sufferer is likely to increase in the western industrial world due to the ageing of the population. The aetiology of the disease is unknown, but is probably multifactoral as with many other rheumatic non-organ specific autoimmune diseases. Medical treatment is mainly targeted at relief of symptoms. A search for improved diagnostic markers is a prioritised field.
Our interest in auto -antibodies/-antigens has lead to us to an extensive examination of the serological pattern of autoantibodies from primary Sjögren’s syndrome patients against the Ro/SSA and La/SSB auto antigens. We found that although a few healthy subjects may have the Ro and La autoantibodies, the SS patients are more frequent carriers of these autoantibodies. This was not a surprise and dismantling the response further, we found that the pSS patients had a stronger and more heterogeneous antibody response. This may be a result of longer and stronger exposure of auto antigens / immune stimulation.
This work has been followed up by increasing the number of patients studied, and using both commercially available and in house developed enzyme linked immunosorbent assay (ELISA) and xMAP (Luminex/multiplex bead ELISA) kits for examining the serological autoantibody repertoire. These results have been linked to clinical data and gene expression of the autoantigens in peripheral blood.

Garberg H, Jonsson R, Brokstad KA.The serological pattern of autoantibodies to the Ro52, Ro60, and La48 autoantigens in primary Sjögren's syndrome patients and healthy controls. Scand J Rheumatol. 2005;34(1):49-55.