Background

Progressive Systemic Sclerosis (PSS, scleroderma) is a chronic-inflammatory, autoimmune mediated disorder of the connective tissue. Its main manifestation is a thickening and hardening of the skin, but inner organs and blood vessels can be affected as well.

PSS patients present characteristic autoantibodies against a variety of nuclear proteins but almost always only one specificity at a time. These antibodies are valuable indicators of different PSS subsets and overlap syndromes with other systemic inflammatory disorders. Depending on the PSS variant, many patients carry antibodies directed against a basic nonhistone protein referred to as Scl-70 (scleroderma-associated 70 kDa autoantigen). It has been identified as DNA-topoisomerase I, a key nuclear enzyme that converts supercoiled DNA to the topological conformation required for DNA replication and transcription.

Scl-70 autoantibodies are considered as reliable marker of PSS. They indicate its severe course (diffuse scleroderma), typically involving lung, kidney or heart.

Technical information

The EULISA Scl-70 IgG is intended for the quantitative or qualitative determination of IgG antibodies in human serum, directed against Scl-70. The antigen used is a highly purified preparation of recombinant human DNA-topoisomerase I, expressed in the baculovirus system. The test is fast (incubation time 30-30-30 minutes) and flexible (break apart wells, ready-to-use reagents). Six calibrators allow quantitative measurements; a negative and a positive control are used to check assay performance.