[The clinical relevance of autoantibody studies in connective tissue diseases and vasculitis].

The relevance of detection, quantification and characterisation of antinuclear antibodies and of anti-neutrophil cytoplasm antibodies in diagnosis of connective tissue disorders and of idiopathic vasculitis, is nowadays quite important. Since many years, antibody detection is routinely performed by indirect immunofluorescence tests; their sensitivity is very high so that several diagnoses might be ruled out in the presence of a negative result. These tests are however not specific. During the last years several progress have been realised in the characterisation of the antigens recognized by these antibodies, allowing the development of new techniques for specifically identifying several autoantibodies. It is therefore possible to detect now routinely with specific and sensitive techniques the presence of anti-double stranded DNA, anti-RNP, anti-Sm, anti-Scl-70, anti-SS-A, anti-SS-B, and anti-myeloperoxidase and anti-proteinase 3. The significance of the presence of these antibodies in serum will be discussed in this paper.