10/04/2007

Orgentec Diagnostika GmbH

A novel high sensitivity ELISA for diagnosis of Wegener’s granulomatosis

Wegener’s granulomatosis is a fatal disease of unknown aetiology. It is characterized by granuloma in the inflamed tissues of the respiratory tract, systemic vasculitis of small blood vessels and glomerulonephritis. Anti-neutrophile cytoplasmatic antibodies (ANCA) against cytoplasmic components of neutrophil granulocytes are diagnostic markers for the disease.

Proteinase 3 is one of the most important antigens for ANCA diagnostics, because antibodies against proteinase 3 discriminate Wegener’s granulomatosis from other ANCA-associated small vessel vasculitides like microscopic polyangiitis and Churg-Strauss syndrome. Therefore reliable diagnosis combines indirect immunofluorescence with an antigen-specific ELISA.

This may change soon: an independent study including patients with Wegener’s granulomatosis confirmed by clinical data and biopsy results demonstrates the great potential of the Anti-PR3 hs ELISA with outstanding sensitivity of 96 % and specificity of 99 %. Anti-PR3 hs by ORGENTEC proved to be superior to immunoblot, direct and capture ELISA and correlates perfectly with indirect immunofluorescence.
The tremendous diagnostic benefit of ORGENTEC’s Anti-PR3 hs has become obvious when sera of patients with confirmed Wegener’s granulomatosis were tested. These sera had been tested negative for proteinase 3 autoantibodies in conventional direct ELISA, but the ORGENTEC Anti-PR3 hs assay detected proteinase 3 antibodies in 71 % of these sera.
One step ahead in diagnosing Wegener’s granulomatosis: Anti-PR3 hs detects patients with localised Wegener’s granulomatosis corresponding to an early stage of the disease.

Due to its outstanding sensitivity, high specificity and excellent correlation with IFT Anti-PR3 hs can replace the need for complex analysis and significantly simplify diagnosis of ANCA.

Literature:
Hellmich B, Csernok E, Fredenhagen G, Gross WL. A novel high sensitivity ELISA for detection of antineutrophil cytoplasm antibodies against proteinase-3. Clin Exp Rheumatol 2007, 25 (Suppl.44):1-5