Comparative analysis of different commercial ELISA systems for the detection of anti-neutrophil cytoplasm antibodies in ANCA-associated vasculitides

CER5493
2012 Vol.30, N°1 ,Suppl.70
PI 0066, PF 0069
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PMID: 22512915 [PubMed]

Received: 24/02/2012
Accepted : 02/03/2012
In Press: 10/05/2012
Published: 10/05/2012

Abstract

OBJECTIVES:
To assess the diagnostic performance of 11 commercial PR3- and MPO-ANCA ELISA systems (direct, capture and high sensitive [hs] ELISA).
METHODS:
Sera from 90 patients with AAV (GPA, MPA and CSS) and 20 disease controls (SLE; RA) and healthy individuals were tested for the presence of ANCA by IFT and by different ELISAs for the presence of PR3-and MPO-ANCA, respectively. Furthermore, the binding capacity of the IUIS-CDC reference sera for PR3-/MPO-ANCA in different commercial assays was analysed.
RESULTS:
Commercial ELISA kits for PR3-ANCA differed moderately in their sensitivity (from 45% to 62.5%). The highest sensitivity for PR3-ANCA was obtained with hs ELISA (kit A) and capture ELISA (kit N). Testing for MPO-ANCA the highest sensitivity (85%) was obtained with direct ELISA (kit D and I). Specificity was high in all kits. Only three PR3-ANCA commercial kits and three MPO-ANCA kits produced binding at the expected value for the IUIS-CDC reference sera (100 U/ml). In all of the kits, serial dilutions of the reference sera did not yield linearity.
CONCLUSIONS:
Second (capture) and third (high sensitivity) generation PR3-ANCA ELISA kits are superior to conventional ELISAs. Direct and capture MPO-ANCA ELISAs showed a good overall performance in all kits. Most of the kits have not been standardised to allow their results to be compared.