Vasculitis

Comparison with EIA Methods

Positive Agreement

A total of 227 retrospective samples positive for anti-MPO (N = 100), anti-PR3 (N = 100) and anti-GBM (N = 27) were testedwith the BioPlex™ 2200 Vasculitis Kit and the corresponding commercially available microplate EIA methods. Thepositive % agreement and overall % agreement between the two methods for each analyte are referenced in thetable below. The BioPlex 2200 Vasculitis Kit demonstrated good positive agreement with commerciallyavailable EIA assays for each analyte.

Negative Agreement

A total of 293 samples from normal blood donors and 300 samples from unselected patient samples previously tested with vasculitis tests were tested with the BioPlex 2200 Vasculitis kit and the corresponding commercially available microplate EIA methods. The negative % agreement and overall % agreement between the two methods for each analyte are referenced in the table below. The BioPlex 2200 Vasculitis kit demonstrated excellent negative agreement with commercially available EIA assays for each analyte.

* Previously tested with vasculitis tests.

Positive Agreement

A total of 200 retrospective positive samples (100 anti-MPO and 100 anti-PR3) were evaluated by a commercially available ANCA IFA method using ethanol-fixed slides. The positive agreement and overall agreement between the two methods are referenced in the tables below. The BioPlex 2200 Vasculitis Kit demonstrated good positive agreement with the ANCA IFA method.

BioPlex 2200 Vasculitis vs. EIA Methods

For the 200 retrospective positive samples described above, a combined positive agreement of 94.1% was observed between BioPlex 2200 Vasculitis anti-MPO/anti-PR3 and ANCA IFA results, compared to a combined positive agreement of 88.2% between anti-MPO/anti-PR3 EIA and ANCA IFA results. Also, a combined overall agreement with ANCA IFA results of 88.5% and 83.0% was observed between BioPlex 2200 and EIA results, respectively. Overall, the BioPlex 2200 Vasculitis Kit demonstrated better concordance with ANCA IFA than the corresponding EIA methods.

Reproducibility

Following CLSI (formerly NCCLS) EP5-A2 guidelines and ISO/TR 22971:2005, two (2) US testing sites and an internal site performed reproducibility testing using the BioPlex™ 2200 vasculitis positive control for 3 days with a total of 36 replicates. The overall performance demonstrated excellent reproducibility ranging from 0.0% to 7.7%.

The low %CV values on the BioPlex™ 2200 Vasculitis Kit can be attributed to:

• Full automation
• Magnetic bead, heterogeneous assay format
• A minimum of 150 measurements per analyte per reaction vessel (up to 3 times more than other multiplex methods)

Vasculitis Assay Procedure

Reagents, Calibrators and Controls

	Vasculitis Reagent Pack Contains all the necessary reagents (sample diluent, beads, and conjugate) to process 100 samples and up to 3 results per sample.
	Vasculitis Calibrator Set Calibrators are ready-to-use and multiplexed. A point-to-point curve fit using four calibrators is used to calculate semi-quantitative results.
	Vasculitis Control Set Quality controls are ready-to-use and multiplexed. The set includes a negative control as well as a multianalyte positive control containing antibodies to analytes within the Reagent Pack.