Évaluation de la spécificité du kit de dépistage EMIT II Plus amphetamines assay (Syva®) sur V-Twin™ (Dade Behring)

We evaluated and compared the specificity of urinary screening tests for amphetamine/methamphetamine: the new EMIT®II Plus amphetamines Assay versus the EMIT®II Plus monoclonal amphetamine/methamphetamine assay. We used the new analyzer V-Twin™ (Dade-Behring, Netherlands). The results obtained are compared to those of the Syva® Rapid Tests (d.a.u.® mAMP and d.a.u. ® 4). We used GC/MS for confirmation of the positive urinary samples for amphetamine/methamphetamine. Out of 2255 samples, 40 were screened positive on the Cobas Mira™ (ABX, France) with the older kit. 52.5% unconfirmed positives (21 samples) are shown with this kit, 7.5% (3 samples) with the two Rapid Tests, 17.5% (7 samples) with the new kit and only 5% (2 samples) if used simultaneously with the two Rapid Tests. This suggests a greater specificity of the new kit antibodies and a smaller number of unconfirmed positives if used concomitantly with immunochrommatographic tests.