ELECSYS DHEA-S

Additional Manufacturer Narrative

INVESTIGATION OF THE SAMPLE MATERIAL CONFIRMED A STREPTAVIDIN INTERFERENCE IN THE SAMPLE, CAUSING THE ELEVATED ELECSYS RESULTS COMPARED TO THE COMPETITOR AND LC-MS. THIS IS A KNOWN INTERFERENCE CLEARLY DISCLAIMED IN THE METHOD SHEET, "IN RARE CASES, INTERFERENCE DUE TO EXTREMELY HIGH TITERS OF ANTIBODIES TO ANALYTE-SPECIFIC ANTIBODIES, STREPTAVIDIN OR RUTHENIUM CAN OCCUR. THESE EFFECTS ARE MINIMIZED BY SUITABLE TEST DESIGN. FOR DIAGNOSTIC PURPOSES, THE RESULTS SHOULD ALWAYS BE ASSESSED IN CONJUNCTION WITH THE PATIENT¿S MEDICAL HISTORY, CLINICAL EXAMINATION AND OTHER FINDINGS." THE INVESTIGATION DID NOT IDENTIFY A PRODUCT PROBLEM.

Description of Event or Problem

THERE WAS AN ALLEGATION OF A QUESTIONABLE ELECSYS DHEA-S ASSAY RESULT FOR A PATIENT SAMPLE TESTED ON A COBAS E 801 ANALYTICAL UNIT. THE INITIAL RESULT WAS >1000 G/DL. THE REPEAT RESULT WAS >1000 G/DL. THE SAMPLE WAS DILUTED 1:2, AND THE RESULT WAS 1028 G/DL. THE SAMPLE WAS DILUTED 1:4, AND THE RESULT WAS 973 G/DL. THE SAMPLE WAS REPEATED ON THE ABBOTT TEST, AND THE RESULT WAS 479.9 G/DL. THE PATIENT¿S CONCURRENT LC-MS (MASS SPECTROMETRY) RESULT WAS 3.14 G/ML. NO ERRONEOUS RESULTS WERE RELEASED. THE TEST WAS REPEATED AS THE RESULT DID NOT MATCH THE PATIENT'S CLINICAL DIAGNOSIS. THE CUSTOMER SUSPECTS INTERFERENCE.

Additional Manufacturer Narrative

THE SERIAL NUMBER OF THE ANALYZER WAS (B)(6). THE SAMPLE MATERIAL WAS REQUESTED FOR INVESTIGATION.