ELECSYS DHEA-S

Additional Manufacturer Narrative

THE E801 ANALYZER SERIAL NUMBER WAS (B)(6). SAMPLE MATERIAL WAS REQUESTED FOR INVESTIGATION.

Description of Event or Problem

THE INITIAL REPORTER COMPLAINED OF DISCREPANT HIGH RESULTS FOR 1 PATIENT TESTED FOR ELECSYS DHEA-S (DHEA-S) ON A COBAS E 801 ANALYTICAL UNIT COMPARED TO THE LIQUID CHROMATOGRAPHY-MASS SPECTROMETRY (LC-MS) METHOD. THE INITIAL RESULT WAS >1000 UG/DL. THE SAMPLE WAS REPEATED "SEVERAL" TIMES AND THE RESULTS REMAINED >1000 UG/DL. THE HIGH RESULTS WERE NOT REPORTED OUTSIDE OF THE LABORATORY. DUE TO THE HIGH RESULTS, REPEAT TESTING BY LC-MS WAS REQUESTED. THE RESULT FROM THE LC-MS METHOD WAS 382.54 UG/DL. THIS RESULT WAS BELIEVED TO BE CORRECT.

Additional Manufacturer Narrative

CALIBRATION AND QC WERE ACCEPTABLE. SAMPLE MATERIAL WAS RECEIVED FOR INVESTIGATION. FURTHER INVESTIGATION OF THE PATIENT SAMPLE SUGGESTS THE PRESENCE OF AN INTERFERENT AGAINST THE STREPTAVIDIN COMPONENT OF THE REAGENT. THIS INTERFERENCE IS COVERED IN PRODUCT LABELING: "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." THE INVESTIGATION DID NOT IDENTIFY A PRODUCT PROBLEM.