ELECSYS TACROLIMUS

Additional Manufacturer Narrative

A GENERAL REAGENT ISSUE CAN BE EXCLUDED AS THE PROVIDED QUALITY CONTROL DATA IS WITHIN EXPECTATIONS. THE CUSTOMER IS USING EPPENDORF CUPS ON TOP OF A TUBE. THIS IS NOT RECOMMENDED AND CAN LEAD TO FALSE MEASUREMENTS. PER PRODUCT LABELING, "TRANSFER EACH SUPERNATANT DIRECTLY INTO AN APPROPRIATE VIAL AND IMMEDIATELY CAP EACH VIAL. THE SAMPLES ARE READY TO BE ASSAYED." THE CUSTOMER IS ALSO NOT CLEANING THE WATER RESERVOIR AS RECOMMENDED. THE INVESTIGATION DETERMINED THE ISSUE IS CONSISTENT WITH THE CUSTOMER NOT FOLLOWING SAMPLE PRE-TREATMENT RECOMMENDATIONS AS PROVIDED IN PRODUCT LABELING.

Description of Event or Problem

THE INITIAL REPORTER STATED THEY RECEIVED DISCREPANT RESULTS FOR TWO PATIENT SAMPLES TESTED WITH ELECSYS TACROLIMUS ON A COBAS E411 RACK. THE DOCTOR QUESTIONED THE INITIAL SAMPLE VALUES AS THESE DID NOT CORRESPOND TO THE CLINICAL HISTORY OF THE PATIENTS. THE SAMPLES WERE REPEATED ON THE SAME ANALYZER AND USING A LIQUID CHROMATOGRAPHY-MASS SPECTROMETRY METHOD. THE FIRST SAMPLE INITIALLY RESULTED IN A TACROLIMUS VALUE OF 17 NG/ML. THIS SAMPLE WAS REPEATED ON THE SAME ANALYZER AND THE RESULT WAS APPROXIMATELY THE SAME. NO SPECIFIC REPEAT VALUE WAS PROVIDED. THE SAMPLE WAS REPEATED USING THE LIQUID CHROMATOGRAPHY-MASS SPECTROMETRY METHOD ON (B)(6) 2025, RESULTING IN A VALUE OF 11.8 NG/ML. THE SECOND SAMPLE INITIALLY RESULTED IN A TACROLIMUS VALUE OF 10.7 NG/ML. THIS SAMPLE WAS REPEATED ON THE SAME ANALYZER AND THE RESULT WAS APPROXIMATELY THE SAME. NO SPECIFIC REPEAT VALUE WAS PROVIDED. THE SAMPLE WAS REPEATED USING THE LIQUID CHROMATOGRAPHY-MASS SPECTROMETRY METHOD ON (B)(6) 2025, RESULTING IN A VALUE OF 8 NG/ML.

Additional Manufacturer Narrative

THE SERIAL NUMBER OF THE E411 ANALYZER IS (B)(6). IT WAS FOUND THAT THE CUSTOMER IS USING AN EPPENDORF CUP ON TOP OF A TUBE. IT WAS ALSO NOTED THAT THE CUSTOMER DOES NOT ROUTINELY CLEAN THE ANALYZER WATER RESERVOIR. THE INVESTIGATION IS ONGOING.