TINA-QUANT CYSTATIN C GEN.2

Additional Manufacturer Narrative

BASED ON THE PROVIDED INFORMATION, A REAGENT OR INSTRUMENT ISSUE CAN BE EXCLUDED. THE ROOT CAUSE WAS CONSISTENT WITH AN ANALYTICAL INTERFERENCE BY ANTI-RABBIT ANTIBODIES. THESE ANTIBODIES BRIDGED THE RABBIT-DERIVED ASSAY REAGENTS, CREATING A FALSE-POSITIVE SIGNAL. THE PRODUCT LABELING STATES: "IN VERY RARE CASES FALSELY ELEVATED RESULTS FOR CYSTATIN C WILL BE OBTAINED FROM SAMPLES TAKEN FROM PATIENTS WHO HAVE BEEN TREATED WITH RABBIT ANTIBODIES OR HAVE DEVELOPED ANTI-RABBIT ANTIBODIES." THE INVESTIGATION DID NOT IDENTIFY A PRODUCT PROBLEM. THE CAUSE OF THE EVENT WAS CONSISTENT WITH A KNOWN INTERFERENCE.

Additional Manufacturer Narrative

THE C702 MODULE SERIAL NUMBER WAS (B)(6). THE INVESTIGATION IS ONGOING.

Description of Event or Problem

WE RECEIVED AN ALLEGATION ABOUT DISCREPANT RESULTS FOR 1 PATIENT SAMPLE TESTED WITH TINA-QUANT CYSTATIN C GEN.2 ASSAY ON A COBAS 8000 C702 MODULE, NOT MATCHING THE PATIENT'S CLINICAL DIAGNOSIS. INITIAL RESULT: 8.66 MG/L (ACCOMPANIED BY A DATA FLAG). THE INITIAL RESULT DID NOT MATCH THE PATIENT'S CLINICAL DIAGNOSIS, PROMPTING THE REPEAT OF THE SAMPLE. NO QUESTIONABLE RESULT WAS REPORTED OUTSIDE THE LABORATORY. RERUN RESULT: 11.90 MG/L (ACCOMPANIED BY A DATA FLAG).