ELECSYS CMV IGM

Additional Manufacturer Narrative

MEDWATCH FIELDS A. PATIENT INFORMATION, B6 RELEVANT TESTS/LABORATORY DATA, AND B7 OTHER RELEVANT HISTORY UPDATED. ON (B)(6) 2024, THE CUSTOMER REPORTED THAT A NEW SAMPLE FROM PATIENT 1 ALSO GAVE DISCREPANT ELECSYS CMV IGM RESULTS: ON (B)(6) 2023: THE RESULT FROM THE COBAS E 801 ANALYTICAL UNIT WAS "NEGATIVE". THE RESULT FROM THE VIDAS ANALYZER WAS 1.09 CUT-OFF INDEX COI (POSITIVE). ON (B)(6) 2024, THE CUSTOMER REPORTED DISCREPANT ELECSYS CMV IGM RESULTS FROM A DIFFERENT PATIENT (PATIENT 2): ON (B)(6) 2023: THE RESULT FROM THE COBAS E 801 ANALYTICAL UNIT WAS "NEGATIVE". THE RESULT FROM THE VIDAS ANALYZER WAS 0.87 COI (POSITIVE). INVESTIGATION RESULTS: PATIENT 1: THE PATIENT SAMPLE WAS RECEIVED FOR INVESTIGATION AND WAS TESTED WITH THE FOLLOWING: ELECSYS CMV IGM AND CMV IGG - THE CUSTOMER'S RESULTS WERE CONFIRMED. CMV IGG AVIDITY TEST - A HIGHER RESULT WAS OBTAINED (INVESTIGATION'S RESULT INTERPRETATION: GRAY ZONE; CUSTOMER'S RESULT INTERPRETATION: LOW AVIDITY). CMV IGG BLOT - BROAD ANTIGEN REACTIVITY WAS DETECTED WITH EARLY AND LATE PHASE ANTIGENS, WHICH INDICATES CMV INFECTION OF >12 WEEKS AGO. ELECSYS CMV IGG AVIDITY ASSAY - A SLIGHTLY INCREASING CMV IGG AVIDITY WAS DETECTED. THE INVESTIGATION DETERMINED THAT THE RESULTS INDICATE A PRIMARY INFECTION IN THE LATE ACUTE INFECTION PHASE BASED ON THE PRESENCE OF INCREASING IGG TITERS, AN INCREASING CMV IGG AVIDITY, AND A DECLINING CMV IGM REACTIVITY; A SECONDARY CMV INFECTION OR A CMV REACTIVATION CANNOT BE COMPLETELY RULED OUT. PATIENT 2: THE INVESTIGATION DETERMINED THAT THE PATIENT'S RESULTS INDICATE A LATE-STAGE CMV INFECTION. PRODUCT LABELING STATES "HOW DOES THE CMV IGM ASSAY PERFORM AND WHAT ARE ITS KEY FEATURES? IN SUMMARY, THE TEST IS DESIGNED TO DETECT ACUTE INFECTIONS WHERE CONGENITAL RISK LIES." THE INVESTIGATION REVIEWED THE HANDLING AND PROCESSING OF PATIENT 1'S SAMPLE; NO ISSUES WERE NOTED. THE INVESTIGATION REVIEWED THE CALIBRATION AND QC DATA; THE RESULTS WERE WITHIN SPECIFICATIONS. THE INVESTIGATION DID NOT IDENTIFY A PRODUCT PROBLEM.

Additional Manufacturer Narrative

THE SERIAL NUMBER OF THE CUSTOMER'S COBAS E 801 ANALYTICAL UNIT IS (B)(6). THE PATIENT SAMPLE WAS REQUESTED FOR INVESTIGATION. THE INVESTIGATION IS ONGOING.

Description of Event or Problem

THE INITIAL REPORTER RECEIVED QUESTIONABLE ELECSYS CMV IGM RESULTS FROM SEVERAL PATIENT SAMPLES TESTED ON THE COBAS E 801 ANALYTICAL UNIT. THE REPORTER WAS ABLE TO PROVIDE ONE PATIENT SAMPLE WITH DISCREPANT RESULTS: THE PATIENT WAS EXPECTED TO BE CMV IGM POSITIVE BASED ON THE PREVIOUS RESULT FROM ANOTHER LABORATORY THAT USES A VIDAS ANALYZER ( ON (B)(6) 2024: 1.25 AU/ML - POSITIVE). ON (B)(6) 2024: THE RESULT FROM THE ANALYZER WAS 0.571 CUT-OFF INDEX COI (NEGATIVE/NON-REACTIVE). THE RESULT FROM THE VIDAS ANALYZER WAS 1.23 COI (POSITIVE).