CMV IGG ELECSYS E2G

Additional Manufacturer Narrative

THE INVESTIGATION TESTED THE RETURNED PATIENT SAMPLES ON A COBAS E801 USING RETENTION MATERIAL. THE CUSTOMER¿S ELECSYS CMV IGG ASSAY RESULTS COULD BE REPRODUCED. THE SAMPLE FROM 05-OCT-2022 HAD THE FOLLOWING RESULTS: ELECSYS CMV IGG 6.94 U/ML (REACTIVE), ELECSYS CMV IGM 0.598 COI (NON-REACTIVE), ELECSYS CMV IGG AVIDITY 67.8% (HIGH). THE SAMPLE FROM (B)(6)-2022 HAD THE FOLLOWING RESULTS: ELECSYS CMV IGG 6.44 U/ML (REACTIVE), ELECSYS CMV IGM 0.594 COI (NON-REACTIVE), ELECSYS CMV IGG AVIDITY 69.3% (HIGH). THE INVESTIGATION IS ONGOING.

Additional Manufacturer Narrative

CALIBRATION DATA WERE WITHIN THE EXPECTED RANGES. QUALITY CONTROL RECOVERY WAS WITHIN SPECIFICATIONS. THE PATIENT SAMPLES WERE RETURNED FOR INVESTIGATION. THE INVESTIGATION IS ONGOING.

Description of Event or Problem

THE INITIAL REPORTER STATED THEY RECEIVED DISCREPANT RESULTS FOR ONE PATIENT SAMPLE TESTED WITH THE ELECSYS CMV IGG ASSAY ON A COBAS 8000 E 801 MODULE (SERIAL NUMBER (B)(4) ). THE SAMPLE INITIALLY RESULTED IN A CMV IGG VALUE OF 6.57 U/ML (REACTIVE) WHEN TESTED ON THE E801 ANALYZER. THE SAMPLE WAS SENT TO ANOTHER LABORATORY FOR TESTING WITH AN UNKNOWN RUBELLA IGG ELISA TEST, WHICH RESULTED AS NEGATIVE. ON (B)(6) 2022, A NEW SAMPLE FROM THE SAME PATIENT WAS TESTED ON THE E801 ANALYZER. THE SAMPLE INITIALLY RESULTED IN A CMV IGG VALUE OF 6.28 U/ML (REACTIVE) AND REPEATED AS 5.50 U/ML (REACTIVE). IT WAS ASKED BUT IT IS UNKNOWN IF THE QUESTIONABLE RESULT WAS REPORTED OUTSIDE OF THE LABORATORY. THE CMV IGG REAGENT LOT WAS 61916801 WITH AN EXPIRATION DATE OF 31-MAR-2023.

Additional Manufacturer Narrative

THE CORRECT TEST PERFORMED WITH THE INITIAL SAMPLE FROM (B)(6)-2022 IN ANOTHER LABORATORY WAS CMV IGG ELISA, WHICH RESULTED AS NEGATIVE. FURTHER INVESTIGATION WITH THE MIKROGEN RECOMLINE CMV IGG BLOT SHOWED REACTIVE RESULTS FOR BOTH PATIENT SAMPLES. BOTH PATIENT SAMPLES SHOWED MAINLY REACTIVITY TOWARDS ONE OUT OF FIVE SUB-MODULES OF THE ROCHE CMV IGG ASSAY, INDICATING THAT A SYSTEMIC ASSAY INTERFERENCE IS UNLIKELY. A HIGH AVIDITY IN LOW REACTIVE IGG SAMPLES WAS CONFIRMED. THE HIGH AVIDITY OF CMV IGG ANTIBODIES COMBINED WITH THE ABSENCE OF CMV IGM REACTIVITY IS NOT INDICATIVE OF AN EARLY PHASE OF INFECTION. A PAST INFECTION STATUS OF THE PATIENT IS PLAUSIBLE, HOWEVER, A FALSE POSITIVE RESULT IN THE ELECSYS CMV IGG ASSAY, DRIVING FALSE HIGH AVIDITY IN THE ELECSYS CMV IGG AVIDITY ASSAY, CANNOT BE EXCLUDED. THE INVESTIGATION DID NOT IDENTIFY A PRODUCT PROBLEM.