BEUDAMED
    FDA Adverse Event Malfunction Summary report: N

    ELECSYS FREE PSA

    MDR report key: 20711617 · Received November 18, 2024

    Report

    Report Number
    1823260-2024-03347
    Event Type
    Malfunction
    Date Received
    November 18, 2024
    Date of Event
    October 29, 2024
    Report Date
    February 28, 2025
    Manufacturer
    ROCHE DIAGNOSTICS
    Product Code
    MTG
    PMA / PMN Number
    P000027
    Product Problem
    Yes
    Report Source
    Manufacturer report
    Reporter Location
    BU
    Reporter Occupation
    OTHER HEALTH CARE PROFESSIONAL
    Health Professional
    Yes

    Narratives

    Additional Manufacturer Narrative · 0

    THE SERIAL NUMBER OF THE CUSTOMER'S E411 ANALYZER IS (B)(6). THE SERIAL NUMBER OF THE SECOND E411 ANALYZER WAS REQUESTED, BUT NOT PROVIDED. THE INVESTIGATION IS ONGOING.

    Additional Manufacturer Narrative · 0

    A SAMPLE FROM THE PATIENT WAS PROVIDED FOR INVESTIGATION. INVESTIGATIONS WERE ABLE TO REPRODUCE THE VALUES OBTAINED BY THE CUSTOMER. THE INVESTIGATION OF ENDOGENOUS INTERFERENCE BY DISPLACEMENT WITH UNLABELED ANTI-F-PSA-ANTIBODY (FREE PSA) SHOWED NO EVIDENCE FOR GENERATION OF UNSPECIFIC SIGNALS IN THE FREE PSA ASSAY. A SIGNIFICANT LOWER RECOVERY OF SPIKED PSA-ACT IN THE INVESTIGATED SAMPLE WAS DETERMINED AND IS EVIDENCE FOR THE PRESENCE OF ENDOGENOUS INTERFERING SUBSTANCE(S) IN THE CLAIMED SAMPLE THAT WOULD DECREASE THE RECOVERY OF TOTAL PSA. RETESTING OF THE SAMPLE ON ELECSYS BY ADDING AN ADDITIONAL ANTI-PSA-ANTIBODY OF A DIFFERENT SPECIFICITY SHOWED THAT THE CONCENTRATION OF TOTAL PSA IS 2.52 NG/ML, WHICH IS SIGNIFICANTLY INCREASED COMPARED TO THE ORIGINAL TPSA MEASURED VALUE OF 0.87 NG/ML. THIS SUGGESTS A PRESENCE OF A SELDOM PSA-ISOFORM THAT CANNOT BE COMPLETELY DETECTED BY THE USAGE OF STANDARD TOTAL PSA ELECSYS ASSAY. ANOTHER POSSIBLE EXPLANATION FOR THE MEASURED RESULTS COULD BE A PRESENCE OF PSA AUTO-ANTIBODIES IN THE SAMPLE, WHICH PREVENT BINDING OF THE PSA-ANTIBODIES USED IN THE ROCHE ASSAY TO THE ANALYTE. THIS LEADS TO FALSELY DECREASED RECOVERY OF BOTH TOTAL PSA VALUES IN THE SAMPLE AND SPIKED PSA-ACT. ADDITION OF AN ADDITIONAL ANTI-PSA-ANTIBODY LEADS TO INCREASED PSA-RECOVERY. PER PRODUCT LABELING FOR THE TOTAL PSA ASSAY, "IT IS KNOWN THAT IN RARE CASES PSA ISOFORMS DO EXIST WHICH MAY BE MEASURED DIFFERENTLY BY DIFFERENT PSA TESTS. FINDINGS OF THIS KIND HAVE OCCASIONALLY BEEN REPORTED FOR PSA TESTS FROM VARIOUS MANUFACTURERS." THE INVESTIGATION DID NOT IDENTIFY A PRODUCT ISSUE.

    Description of Event or Problem · 0

    THE INITIAL REPORTER STATED THEY RECEIVED QUESTIONABLE RESULTS FOR ONE PATIENT SAMPLE TESTED WITH ELECSYS TOTAL PSA AND ELECSYS FREE PSA ON TWO COBAS E411 ANALYZERS. THE FREE PSA VALUE WAS GREATER THAN THE TOTAL PSA VALUE. THIS MEDWATCH WILL APPLY TO THE FREE PSA ASSAY. PLEASE REFER TO THE MEDWATCH WITH A1. PATIENT IDENTIFIER PT-0072356 FOR INFORMATION RELATED TO THE TOTAL PSA ASSAY. THE SAMPLE RESULTED IN A FREE PSA VALUE OF 2.490 NG/ML AND A TOTAL PSA VALUE OF 0.938 NG/ML WHEN TESTED ON THE CUSTOMER'S E411 ANALYZER. THE SAMPLE WAS SENT TO ANOTHER LABORATORY WHERE REPEAT TESTING WAS PERFORMED ON A SECOND E411 ANALYZER. THE REPEAT RESULTS WERE 2.45 NG/ML FOR FREE PSA AND 0.85 NG/ML FOR TOTAL PSA.

    Devices

    Seq Brand Generic Product Code Manufacturer Model Lot UDI-DI
    2112534 ELECSYS FREE PSA TEST, PROSTATE SPECIFIC ANTIGEN, FREE, (NONCOMPLEXED) TO DISTINGUISH PROSTATE CA MTG ROCHE DIAGNOSTICS 78583901

    Patients

    Seq Age Sex Outcome Treatment
    1 NA Unknown