BEUDAMED
    FDA Adverse Event Malfunction Summary report: N

    UNICEL ¿ DXI 800 ACCESS ® IMMUNOASSAY SYSTEM

    MDR report key: 2375207 · Received December 15, 2011

    Report

    Report Number
    2122870-2011-06374
    Event Type
    Malfunction
    Date Received
    December 15, 2011
    Date of Event
    November 2, 2011
    Report Date
    November 15, 2011
    Manufacturer
    BECKMAN COULTER INC.
    Product Code
    JJE
    PMA / PMN Number
    K023764
    Removal / Correction Number
    N/A
    Product Problem
    Yes
    Report Source
    Manufacturer report
    Reporter Location
    BE
    Reporter Occupation
    OTHER

    Narratives

    Additional Manufacturer Narrative · 1

    INVESTIGATION SUMMARY PATIENT SAMPLE WERE FIRST TESTED AFTER CENTRIFUGATION FOR FTSH AND FT4 TO CONFIRM CUSTOMER'S RESULTS. SECOND, DILUTION TEST WAS PERFORMED BY CPLS ON FTSH ASSAY HETEROPHILE TESTING (USING POOLS OF DIFFERENT BLOCKERS) WAS THEN CARRIED OUT FINALLY, A 1:10 DILUTION OF SAMPLE S4 WAS ANALYZED BY GEL FILTRATION CHROMATOGRAPHY (GFC OR SIZE EXCLUSION CHROMATOGRAPHY). THIS TECHNIQUE IS WIDELY USED IN BIOCHEMISTRY TO PURIFY PROTEINS OF INTEREST AND IS BASED ON THE SEPARATION OF MOLECULES DEPENDING ON THEIR SIZE (MOLECULAR WEIGHT). IN OUR INVESTIGATION, THE ELUTION FRACTIONS CORRESPONDING TO PURIFIED MOLECULE WERE TESTED ON THE ACCESS ASSAY. (SEE WORKSHEET "GFC PRINCIPLE" AND "GFC CALIBRATION"). RESULTS AND CONCLUSION: WE IDENTIFIED 3 DIFFERENT CASES: SAMPLES S1 AND S3 : CPLS REPEATED CUSTOMER'S TSH RESULTS ON NEAT SAMPLES. RESULTS WERE ABOVE CUSTOMER'S REFERENCE RANGE. FT4 WAS ALSO TESTED AND FOUND WITHIN ACCESS IFU REFERENCE RANGE. DILUTION TEST WAS NOT CONCLUSIVE FOR THE PRESENCE OF INTERFERING COMPOUNDS. INDEED GOOD RECOVERIES WERE OBSERVED EXCEPT FOR THE 1:32 DILUTIONS WHERE RECOVERY WAS BETWEEN 120 AND 130%. HETEROPHILE TESTING PERFORMED WITH 9 DIFFERENT BLOCKERS CONTAINED IN TWO DIFFERENT POOLS DID NOT DEMONSTRATE ANY INTERFERENCE. OUR INVESTIGATION TENDS THEREFORE TO CONFIRM THE ACCURACY OF THE TSH RESULTS OBTAINED WITH ACCESS INSTRUMENT ON THESE TWO SAMPLES. SINCE TSH RESULTS ARE WITHIN THE IFU REFERENCE RANGE (0.34 - 5.6 MIU/ML), IT APPEARS THEREFORE IMPORTANT TO CHECK IF TSH REFERENCE RANGE USED BY CUSTOMER IS SUITABLE WITH THE POPULATION TESTED IN THE LAB. AS STATED IN ACCESS IFU'S: "EACH LABORATORY SHOULD ESTABLISH ITS OWN REFERENCE RANGES TO ASSURE PROPER REPRESENTATION OF SPECIFIC POPULATIONS". SAMPLE S2 : CPLS REPEATED CUSTOMER'S RESULTS ON NEAT SAMPLE. TSH RESULT WAS ABOVE CUSTOMER'S REFERENCE RANGE. FT4 WAS ALSO TESTED AND FOUND ABOVE ACCESS REFERENCE RANGE (IFU) WHICH IS NOT CONSISTENT WITH A HIGH TSH VALUE. WE PERFORMED A DILUTION TEST WHICH WAS NOT CONCLUSIVE FOR THE PRESENCE OF INTERFERING COMPOUND. INDEED GOOD RECOVERIES WERE OBSERVED . HETEROPHILE TESTING WAS PERFORMED WITH 9 DIFFERENT BLOCKERS CONTAINED IN TWO DIFFERENT POOLS. ONE POOL OF BLOCKERS SIGNIFICANTLY LOWERED THE SIGNAL SHOWING THE PRESENCE OF AN INTERFERING COMPOUND IN PATIENT BLOOD. IT SHOULD BE MENTIONED THAT HETEROPHILE ANTIBODIES INTERACTION IS WELL KNOW BY ALL MANUFACTURERS. EVEN THOUGH THE OCCURRENCE OF SUCH INTERFERENCE IS VERY LOW, A STATEMENT IN THE SECTION LIMITATION IS ALWAYS PRESENT IN ALL INSERTS OF MOST MANUFACTURERS. AS AN EXAMPLE BELOW IS THE BECKMAN COULTER STATEMENT: "FOR ASSAYS EMPLOYING ANTIBODIES, THE POSSIBILITY EXISTS FOR INTERFERENCE BY HETEROPHILE ANTIBODIES IN THE PATIENT SAMPLE. PATIENTS WHO HAVE BEEN REGULARLY EXPOSED TO ANIMALS OR HAVE RECEIVED IMMUNOTHERAPY OR DIAGNOSTIC PROCEDURES UTILIZING IMMUNOGLOBULINS OR IMMUNOGLOBULIN FRAGMENTS MAY PRODUCE ANTIBODIES, E.G. HAMA, THAT INTERFERE WITH IMMUNOASSAYS. ADDITIONALLY, OTHER HETEROPHILE ANTIBODIES SUCH AS HUMAN ANTI-GOAT ANTIBODIES MAY BE PRESENT IN PATIENT SAMPLES. SUCH INTERFERING ANTIBODIES MAY CAUSE ERRONEOUS RESULTS. CAREFULLY EVALUATE THE RESULTS OF PATIENTS SUSPECTED OF HAVING THESE ANTIBODIES." SAMPLE S4 : CPLS REPEATED CUSTOMER'S RESULTS ON NEAT SAMPLE SINCE TSH RESULT WAS VERY HIGH. IT SHOULD BE ALSO NOTED THAT ARCHITECT TESTINGS PERFORMED BY CUSTOMER CONFIRMED A HIGH LEVEL OF TSH IN THIS SAMPLE. FT4 WAS ALSO TESTED AND FOUND BELOW ACCESS REFERENCE RANGE (IFU) WHICH IS CONSISTENT WITH HIGH TSH RESULTS. WE PERFORMED A DILUTION TEST WHICH WAS CONSIDERED AS NOT CONCLUSIVE FOR THE PRESENCE OF INTERFERING COMPOUND BASED ON GOOD RECOVERIES AT THE 1:2 AND 1:4 DILUTIONS. HETEROPHILE TESTING PERFORMED WITH 9 DIFFERENT BLOCKERS CONTAINED IN TWO DIFFERENT POOLS DID NOT DEMONSTRATE ANY INTERFERENCE. A CHROMATOGRAPHIC ANALYSIS WAS THEN PERFORMED ON THE 1:10 DILUTION OF SAMPLE S4 SINCE VOLUME AVAILABLE WERE LIMITED. ELUTION FRACTIONS CORRESPONDING TO THE TSH MOLECULE (44 KDA) WERE TESTED ON THE ACCESS ASSAY AND WERE FOUND REACTIVE FOR TSH AND WERE CONSISTENT WITH THE TSH DOSE OF SAMPLE. OUR INVESTIGATION THEREFORE CONFIRMS THE VERY HIGH LEVEL OF TSH IN THIS SAMPLE.

    Description of Event or Problem · 1

    THE CUSTOMER REPORTED THEIR UNICEL DXI 800 ACCESS IMMUNOASSAY ANALYZER GENERATED HIGHER THAN EXPECTED TSH RESULTS ABOVE THEIR NORMAL REFERENCE RANGE FOR SIX PATIENTS. THESE SAMPLES WERE TESTED ON AN ABBOTT ARCHITECT AND 5 PRODUCED DISCORDANTLY LOWER RESULTS, WITHIN THE NORMAL REFERENCE RANGE; 1 SAMPLE RECOVERED LOWER, BUT REMAINED ABOVE THE NORMAL REFERENCE RANGE. PATIENT RESULTS ARE ATTACHED. THE RESULTS WERE NOT REPORTED OUT OF THE LABORATORY; HENCE PATIENT TREATMENT WAS NOT IMPACTED BY THE EVENT. THE CUSTOMER INDICATES THAT DILUTION TESTING WAS PERFORMED, ALTHOUGH THAT DATA WAS NOT SUPPLIED TO US. SYSTEM DETAIL AND/OR INFORMATION WERE NOT PROVIDED. SERVICE WAS NOT DISPATCHED. SERVICE WAS NOT DISPATCHED FOR THIS EVENT. THE SAMPLES WERE SUBMITTED TO CUSTOMER PRODUCT LINE SUPPORT (CPLS) EAST FOR ADDITIONAL TESTING.

    Devices

    Seq Brand Generic Product Code Manufacturer Model Lot UDI-DI
    1 UNICEL ¿ DXI 800 ACCESS ® IMMUNOASSAY SYSTEM ANALYZER, CHEMISTRY (PHOTOMETRIC, DISCRETE), FOR CLINICAL USE JJE BECKMAN COULTER INC. DXI 800 N/A

    Patients

    Seq Age Sex Outcome Treatment
    1