COBAS E-ELECSYS ANTI-CCP

Description of Event or Problem

THE CUSTOMER ALLEGED THEY RECEIVED QUESTIONABLE ANTIBODY TO CYCLIC CITRULLINATED PEPTIDE (ACCP) RESULTS OF ONE PATIENT ON THEIR E-MODULE. THE SPECIFIC DATE OF THIS EVENT WAS REQUESTED BUT NOT PROVIDED. THE PATIENT'S SAMPLE WAS INITIALLY TESTED UNDILUTED, DILUTED 1:10, AND DILUTED 1:100, AND ALL THREE TESTS RESULTS WERE OVER THE MEASURING RANGE. THE PATIENT THEN HAD ANOTHER SAMPLE TESTED UNDILUTED AND THE RESULT WAS 125.1 U/ML. THE SECOND SAMPLE WAS THEN DILUTED 1:10 AND THE RESULT WAS OVER THE MEASURING RANGE. THE SECOND SAMPLE WAS THEN DILUTED 1:100 AND THE RESULT WAS 10870 U/ML. THE SECOND SAMPLE WAS THEN DILUTED 1:1000 AND THE RESULT WAS 11780 U/ML. THE CUSTOMER THEN RE-TESTED THE ORIGINAL SAMPLE AND THE RESULT WAS WITHIN RANGE AT ABOUT 120 U/ML, AND IT WAS REPORTED OUTSIDE THE LABORATORY. INFORMATION ON WHETHER ANY OF THE DISCREPANT RESULTS WERE REPORTED OUTSIDE THE LABORATORY WAS REQUESTED BUT NOT PROVIDED. INFORMATION ON WHETHER THE PATIENT WAS ADVERSELY AFFECTED WAS REQUESTED BUT NOT PROVIDED. THE ACCP REAGENT LOT NUMBER AND EXPIRATION DATE WERE REQUESTED BUT NOT PROVIDED

Additional Manufacturer Narrative

THIS EVENT OCCURRED IN (B)(6) NO INFORMATION WAS PROVIDED ON THE SPECIFIC PART NUMBER INVOLVED IN THIS EVENT.

Additional Manufacturer Narrative

A DEFINITIVE ROOT CAUSE COULD NOT BE DETERMINED. IT WAS NOTED THAT AUTOANTIBODIES ARE HETEROGENEOUS AND THIS GIVES RISE TO NON-LINEAR DILUTION PHENOMENA FOR CERTAIN INDIVIDUAL SAMPLES. IT WAS NOTED THAT THE PATIENT'S RESULTS WERE ALL ABOVE THE STATED CUT OFF FOR THE ASSAY. IT WAS POSSIBLE DISCREPANT RESULTS WERE FROM HOOK EFFECT DUE TO THE HIGH ACCP CONCENTRATIONS. THIS LIMITATION IS COVERED IN THE PACKAGE LABELING. (B)(4).