Description of Event or Problem · 0
A CUSTOMER REPORTED TO THE BINDING SITE AN ERRONEOUSLY LOW KAPPA FREE LIGHT CHAIN (FLC) RESULT (28.3 MG/L; REF RANGE: 3.30 - 19.40 MG/L) OBTAINED USING THE OPTILITE® FREELITE® KAPPA FREE KIT (PRODUCT CODE: LK016.OPT.A), ON (B)(6) 2025. THE RESULT WAS INCONSISTENT WITH EARLIER RESULTS (839.6 & 789 MG/L) FROM SAMPLE DATED (B)(6) 2025 (CONFIRMED BY ERROR REPORT ANALYSIS) AND A STRONGER MONOCLONAL PROTEIN BAND BY SERUM ELECTROPHORESIS. LAMBDA FLC LEVELS WERE CONSISTENTLY LOW AND THE KAPPA/ LAMBDA RATIO WAS ABNORMAL THROUGHOUT. THERE WAS NO ALLEGATION OF SERIOUS INJURY, ALTHOUGH TREATMENT WAS TEMPORARILY PAUSED WHILE THE DISCREPANCY WAS INVESTIGATED. QUALITY CONTROLS (QC) WERE WITHIN RANGE AND ACCEPTABLE THROUGHOUT TESTING. A SUBSEQUENT SAMPLE FROM THE (B)(6) SHOWED AN INCREASE IN KAPPA FLC LEVELS (6426 MG/L). ALTHOUGH THERE HAVE BEEN NO REPORTS OF SERIOUS HARM OR INAPPROPRIATE THERAPY, THE DECISION WAS TAKEN TO REPORT AS A MATTER OF CAUTION. IF THE ERROR WAS TO RECUR THERE IS A POSSIBILITY OF SERIOUS INJURY IF SAMPLE RESULTS WERE CONSIDERED IN ISOLATION. AS PER THE IFU, INS016.OPT.A, RESULTS OF THE FREE LIGHT CHAIN MEASUREMENTS SHOULD ALWAYS BE INTERPRETED IN CONJUNCTION WITH OTHER LABORATORY AND CLINICAL FINDINGS.