N LATEX FLC KAPPA

Additional Manufacturer Narrative

AN OUTSIDE OF THE UNITED STATES (OUS) CUSTOMER CONTACTED A SIEMENS CUSTOMER CARE CENTER (CCC). SIEMENS IS INVESTIGATING THE ISSUE. ADDITIONAL MDRS WILL BE FILED FOR THE RESULTS OBTAINED ON 16-OCT-2024 AND 18-OCT-2024.

Description of Event or Problem

THE CUSTOMER CONTACTED SIEMENS AND REPORTED THAT INCONSISTENT FREE LIGHT CHAINS, TYPE KAPPA (FLC KAPPA) RESULTS WERE OBTAINED ON A BN II SYSTEM USING N LATEX FLC KAPPA REAGENT USING DIFFERENT SAMPLE DILUTIONS. THE SAMPLE WAS RUN FOR FLC KAPPA TWO TIMES USING A 1:100 SAMPLE DILUTION AND ANOTHER TIME USING A 1:400 SAMPLE DILUTION. THE 1:400 DILUTION RESULT RECOVERED HIGHER THAN THE 1:100 DILUTION RESULTS. THE FOLLOWING DAY THE SAMPLE WAS REPEATED FOR FLC KAPPA USING A 1:2000 DILUTION AND RECOVERED HIGHER. TWO DAYS LATER, THE SAMPLE WAS RUN USING A 1:100, 1:400, 1:2000 AND 1:8000 SAMPLE DILUTION. THE RESULTS RECOVERED HIGHER THAN THE ORIGINAL RESULTS OBTAINED WITH THESE DILUTIONS. THE SAMPLE WAS THEN MANUALLY DILUTED 1:2, 1:4, 1:8, AND 1:16 AND WAS RUN USING A 1:100 AUTOMATIC SAMPLE DILUTION. THESE RESULTS ALL RECOVERED LOWER AND MATCHED WITH PATIENT HISTORY. THE LOWER FLC KAPPA RESULTS WERE CONSIDERED TO BE THE CORRECT RESULTS. THERE ARE NO KNOWN REPORTS OF PATIENT INTERVENTION OR ADVERSE HEALTH CONSEQUENCES DUE TO THE ERRONEOUS FLC KAPPA RESULTS.

Additional Manufacturer Narrative

SIEMENS FILED THE INITIAL MDR ON 19-NOV-2024. ADDITIONAL INFORMATION (22-NOV-2024): QUALITY CONTROLS (QC) RECOVERED IN RANGE AT THE TIME OF THE EVENT. THE TROUBLESHOOTING FILE PROVIDED BY THE CUSTOMER DID NOT CONTAIN THE RESULT DATA FOR THE AFFECTED PATIENT SAMPLE. THEREFORE SIEMENS WAS NOT ABLE TO ANALYZE AND EVALUATE KINETICS ASSOCIATED WITH THE ERRONEOUS RESULTS. NO ISSUE WITH THE ASSAY OR SYSTEM COULD BE IDENTIFIED. AS PER THE INSTRUCTIONS FOR USE (IFU) FOR N LATEX FLC KAPPA: "EXCESSIVELY ELEVATED MONOCLONAL IMMUNOGLOBULIN CONCENTRATIONS MIGHT HAVE THE POTENTIAL TO SUPPRESS THE REACTION OF ANTI-FLC ANTIBODIES WITH FREE LIGHT CHAIN MOLECULES. IF RESULTS DO NOT FIT TO PREVIOUS ONES, OR TO RESULTS OF OTHER TESTS (E. G. SERUM IMMUNOELECTROPHORESIS, IMMUNOFIXATION, DIFFERENTIAL BLOOD CELL COUNT) AND/OR TO THE CLINICAL SITUATION, IT IS RECOMMENDED TO RE-ANALYZE THE SAMPLE IN A HIGHER SAMPLE DILUTION." THE PATIENT SUFFERS FROM MULTIPLE MYELOMA AND HIGH MONOCLONAL PROTEIN WAS DETECTED, SO A SAMPLE SPECIFIC ISSUE CANNOT BE RULED OUT AS A CAUSE OF THE EVENT. THE REAGENT IS PERFORMING ACCORDING TO SPECIFICATIONS. NO FURTHER EVALUATION OF THIS DEVICE IS REQUIRED. THE INVESTIGATION FINDINGS AND INVESTIGATION CONCLUSIONS CODES IN SECTION H6 WERE UPDATED BASED ON THE ADDITIONAL INFORMATION. MDRS 9610806-2024-00053 AND 9610806-2024-00054 WERE FILED FOR THE ERRONEOUS RESULTS OBTAINED ON 16-OCT-2024 AND 18-OCT-2024, RESPECTIVELY. SUPPLEMENTAL MDRS 9610806-2024-00053_S1 AND 9610806-2024-00054_S1 WERE ALSO FILED FOR THE ADDITIONAL INFORMATION.