ADVIA CENTAUR XP CEA ASSAY

Additional Manufacturer Narrative

SIEMENS FILED THE INITIAL MDR 1219913-2016-00177 ON 10/11/2016 FOR A FALSELY LOW ADVIA CENTAUR XP CARCINOEMBRYONIC ANTIGEN (CEA) RESULT OBTAINED ON A PATIENT SAMPLE. ON 10/18/2016 - ADDITIONAL INFORMATION: THE CUSTOMER'S SAMPLE WAS TESTED BY SIEMENS ON THE ADVIA CENTAUR XP WITH TWO REAGENT LOTS, AND THE RESULTS WERE CONSISTENT LOT TO LOT. THE SAMPLE WAS TESTED ON THE DIMENSION VISTA 1500 CEA ASSAY, AND THE RESULT WAS SIMILAR TO THE ADVIA CENTAUR XP. THE ADVIA CENTAUR XP AND DIMENSION VISTA 1500 CEA ASSAYS USE DIFFERENT ANTIBODIES FOR BOTH CAPTURE AND DETECTION, HOWEVER BOTH ASSAYS DO NOT CROSS REACT WITH NONSPECIFIC CROSS-REACTING ANTIGEN 2 (NCA-2). THE SAMPLE WAS TESTED WITH THE IMMULITE 2000 XPI CEA ASSAY, AND THE SAMPLE RESULT WAS HIGHER, HOWEVER THE IMPACT OF NCA-2 ON THE IMMULITE 2000 XPI CEA ASSAY HAS NOT BEEN EVALUATED. THERE WAS NOT ENOUGH SAMPLE VOLUME REMAINING FOR SIEMENS TO PERFORM HETEROPHILIC BLOCKING TUBE (HBT) TESTING. THE PATIENT SAMPLE RESULT (1.8 UG/L) THAT WAS ORIGINALLY REPORTED BY SIEMENS ON THE SECOND ALTERNATE CEA TEST METHOD (BECKMAN COULTER) DOES NOT CROSS REACT WITH NONSPECIFIC CROSS-REACTING ANTIGEN 2 (NCA-2). IN SUMMARY, THE CAUSE FOR THE HIGHER CEA ALTERNATE TEST METHOD RESULT (9.2 UG/L) MAY BE ATTRIBUTED TO AN INTERFERING/CROSS REACTING SUBSTANCE. SIEMENS CEA PATIENT SAMPLE TEST RESULTS: ADVIA CENTAUR SYSTEM: (B)(6). DIMENSION VISTA 1500 MEAN RESULT: 1.65 NG/ML. IMMULITE 2000 XPI MEAN RESULT: 3.61 NG/ML. THE INSTRUCTION FOR USE (IFU) UNDER THE LIMITATION NOTE SECTION STATES THE FOLLOWING: "DO NOT INTERPRET LEVELS OF CEA AS ABSOLUTE EVIDENCE OF THE PRESENCE OR THE ABSENCE OF MALIGNANT DISEASE. MEASUREMENTS OF CEA SHOULD ALWAYS BE USED IN CONJUNCTION WITH OTHER DIAGNOSTIC PROCEDURES, INCLUDING INFORMATION FROM THE PATIENT'S CLINICAL EVALUATION. THE CONCENTRATION OF CEA IN A GIVEN SPECIMEN DETERMINED WITH ASSAYS FROM DIFFERENT MANUFACTURERS CAN VARY DUE TO DIFFERENCES IN ASSAY METHODS, CALIBRATION, AND REAGENT SPECIFICITY. CEA DETERMINED WITH DIFFERENT MANUFACTURERS' ASSAYS WILL VARY DEPENDING ON THE METHOD OF STANDARDIZATION AND ANTIBODY SPECIFICITY." THE INSTRUMENT IS PERFORMING WITHIN SPECIFICATIONS. NO FURTHER INVESTIGATION IS REQUIRED.

Additional Manufacturer Narrative

THE CAUSE FOR THE FALSELY LOW ADVIA CENTAUR XP CEA RESULTS IS UNKNOWN. SIEMENS HAD THE PATIENT SAMPLE TESTED ON A SECOND ALTERNATE CEA TEST METHOD, AND THE RESULT WAS SIMILAR (1.8UG/L) TO THE ADVIA CENTAUR XP RESULT. SIEMENS IS INVESTIGATING. THE INSTRUCTION FOR USE (IFU) UNDER THE INTERPRETATION OF RESULTS SECTION STATES THE FOLLOWING: "RESULTS OF THIS ASSAY SHOULD ALWAYS BE INTERPRETED IN CONJUNCTION WITH PATIENT'S MEDICAL HISTORY, CLINICAL PRESENTATION AND OTHER FINDINGS." THE INSTRUCTION FOR USE (IFU) UNDER THE LIMITATION NOTE SECTION STATES THE FOLLOWING: "DO NOT INTERPRET LEVELS OF CEA AS ABSOLUTE EVIDENCE OF THE PRESENCE OR THE ABSENCE OF MALIGNANT DISEASE. MEASUREMENTS OF CEA SHOULD ALWAYS BE USED IN CONJUNCTION WITH OTHER DIAGNOSTIC PROCEDURES, INCLUDING INFORMATION FROM THE PATIENT'S CLINICAL EVALUATION. THE CONCENTRATION OF CEA IN A GIVEN SPECIMEN DETERMINED WITH ASSAYS FROM DIFFERENT MANUFACTURERS CAN VARY DUE TO DIFFERENCES IN ASSAY METHODS, CALIBRATION, AND REAGENT SPECIFICITY. CEA DETERMINED WITH DIFFERENT MANUFACTURERS' ASSAYS WILL VARY DEPENDING ON THE METHOD OF STANDARDIZATION AND ANTIBODY SPECIFICITY."

Description of Event or Problem

A FALSELY LOW ADVIA CENTAUR XP CARCINOEMBRYONIC ANTIGEN (CEA) RESULT WAS OBTAINED BY THE CUSTOMER, AND THE RESULT WAS QUESTIONED BY THE PHYSICIAN. THE LOW CEA RESULT DID NOT AGREE THE CLINICAL PICTURE OF THE PATIENT. THE SAME PATIENT SAMPLE WAS REPEATED ON ANOTHER ADVIA CENTAUR XP SYSTEM IN THE LABORATORY, AND THE CEA RESULT WAS LOW. THE PATIENT SAMPLE WAS SENT TO AN ALTERNATE LABORATORY AND CEA TEST METHOD, AND THE CEA RESULT WAS HIGHER. THE HIGHER CEA RESULT WAS IN AGREEMENT WITH THE PATIENT'S CLINICAL PICTURE. A CORRECTED CEA TEST RESULT WAS ISSUED BY THE CUSTOMER. THERE ARE NO REPORTS THAT TREATMENT WAS ALTERED OR PRESCRIBED OR ADVERSE HEALTH CONSEQUENCES DUE TO THE DISCORDANT ADVIA CENTAUR XP CEA RESULT.