ELECSYS PROBNP II

Description of Event or Problem

THERE WAS AN ALLEGATION OF QUESTIONABLE ELECSYS PROBNP II RESULTS COMPARED TO BNP FOR TWO SAMPLES FROM ONE PATIENT USING A COBAS E 801 ANALYTICAL UNIT. THE CLINICIAN DETERMINED THE RESULTS WERE NOT CONSISTENT WITH THE CLINICAL FINDINGS. SAMPLE 1 WAS COLLECTED ON (B)(6) 2024. THE PROBNP RESULT WAS <5 PG/ML AND THE BNP RESULT BY ANOTHER UNKNOWN METHOD WAS 697 PG/ML. ON (B)(6) 2024, THE INITIAL INVESTIGATION OF THE SAMPLE USING ANOTHER COBAS E801 AND REAGENT LOT NUMBER 732327 HAD A PROBNP RESULT OF <5 PG/ML. SAMPLE 2 WAS COLLECTED ON (B)(6) 2024. THE PROBNP RESULT WAS <5 PG/ML AND THE BNP RESULT BY ANOTHER UNKNOWN METHOD WAS 456 PG/ML. ON (B)(6) 2024, THE INITIAL INVESTIGATION OF THE SAMPLE USING ANOTHER COBAS E801 AND REAGENT LOT NUMBER 732327 HAD A PROBNP RESULT OF <5 PG/ML.

Additional Manufacturer Narrative

THE COBAS E 801 ANALYTICAL UNIT SERIAL NUMBER WAS (B)(6). SAMPLE FROM THE PATIENT WAS REQUESTED FOR FURTHER INVESTIGATION.

Additional Manufacturer Narrative

SAMPLE FROM THE PATIENT WAS INVESTIGATED AND THE CUSTOMER¿S RESULT WAS CONFIRMED. FURTHER TESTING REVEALED THE SAMPLE CONTAINED TWO POINT MUTATIONS (R72H AND E69D) IN THE EPITOPE OF THE DETECTION ANTIBODY AND WAS THEREFORE NOT DETECTED BY ELECSYS PROBNP II ASSAY. PER PRODUCT LABELING FOR THE ASSAY: IN EXTREMELY RARE CASES (GLOBAL INCIDENCE: < 1 IN 10 MILLION), PATIENTS MAY SHOW DISCREPANT RESULTS WHEN TESTED WITH THE ASSAY KIT (VALUES < LIMIT OF DETECTION) DUE TO A NT-PROBNP GENETIC VARIANT. FOR DIAGNOSTIC PURPOSES, THE RESULTS SHOULD ALWAYS BE ASSESSED IN CONJUNCTION WITH THE PATIENT¿S MEDICAL HISTORY, CLINICAL EXAMINATION, AND OTHER FINDINGS.