ELECSYS PROBNP II

Additional Manufacturer Narrative

THE COBAS PURE E 402 ANALYTICAL UNIT SERIAL NUMBER IS (B)(6). THE PATIENT'S SAMPLES WERE RECEIVED FOR INVESTIGATION. THE INVESTIGATION IS ONGOING.

Description of Event or Problem

THE INITIAL REPORTER RECEIVED QUESTIONABLE ELECSYS PROBNP II RESULTS FROM FOUR SAMPLES FROM THE SAME PATIENT TESTED ON THE COBAS E 402 ANALYTICAL UNIT. ON (B)(6) 2025, THE RESULT FROM THE ANALYZER WAS <5.00 PG/ML WITH A DATA FLAG. THE REPORTER STATED THAT THE RESULTS WERE DISCREPANT WITH THE PATIENT'S CLINICAL FINDINGS. ON (B)(6) 2025, THE INVESTIGATION LABORATORY RERAN THE PATIENT'S SAMPLES. THE RESULT OF THE PATIENT'S SAMPLE COLLECTED ON (B)(6) 2025 WAS <5.00 PG/ML WITH A DATA FLAG. THE RESULT OF THE PATIENT'S SAMPLE COLLECTED ON (B)(6) 2025 WAS <5.00 PG/ML WITH A DATA FLAG. THE RESULT OF THE PATIENT'S SAMPLE COLLECTED ON (B)(6) 2025 WAS <5.00 PG/ML WITH A DATA FLAG.

Additional Manufacturer Narrative

THE INVESTIGATION TESTED THE PATIENT SAMPLE FOR ELECSYS PROBNP II, WHICH CONFIRMED THE CUSTOMER'S RESULTS. THE INVESTIGATION ALSO TESTED THE PATIENT SAMPLE FOR INTERFERENTS. THE INVESTIGATION CONFIRMED THE PRESENCE OF AN EXTREMELY RARE POINT MUTATION IN THE PATIENT SAMPLE NOT DETECTED BY THE ELECSYS PROBNP II ASSAY, PRODUCT LABELING STATES, "IN RARE CASES, INTERFERENCE DUE TO EXTREMELY HIGH TITERS OF ANTIBODIES TO ANALYTE-SPECIFIC ANTIBODIES, STREPTAVIDIN OR RUTHENIUM CAN OCCUR. THESE EFFECTS ARE MINIMIZED BY SUITABLE TEST DESIGN. IN EXTREMELY RARE CASES (GLOBAL INCIDENCE: < 1 IN 10 MILLION; REPORTED FROM JAPAN), PATIENTS MAY SHOW FALSE LOW RESULTS WHEN TESTED WITH THE ASSAY KIT (VALUES UNDETECTABLE) DUE TO A NT-PROBNP VARIANT. FOR DIAGNOSTIC PURPOSES, THE RESULTS SHOULD ALWAYS BE ASSESSED IN CONJUNCTION WITH THE PATIENT¿S MEDICAL HISTORY, CLINICAL EXAMINATION AND OTHER FINDINGS." THE INVESTIGATION DETERMINED THAT THE MUTATION IN THE PATIENT'S SAMPLE WAS THE CAUSE OF THE EVENT. THE INVESTIGATION DID NOT IDENTIFY A PRODUCT PROBLEM.