PROBNP II, N-TERMINAL PRO B-TYPE NATRIURETIC PEPTIDE

Additional Manufacturer Narrative

SAMPLE FROM THE PATIENT WAS SUBMITTED FOR INVESTIGATION AND THE CUSTOMER¿S RESULT OF < 10 PG/ML WAS CONFIRMED. TWO POINT MUTATIONS (R72H AND E69D) IN THE EPITOPE OF THE DETECTION ANTIBODY WERE SUSPECTED. TESTING WITH THE PROBNP II REAGENT SUPPLEMENTED WITH ADDITIONAL DETECTION ANTIBODIES FOR THESE MUTATIONS SHOWED THAT THE BNP IN THE SAMPLE CONTAINED THE R72H MUTATION. THEREFORE, IT IS NOT DETECTED BY THE ELECSYS PROBNP II IMMUNOASSAY. THIS TYPE OF POINT MUTATION IS EXTREMELY RARE AND HAS ONLY BEEN FOUND IN COMPLAINT SAMPLES FROM (B)(6). A DISCLAIMER WAS ADDED TO PRODUCT LABELING.

Additional Manufacturer Narrative

UNIQUE IDENTIFIER (UDI)#: (B)(4). THIS EVENT OCCURRED IN (B)(6).

Description of Event or Problem

THE CUSTOMER QUESTIONED THE DIFFERENCE IN RESULTS BETWEEN THE ELECSYS PROBNP II IMMUNOASSAY AND ANOTHER BNP ASSAY FOR ONE PATIENT. THE PATIENT WAS MOVED FROM THE PEDIATRIC DEPARTMENT TO A CARDIOVASCULAR DEPARTMENT. THE CARDIOVASCULAR PHYSICIAN TESTED THE PATIENT'S PROBNP AND THE RESULT WAS < 10 PG/ML. THE RESULT FOR THE BNP ASSAY WAS >800 PG/ML FROM THE SAME SAMPLE. THE PHYSICIAN CHECKED THE MEDICAL HISTORY FOR THE PATIENT AND FOUND THE RESULT FOR THE BNP ASSAY MORE CLOSELY MATCHED THE CLINICAL PICTURE FOR THE PATIENT. HE ALSO FOUND THAT THE DISCREPANCY BETWEEN THE PROBNP AND BNP RESULTS HAS BEEN ONGOING FOR FIVE YEARS FOR THIS PATIENT. THERE WAS NO ALLEGATION OF AN ADVERSE EVENT. THE CUSTOMER USED A COBAS 8000 E 602 MODULE. THE SERIAL NUMBER WAS REQUESTED BUT WAS NOT PROVIDED.