ADVIA CENTAUR FERRITIN (FER) ASSAY

Additional Manufacturer Narrative

THE CAUSE FOR THE DISCORDANT FERRITIN RESULTS IS UNKNOWN. THE HOOK EFFECT IS A POSSIBLE CAUSE. THE INSTRUMENT IS PERFORMING WITHIN SPECIFICATIONS. NO FURTHER EVALUATION OF THE DEVICE IS REQUIRED. THE IFU STATES IN THE HIGH DOSE HOOK EFFECT SECTION: "PATIENT SAMPLES WITH HIGH FERRITIN LEVELS CAN CAUSE A PARADOXICAL DECREASE IN THE RLUS (HIGH DOSE HOOK EFFECT). IN THIS ASSAY, PATIENT SAMPLES WITH FERRITIN LEVELS AS HIGH AS 80,000 NG/ML (176,000 PMOL/L) WILL ASSAY GREATER THAN 1650 NG/ML (3630 PMOL/L)." THE IFU STATES IN THE DILUTIONS SECTION: "SAMPLES WITH FERRITIN LEVELS GREATER THAN 1650 NG/ML (3630 PMOL/L) MUST BE DILUTED AND RETESTED TO OBTAIN ACCURATE RESULTS."

Description of Event or Problem

DISCORDANT ADVIA CENTAUR FERRITIN RESULTS WERE OBTAINED ON SIX SAMPLES FROM THE SAME PATIENT. PATIENT HISTORY IS HEMOPHAGOCYTIC LYMPHOHISTIOCYTOSIS (HLH). THE PATIENT SAMPLES WERE TESTED WITHIN 6 DAYS AND WERE ALL FRESH DRAWS. REPEAT TESTING WAS PERFORMED ON THE SAMPLES AND THE RESULTS WERE ALL HIGH. IT IS UNKNOWN IF PATIENT TREATMENT WAS PRESCRIBED OR ALTERED. THERE WAS NO REPORT OF ADVERSE HEALTH CONSEQUENCES DUE TO THE DISCORDANT FERRITIN RESULTS.