ELECSYS FT4 IV

Additional Manufacturer Narrative

THE SAMPLE MATERIAL WAS SENT FOR INVESTIGATION. THE CUSTOMER RESULT WAS CONFIRMED. UPON FURTHER INVESTIGATION OF THE SAMPLE WITH DIFFERENT RESEARCH TOOLBOXES, NO ASSAY INTERFERENCE FOR THE FT4 ASSAY WAS DETECTED. THE VALUE DIFFERENCES OBTAINED WITH THE FT4 ASSAYS RELATE TO THE DIFFERENCES IN THE SETUP OF THE ASSAYS, THE ANTIBODIES USED, AND THE DIFFERENCES IN THE STANDARDIZATION MATERIALS AND PROCEDURES USED. FOR DIAGNOSTIC PURPOSES, THE RESULTS SHOULD ALWAYS BE ASSESSED IN CONJUNCTION WITH THE PATIENT´S MEDICAL HISTORY, CLINICAL EXAMINATION AND OTHER FINDINGS. THE INVESTIGATION DID NOT IDENTIFY A PRODUCT PROBLEM.

Description of Event or Problem

THERE WAS AN ALLEGATION OF QUESTIONABLE ELECSYS FT4 IV ASSAY RESULTS WITH TWO SAMPLES FROM ONE PATIENT TESTED ON A COBAS E 801 ANALYTICAL UNIT WHEN COMPARED TO A COMPETITOR TEST. SAMPLE 1 (B)(6) 2025): THE RESULT USING THE ARCHITECT ASSAY WAS 1.37 NG/DL. THE RESULT USING THE E801 WAS 2.32 NG/DL. ON (B)(6) 2025, ANTI-T4 ANTIBODIES WERE DETERMINED AND WERE NEGATIVE. THE SAMPLE WAS INCUBATED WITH MICROPARTICLES FOR THE STUDY OF STREPTAVIDIN AND BIOTIN INTERFERENCE; THE RESULT WAS FT4: 2.42 NG/DL. THE SAMPLE WAS ALSO TREATED WITH HBR SCANTIBODIES TUBES TO ELIMINATE INTERFERENCE FROM HETEROPHILE ANTIBODIES; THE RESULT WAS FT4: 2.40 NG/DL. SAMPLE 2 (B)(6) 2025): THE RESULT USING THE E801 WAS 2.41 NG/DL.

Additional Manufacturer Narrative

THE SERIAL NUMBER OF THE ANALYZER WAS (B)(6). THE SAMPLE MATERIAL WAS REQUESTED FOR INVESTIGATION.