ELECSYS FT3 III

Additional Manufacturer Narrative

THE FT3 III REAGENT LOT NUMBER USED AT THE CUSTOMER SITE'S E 601 WAS REQUESTED BUT NOT PROVIDED. THE FT3 III REAGENT LOT NUMBER USED AT THE INVESTIGATION SITE'S E 601 IS 686656 WITH AN EXPIRATION DATE OF 01-APR-2024. THE PATIENT SAMPLE WAS REQUESTED FOR INVESTIGATION.

Description of Event or Problem

THE INITIAL REPORTER RECEIVED QUESTIONABLE ELECSYS TSH ASSAY, ELECSYS FT4 III ASSAY, ELECSYS FT3 III ASSAY AND ELECSYS FT4 IV ASSAY RESULTS FROM ONE PATIENT SAMPLE TESTED ON THE CUSTOMER'S COBAS 6000 E 601 WITH SERIAL NUMBER (B)(6) AND THE INVESTIGATION SITE'S COBAS 6000 E 601 WITH SERIAL NUMBER (B)(6). THE INITIAL RESULT WAS NOT REPORTED OUTSIDE OF THE LABORATORY. THE DATE OF BLOOD SAMPLING WAS USED AS THE DATE OF EVENT. THE REPORTER SUSPECTED ABNORMAL TSH RESULTS IN THE ROCHE ASSAYS. THEY THEN SENT THE PATIENT SAMPLE TO THE INVESTIGATION LABORATORY AND SUBSEQUENTLY SUBMITTED THE PATIENT SAMPLE TO AN OUTSOURCED LABORATORY FOR FURTHER INVESTIGATION. THIS MDR IS FOR THE FT3 III V2 ASSAY. PLEASE REFER TO: MDR WITH A1. PATIENT IDENTIFIER (B)(6) FOR THE TSH ASSAY. MDR WITH A1. PATIENT IDENTIFIER (B)(6) FOR THE FT4 III ASSAY. MDR WITH A1. PATIENT IDENTIFIER (B)(6) FOR THE FT4 IV ASSAY. PLEASE REFER TO THE ATTACHMENT (B)(6) FOR THE TABLE CONTAINING THE HIGHLIGHTED QUESTIONABLE RESULTS.

Additional Manufacturer Narrative

G4 PMA / 510K (PREMARKET NUMBERS) WAS UPDATED. THE PATIENT SAMPLE WAS RECEIVED FOR INVESTIGATION. THE INVESTIGATION CONFIRMED THE CUSTOMER'S FT4 III, FT4 IV AND FT3 III RESULTS. THE TSH RESULT COULD NOT BE REPRODUCED. THE INVESTIGATION ANALYZED THE PATIENT SAMPLES USING RESEARCH VERSIONS OF THE ELECSYS FT4 AND FT3 ASSAYS WITH AN ALTERNATIVE CHEMICAL RUTHENIUM LABEL STRUCTURE (BPRU ASSAY VERSIONS) FOR THE PRESENCE OF INTERFERENCE; SIGNIFICANTLY REDUCED RESULTS WERE OBTAINED. THE RESULTS CONFIRMED THE PRESENCE OF AN INTERFERENCE FACTOR AGAINST THE CHEMICAL RUTHENIUM (RU) LABEL STRUCTURE OF THE ASSAYS IN THE PATIENT SAMPLE, CAUSING THE FALSELY ELEVATED FT4 III, FT4 IV, AND FT3 III RESULTS. 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. 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 A RUTHENIUM-INTERFERING FACTOR CAUSED THE FALSELY ELEVATED FT4 III/IV AND FT3 III RESULTS. THE CAUSE OF THE FALSELY ELEVATED TSH RESULT COULD NOT BE DETERMINED. THE INVESTIGATION DID NOT IDENTIFY A PRODUCT PROBLEM.