FERR4

Additional Manufacturer Narrative

ONE SAMPLE OF THE PATIENT WAS PROVIDED FOR INVESTIGATION. THE INVESTIGATION TESTED THE PATIENT¿S SAMPLE IN NORMAL AND DECREASED MODE, RESULTING IN FERR4 VALUES OF 315.7 UG/L AND 285.5 UG/L. THE SAMPLE WAS ALSO TESTED WITH THE ELECSYS FERRITIN ON A COBAS E602, RESULTING IN A FERR VALUE OF 131.8 NG/ML. THE SAMPLE WAS ALSO TESTED ON A COBAS C503 WITH FURTHER ASSAYS, RESULTING IN THE FOLLOWING RESULTS: IGA2 = 2.95 G/L, IGM2 = 1.10 G/L, IGG2 = 10.3 G/L, KAPP2 = 2.73 G/L, LAMB2 = 1.53 G/L. THE INVESTIGATION IS ONGOING.

Description of Event or Problem

THE INITIAL REPORTER STATED THEY RECEIVED QUESTIONABLE FERR4 (TINA-QUANT FERRITIN GEN.4) RESULTS FOR SEVERAL SAMPLES FROM ONE PATIENT, TESTED ON A COBAS 8000 C702 MODULE. IT WAS ASKED BUT IT IS UNCLEAR IF ALL RESULTS WERE MEASURED FROM THE SAME SAMPLE MATERIAL OR FROM DIFFERENT DRAWINGS. ACCORDING TO THE PHYSICIAN AND THE RESULTS OF MYELOGRAPHY, THE RESULTS DID NOT FIT TO THE PATIENT¿S CLINICAL PICTURE. ON (B)(6) 2022, THE PATIENT HAD A FERR4 VALUE OF 224.8 UG/L. ON (B)(6) 2022, THE PATIENT HAD A FERR4 VALUE OF 235.3 UG/L. ON (B)(6) 2022, THE PATIENT HAD A FERR4 VALUE OF 221.6 UG/L. ON (B)(6) 2022, THE PATIENT HAD A FERRITIN VALUE OF 5 UG/L, TESTED WITH A COMPETITOR METHOD. THIS RESULT WAS DEEMED CORRECT. ON (B)(6) 2022, THE PATIENT HAD A FERR4 VALUE OF 207.7 UG/L. THE QUESTIONABLE RESULTS WERE REPORTED OUTSIDE OF THE LABORATORY. THE FERR4 REAGENT LOT WAS 63670701 WITH AN EXPIRATION DATE OF 30-APR-2023.

Additional Manufacturer Narrative

THE SAMPLE WAS FURTHER TESTED NON-DILUTED AND BY USING A 1:20 DILUTION, RESULTING IN FERR4 VALUES OF 314 UG/L AND 300 UG/L. THE SAMPLE WAS THEN TESTED NON-DILUTED AND BY USING A 1:10 DILUTION ON A SIEMENS BN PROSPEC ANALYZER, RESULTING IN FERR VALUES OF 110 UG/L AND 122 UG/L. THE INVESTIGATION DID NOT DETECT AN INTERFERENCE BY GAMMOPATHY. THE INVESTIGATION DETERMINED THAT THE SAMPLE MATERIAL SHOWS NON-REPRODUCIBLE RESULTS WHEN DIFFERENT ANALYTICAL METHODS ARE USED. THE ANTIBODIES USED IN THE TEST REAGENTS DIFFER IN SPECIFICITY WHICH MAY ACCOUNT FOR NON-REPRODUCIBLE RECOVERIES ON SPECIFIC SAMPLES. THE ISSUE IS CONSISTENT WITH A RARE COMMUTABILITY ISSUE OF THE BIOLOGICAL MATERIAL. THERE IS NO INDICATION FOR A GENERAL PRODUCT PROBLEM.

Additional Manufacturer Narrative

IT WAS CONFIRMED THAT THE RESULTS WERE OBTAINED FROM DIFFERENT SAMPLE DRAWINGS.