ELECSYS CMV IGG

Additional Manufacturer Narrative

THE ANALYZER SERIAL NUMBER IS (B)(6). THE CALIBRATION AND QC RECOVERY DATA PROVIDED WAS WITHIN SPECIFICATION. THE DETECTION OF CMV-SPECIFIC IGG ANTIBODIES IN A SINGLE SAMPLE INDICATES A PREVIOUS EXPOSURE TO CMV BUT IS NOT ALWAYS SUFFICIENT TO DISTINGUISH BETWEEN AN ACUTE OR LATENT INFECTION (IRRESPECTIVE OF THE LEVEL OF THE IGG ANTIBODY TITER). IN RARE CASES OF PRIMARY CMV INFECTION IGG ANTIBODY MAY BE PRESENT BEFORE A SPECIFIC IGM ANTIBODY RESPONSE IS DETECTED. IT IS RECOMMENDED THAT A FOLLOW-UP SAMPLE BE TESTED AFTER 2 WEEKS. IF THE CMV IGG ANTIBODY TITER REMAINS STABLE, A PRIMARY INFECTION CAN BE EXCLUDED. THE INVESTIGATION DID NOT IDENTIFY A PRODUCT PROBLEM.

Description of Event or Problem

THERE WAS AN ALLEGATION OF A QUESTIONABLE ELECSYS CMV IGG RESULT FOR 1 PATIENT SAMPLE ON A COBAS E 801 ANALYTICAL UNIT COMPARED TO A DIASORIN ANALYZER. FOR INFORMATION RELATED TO THE CMV IGM ASSAY, PLEASE REFER TO MFG REPORT 1823260-2026-01549 THIS MDR IS BEING SUBMITTED IN AN ABUNDANCE OF CAUTION. ON (B)(6) 2025, THE CMV IGM RESULT WAS 0.48 IU/ML (NEGATIVE) AND THE CMV IGG RESULT WAS 3.91 IU/ML (POSITIVE). THE PATIENT WAS 9 WEEKS AND 2 DAYS PREGNANT, AND THE RESULTS INDICATED CMV IMMUNITY. WHEN THE PATIENT WAS 22 WEEKS PREGNANT, SEVERE FETAL BRAIN ABNORMALITIES WERE DETECTED SUGGESTING FETAL CYTOMEGALOVIRUS INFECTION. AMNIOCENTESIS WAS PERFORMED AND CMV PCR IN AMNIOTIC FLUID GAVE A POSITIVE RESULT, CONFIRMING FETAL CMV INFECTION. THE SEVERITY OF THE BRAIN LESIONS WAS CONFIRMED BY MRI OF THE FETAL BRAIN AND TERMINATION OF PREGNANCY WAS PERFORMED. THE PATIENT SAMPLE FROM (B)(6) 2025 WAS RETESTED ON A DIASORIN ANALYZER AND THE CMV IGM RESULT WAS 51.7 IU/ML (POSITIVE) AND THE CMV IGG RESULT WAS <5 IU/ML (NEGATIVE). THE EXACT DATE OF TESTING WAS NOT PROVIDED. ON (B)(6) 2026, THE SAMPLE FROM (B)(6) 2025 WAS REPEATED ON LINE 1 OF THE COBAS ANALYZER AND THE CMV IGM RESULT WAS 0.51 (NEGATIVE) IU/ML AND THE CMV IGG RESULT WAS 3.43 IU/ML (POSITIVE). THE SAMPLE WAS REPEATED AGAIN ON LINE 2 AND THE IGM RESULT WAS 0.54 IU/ML (NEGATIVE) AND THE IGG RESULT WAS 3.12 IU/ML (POSITIVE).