MAUDE Adverse Event Report: ROCHE DIAGNOSTICS ELECSYS HBSAG II; TEST, HEPATITIS B

Catalog Number	08814848190
Medical Device Problem Code	False Positive Result (1227)
Health Effect - Clinical Code	No Clinical Signs, Symptoms or Conditions (4582)
Date of Event	02/04/2026
Type of Reportable Event	Malfunction
Additional Manufacturer Narrative
The analyzer's serial number is (b)(6).The calibration and qc were acceptable.The constellation of being hbsag positive but hbv dna negative occurs because these two markers represent different parts of the virus and the life cycle of the virus.The issue is consistent with a weak positive result due to a possible early acute infection.During the "incubation period" of hepatitis b, the virus is just beginning to replicate.Hbsag is the first marker to appear, and if the blood is drawn right as the levels are rising, the result will be weakly positive.The issue is also consistent with a resolving or "occult" infection.If a patient is recovering from an acute infection, the hbsag levels will drop.The result could be at the very end of the clearance phase.The large differences in hbsag results (both qualitative and quantitative) for the same patient between roche (elecsys) and abbott (architect/alinity) instruments can be attributed to several factors regarding assay design, antibody composition, and calibration.All initially reactive or borderline samples should be re-determined in duplicate using the elecsys hbsagii assay.Repeatedly reactive samples must be confirmed using a neutralization test (elecsys hbsag confimatory test or elecsys hbsag ii auto confirm).Results confirmed by neutralization with anti-hbs are regarded as positive for hbsag.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 the issue was consistent with a sample-specific discrepancy.However, the investigation did not identify a specific cause of the event.The elecsys hbsagii performs within specification.
Event or Problem Description
There was an allegation of a false-positive elecsys hbsag ii result for 1 patient on a cobas e 801 analytical unit.The patient's elecsys hbsag result was 2.98 coi (positive).The patient's hbv dna test result was negative.The patient's anti-hbs, hbeag, anti-hbe, and anti-hbc results were negative.The sample was tested at another facility using another cobas e 801 module, and the elecsys hbsag result was consistent with the initial result (positive).The numerical value for the result was not provided.The hbsag result with the abbott method was 0.01 iu/ml (negative).A confirmatory test was not performed.

• Brand Name: ELECSYS HBSAG II
• Common Device Name: TEST, HEPATITIS B
• Manufacturer (Section D): ROCHE DIAGNOSTICS; 9115 hague road; indianapolis IN 46250 0457
• Manufacturer (Section G): ROCHE DIAGNOSTICS GMBH; sandhofer strasse 116; mannheim (baden-wurttemberg) 68305 ; GM 68305
• Manufacturer Contact: natalie catton ; 9115 hague road; indianapolis, IN 46250
• MDR Report Key: 24474955
• Report Number: 1823260-2026-00734
• Device Sequence Number: 21227800
• Product Code: LOM
• UDI-Device Identifier: 07613336168103
• UDI-Public: 07613336168103
• Combination Product (Y/N): N
• Initial Reporter Country: CH
• PMA/510(K) Number: P160019/S010
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Serviced by Third Party (Y/N): Unknown
• Reporter Type: Manufacturer
• Report Source: Foreign,Health Professional,User Facility
• Initial Reporter Occupation: Other Health Care Professional
• Type of Report: Initial
• Report Date (Section B): 02/27/2026

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: No
• Is this a Product Problem Report?: Yes
• Operator of Device: Health Professional
• Device Catalogue Number: 08814848190
• Device Lot Number: 86355300
• Was Device Available for Evaluation?: Yes
• Is the Reporter a Health Professional?: Yes
• Type of Report(Section G): Initial
• Initial Date Received by Manufacturer: 02/04/2026
• Initial Report FDA Received Date: 02/27/2026
• Was Device Evaluated by Manufacturer? (Y/N): Yes
• Is the Device Labeled for Single Use? (Y/N): No
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Patient Sequence Number: 1
• Patient Age: 29 YR
• Patient Sex: Unknown
• Patient Race: Asian