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

Catalog Number	08814848190
Medical Device Problem Codes	False Positive Result (1227); Non Reproducible Results (4029)
Health Effect - Clinical Code	No Clinical Signs, Symptoms or Conditions (4582)
Date of Event	03/17/2026
Type of Reportable Event	Malfunction
Additional Manufacturer Narrative
The cobas e 801 analytical unit serial number was (b)(6).The calibration and qc were within the ranges.The alarm trace showed no abnormalities.The field service engineer performed hardware maintenance (intensive cleaning of the sample probe).The product labeling states: "all initially reactive or borderline samples should be redetermined in duplicate using the elecsys hbsag ii assay.If cutoff index values < 0.90 are found in both cases, the sample is considered negative for hbsag." the product labeling also states: "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.The elecsys hbsagii assay performs within specifications.The cause of the event was due to a preanalytic (inadequate clotting time) issue at the customer site.Preanalytics are within the customer's responsibility.
Event or Problem Description
We received an allegation about discrepant results for 1 patient sample tested with elecsys hbsag ii assay on a cobas e 801 analytical unit.The initial result was 8.34 coi (positive).The repeat results were 0.397 coi and 0.357 coi (negative).

• 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: 24816656
• Report Number: 1823260-2026-01339
• Device Sequence Number: 6146327
• Product Code: LOM
• UDI-Device Identifier: 07613336168103
• UDI-Public: 07613336168103
• Combination Product (Y/N): N
• Initial Reporter Country: GR
• 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): 04/08/2026

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: 89826501
• Was Device Available for Evaluation?: Yes
• Is the Reporter a Health Professional?: Yes
• Type of Report(Section G): Initial
• Initial Date Received by Manufacturer: 03/18/2026
• Initial Report FDA Received Date: 04/08/2026
• 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 Sex: Unknown