MAUDE Adverse Event Report: ROCHE DIAGNOSTICS ELECSYS HBSAG II AUTO CONFIRM; HEPATITIS B (B CORE, BE ANTIGEN, BE ANTIBODY, B CORE IGM) TEST

Catalog Number	08741034190
Medical Device Problem Code	False Positive Result (1227)
Health Effect - Clinical Code	No Clinical Signs, Symptoms or Conditions (4582)
Date of Event	07/29/2025
Type of Reportable Event	Malfunction
Additional Manufacturer Narrative
The analyzer serial number is (b)(6).The calibration and qc recovery data provided was acceptable.The alarm trace did not contain a conspicuous event.The investigation is ongoing.
Event or Problem Description
There was an allegation of questionable elecsys hbsag ii auto confirm results for 1 patient on a cobas e 801 analytical unit.The initial hbsag result was 1.14 coi, interpreted as reactive.The same was repeated and the result was 0.974 coi, interpreted as indeterminate.The confirmatory test was performed and the result was 42.2%, interpreted as reactive.The sample was repeated again and the hbsag result was 0.88 coi, interpreted as non-reactive.Another patient sample collected at the same time was also tested for hbsag and the result was 0.782 coi, interpreted as non-reactive.The confirmatory test was performed and the result was 42.5%, interpreted as indeterminate.The original sample was repeated three more times and the results were 0.625 coi, 0.624 coi, and 0.624 coi, all interpreted as non-reactive.The patient samples were re-centrifuged prior to every test.The patient sample was also tested on a mini vidas analyzer and the hbsag result was non-reactive.The non-reactive result was deemed correct.
Additional Manufacturer Narrative
The hbsag result of the reported patient sample from an external laboratory was negative.The field service engineer (fse) confirmed the analyzer was clean and had no misalignments.It was found that the customer centrifuged the affected sample at 2000 g, which is too low.The investigation noted that the elecsys hbsag ii results dropped from 1.14 coi (near cut off) to 0.6 coi after five centrifugation steps.The customer used an hbsag negative sample for the elecsys hbsag ii confirmatory test.Per product labeling, "intended use - immunoassay for in vitro confirmation of the presence of hepatitis b surface antigen in human serum and plasma samples repeatedly reactive when tested with the elecsys hbsag ii assay." the investigation determined the event was consistent with a preanalytic issue at the customer site (low centrifugation speed).Preanalytics are within the customer's responsibility.There was no indication of a device malfunction.

• Brand Name: ELECSYS HBSAG II AUTO CONFIRM
• Common Device Name: HEPATITIS B (B CORE, BE ANTIGEN, BE ANTIBODY, B CORE IGM) TEST
• 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: 22850389
• Report Number: 1823260-2025-02559
• Device Sequence Number: 4461580
• Product Code: LOM
• UDI-Device Identifier: 07613336172902
• UDI-Public: 07613336172902
• Combination Product (Y/N): N
• Initial Reporter Country: HK
• PMA/510(K) Number: P160019/S014
• 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
• Initial Reporter Occupation: Other Health Care Professional
• Type of Report: Initial,Followup
• Report Date (Section B): 09/16/2025

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 Expiration Date: 05/31/2026
• Device Catalogue Number: 08741034190
• Device Lot Number: 82022101
• Was Device Available for Evaluation?: Yes
• Is the Reporter a Health Professional?: Yes
• Type of Report(Section G): Follow-Up
• Initial Date Received by Manufacturer: 07/31/2025
• Supplement Date Received by Manufacturer: 08/25/2025
• Initial Report FDA Received Date: 08/20/2025
• Supplement Report FDA Received Date: 09/16/2025
• 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