MAUDE Adverse Event Report: SIEMENS HEALTHCARE DIAGNOSTICS PRODUCTS, LTD. IMMULITE 2000 ANTI-TG AB; SYSTEM, TEST, THYROID AUTOANTIBODY

Model Number	IMMULITE 2000 ANTI-TG AB
Medical Device Problem Code	Low Test Results (2458)
Health Effect - Clinical Code	No Clinical Signs, Symptoms or Conditions (4582)
Date of Event	01/14/2026
Type of Reportable Event	Malfunction
Event or Problem Description
The customer contacted siemens and indicated that a false low anti-thyroglobulin (atg) result was obtained on a patient sample on an immulite 2000 xpi system using immulite 2000 atg reagent.The false low result was reported and questioned.The following day, the sample was run for atg in another laboratory using a non-siemens method and the result recovered higher.The higher result was reported, as the correct result, to the physician(s).There are no known reports of patient intervention or adverse health consequences due to low atg result.
Additional Manufacturer Narrative
An outside of the united states (ous) customer contacted a siemens customer care center (ccc).The customer provided spy files, error logs, and main data for analysis.Analysis of the spy files and error logs showed no abnormalities.Review of the main data confirmed that the most recent calibration was performed on (b)(6) 2025.Although the calibration itself appeared unremarkable, the instructions for use recommend performing an adjustment every two weeks.Since the measurements took place on (b)(60 2026, the adjustment was overdue.Control performance in the main data was also reviewed.On the sample testing date (january 14th), quality controls (qc) level 1 recovered in range.Control level 2 was not tested on the measurement date.A past history request indicated no additional tickets in the past two years related to atg false-negative results for lot 804.The cause for the false negative result could not be identified.Pre-analytical factors or handling issues cannot be ruled out as potential sources of the event.Siemens recommends adhering to the adjustment interval of every two weeks as described in the instructions for use.The reagent is performing according to specifications.No further evaluation of this device is required.

• Brand Name: IMMULITE 2000 ANTI-TG AB
• Common Device Name: SYSTEM, TEST, THYROID AUTOANTIBODY
• Manufacturer (Section D): SIEMENS HEALTHCARE DIAGNOSTICS PRODUCTS, LTD.; glyn rhonwy, llanberis; gwynedd LL55 4EL; UK LL55 4EL
• Manufacturer (Section G): SIEMENS HEALTHCARE DIAGNOSTICS PRODUCTS, LTD.; uk registration #: 3002806944; glyn rhonwy, llanberis; gwynedd LL55 4EL; UK LL55 4EL
• Manufacturer Contact: christopher aebig ; 333 coney st.; east walpole, MA 02032 ; 9144153450
• MDR Report Key: 24206836
• Report Number: 1219913-2026-00027
• Device Sequence Number: 5534620
• Product Code: JZO
• UDI-Device Identifier: 00630414962108
• UDI-Public: (01)00630414962108(10)804(17)260417
• Combination Product (Y/N): N
• Initial Reporter Country: GM
• PMA/510(K) Number: K991094
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Serviced by Third Party (Y/N): N
• 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): 01/29/2026

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 Expiration Date: 04/17/2026
• Device Model Number: IMMULITE 2000 ANTI-TG AB
• Device Catalogue Number: 10381659
• Device Lot Number: 804
• Was Device Available for Evaluation?: No
• Is the Reporter a Health Professional?: Yes
• Type of Report(Section G): Thirty-Day
• Initial Date Received by Manufacturer: 01/19/2026
• Initial Report FDA Received Date: 01/29/2026
• Was Device Evaluated by Manufacturer? (Y/N): No
• Date Device Manufactured: 04/17/2025
• 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
• Usage of Device: Initial
• Patient Sequence Number: 1
• Patient Age: 68 YR
• Patient Sex: Female