MAUDE Adverse Event Report: INSTRUMENTATION LABORATORY CO. HEMOSIL HIT- AB(PF4-H); PLATELET FACTOR 4 RADIOIMMUNOASSAY

Catalog Number	00020014600
Medical Device Problem Code	False Negative Result (1225)
Health Effect - Clinical Codes	Stroke/CVA (1770); Thrombosis/Thrombus (4440)
Date of Event	05/23/2025
Type of Reportable Event	Death
Additional Manufacturer Narrative
This is an initial report.A follow-up report will be submitted upon completion of the investigation.
Event or Problem Description
A complaint has been filed for a discrepant hit test result.The patient sample id (b)(6), tested on the acl top using reagent/calibrator pn 00020014600, yielded a negative result.The same sample, when sent to mayo clinic, returned a positive sra result (cut-off: >0.400 positive).The sample was initially sent to mayo after pharmacy questioned the negative result, given the patient's clinical history of a left apical thrombus, stroke, and subsequent death under palliative care.The site has now discontinued hit testing on the acl top and is sending samples to quest.
Additional Manufacturer Narrative
Qc and manufacturing data for hemosil hit-ab(pf4-h) lot b37250 were reviewed and no issues or trends were identified with the impacted lot.Review of submitted calibration report confirms that hit-ab lot b37250 was calibrated on 4/17/2025 april 17, 2025, using the correct target value of 5.5 u/ml, and the results were proprely validated.Qc results were performed after the calibration was validated and were confirmed within acceptable range for hit_ab controls lot b37286.Review of the submitted qc levey jennings charts for 05/01/2025 to 05/19/2025 shows the hit antibodies for acl top 350, hit low and high lot # b37286 reported acceptable results on 05/08/2025 prior to sample testing.Review of the service history shows call 2005283457 on 5/27/2025 - the field service engineer verified the instrument for the hit discrepant results.Preventative maintenance for the instrument was last completed on 4/25/25.No instrument issues found at that time.Reviewed general log list, cleaned and inspected instrument; no issues found.Fluidic precision passes both arms.Flow rate performed and passed.No leaks found.Optical reading unit (oru) reference readings in range and stable.Liquid level detection (lld) counts for both probes were normal and stable.Coordinate deltas were low and stable.No instrument related issues were identified.Since the affected sample is not available to perform testing, no further investigational testing can be done to determine the root cause of the reported issue.The instructions for use (ifu) of the product reports a total percentage agreement of 82% in method comparison and 90% in external validation, vs elisa assay, 87% vs sra.These figures suggest that discrepancies may arise in specific samples when comparing hemosil hit-ab(pf4-h) with other methodologies.For this reason, the ifu states that confirmation of results with a functional test is recommended and that the assay results should be used with other information, including the clinical context in forming a diagnosis.Based on this assessment, no remedial action is required.This incident will be monitored through trending analysis.

• Brand Name: HEMOSIL HIT- AB(PF4-H)
• Common Device Name: PLATELET FACTOR 4 RADIOIMMUNOASSAY
• Manufacturer (Section D): INSTRUMENTATION LABORATORY CO.; 180 hartwell road; bedford MA 01730 2443
• Manufacturer (Section G): INSTRUMENTATION LABORATORY CO.; 180 hartwell road; bedford MA 01730 2443
• Manufacturer Contact: anuja khan ; 180 hartwell road; bedford, MA 01730-2443
• MDR Report Key: 22100252
• Report Number: 1217183-2025-00032
• Device Sequence Number: 17981156
• Product Code: LCO
• UDI-Device Identifier: 08426950975380
• UDI-Public: (01)08426950975380(11)241119(17)260430(10)B37250
• Combination Product (Y/N): N
• Initial Reporter State: FL
• Initial Reporter Country: US
• PMA/510(K) Number: K153137
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Serviced by Third Party (Y/N): Unknown
• Reporter Type: Manufacturer
• Report Source: Health Professional
• Initial Reporter Occupation: Other Health Care Professional
• Type of Report: Initial,Followup
• Report Date (Section B): 07/17/2025

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: No
• Device Expiration Date: 04/30/2026
• Device Catalogue Number: 00020014600
• Device Lot Number: B37250
• Was Device Available for Evaluation?: No
• Is the Reporter a Health Professional?: Yes
• Type of Report(Section G): Initial
• Initial Date Received by Manufacturer: 05/23/2025
• Supplement Date Received by Manufacturer: Not provided
• Initial Report FDA Received Date: 05/28/2025
• Supplement Report FDA Received Date: 07/18/2025
• Was Device Evaluated by Manufacturer? (Y/N): No
• 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: Unknown
• Patient Sequence Number: 1
• Outcome Attributed to Adverse Event: Death
• Patient Sex: Unknown