PharmacovigilanceOfficial

FDA flags most serious recall of Werfen HemosIL AcuStar HIT-IgG(PF4-H) lots

🇺🇸 FDA MedWatch · Fri 30 Oct 2026

Four lots of the heparin-induced thrombocytopenia antibody assay show negative bias that routine calibration and quality control may miss, and a supply interruption is expected.

Instrumentation Laboratories (Werfen) has told customers to remove four lots of its HemosIL AcuStar HIT-IgG(PF4-H) assay from use, according to an FDA MedWatch notice dated 30 October 2026. The FDA has classed the action as the most serious type of recall, saying the device may cause serious injury or death if it continues to be used.

The affected lots are B40005 and B38062 (part no. 0009800127) and B40006 and B38063 (part no. 0009802028). The B38062 and B38063 lots expire on 1 November 2026, while B40005 and B40006 expire on 16 January 2027. The notice also lists UDIs 08426951126545 and 08426950545774 for the two part numbers.

Werfen said customer complaints described invalid calibration curves and, in one case, a negative mean bias of 47% with patient samples. Its investigation confirmed performance variability, with a negative bias of 20–35% in the affected lots. The company says this may not be reliably detected by routine calibration and quality control. The root cause investigation is continuing.

The concern is that samples could be reported below the assay cut-off of 1.00 U/mL and read as "HIT IgG Antibody negative". That could delay recognition of heparin-induced thrombocytopenia (HIT) and affect clinical management. The notice adds that continued heparin exposure in patients with HIT may raise the risk of thrombotic complications. As of 3 September, Werfen had reported no serious injuries or deaths linked to the issue.

Users are asked to check inventory, destroy remaining product from the four lots under their facility's standard procedures, and record the quantity and date on the Urgent Mandatory Response Tracking Form. Because a supply interruption is expected, laboratories should arrange an alternative HIT antibody testing method with their local Werfen representative. Decisions on reviewing past results, patient follow-up or repeat testing rest with the laboratory or treating clinician under local procedures. US customers can contact Werfen Client Services on 1-800-955-9525.

What it means for your team

  • Laboratories should quarantine and destroy lots B40005, B40006, B38062 and B38063, and document destruction on the Urgent Mandatory Response Tracking Form.
  • Because routine calibration and QC may not detect the bias, quality teams should note that passing QC does not rule out the problem for these lots.
  • Laboratory directors and clinicians should decide, under local procedures, whether previously reported HIT results need review or repeat testing.
  • Business continuity plans should cover an alternative HIT antibody assay, since a supply interruption is expected.

Official source: FDA MedWatch ↗

Article written by VigiEye from the official source (FDA MedWatch). AI-assisted; check the source before acting.

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