Instrumentation Laboratories recalls several lots of HemosIL AcuStar HIT-IgG(PF4-H) assay due to false-negative risk

Instrumentation Laboratories (Werfen) has issued a recall of specific lots of its HemosIL AcuStar HIT-IgG(PF4-H) radioimmunoassay after the FDA identified a performance issue that could produce false‑negative results for heparin‑induced thrombocytopenia (HIT). The recall is classified as the most serious type because continued use may lead to delayed diagnosis and serious patient harm.

The affected lots are identified by lot numbers B40005, B40006, B38062, and B38063. Users are instructed to locate any inventory containing these lots, remove the devices from use, and destroy them according to standard facility procedures. Documentation of the destruction must be recorded on the Urgent Mandatory Response Tracking Form, noting quantities and dates.

Laboratories should arrange for an alternative HIT antibody testing method while the recalled product is unavailable. Werfen representatives are available to provide guidance and support for the transition to a substitute assay. Facilities are also advised to review any previously reported patient results that may have been generated with the recalled lots and consider appropriate follow‑up.