Summary This nutshell review discusses the pathophysiology, diagnostic features, treatment strategies and avenues for future research in a recently identified thrombotic entity, monoclonal gammopathy of thrombotic significance (MGTS). MGTS is an anti‐platelet factor 4 (PF4) antibody‐mediated disorder distinct from heparin‐induced thrombocytopenia (HIT) and vaccine‐induced thrombotic thrombocytopenia (VITT), as it involves the production of persistent, monoclonal anti‐PF4 antibodies. Several subtypes of MGTS, including ‘HIT‐like’, ‘VITT‐like’ and ‘non‐HIT/VITT‐like’, exhibit unique serological profiles that can complicate diagnosis. Recognition of ‘HIT‐like’ MGTS is critical to avoid heparin exposure in these patients, which can result in adverse effects like those seen in heparin‐exposed HIT patients. ‘Non‐HIT/VITT‐like’ MGTS antibodies have only been detected in PF4‐enhanced functional testing; therefore, we recommend using these platelet‐based tests as the front‐line assay for detecting MGTS antibodies. Mass profiling using mass spectrometry is critical for the ‘fingerprinting’ of monoclonal antibodies to establish a diagnosis of MGTS. Treatments used in HIT and VITT, such as non‐heparin anticoagulants and intravenous immunoglobulin G, are typically insufficient for managing MGTS. Emerging MGTS therapies, such as plasma cell‐directed drugs and Bruton tyrosine kinase inhibitors, are discussed. The review concludes with an emphasis on areas of future research in MGTS.
Kanack et al. (Tue,) studied this question.