A Rare, Chronic Disorder to Consider in Patients with Unexplained Thrombophilia

Vaccine-induced thrombocytopenia and thrombosis (VITT), also known as vaccine-induced immune thrombotic thrombocytopenia, is characterized by acute, transient thrombocytopenia triggered by vaccines for COVID-19 or, in some cases, adenovirus infection. VITT antibodies are generally transient, and tests becomes negative at a median of 16 weeks. VITT-like monoclonal gammopathy of thrombotic significance (MGTS) is a chronic prothrombotic disorder characterized by anticoagulant-refractory thromboses and intermittent thrombocytopenia, associated with VITT-like antibodies.

This report describes four new patients and one index patient with VITT-like MGTS, all of whom had recurrent thrombosis despite anticoagulation. The anti–platelet factor 4 (PF4) …