Thrombosis associated with cytomegalovirus infection in patients with ANCA-positive vasculitis

Three cases of venous thrombosis with pulmonary embolism in two patients associated with underlying antineutrophil cytoplasmic autoantibody (ANCA)-positive vasculitis and reactivated cytomegalovirus (CMV) infection are described. In vitro studies previously have shown that infection of endothelium with CMV increases the release of procoagulant factors and stimulates the expression of adhesion molecules. Because the endothelial cell plays a pivotal role in maintaining the equilibrium between procoagulant and anticoagulant states, injury by ANCA-positive vasculitis and additional infection with CMV may ignite a local thrombosis easily. Although venous thrombosis is uncommon in CMV infection (eg, in the immunosuppressed state after organ transplantation), the combination of vasculitis and reactivated CMV infection may have contributed to injury of the vessel wall with subsequent development of thrombosis. A better awareness of this association could improve morbidity and may lead to prevention of potentially life-threatening pulmonary embolism. Patients with ANCA-positive vasculitis and CMV infection may profit from prophylactic anticoagulant therapy with heparin or low-molecular-weight heparin.