A Patient with Severe Fever with Thrombocytopenia Syndrome, Activated Partial Thromboplastin Time Prolongation, and Transient Antiphospholipid Antibodies

A prolonged activated partial thromboplastin time (APTT) is observed in patients with severe fever with thrombocytopenia syndrome (SFTS) and is one of the risk factors for severe disease. The mechanism under-lying a prolonged APTT is largely unknown. The presence of antiphospholipid (aPL) antibodies in various viral infections has been documented but never reported in a patient with SFTS. We herein report the first SFTS patient with APTT prolongation and concurrent transiently positive aPL antibodies (lupus anticoagu-lants and anticardiolipin antibodies) with no coagulation factor deficiency.

Automated summary

Severe fever with thrombocytopenia syndrome (SFTS) patients often have a prolonged activated partial thromboplastin time (APTT), which is a risk factor for severe disease. The exact mechanism behind this prolonged APTT is not well understood. While the presence of antiphospholipid (aPL) antibodies has been documented in viral infections, it has never been reported in SFTS patients. Here, we report the first SFTS patient with both prolonged APTT and transiently positive aPL antibodies (lupus anticoagulants and anticardiolipin antibodies) without any coagulation factor deficiency.