Open AccessWhy does activated partial thromboplastin time prolongation occur in severe fever with thrombocytopenia syndrome?
Author(s) -
Atsushi Mizoe,
Junya Sakaue,
Noriko Takahara
Publication year - 2020
Publication title -
bmj case reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.231
H-Index - 26
ISSN - 1757-790X
DOI - 10.1136/bcr-2020-235447
Subject(s) - partial thromboplastin time , medicine , prolongation , prothrombin time , severe fever with thrombocytopenia syndrome , disseminated intravascular coagulation , coagulation , thromboplastin , anesthesia , gastroenterology , immunology , virus
Severe fever with thrombocytopenia syndrome (SFTS) is caused by infection with SFTS virus and this mortality rate is 16.2% to 30%. An 85-year-old male patient presented to the emergency department of the hospital with primary complaints of fever and consciousness disturbance. Haemophagocytic syndrome and prolonged activated partial thromboplastin time (APTT) without associated prolonged prothrombin time were observed, suggesting SFTS, which was eventually diagnosed. APTT-only prolongation has been reported previously with SFTS, but the mechanism is unknown. The absence of coagulation factors was determined by a cross-mixing study. In addition, examination of intrinsic coagulation factors showed reduced factor XI activity. These results suggest that factor XI is causally related to APTT-only prolongation in SFTS.