[A Case of Lupus Anticoagulant-Hypoprothrombinemia Syndrome with Phosphatidylserine-Dependent Anti-Prothrombin Antibody].

Lupus anticoagulant-hypothrombinemia syndrome (LAHS) is a rare disease involving hemorrhagic diathe- sis due to hypothrombinemia with lupus anticoagulant. We report a 28-week-pregnant woman at twenty years of age, who had been hospitalized with jaundice. In laboratory data, AST, ALT, and bilirubin were elevated and the prothrombin time (PT) and activated partial thromboplastin time (APTT) were prolonged. Although the liver failure was improved after she delivered a baby by Caesarean section, postoperative intraperitoneal bleeding persisted. The diagnosis by liver biopsy was autoimmune hepatitis. Although the bleeding was stopped on the seventh postoperative day, the prolongation of PT and APTT remained. LA was positive in the diluted Russell's viper venom time. Anti-cardiolipin and anti-beta-2-glycoprotein anti- bodies were also positive. The prothrombin activity was reduced. A high titer of phosphatidylserine- dependent antiprothrombin antibody (aPS/PT), which causes bleeding, was observed. Based on these data, she was diagnosed with LAHS. The liver dysfunction and prolongation of PT and APTT were normalized following the administration of corticosteroids. In this case, aPS/PT may have contributed to the pathological physiology of LAHS. [Case Report].