Rituximab in lupus anticoagulant hypoprothrombinemia syndrome: A case report

Lupus anticoagulant hypoprothrombinemia syndrome (LAHPS) is a rare autoimmune condition characterized by acquired prothrombin (FII) deficiency associated with antiphospholipid syndrome (APS) and life-threatening bleeding. We present the case of a 34-year-old woman with heavy menstrual bleeding (HMB), positive Lupus anticoagulant (LA) test, and high titer anticardiolipin antibodies Immunoglobulin G (ACA IgG) and anti-β2 glycoprotein I antibodies IgG (antiB2GPI IgG). Severe iron deficiency anemia necessitated recurrent blood transfusions and intravenous iron infusions from 2018 to 2021.

In January 2022, she was admitted to our clinic. Von Willebrand disease screening and platelet function analysis (PFA100) were normal. FII and FIX deficiencies were detected, without factor IX inhibitors. Anti-phosphatidylserine/prothrombin antibodies were confirmed by Padua University lab. To reduce antibody titers and menstrual bleeding, immunosuppressive therapy (Rituximab 375 mg/m2 weekly ×4 weeks) and hormonal therapy (desogestrel 75 mcg/day) were initiated.

After 1-year, complete remission of clinical symptoms was achieved, with normalization of FII and FIX values and moderate reduction of aPS/PT titers, especially IgM isotype.