Combined Ala601-Thr-type dysplasminogenaemia and antiphospholipid antibody syndrome in a patient with recurrent thrombosis

Abstract A 44-year-old man was admitted to our hospital because of recurrent thrombosis. Laboratory findings showed that he had antiphospholipid antibody syndrome (APS) associated with systemic lupus erythematosus. Plasminogen activity was reduced (21%), but its antigenic level was rather elevated (16.4 mg/dl). The discrepancy of plasminogen activity and antigen levels was also found in his three daughters. Gene analysis revealed a homozygous missense mutation (Ala601→Thr) at exon 15 of the plasminogen gene in the patient and a heterozygous mutation in his three daughters, suggesting that the patient has dysplasminogenaemia, which was reported as “plasminogen Tochigi.” Although it still remains controversial whether both dysplasminogenaemia and plasminogen deficiency are relevant independent thrombotic risk factors, the combination of this deficiency and APS should be considered as a strong predisposition to thrombosis in this patient.