Abstract
A 4-year-old previously healthy boy developed spontaneous inhibitors to Factor IX and lupus-like anticoagulant. A brief illness of presumed viral origin preceded hemorrhagic symptoms. Cutaneous ecchymosis and nasal bleeding were the predominant clinical features in this case. Hemorrhagic abnormalities and bruising tendency disappeared simultaneously without any treatment. Inhibitor to factor IX, approximately 1.2 Bethesda units/ml, was detected. Hypoprothrombinemia and delayed recovery of APTT made us suspect the existence of lupus-like anticoagulant. The existence of lupus-like anticoagulant was unmasked by the use of dilute thromboplastin (Tissue thromboplastin inhibition test) and was neutralized by rabbit brain phospholipid (Rabbit brain neutralization), and was sensitive to dilution. From these results, coexistence of lupus-like anticoagulant along with Factor IX inhibitor, which is a very rare event, was suggested.
