Patient with lupus anticoagulant caused aPTT prolongation corrected with prednisolone treatment and later anticoagulation treatment due to chronic atrial fibrillation.

Key Clinical Message: Lupus anticoagulant caused aPTT prolongation in rare case can cause bleeding tendency especially when combined with other hemostasis abnormalities. In such cases, aPTT value can be corrected by immunosuppressants within several days of treatment. When anticoagulation therapy is needed vitamin K antagonist are a good option for the initial treatment.