Catastrophic haemorrhage in a case of paediatric primary antiphospholipid syndrome and factor II deficiency

The first case of primary antiphospholipid syndrome associated with recurrent life-threatening haemorrhages, due to the coexistence of acquired prothrombin deficiency, is described. Attention is drawn to the difficulty in diagnosing this situation, and therapeutic options are reviewed. Evidence is presented that implicates prothrombin as the protein cofactor for this lupus anticoagulant.