Sequential thrombosis and bleeding in a woman with a prolonged activated partial thromboplastin time

The differential diagnosis of a prolonged aPTT (activated partial thromboplastin time) is manifold and necessitates an algorithm to indicate factor deficiencies or the presence of inhibitors that could be lupus like, heparin like or specific to a clotting factor [1]. A quick and correct laboratory diagnosis is of the utmost importance in the emergency setting when a clinician is faced with a critical haemorrhage in a previously healthy individual. We describe the sequential occurrence of thrombosis and haemorrhage developing over a nine day period in a young woman with a prolonged aPTT ratio.A 37 year old woman presented to casualty for pain and swelling in the right calf; her Well's score was 5, D-dimer elevated at 422 ng/ml (cut-off limit 230 ng/ml) and a Doppler ultrasound revealed a clot in the upper portion of the right femoral vein and in the deep veins of the right calf. With regards to thrombosis risk factors, she was 5 weeks post caesarean delivery, had been on oral contraception for the previous three weeks, had a body mass index of 24.5 (normal 18.5-24.9) had no varicose veins, and had not been on any long haul trips by either plane or car since delivery. Her personal history was uneventful, this being her first pregnancy during which she had no complications. There was no family history of thrombosis or recurrent miscarriages. Her aPTTr was 3.01 (normal range 0.88 -1.16) and prothrombin time ratio (PTr) was normal. Her Hb was 9.1 g/dl with a slight microcytosis. Low molecular weight heparin (LMWH) at treatment dose was started embricated with warfarin then stopped after four days when her international normalised ratio (INR) was 2.3. A week later she re-attended casualty for spontaneous bruising on upper limbs and worsening of the pain and swelling in the right leg that was markedly ecchymotic. Blood tests on admission revealed Hb 8.1 g/dl, platelets 557 × 109/L and C-reactive protein at 247 mg/L (normal < 5 mg/L). Urine and blood cultures were negative.