Patient 2
A 5-year old girl was admitted to a hospital with petechiae and ecchymoses after a mild respiratory illness. CBC showed thrombocytopenia (5 × 109/L), low Hb (6.8 g/dL), and normal WBC (5.5 х 109/L). The patient was diagnosed with ITP, and IVIG was administered, which resulted in an increased platelet count of 139 × 109/L and Hb > 10.0 g/dl. A month later the platelets dropped 12 × 109/L, although her Hb remained at 12.1 g/dL, with the presence of rare schistocytes on blood smears. A second course of IVIG was delivered, and her platelet count rose to 301 × 109/L. After 9 months, the patient developed a petechial rash. Her CBC was indicated thrombocytopenia (19 × 109/L), low Hb (4.9g/dL), reticulocytosis (4.1%), and the presence of 3-5 schistocytes per high-power view. The patient’s LDH was 1183 U/L, urea was 4.5 mmol/L, and creatinine was 45 µmol/L. The direct Coombs test was negative. ADAMTS13 was 0%, and anti-ADAMTS13 inhibitory antibodies were > 4.5 Bethesda units. The patient was diagnosed with immune TTP, and high dose IV methylprednisolone 500 mg/d was administered for 3 days, and FFP infusions of 20 ml/kg day were started.
The patient was referred to our centre. Upon admission, the patient was fatigued, with extensive cutaneous haemorrhages. The patient’s CBC showed low Hb (9.6 g/dL), reticulocytes (20.5%), schistocytes (2.8%), and low platelets (8 х 109/L). The total bilirubin level was 47.2 µmol/L, LDH was 1551 U/L, urea was 6.6 mmol/L, creatinine was 43 μmol/L, and proteinuria was indicated at 2.0 g/L. ADAMTS13 activity was 0%. The patient underwent PEX daily, rituximab 375 mg/m2 was administered twice weekly for 7 doses. After 8 PEX procedures, the patient’s platelets recovered to > 150 х 109/L, and the frequency of the procedure dropped to every other day. Ten days after the last PEX procedure, the patient’s platelets dropped to 90 х 109/L, and her Hb decreased to 10.0 g/dL. ADAMTS13 activity was 10%. PEX was resumed, and the patient received bortezomib, 1.3 mg/m2 on days 1, 4, 8, and 11. After 2 courses of PEX, the patient’s platelets increased to 249 × 109/L, and ADAMTS13 activity increased to 24%. After two months, her platelets had stabilised at > 300 x 109/L, ADAMTS13 activity had reached 60%, and inhibitors were no longer detectable. Twelwe months after the last bortezomib dose, the patient remains free of disease, with normal ADAMTS13 activity and no inhibitors (figure 2).