Roger Williams Medical Center/Boston University Providence, Rhode Island, United States
Background/Case Studies: Thrombotic thrombocytopenic purpura (TTP) is a life-threatening hematological condition characterized by thrombocytopenia, microangiopathic hemolytic anemia, and severe deficiency (< 10%) of ADAMTS13. The current standard of care is therapeutic plasma exchange (TPE) and treatment with systemic corticosteroids (SC), rituximab, and caplacizumab is considered adjunctive. Treatment with SC alone is not considered appropriate.
Study
Design/Methods: A retrospective chart review of patient cases with thrombocytopenia, initially diagnosed as ITP, but where a subsequent diagnosis of TTP was made based on the results of severe ADAMTS13 deficiency
Results/Findings: Two patients were identified. Patient 1 is a 39-year-old woman initially admitted to an outside hospital with a platelet count of 22 x 109/L and treated with SC. The patient was transferred to our hospital based on a peripheral blood smear review showing schistocytes. Nevertheless, she was continued on SC and the platelet counts improved to 105x109/L over the next few days. However, a diagnosis of TTP was confirmed with an ADAMTS13 level of 9% from a sample collected initially at the outside hospital. The platelet count at this time was 139x109/L. The patient received 4 daily procedures and was discharged home after achieving a platelet count >150x109/L and normal LDH.
Patient 2 is a 69-year-old female with Sjogren's syndrome, and chronic ITP who was transferred from an outside hospital for severe thrombocytopenia with a platelet count of 9x109/L, where she had been treated for presumptive relapsed ITP with intravenous immunoglobulin and systemic corticosteroids. An in-house ADAMTS 13 assay on the day of admission was 23%, and she was continued on SC. On day 5, the platelet count had increased to 15x109/L and the ADAMTS13 was 56%, however, the ADAMTS13 assay collected from the outside hospital returned as < 10%. On account of this alone, TPE was initiated but discontinued after one procedure. The platelet counts subsequently increased on SC alone, to 159 x 109/L by day 9.
Conclusions: These two patients suggest that in clinically stable patients the use of high-dose corticosteroids and careful observation may be an acceptable approach in selected patients with TTP who are exhibiting a platelet count response.
