Cabanillas Gerardo, Popescu-Martinez Andrea
Department of Medicine, New York Medical College Metropolitan Hospital Center, New York, NY.
Am J Ther. 2016 Sep-Oct;23(5):e1277-9. doi: 10.1097/MJT.0000000000000386.
Thrombotic thrombocytopenic purpura (TTP) is a microangiopatic thrombotic state associated with a deficiency on the cleavage function of the Von Willebrand factor polymers by a disintegrin and metalloprotease with a thrombospondin type 1 motif, member 13. We report a patient with relapsing TTP successfully treated with N-acetylcysteine (NAC) after failure of plasma exchange (PE) with steroids, rituximab, cyclophosphamide, vincristine, and azathioprine. A 51-year-old male who had an altered mental status while he was on rehabilitation for a previously treated TTP with a subsequent neurologic deficit. He was treated 7 days ago with PE plus steroids and subsequently discharged to our facility for rehabilitation. He was found to have a platelet level of 153,000/mm, hemoglobin decreased from 9.2 to 6.2 g/dL, creatinine raised from 1.0 to 2.4 mg/dL, and the peripheral smear showed schistocytes. A brain computed tomography showed a subacute infarction in the left frontal lobe and an abdominal-pelvic computed tomography disclosed a retroperitoneal hematoma. PE and steroids were started for 14 days. On day 15th, rituximab was added weekly for 10 cycles. A disintegrin and metalloprotease with a thrombospondin type 1 motif, member 13 activity level was 95% without platelet count improvement. We started cyclophosphamide, then vincristine, and finally azathioprine. His platelet were maintained above 150,000/mm for a few days. He had several episodes of sepsis after every chemotherapeutic drug. On day 135th, NAC was commenced at 150 mg/kg for 10 days along with PE and low-dose steroids for 10 days. Complete recover of platelet count was achieved and the patient was successfully discharged. Relapsing TTP is often difficult to manage and may last longer than expected carrying several comorbidities and complications. PE plus steroids are the mainstay of TTP treatment and Rituximab is the drug of choice after they have failed. The patient had a complete remission after NAC therapy. Hence, NAC likely can be considered an earlier choice of treatment after rituximab, before the use of chemotherapeutic agents, considering its toxic and adverse effects.
血栓性血小板减少性紫癜（TTP）是一种微血管血栓形成状态，与具有血小板反应蛋白1型基序的解整合素和金属蛋白酶13对血管性血友病因子聚合物的裂解功能缺陷有关。我们报告了一名复发性TTP患者，在使用类固醇、利妥昔单抗、环磷酰胺、长春新碱和硫唑嘌呤进行血浆置换（PE）失败后，成功接受了N-乙酰半胱氨酸（NAC）治疗。一名51岁男性，在因先前治疗的TTP进行康复治疗时出现精神状态改变，并伴有随后的神经功能缺损。7天前他接受了PE加类固醇治疗，随后出院到我们的机构进行康复治疗。发现他的血小板水平为153,000/mm，血红蛋白从9.2 g/dL降至6.2 g/dL，肌酐从1.0 mg/dL升至2.4 mg/dL，外周血涂片显示有裂红细胞。脑部计算机断层扫描显示左额叶有亚急性梗死，腹部盆腔计算机断层扫描显示有腹膜后血肿。开始进行为期14天的PE和类固醇治疗。在第15天，每周添加利妥昔单抗，共10个周期。具有血小板反应蛋白1型基序的解整合素和金属蛋白酶13活性水平为95%，血小板计数未改善。我们开始使用环磷酰胺，然后是长春新碱，最后是硫唑嘌呤。他的血小板在几天内维持在150,000/mm以上。每次化疗药物治疗后他都有几次败血症发作。在第135天，开始使用NAC，剂量为150 mg/kg，持续10天，同时进行PE和低剂量类固醇治疗10天。血小板计数完全恢复，患者成功出院。复发性TTP通常难以管理，可能持续时间比预期更长，并伴有多种合并症和并发症。PE加类固醇是TTP治疗的主要方法，利妥昔单抗是在它们失败后的首选药物。患者在NAC治疗后完全缓解。因此，考虑到其毒性和不良反应，在使用化疗药物之前，NAC可能可以被视为利妥昔单抗之后的更早治疗选择。
