Division of Hematology, Department of Medicine, University of Utah, Salt Lake City, Utah
Division of Hematology, Department of Medicine, University of Washington, School of Medicine, Seattle, Washington
J Natl Compr Canc Netw. 2017 Jun;15(6):757-760. doi: 10.6004/jnccn.2017.0108.
Pegylated interferon alfa-2a (pegIFNa) is being increasingly used for treatment of myeloproliferative neoplasms; however, its side effects, including autoimmune complications, are not unusual. We report on a 47-year-old woman with polycythemia vera (PV) treated with pegIFNa and in complete hematologic remission who developed thrombotic thrombocytopenic purpura (TTP). To our knowledge, thrombotic microangiopathy has been reported as a side effect of interferon (IFN) use in patients with hepatitis and chronic myeloid leukemia, but not in those with PV. Our patient had a low ADAMTS13 level due to an inhibitor, which normalized after withholding pegIFNa and initiating treatment for TTP with therapeutic plasma exchange and corticosteroids. She experienced refractory TTP, necessitating treatment with rituximab and splenectomy. Postsplenectomy, she developed a high platelet count, warranting the need to restart treatment for PV. However, allelic burden by real-time PCR was 0.7%, indicating that the increased platelet count was likely secondary to splenectomy. Therefore, we elected to monitor her counts and allelic burden closely. With this case report, we hope to alert treating physicians that TTP should be considered as a complication of pegIFNa therapy in PV and that prompt discontinuation of the drug with necessary treatment should be instituted to prevent fatal complications.
聚乙二醇干扰素 α-2a（pegIFNa）越来越多地用于治疗骨髓增生性肿瘤；然而，其副作用，包括自身免疫并发症，并不罕见。我们报告了一例 47 岁的真性红细胞增多症（PV）患者，该患者接受 pegIFNa 治疗并完全血液学缓解，但出现血栓性血小板减少性紫癜（TTP）。据我们所知，血栓性微血管病已被报道为干扰素（IFN）在肝炎和慢性髓性白血病患者中的副作用，但在 PV 患者中尚未报道。我们的患者由于抑制剂导致 ADAMTS13 水平降低，在停用 pegIFNa 并开始用治疗性血浆置换和皮质类固醇治疗 TTP 后，该水平恢复正常。她经历了难治性 TTP，需要用利妥昔单抗和脾切除术进行治疗。脾切除术后，她的血小板计数升高，需要重新开始治疗 PV。然而，实时 PCR 的等位基因负担为 0.7%，表明血小板计数升高很可能是脾切除的结果。因此，我们选择密切监测她的计数和等位基因负担。通过本病例报告，我们希望提醒治疗医生，TTP 应被视为 PV 患者 pegIFNa 治疗的并发症，应立即停止药物治疗并进行必要的治疗，以预防致命的并发症。
