Imataki Osamu, Iseki Kikuo, Uchida Shumpei, Uemura Makiko, Kadowaki Norimitsu
Division of Hematology, Department of Internal Medicine, Faculty of Medicine, Kagawa University.
Division of Transfusion Medicine, Kagawa University Hospital, Kagawa, Japan.
Medicine (Baltimore). 2020 Feb;99(6):e18984. doi: 10.1097/MD.0000000000018984.
Autoimmune hemolytic AQ5 anemia (AIHA) is an immune disorder caused by antibodies directed against unmodified autologous red blood cells. In rare cases, AIHA is comorbid with other immunological disorders; for instance, when AIHA is complicated with immunologic thrombocytopenic purpura (ITP) it is called Evans Syndrome (ES). These multiple autoimmune mechanisms are referred to as "immunological tolerance loss," which is known as a characteristic autoimmunity specific for AIHA. And there are no estimation of the risk for thromboembolism in the "immunological tolerance loss" case.
A 66-year-old man was diagnosed with ES after autologous stem cell transplantation for malignant lymphoma. His background immunological status was complicated because AIHA was mixed-type (warm and cold antibody type). The direct/indirect Coombs tests were positive. The anticomplement antibody was positive and his cold hemagglutinin level had increased. Anticardiolipin antibodies were negative: anticardiolipin β2GPI antibody ≤1.2 U/mL (<3.5), anticardiolipin immunoglobulin G antibody ≤8 U/mL (<10), and anticardiolipin immunoglobulin M antibody ≤5 U/mL (<8).
ITP and mixed-type AIHA.
The patient achieved complete response by initial prednisolone therapy; however, he did not respond to corticosteroid therapy after AIHA recurrence. He required the red blood cell transfusion due to the progression of hemolytic anemia.
On the fourth day of refractory treatment following AIHA recurrence, the patient had acute respiratory failure with severe hypoxia and died. The cause of death was identified as pulmonary embolism (PE) based on the laboratory data and echocardiography findings, and a literature search suggested rapidly progressive hemolysis-induced PE.
Although infrequent, comorbid thromboembolism to AIHA is well documented; however, a mixed-type AIHA case complicated with thromboembolism has not been previously reported. The combined pathophysiology of AIHA and thromboembolism should be considered in the clinical course of hemolysis. Our case suggested multiple immunological background, ITP, and mixed type AIHA, could be associated to a risk for thromboembolism (TE).
自身免疫性溶血性贫血（AIHA）是一种由针对未修饰自体红细胞的抗体引起的免疫紊乱。在罕见情况下，AIHA与其他免疫性疾病合并存在；例如，当AIHA合并免疫性血小板减少性紫癜（ITP）时，称为伊文斯综合征（ES）。这些多种自身免疫机制被称为“免疫耐受丧失”，这是AIHA特有的一种自身免疫特征。并且在“免疫耐受丧失”情况下，尚无对血栓栓塞风险的评估。
一名66岁男性在因恶性淋巴瘤接受自体干细胞移植后被诊断为ES。他的基础免疫状态较为复杂，因为AIHA为混合型（温抗体型和冷抗体型）。直接/间接抗人球蛋白试验呈阳性。抗补体抗体呈阳性，且他的冷凝集素水平升高。抗心磷脂抗体为阴性：抗心磷脂β2糖蛋白I抗体≤1.2 U/mL（<3.5），抗心磷脂免疫球蛋白G抗体≤8 U/mL（<10），抗心磷脂免疫球蛋白M抗体≤5 U/mL（<8）。
ITP和混合型AIHA。
患者通过初始泼尼松龙治疗获得完全缓解；然而，AIHA复发后他对皮质类固醇治疗无反应。由于溶血性贫血进展，他需要输注红细胞。
AIHA复发后难治性治疗的第四天，患者出现急性呼吸衰竭伴严重缺氧并死亡。根据实验室数据和超声心动图检查结果，死亡原因被确定为肺栓塞（PE），文献检索提示为快速进展的溶血诱导的PE。
虽然AIHA合并血栓栓塞不常见，但有充分记录；然而，此前尚未报道过混合型AIHA合并血栓栓塞的病例。在溶血的临床过程中应考虑AIHA和血栓栓塞的联合病理生理学。我们的病例提示多种免疫背景、ITP和混合型AIHA可能与血栓栓塞（TE）风险相关。
