Universidade Federal São Paulo, São Paulo, Brazil.
Transfus Med Rev. 2010 Jul;24(3):195-210. doi: 10.1016/j.tmrv.2010.03.002.
Autoimmune hemolytic anemia (AIHA) is defined as a condition associated with the increased destruction of red blood cells (RBCs) associated with the presence of IgG anti-RBC autoantibodies. The etiology underlying the pathogenesis of such autoantibodies is still uncertain. In the present article, we will discuss the postulated mechanisms that produce a breakdown of immunologic tolerance leading to warm AIHA including the possible roles of RBC autoantigens and the complement system, the lack of effective presentation of autoantigens, functional abnormalities of B and T cells resulting in polyclonal lymphocyte activation and alteration of cytokine production, and the role of immunoregulatory T cells. Because warm AIHA is a relatively rare clinical entity, current recommended therapeutic strategies for patients with warm AIHA are mainly based on results from small cohort studies. Clinicians must also balance the risk of withholding RBC transfusions against the possible benefit of ameliorating the hemoglobin level with such transfusions particularly in critically ill patients with warm AIHA. Glucocorticoids are the first-line treatment for patients with warm AIHA resulting in an 80% clinical response after 3 weeks of treatment. The latter, however, also may cause adverse events such as excessive weight gain, neuropsychiatric disorders, endocrine, or cardiovascular events. Splenectomy should be considered for patients who do not show a satisfactory response to glucocorticoids and may offer a success rate of up to 70% in patients with idiopathic warm AIHA. Rituximab treatment in patients with refractory warm AIHA has been well tolerated with an overall median response rate of approximately 60%. Danazol, intravenous immunoglobulin, alemtuzumab, as well as other immunosuppressive drugs have also been successfully used in patients with warm AIHA, refractory to glucocorticoids, splenectomy, and rituximab.
自身免疫性溶血性贫血（AIHA）被定义为一种与 IgG 抗 RBC 自身抗体存在相关的红细胞（RBC）破坏增加的病症。导致此类自身抗体发病机制的病因仍不确定。在本文中，我们将讨论导致温抗体型 AIHA 产生免疫耐受破坏的假设机制，包括 RBC 自身抗原和补体系统的可能作用、自身抗原的有效呈递缺乏、B 和 T 细胞的功能异常导致多克隆淋巴细胞激活和细胞因子产生改变，以及免疫调节性 T 细胞的作用。由于温抗体型 AIHA 是一种相对罕见的临床实体，目前推荐的温抗体型 AIHA 患者治疗策略主要基于小队列研究的结果。临床医生还必须权衡因输注红细胞而可能导致的风险与因输注红细胞而改善血红蛋白水平的可能益处，尤其是在患有温抗体型 AIHA 的危重症患者中。糖皮质激素是治疗温抗体型 AIHA 的一线药物，在治疗 3 周后有 80%的临床反应。然而，后者也可能导致不良反应，如体重过度增加、神经精神障碍、内分泌或心血管事件。对于那些对糖皮质激素反应不佳的患者，应考虑脾切除术，脾切除术可能在特发性温抗体型 AIHA 患者中提供高达 70%的成功率。对于难治性温抗体型 AIHA 患者，利妥昔单抗治疗具有良好的耐受性，总体中位反应率约为 60%。丹那唑、静脉注射免疫球蛋白、阿仑单抗以及其他免疫抑制药物也已成功用于对糖皮质激素、脾切除术和利妥昔单抗耐药的温抗体型 AIHA 患者。
