Abstract：
BACKGROUND: Pure red cell aplasia (PRCA) following allogeneic hematopoietic stem cell transplantation (allo-HSCT) with ABO major incompatibility is characterized by transfusion dependent anemia. No standard treatment existed for PRCA following allo-HSCT yet.
METHODS: We conducted a retrospective study, and reported our experience with the use of avatrombopag and lower dose rituximab to treat five patients with PRCA subsequent to major ABO-incompatible allo-HSCT.
RESULTS: Five cases of PRCA were identified from 72 patients who underwent allo-HSCT with major or bidirectional ABO mismatch. Cumulative incidence at Day +60 was 6.9% (5/72) at our center. All donor and recipient blood groups were A+ and O+ , respectively. In the first three cases we reported, patients received erythropoietin, plasma exchange, and donor lymphocyte infusion, but none of them had any effect. After 4 weeks of treatment with low dose rituximab (100 mg/week) combined with avatrombopag (40 mg/day), favorable outcomes were obtained. According to the aforementioned experience, Cases 4 and 5 were administered low-dose rituximab and avatrombopag in 3 months after transplantation, and erythroid response was observed on 3 weeks after treatment. Our patients tolerated low-dose rituximab and avatrombopag well and experienced rapid efficacy, with a median duration of 3 weeks. Furthermore, no severe infection or thrombocytosis necessitated a dose adjustment.
CONCLUSIONS: Low-dose rituximab and avatrombopag may be an effective treatment for patients with PRCA after major ABO-incompatible allo-HSCT. The patients should be treated at least 90 days post transplantation if conventional erythropoietin therapy fails.
METHODS: We conducted a retrospective study, and reported our experience with the use of avatrombopag and lower dose rituximab to treat five patients with PRCA subsequent to major ABO-incompatible allo-HSCT.
RESULTS: Five cases of PRCA were identified from 72 patients who underwent allo-HSCT with major or bidirectional ABO mismatch. Cumulative incidence at Day +60 was 6.9% (5/72) at our center. All donor and recipient blood groups were A+ and O+ , respectively. In the first three cases we reported, patients received erythropoietin, plasma exchange, and donor lymphocyte infusion, but none of them had any effect. After 4 weeks of treatment with low dose rituximab (100 mg/week) combined with avatrombopag (40 mg/day), favorable outcomes were obtained. According to the aforementioned experience, Cases 4 and 5 were administered low-dose rituximab and avatrombopag in 3 months after transplantation, and erythroid response was observed on 3 weeks after treatment. Our patients tolerated low-dose rituximab and avatrombopag well and experienced rapid efficacy, with a median duration of 3 weeks. Furthermore, no severe infection or thrombocytosis necessitated a dose adjustment.
CONCLUSIONS: Low-dose rituximab and avatrombopag may be an effective treatment for patients with PRCA after major ABO-incompatible allo-HSCT. The patients should be treated at least 90 days post transplantation if conventional erythropoietin therapy fails.
摘要：
背景：与ABO主要不相容性的异基因造血干细胞移植（allo-HSCT）后的纯红细胞再生障碍（PRCA）的特征是输血依赖性贫血。在allo-HSCT之后还没有PRCA的标准治疗。
方法：我们进行了一项回顾性研究，并报告了我们使用avatrombopag和较低剂量利妥昔单抗治疗5例主要ABO不相容allo-HSCT后PRCA患者的经验。
结果：从72例患者中发现了5例PRCA，这些患者接受了严重或双向ABO错配的allo-HSCT。在我们的中心，第60天的累积发病率为6.9％（5/72）。所有供体和受体血型均为A+和O+，分别。在我们报告的前三个案例中，患者接受促红细胞生成素，血浆置换,和供体淋巴细胞输注，但都没有效果.低剂量利妥昔单抗（100mg/周）联合avatrombopag（40mg/天）治疗4周后，获得了良好的结果。根据上述经验,病例4和5在移植后3个月内分别给予低剂量利妥昔单抗和avatrombopag，治疗3周后观察到红细胞反应。我们的患者耐受低剂量利妥昔单抗和avatrombopag良好，并经历了快速疗效，中位持续时间为3周。此外，没有严重的感染或血小板增多需要调整剂量。
结论：低剂量利妥昔单抗和avatrombopag可能是主要ABO不相容allo-HSCT后PRCA患者的有效治疗方法。如果常规促红细胞生成素治疗失败，则应在移植后至少90天治疗患者。
方法：我们进行了一项回顾性研究，并报告了我们使用avatrombopag和较低剂量利妥昔单抗治疗5例主要ABO不相容allo-HSCT后PRCA患者的经验。
结果：从72例患者中发现了5例PRCA，这些患者接受了严重或双向ABO错配的allo-HSCT。在我们的中心，第60天的累积发病率为6.9％（5/72）。所有供体和受体血型均为A+和O+，分别。在我们报告的前三个案例中，患者接受促红细胞生成素，血浆置换,和供体淋巴细胞输注，但都没有效果.低剂量利妥昔单抗（100mg/周）联合avatrombopag（40mg/天）治疗4周后，获得了良好的结果。根据上述经验,病例4和5在移植后3个月内分别给予低剂量利妥昔单抗和avatrombopag，治疗3周后观察到红细胞反应。我们的患者耐受低剂量利妥昔单抗和avatrombopag良好，并经历了快速疗效，中位持续时间为3周。此外，没有严重的感染或血小板增多需要调整剂量。
结论：低剂量利妥昔单抗和avatrombopag可能是主要ABO不相容allo-HSCT后PRCA患者的有效治疗方法。如果常规促红细胞生成素治疗失败，则应在移植后至少90天治疗患者。
