慢性淋巴细胞性白血病（CLL）是一种常见的血小板减少症并发症。鉴别自身免疫性血小板减少症和骨髓浸润引起的血小板减少症对于恰当的治疗是必要的，但有时也很困难。在这里，我们报告了一名60岁男性患者，他在出现症状前两年曾接受氟达拉滨、环磷酰胺和利妥昔单抗治疗后取得完全缓解。他因严重血小板减少症入院，而静脉免疫球蛋白治疗无效。影像学研究显示全身淋巴结肿大，骨髓穿刺检查呈高细胞密度，> 95%淋巴细胞和少量巨核细胞。给予阿可替尼200 mg/天治疗CLL恶化。观察到CLL细胞逐渐减少，骨髓中巨核细胞恢复，但血小板计数仍然低。同时开始使用泼尼松龙0.5 mg/kg全身治疗，考虑到自身免疫性血小板减少症的贡献；血小板恢复迅速且持续了一年以上。即使骨髓检查提示血小板减少症由直接白血病浸润引起，也难以排除伴发免疫原性血小板减少症的可能性。我们得出结论，对于严重血小板减少症的CLL患者，重复骨髓检查并同时进行免疫抑制疗法和基本CLL的治疗可能是有益的。

Thrombocytopenia is a frequent complication in chronic lymphocytic leukemia (CLL). Differentiating autoimmune thrombocytopenia from thrombocytopenia due to bone marrow infiltration is necessary for appropriate treatment, but sometimes difficult. Here we report a 60-year-old male patient with CLL who had achieved complete response after treatment with fludarabine, cyclophosphamide, and rituximab two years prior to presentation. He was admitted with severe thrombocytopenia that was unresponsive to intravenous immunoglobulin. Imaging studies revealed systemic enlarged lymph nodes and bone marrow aspiration was hypercellular with > 95% lymphocytes and scant megakaryocytes. Acalabrutinib 200 mg/day was administered for the treatment of CLL exacerbation. A gradual decrease in CLL cells and recovery of megakaryocytes in bone marrow were observed, but platelet counts remained low. Systemic administration of prednisolone 0.5 mg/kg, in addition to acalabrutinib, was started, considering the contribution of autoimmune thrombocytopenia; platelet recovery was rapid and sustained for more than a year. Even if bone marrow examination suggested thrombocytopenia due to direct leukemic infiltration, it is difficult to exclude the possibility of concomitant immunogenic thrombocytopenia. We conclude that for CLL patients with severe thrombocytopenia, repeating bone marrow examination and concurrent immunosuppressive therapies and treatment of the underlying CLL may be beneficial.