Supplementary Material for: Haploidentical stem cell transplantation using post-transplant cyclophosphamide for T-cell prolymphocytic leukemia after alemtuzumab induction therapy: a case report

T-cell prolymphocytic leukemia (T-PLL) is a rare aggressive disease with a poor prognosis. Allogeneic stem cell transplantation (allo-SCT) followed by administration of alemtuzumab is the most promising treatment for T-PLL but is associated with a higher risk of infections since alemtuzumab strongly suppresses cellular immunity, leading to high transplant-related mortality and unsatisfactory survival. In addition, for patients without human leukocyte antigen-matched donors, haploidentical stem cell transplantation (haplo-SCT) using post-transplant cyclophosphamide (PTCy) has been used because of the ready availability of donors and results comparable to transplantation with human leukocyte-antigen matched donors. However, there are only a few reports on such transplantation for T-PLL, and the safety and efficacy of haplo-SCT after alemtuzumab therapy has remained unclear. Here, we describe a 66-year-old Japanese male patient with T-PLL treated successfully with haplo-SCT after induction therapy of alemtuzumab for T-PLL. About three months after the achievement of complete remission by alemtuzumab for T-PLL, haplo-SCT with reduced-intensity conditioning and PTCy was performed. Infectious complications were improved by early therapeutic interventions, and peripheral T cell counts gradually recovered. The patient has remained alive for more than 16 months after allo-SCT with no signs of relapse. Thus, haplo-SCT using PTCy should be considered as an option after alemtuzumab treatment for T-PLL.

T细胞幼淋巴细胞白血病（T-cell prolymphocytic leukemia, T-PLL）是一种罕见的侵袭性疾病，预后不良。异基因造血干细胞移植（allogeneic stem cell transplantation, allo-SCT）联合阿仑单抗（alemtuzumab）给药是目前治疗T-PLL最具前景的方案，但由于阿仑单抗可强烈抑制细胞免疫，该疗法会带来更高的感染风险，进而导致较高的移植相关死亡率及不理想的生存结局。此外，对于缺乏人类白细胞抗原（human leukocyte antigen, HLA）配型相合供者的患者，由于供者来源便捷，采用移植后环磷酰胺（post-transplant cyclophosphamide, PTCy）的单倍体相合造血干细胞移植（haploidentical stem cell transplantation, haplo-SCT）已应用于临床，且其疗效可与HLA配型相合的造血干细胞移植相媲美。然而，目前针对T-PLL开展此类移植的报道极少，且阿仑单抗治疗后行haplo-SCT的安全性与有效性仍不明确。本文报告1例66岁日本男性T-PLL患者，在接受阿仑单抗诱导治疗T-PLL后成功接受了haplo-SCT。该患者在阿仑单抗治疗达到完全缓解约3个月后，接受了减强度预处理联合PTCy的haplo-SCT。早期干预治疗改善了感染并发症，外周血T细胞计数逐渐恢复。患者在异基因造血干细胞移植后已存活超过16个月，且无复发迹象。因此，对于接受阿仑单抗治疗的T-PLL患者，采用PTCy的haplo-SCT可作为一种可选治疗方案。