Abstract

How low-dose anti-thymocyte globulin (ATG) for prophylaxis of graft-versus-host disease (GVHD) influences immune reconstitution after allogeneic hematopoietic stem cell transplantation (allo-HCT) remains incompletely understood. We prospectively enrolled 41 consecutive adult patients and conducted cytometry-based immunophenotyping for 12 months after allo-HCT. Rabbit ATG (Thymoglobulin) was administered at a median total dose of 1.75 mg/kg in 16 of the 41 patients. Compared with patients who did not receive ATG, those who did had a significantly smaller number of naïve T cells (especially CD4+ ) within three months after allo-HCT. No significant difference was observed between the two groups in the reconstitution of other T cells (effector, memory, Th1, Th2, Th17, Treg, and Tfh), B cells (transitional, naïve, memory, and plasmablast), NK cells (regulatory and cytolytic), or dendritic cells (myeloid and plasmacytoid). Patients with fewer CD4+ naïve T cells than the median count (7.60 cells/µL) at two months after allo-HCT developed chronic GVHD less frequently than those with CD4+ naïve T cells above the median count (2-year cumulative incidences were 0.31 and 0.53, respectively; p = 0.133). This pilot study suggests low-dose Thymoglobulin suppresses the recovery of naïve T cells after allo-HCT, which may contribute to a lower incidence of chronic GVHD.

中文翻译：

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小剂量抗胸腺细胞球蛋白对异基因造血细胞移植后免疫重建的影响

摘要

异基因造血干细胞移植（allo-HCT）后，低剂量抗胸腺细胞球蛋白（ATG）如何预防移植物抗宿主病（GVHD）如何影响免疫重建。我们前瞻性招募了41名连续成年患者，并在异基因HCT后进行了12个月的基于细胞计数的免疫表型分析。41例患者中有16例以平均总剂量1.75 mg / kg施用兔ATG（胸腺球蛋白）。与未接受ATG的患者相比，接受同种HCT后三个月内的初次T细胞（尤其是CD4 +）的数量明显减少。在其他T细胞（效应子，记忆，Th1，Th2，Th17，Treg和Tfh），B细胞（过渡，幼稚，记忆和成浆细胞）的重组方面，两组之间没有观察到显着差异，NK细胞（调节性和细胞溶解性）或树突状细胞（髓样和浆细胞样）。异基因HCT后两个月中，CD4 +幼稚T细胞少于中位数（7.60细胞/ µL）的患者发生慢性GVHD的频率低于CD4 +幼稚T细胞高于中位数（2年累积发生率是0.31和0.53 ， 分别;p  = 0.133）。这项初步研究表明，低剂量的胸腺球蛋白可抑制异源HCT后幼稚T细胞的恢复，这可能有助于降低慢性GVHD的发生率。