Chalmers E A, Sproul A M, Mills K I, Stewart J, McNee S, Jones R, Barrett A, Simpson E, Gibson B E, Robertson A G
Department of Haematology, Glasgow Royal Infirmary, UK.
Bone Marrow Transplant. 1992 Nov;10(5):425-30.
The presence of mixed haemopoietic chimerism (MXC) was evaluated by cytogenetic and molecular analysis in 48 patients undergoing T cell-depleted BMT. The dose of total body irradiation (TBI) prescribed to all patients (14.4 Gy) was calculated to compensate for the absence of T cells in the graft. The actual midline dose of TBI received, however, differed significantly depending on the method of TBI administration. Thus, 35 adult patients received an average midline dose of 14.3 Gy, while 13 children received a lower dose of 13 Gy. The incidence of MXC in the adult group, who had received very close to 14.4 Gy to the midline, was 34% (12/35), which is lower than in most reported T cell-depleted series. During follow-up, chimerism remained relatively stable with time but varied between haemopoietic lineages. There was no relationship with relapse. MXC in the 13 children who had received a lower midline TBI dose was significantly higher at 69% (9/13) (p < 0.05) and increased to 90% (9/10) if patients who received additional chemotherapy in their conditioning were excluded (p = 0.001). This suggests that, in terms of marrow ablation, relatively small changes in the dose of TBI may be biologically significant, at least at this dose range. Again, in the lower TBI group MXC was not predictive of relapse.
通过细胞遗传学和分子分析评估了48例接受T细胞去除型骨髓移植（BMT）患者的混合造血嵌合体（MXC）情况。给所有患者规定的全身照射（TBI）剂量（14.4 Gy）是为了补偿移植物中T细胞的缺失而计算得出的。然而，实际接受的TBI中线剂量因TBI给药方法的不同而有显著差异。因此，35例成年患者接受的平均中线剂量为14.3 Gy，而13例儿童接受的剂量较低，为13 Gy。成年组接受的中线剂量非常接近14.4 Gy，其MXC发生率为34%（12/35），低于大多数报道的T细胞去除系列。在随访期间，嵌合体随时间相对稳定，但在造血谱系之间有所不同。与复发无关。13例接受较低中线TBI剂量的儿童中，MXC显著更高，为69%（9/13）（p<0.05），如果排除在预处理中接受额外化疗的患者，则升至90%（9/10）（p = 0.001）。这表明，就骨髓消融而言，TBI剂量的相对小变化可能具有生物学意义，至少在这个剂量范围内是如此。同样，在较低TBI组中，MXC不能预测复发。
