Department of Laboratory Medicine, Memorial Sloan Kettering Cancer Center, New York, New York, USA.
Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, New York, USA.
Transfusion. 2021 Sep;61(9):2775-2781. doi: 10.1111/trf.16551. Epub 2021 Jun 23.
Adequate CD34+ collection efficiency (CE) is critical to achieve target CD34+ cell doses in hematopoietic progenitor cell (HPC) collections. Autologous HPC collection in sickle cell disease (SCD) is associated with unstable collection interfaces and low CD34+ CEs. We hypothesized that variables specific to SCD, activation of blood cells and elevated viscosity, might contribute to these issues and made adjustments to the collection process and procedure to address our hypothesis.
In two patients with SCD undergoing autologous HPC collection on our clinical trial (NCT02193191), we therefore implemented adjustments to the process and procedure in the following areas: proximity of RBC exchange to HPC collection, the type of anticoagulation, and the packing factor setting.
There was no collection interface instability. Our CD34+ CE1s were high at 70% and 51%, and granulocyte CE, platelet CE, and product granulocyte % were remarkably low. Product hematocrits were not as high as previously reported to be required to obtain adequate CEs. Interestingly, one HPC product showed a hemoglobin S (HbS) of 91% at the same time that the peripheral blood (PB) showed a HbS of 22%.
Adjustments to the HPC collection process and procedure were associated with adequate CD34+ CEs and low granulocyte and platelet contamination in HPC products from SCD patients. Given the discrepancy in the percentage of sickle RBCs in the product versus the PB, we hypothesize that CD34+ cells and RBCs may aggregate. Our interventions and hypothesis should be further investigated in larger studies.
足够的 CD34+ 采集效率（CE）对于在造血祖细胞（HPC）采集时达到目标 CD34+ 细胞剂量至关重要。镰状细胞病（SCD）患者的自体 HPC 采集与不稳定的采集界面和低 CD34+ CE 相关。我们假设 SCD 特有的变量，即血细胞的激活和升高的黏度，可能导致这些问题，并对采集过程和程序进行了调整以验证我们的假设。
在我们的临床试验（NCT02193191）中，两名 SCD 患者接受自体 HPC 采集，我们因此对以下领域的过程和程序进行了调整：RBC 交换与 HPC 采集的接近程度、抗凝类型和包装因子设置。
没有采集界面不稳定的情况。我们的 CD34+ CE1 为 70%和 51%，高，粒细胞 CE、血小板 CE 和产品粒细胞%极低。产品红细胞压积没有像以前报道的那样高，以获得足够的 CE。有趣的是，一个 HPC 产品的血红蛋白 S（HbS）为 91%，而外周血（PB）的 HbS 为 22%。
对 HPC 采集过程和程序的调整与 SCD 患者 HPC 产品中足够的 CD34+ CE 和低粒细胞和血小板污染相关。鉴于产品中镰状红细胞的百分比与 PB 中的百分比存在差异，我们假设 CD34+ 细胞和 RBC 可能聚集。我们的干预措施和假设应在更大的研究中进一步调查。
