BACKGROUND Measurement of the stem cells collected by leukapheresis has undergone marked improvement through the recent advent of CD34 analysis with flow cytometry. METHODS The relationship between CD34+ cell count in the peripheral blood (PB) and the leukapheresis product CD34+ cell yield was examined. One hundred patients with hematologic and non-hematologic malignancies underwent mobilization, with either growth factors combined with chemotherapy, or growth factors alone. Prior to each leukapheresis, PB was obtained for measuring the WBC, differential and percentage of CD34+ cells. The same tests were then performed for the corresponding leukapheresis products and the following correlations quantified: PB to product CD34+%, PB to product CD34+ cell concentration and PB CD34+ cell concentration, WBC and mononuclear cell (MNC) concentration to product CD34+ cell yield/kg. RESULTS The best predictor of product yield of CD34+ cells/kg x 10(6) was the PB CD34+ cell concentration with r = 0.93. The resulting regression formula (on log-log scale), log10 yield/kg = 1.52 + (0.99 x log10 PB CD34+ cell concentration x 10(6)/mL), predicts, with 50% probability, a minimally acceptable yield of 0.2 x 10(6) CD34+ cells/kg with a CD34+ cell concentration equal to 0.006 CD34+ cells x 10(6)/mL. A cell concentration of > or = 0.023 CD34+ cells/mL will ensure that a very high fraction (> 97%) of the patient population exceeds the minimally-acceptable yield. DISCUSSION The CD34+ cell concentration measured in the PB prior to leukapheresis is an excellent predictor of the yield of CD34+ cells generated in the PB stem cell product and should be used to signal the initiation of leukapheresis for post-mobilized patients.

中文翻译：

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外周血中 CD34+ 细胞浓度预测白细胞分离产品中 CD34+ 细胞产量

背景 通过最近出现的使用流式细胞术进行 CD34 分析，对通过白细胞去除术收集的干细胞的测量已经得到显着改进。方法检查外周血(PB)中CD34+细胞计数与白细胞去除产物CD34+细胞产量之间的关系。100 名患有血液系统和非血液系统恶性肿瘤的患者接受了动员，使用生长因子联合化疗或单独使用生长因子。在每次白细胞去除术之前，获得 PB 以测量 WBC、CD34+ 细胞的差异和百分比。然后对相应的白细胞去除术产品进行了相同的测试，并量化了以下相关性：PB 与 CD34+% 产物、PB 与 CD34+ 细胞浓度和 PB CD34+ 细胞浓度，WBC 和单核细胞 (MNC) 浓度以产生 CD34+ 细胞产量/kg。结果 CD34+ 细胞/kg x 10(6) 产品产量的最佳预测因子是PB CD34+ 细胞浓度，r = 0.93。得到的回归公式（在对数对数尺度上），log10 产量/kg = 1.52 + (0.99 x log10 PB CD34+ 细胞浓度 x 10(6)/mL)，以 50% 的概率预测最低可接受的产量为 0.2 x 10(6) CD34+ 细胞/kg，CD34+ 细胞浓度等于 0.006 CD34+ 细胞 x 10(6)/mL。> 或 = 0.023 CD34+ 细胞/mL 的细胞浓度将确保非常高比例 (> 97%) 的患者群体超过最低可接受的产量。