Prospective flow cytometric evaluation of nucleated red blood cells in cord blood units and relationship with nucleated and CD34(+) cell quantification

BACKGROUND: Cord blood (CB) represents an alternate source of stem cells in transplantation. Nucleated red blood cells (NRBCs) are a physiological subset of CB population. Although it is important to have an accurate estimate of CD34(+) cell number, NRBCs could compromise white blood cell count and interfere with CD34(+) cell quantification. STUDY DESIGN AND METHODS: A total of 826 CB units were analyzed for total nucleated cells (TNCs), NRBCs, and CD34(+) cells by flow cytometry. NRBCs were also counted conventionally by manual microscopy. Percentages of CD34(+) cells corrected by NRBC count (CD34+c) were determined as follows: %CD34+c = CD34(+)/CD45(+) (x10(6))/(TNCs (x10(8)) - NRBCs (x10(8))). RESULTS: The mean percentages of CD34+ cells and NRBCs were 0.27 percent (range, 0.01%-1.25%) and 7.64 percent (range, 0.13%-84%), respectively. Comparison between flow cytometric and microscopic NRBC count showed a regression of y = 0.685 + 0.719x and a coefficient of determination of r(2) = 0.721. When corrected with NRBC count, the mean percentage of CD34(+) c cells was 0.295 percent (p = 0.0008 compared with CD34(+)%) and mean TNCc count was 14.8 x 10(8) (p < 10(-4) compared to TNC count). CONCLUSION: The determination of NRBCs with a flow cytometric method might represent a new strategy for providing satisfactory quality assurance controls of CB products.     

骨髓基质细胞联合细胞因子对脐血单个核细胞表面抗原表达的影响

背景：课题组已建立胎儿骨髓基质细胞联合细胞因子的造血细胞体外培养体系,该培养体系能否有效扩增各个发育阶段的造血细胞有待验证。目的：观察骨髓基质细胞联合细胞因子培养体系对脐血单个核细胞表面抗原CD133、CD34表达的影响。方法：将从脐血标本中分离出来的单个核细胞接种于无血清培养体系,实验分为3组：①F组：干细胞因子＋Flt3配体＋促血小板生成素＋单个核细胞。②S组：基质细胞＋单个核细胞。③SF组：基质细胞＋干细胞因子＋Flt3配体＋促血小板生成素＋单个核细胞。在第0,6,10,14天检测有核细胞总数、CD133^＋、CD34^＋、CD133^＋CD34^＋细胞数以及集落形成单位数。结果与结论：SF组有核细胞总数在各个检测时间点均比其他两组高;除了第14天外,第6、10天两个时间点SF组中CD133^＋、CD34^＋、CD133^＋CD34^＋细胞及集落形成单位数均高于其他组;含骨髓基质细胞的S组和SF组中CD133＋细胞/有核细胞、CD34＋细胞/有核细胞、CD133＋CD34＋细胞/有核细胞的比例保持在较高的水平。结果说明骨髓基质细胞联合细胞因子能有效的扩增脐血单个核细胞及其中的CD133^＋、CD34^＋、CD133^＋CD34^＋细胞,基质细胞对维持造血干细胞的原始性具有重要的作用。     

Increased numbers of total nucleated and CD34+ cells in blood group O cord blood: an analysis of neonatal innate factors in the Korean population

BACKGROUND: We analyzed neonatal factors that could affect hematopoietic variables of cord blood (CB) donated from Korean neonates. STUDY DESIGN AND METHODS: The numbers of total nucleated cells (TNCs), CD34+ cells, and CD34+ cells/TNCs of CB in neonates were compared according to sex, gestational age, birth weight, birth weight centile for gestational age, and ABO blood group. RESULTS: With 11,098 CB units analyzed, blood group O CB showed an increased number of TNCs, CD34+ cells, and CD34+ cells/TNCs compared with other blood groups. Although TNC counts were lower in males, no difference in the number of CD34+ cells was demonstrated because the number of CD34+ cells/TNCs was higher in males. An increase in the gestational age resulted in an increase in the number of TNCs and decreases in the number of CD34+ cells and CD34+ cells/TNCs. The numbers of TNCs, CD34+ cells, and CD34+ cells/TNCs increased according to increased birth weight centile as well as birth weight. CONCLUSION: CB with blood group O has unique hematologic variables in this large‐scale analysis of Korean neonates, although the impact on the storage policies of CB banks or the clinical outcome of transplantation remains to be determined.     

供者特征对脐带血造血功能的影响

目的 分析可能影响脐带血造血功能的供者特征.方法 对广州脐带血库1998年6月至2008年12月保存的4 358份脐带血的供者特征(包括母亲年龄、分娩方式、妊娠期、婴儿体重、婴儿性别)和脐带血采集量及造血功能的指标(包括总有核细胞数、CD34+细胞、干细胞集落等)进行相关性分析.结果 婴儿体重、分娩方式及婴儿性别是影响脐带血采集量、总有核细胞数、CD34+细胞数、CFUs及CFU-GM的主要因素.随着婴儿体重的增加,脐带血采集量、总有核细胞数、CD34+细胞数、CFUs、CFU-GM均呈上升趋势(P=0.000).阴道分娩时脐带血的采集量虽然低于刮宫产(P=0.000),但总有核细胞数、CD34+细胞数、CFUs,CFU-GM均高于剖宫产(P=0.000).女婴脐带血中总有核细胞数含量高于男婴(P=0.000),但脐带血采集量(P=0.000)、CD34+细胞数(P=0.002)均低于男婴.随着妊娠期的延长,脐带血中总有核细胞数增加(P=0.000),但CD34+细胞数减少(P=0.001).结论 某些脐带血供者特征对脐带血造血功能指标有积极影响.     

气相液氮罐内温度差异对脐带血造血干细胞保存质量的影响

目的 研究气相液氮罐内因位置不同而导致的温度差异对脐带血造血干细胞保存质量的影响.方法 选取位于液氮中的脐血干细胞20份作为对照组A组,保存在气相液氮罐内最低温度保存处的20份样本为实验B组,最高温度保存处的20组样品为实验C组.各组细胞解冻复苏后进行有核细胞计数、有核细胞活性、CD34+％、CFU-GM等检测,进行单...     

脐血造血干/祖细胞免疫表型的流式细胞术双标法分析及其意义

目的比较脐血和骨髓中造血干/祖细胞(HSPC)的免疫表型差异.方法使用流式细胞术(FCM)双标法对38份脐血及10份骨髓HSPC进行免疫表型分析.结果①脐血有核细胞中CD34+细胞所占比例与骨髓中相近,约为0.5%;②脐血CD34+细胞中CD34+CD38-[(17.C4±5.37)%]、CD34+HLA-DR-[(32.65±10.71)%]及CD34+H-CAM+(CD44+)[(77.84±7.69)%]亚群含量均高于骨髓[含量分别为(8.26±3.19)%、(14.05±1.67)%和(70.02±6.40)%],CD34+CD13+、CD34+CD19+亚群比例低于骨髓.结论脐血与骨髓CD34+细胞比例相近,但前者较原始的干细胞含量更高,故脐血是极具潜力的HSPC来源;而脐血CD34+细胞中髓系及淋系祖细胞含量低于骨髓,可能是脐血移植后造血及免疫重建缓慢的原因之一.     

Increased Nucleated RBCs in Cord Blood: Not an Exclusion Criterion but a Quality Indicator for Hematopoietic Progenitor Cell Transplantation

Increased nucleated red blood cell (NRBC) counts have been reported to be associated with adverse fetal outcomes, and cord blood units (CBUs) with increased NRBC counts require a 2^nd questionnaire to determine their suitability for transplantation. However, a recent study demonstrated a positive correlation of NRBCs with CD34⁺ cells and total nucleated cells (TNCs). We evaluated the association between the NRBC count and hematopoietic progenitor cell (HPC) content (TNC and CD34⁺ cell counts) in Korean full-term newborn CBUs. In addition, we assessed whether an increased NRBC count is associated with newborn health problems that impair CBU safety. Among the 32,876 units processed from May 2006 to December 2018, a total of 23,385 CBUs with a TNC count ≥ 7 × 10⁸ and reliable perinatal information were analyzed to assess the association of the NRBC count with CBU parameters, and the newborns associated with 457 CBUs that required the 2^nd questionnaire due to an increased NRBC (≥ 15 NRBCs/100 WBCs) were assessed at one year for health problems that threatened CBU safety. The majority of the CBUs that required the 2^nd questionnaire due to an increased NRBC count (96.9%) were determined to be suitable for transplantation. Those with an increased NRBC count showed significantly higher CD34⁺ cell and TNC counts and a higher rate of transplantation (P < 0.001, < 0.001 and 0.025, respectively). NRBCs showed a significant positive correlation with TNCs and CD34⁺ cells and a significant negative correlation with birth weight (all P < 0.001; adjusted r = 0.185, 0.369 and - 0.029, respectively). In the multiple linear regression analysis, NRBCs showed independent and positive correlations with TNCs and CD34⁺ cells after adjustments for birth weight and gestational age (all P < 0.001; β = 0.182, adjusted R² = 0.053 and β = 0.367, adjusted R² = 0.418). An increased NRBC count in full-term normal delivery is a surrogate marker of HPCs in CBUs rather than an exclusion criterion for CBU safety. Moreover, providing the NRBC count together with the NRBC-corrected TNC count will be useful for clinicians to select CBUs for transplantation.     

Cord Blood Banking and Transplantation in China: A Ten Years Experience of a Single Public Bank

Background

Umbilical cord blood (UCB) has successfully used for transplantation to treat hematologic malignancies and genetic diseases. Herein, we describe the experience generated in a single public UCB bank at Zhejiang Province in China.

Methods

Good manufacturing practice and standard operating procedures were used to address donor selection as well as UCB collection, processing, and cryopreservation. Total nucleated cells (TNCs), cellular viability, CD34+ cells, and colony-forming units were determined, and infectious diseases screening test, sterility test, and HLA typing for UCB units were done.

Results

Only 18.51% of all collected UCB units met storage criteria, and 7,056 UCB units were cryopreserved in 10 years. The volume of UCB units was 95.0 ± 22.0 ml. The number of TNCs before and after processing was 13.32 ± 3.63 × 10⁸ and 10.63 ± 2.80 × 10⁸, respectively, and the recovery rate was 80.71 ± 11.26%. 0.4344 ± 0.1874% of the TNCs were CD34+ cells. The CFU-GM was 32.1 ± 28.0 colonies per 1 × 10⁵ nucleated cells. Based mainly on HLA and nucleated cell content, 26 UCB units were released for transplantation.

Conclusions

A public UCB bank was successfully established in China; collection and processing of UCB units should be optimized in order to gain maximum volume and cell count.     

Competitive repopulation assay of two gene-marked cord blood units in NOD/SCID/gammac(null) mice.

In multiunit cord blood transplantation, hematopoietic stem cells from each unrelated cord blood (UCB) unit competitively reconstitute the hematopoietic system in a recipient. To evaluate the fate of the progeny of each UCB unit and to determine the effects of graft-versus-graft reaction, we established a novel competitive repopulation assay using NOD/SCID/gammac(null) mice in which human T lymphocytes develop from CD34+ cells. CD34+ cells from each UCB unit were labeled with recombinant lentivirus vectors carrying genes encoding either enhanced green fluorescent protein (EGFP) or enhanced yellow fluorescent protein (EYFP). Hematopoietic chimerism composed of both EGFP+ and EYFP+ cells was stably maintained up to 6 months after transplantation with purified CD34+ cells; the ratio of EGFP+ to EYFP+ cells in peripheral blood and bone marrow posttransplantation was equivalent to the ratio of these cells at transplantation. However, when mononuclear cells from two UCB units were cotransplanted with CD34+ cells, engraftment was highly competitive, with cells from only one or the other of the two UCB units surviving. Further subfractionations of mononuclear cells indicate that the skewed chimerism that is often observed in clinical multiunit cord blood transplantation may be mediated by the cooperation of both CD4+ and CD8+ T cells. The assay established here will be a useful tool for analyzing hematopoietic reconstitution in clinical multiunit cord blood transplantation.     

Ex vivo expansion of CD34+ umbilical cord blood cells in a defined serum-free medium (QBSF-60) with early effect cytokines

To investigate the clinically applicable conditions that support substantial expansion of both primitive and more mature hematopoietic cells of umbilical cord blood (UCB) for transplantation in adults, enriched CD34+ cells from 8 fresh UCB samples and 4 expanded UCB products were cultured in defined serum-free medium (QBSF-60) in the presence of a cytokine combination of SCF, Flt-3-ligand (FL), thrombopoietin (TPO), IL-3 for up to 2 weeks. Fresh medium with cytokines was supplemented or exchanged at day 4, day 7, and day 10. The proliferative response was assessed at day 7, day 10, and day 14 by evaluating the following parameters: nucleated cell (NC), clonogenic progenitors (colony-forming unit-granulocyte-macrophage [CFU-GM], burst-forming unit-erythrocyte [BFU-E], CFU-GEMM, and high-proliferative potential colony-forming cell [HPP-CFC]), immunophenotypes (CD34+ cells and CD34+ subpopulations), and LTCIC. Simultaneously numerical expansion of various stem/progenitor cells, including primitive CD34+CD38-HLA-DR- subpopulation and LTCIC, CD34+ cells, and clonogenic progenitors to mature nucleated cells, were continuously observed during the culture. An average 103.32 +/- 71.37 x 10(6) CD34+ cells (range 10.12 x 10(6)-317.9 x 10(6)) could be obtained from initial 1.72 +/- 1.13 x 10(6) UCB CD34+ cells after 10-14 days cultured under the described conditions. Sufficient CD34+ cells (>50.0 x 10(6)) for transplantation in adults would be available in all but one UCB collections after 10-14 days expansion. The expanded CD34+ cells sustained most of the in vitro characteristics of initial unmanipulated CD34+ cells, including clonogenic efficiency (of both primitive and committed progenitors), the proportion of CD34+CD38-HLA-DR- subpopulation, and the expansion potential. Initial addition of IL-3 to the cocktail of SCF + FL + TPO had positive effects on the expansion of both primitive and, especially, the more mature hematopoietic cells. It accelerated the expansion speed and shortened the optimal culture time from 14 days to 10 days. These results indicated that our proposed short-term culture system, consisting of QBSF-60 serum-free medium with a simple early acting cytokine combination of SCF + FL + TPO, could substantially support simultaneous expansion of various stem/progenitor cell populations involved in the different phases of engraftment. It would be a clinically applicable protocol for ex vivo expansion of CD34+ UCB cells.     

Factors affecting banking quality of umbilical cord blood for transplantation

BACKGROUND: The most important objective for cord blood banks is to store cord blood units of high quality, which is determined by total nucleated cells (TNCs) and CD34+ cells. Determining the factors affecting the stored life‐saving cells would be beneficial to the field. STUDY DESIGN AND METHODS: A total of 4930 cord blood units were collected between January 2007 and October 2009 and processed using a double extraction technique to sediment red blood cells with variable centrifugation time determined by the formula CT = KL – M, where CT is centrifuge time, K is 7.7227, M is 29.742, and L is ln (volume of cord blood with anticoagulant). The recovery rate of TNCs and other relevant factors affecting banking quality were analyzed. RESULTS: The mean recovery rate of TNCs was 97.7 ± 2.5% with 0.04% (2/4930) units below 80% and 10.8% (532/4930) units below 95%. The TNCs per unit was affected by gestation duration (p < 0.01), sex of infant (p < 0.01), mode of delivery (p < 0.01), collection method (p < 0.01), and ethnicity (p < 0.001). The number of postprocessing CD34+ cells was affected only by sex of the infant (p < 0.05). The viability of nucleated cells after processing was 94.8 ± 4.8% and was affected by the number of hours between collection and processing (p < 0.01). In contrast, the viability of CD34+ cells was 99.5 ± 1.0% (n = 30) when samples with low viability of TNCs were assessed. The results did not reveal a significant correlation (r = 0.07, p = 0.38). CONCLUSION: The double extraction technique provides a high and consistent recovery of TNCs, which ensures that more life‐saving cells will be banked for transplants.     

TRANSPLANTATION AND CELLULAR ENGINEERING: Association of stress‐related perinatal factors and cord blood unit hematopoietic progenitors is dependent on delivery mode

BACKGROUND: Perinatal characteristics, variably utilized in cord blood (CB) selection for banking, affect CB hematopoietic progenitor cells (HPCs). The association between perinatal stress factors and CB unit HPCs was evaluated. STUDY DESIGN AND METHODS: Umbilical arterial (UA) pH, absolute and relative birth weight (BW) and placental weight (PW), and PW/BW ratio of 167 healthy, full‐term infants were compared with CB unit prefreeze total nucleated cells (TNCs), total CD34+ (TCD34+) cells, and total colony‐forming unit (CFU‐TOT) number. Cesarean section (C‐section, n = 104) and vaginal delivery subgroups were also analyzed. RESULTS: UA pH (median, 7.28; range, 7.04‐7.40) correlated with CB unit CFU‐TOT number (n = 166; r = ?0.32, p < 0.0001), TCD34+ cells (r = ?0.31, p < 0.0001), and TNCs (r = ?0.29, p = 0.0002). Similarly, BW, PW, and PW/BW ratio correlated with HPCs. In multiple linear regression analysis, CFU‐TOT number was predicted by collected CB TNCs and UA pH in vaginal deliveries (R² = 0.53), in contrast with TNCs, PW, and BW in C‐sections (R² = 0.37). TCD34+ cells were predicted by adding UA pH (vaginal deliveries, R² = 0.75) or PW (C‐sections, R² = 0.36) to collected CB TNCs. CONCLUSIONS: Stress‐related perinatal factors, particularly UA pH, are associated with CB unit HPCs and may improve unit selection. Multiple linear regression models may prove useful for predicting HPCs. Mode of delivery affects model choice; UA pH has a strong effect on HPCs in vaginal deliveries.     

Viability does not necessarily reflect the hematopoietic progenitor cell potency of a cord blood unit: results of an interlaboratory exercise

BACKGROUND: Clinical transplant outcome with umbilical cord blood (UCB) as source of hematopoietic progenitor cells (HPCs) is, among other factors, determined by the total number of viable nucleated cells and/or CD34+ cells in the unit. Quantitative and qualitative losses by processing and cryopreservation and by thawing and washing before transfusion may occur, however. Another reason for a discrepancy between the number of cells in the unit released by the cord blood bank and found in the transplant center may be technical differences in cell counting methods between the two sites. STUDY DESIGN AND METHODS: With the collaborative group for Biomedical Excellence for Safer Transfusion (BEST), an interlaboratory exercise was conducted among nine sites for thawed UCB variables: total nucleated cells, CD34+ cells, viability, and HPC cultures. Three frozen UCB samples were shipped, with instructions for thawing, counting, and HPC plating. RESULTS: Unexpectedly samples arrived at all nine receiving centers without detectable hematopoietic progenitor colony-forming cells. Nevertheless, wide interlaboratory ranges for viability were obtained. The proportion of viable cells was found higher with manual methods, but all viability assays used in the study overestimated functional progenitor cells. CONCLUSIONS: The results underscore the complexity of evaluation of frozen-thawed cord blood cells and the need for standardization of assessment.     

Developmental variation in stem-cell markers from human fetal liver and umbilical cord blood leukocytes

Fetal tissues containing haematopoietic stem cells (HSC) are of potential value for allogeneic transplantation and gene therapy. Flow cytometry was used to investigate CD34+ cells from human fetal livers and umbilical cord (placental) blood (UCB). CD34+ cells, expressed as a proportion of CD45-positive leukocytes, were much more abundant in fetal livers (mean 38%) than in UCB (mean 0.3%), but fetal liver cells had lower proportions of CD34+HLA-DR+ and CD34+ CD38+ subsets. In fetal liver, there was a strong and highly significant inverse correlation between CD34+ cells (as a proportion of total leukocytes) and gestational age; no such relationship was found for subsets of CD34+ cells coexpressing CD38 or CDw90 (Thy-1), but CD34+HLA-DR+ cells were less abundant in first- compared to second-trimester livers. In UCB, a trend towards decreasing CD34+ cells (as a proportion of total leukocytes) with increasing gestational age in late pregnancy was also observed. The composition of fetal leukocytes changes during development, and therefore the timing of fetal HSC harvesting could be of relevance to transplantation outcome.     

Influence of mode of birth and collection on WBC yields of umbilical cord blood units

BACKGROUND: The aim of this study was to determine the influence of mode of birth and umbilical cord blood (CB) collection before (in utero) or after delivery of the placenta (ex utero) on total number of WBCs and CD34+ cells in CB units. STUDY DESIGN AND METHODS: Consecutively donated, banked CB units were assessed for net volume, WBC concentration, total number of WBCs, proportion of CD34+ cells, and total number of CD34+ cells. These parameters were then correlated with the mode of birth and the mode of CB collection relative to the delivery of the placenta. RESULTS: A significantly higher CB volume was seen following cesarean section (n = 61) than following vaginal delivery (n = 157; median volume, 76 vs. 63 mL, respectively; p < 0.0001). In contrast, CB from vaginal delivery had a significantly higher WBC concentration compared with CB from cesarean section (medians, 17.1 x 10(9) and 13.6 x 10(9) WBCs/L, respectively; p < 0.0001). The mode of birth did not influence the proportion of CD34+ cells. A correlation was demonstrated between the total number of CD34+ cells and the total number of WBCs. As a consequence of the opposing effects on volume and WBC counts by cesarean section and vaginal delivery, there were no significant differences in the total number of WBCs or CD34+ cells for the CB units with mode of delivery in this study. No significant differences were found in CB with mode of CB collection (in utero [n = 58] or ex utero [n = 99]) following vaginal delivery. CONCLUSIONS: The mode of birth influences the CB WBC concentration and volume collected and should be taken into consideration for establishing any acceptance limits for CB units to be banked. There were no differences in CB with in utero or ex utero collections.     

Ten-year quality control of a semiautomated procedure of cord blood unit volume reduction

BACKGROUND: Volume reduction of cord blood units decreases the cost of cryogenic storage. This study reports the analysis of a 10-year quality control program of a semiautomated cord blood volume reduction procedure.
STUDY DESIGN AND METHODS: Cord blood was collected in a plastic bag containing 29 mL citrate-phosphate-dextrose, centrifuged at 2124 ×  g for 12 minutes, and processed with a semiautomated device. The procedure was aimed at removing most red blood cells and plasma and concentrating hematopoietic progenitors in the buffy coat (BC), thus reducing the unit volume and saving cryogenic space. Finally, the BC was cryopreserved with an equal volume of 20 percent dimethyl sulfoxide. Total nucleated cells (TNCs) were counted before and after processing in the 4311 units banked from 1998 through 2007, whereas CD34+ cells and colony-forming units–granulocyte-macrophage (CFU-GM) were counted in 420 random units from 2001 through 2007.
RESULTS: Mean postvolume reduction annual recoveries of TNCs, CD34+ cells, and CFU-GM ranged from 82.8 ± 12.3 (standard deviation) to 91.4 ± 6.4 percent, from 87.8 ± 14.1 to 95.2 ± 23.8 percent, and from 101.5 ± 51.4 to 117.8 ± 59.5 percent, respectively. Very strong correlations were found (r > 0.87) between postprocessing versus preprocessing TNCs, CD34+ cells, and CFU-GM; a moderate correlation between initial TNC count and unit's volume (r = 0.51); and no correlation between TNC percentage of recovery in the BC and initial unit's volume. The latter data indicate that most TNCs concentrate in the BC.
CONCLUSIONS: The semiautomated procedure of cord blood unit volume reduction used in this study provides high and stable cellular recoveries during several years of routine cord blood banking.     

人胎盘组织来源造血干/祖细胞及其特性

背景:近年来的研究表明,除已知的人骨髓、外周血和脐带血中存在造血干/祖细胞外,人胎盘组织中也有造血干/祖细胞存在.目前为止,还缺乏对人胎盘组织造血干/祖细胞的增殖分化特性及人胎盘组织淋巴细胞亚群组成和免疫原性等的深入研究.目的:探究人胎盘组织是否含有比脐带血更丰富的造血干/祖细胞,并对其造血祖细胞系增殖分化能力进行检测,同时对人胎盘组织淋巴细胞亚群组成及表型特征进行分析.设计、时间及地点:开放性实验,于2004-01/2006-12在贵州省细胞工程重点实验室完成.材料:经产妇知情同意,无菌采集遵义医学院附属医院产科健康足月分娩新生儿胎盘和脐带血共12份.淋巴细胞亚群检测试剂盒,CD34绝对计数试剂盒(Becton Dickinson公司):CD34磁珠分选试剂盒,FITC标记的CD38单克隆抗体,抗FITC磁珠和MS/LS免疫磁式细胞分选柱(Miltenyi Biotec).方法:脐带血与RPMI-1640培养基(含体积分数为0.1的胎牛血清)按1:1的比例混合,采用Ficoll-Histopaque分离液离心30min,吸取界面层细胞,PBS洗涤一次,获得脐带血单个核细胞.采用机械法加0.25g/L胶原酶消化制备胎盘组织单个细胞悬液,之后同脐带血单个核细胞分离步骤分离胎盘单个核细胞.流式细胞仪检测胎盘单个核细胞中CD34 CD38-, CD34 CD38 造血干/祖细胞(HSPCs)和淋巴细胞亚群的组成比例.免疫磁珠分选法分选人胎盘CD34 CD38-,CD34 D38 造血干/祖细胞,并分别进行粒细胞-单核细胞集落生成单位、红细胞爆裂型集落生成单位、混合集落生成单位系集落形成培养,以评价其造血祖细胞系增殖分化能力.实验全程用脐带血作平行比较分析.主要观察指标:胎盘和脐带血CD34 造血干/祖细胞组成百分率、祖细胞系集落形成能力、淋巴细胞亚群表型及组成特点.结果:[1]胎盘CD34 造血干/祖细胞百分率是脐带血的8.8倍,差异有显著性意义(P<0.01).[2]胎盘中的淋巴细胞总数、T细胞(CD3 CD2 )、B细胞(CD19 )、Th(CD3 CD4 )细胞及Th/Ts比值均明显低于脐带血,而CD8 CD28-T抑制细胞则明显高于脐带血,差异有显著性意义(P<0.01).[3]胎盘CD34 CD38 造血干/祖细胞亚群培养形成的粒细胞-单核细胞集落生成单位、红细胞爆裂型集落生成单位、混合集落生成单位集落数明显高于CD34 CD38-造血干/祖细胞亚群(P<0.01);胎盘与脐带血造血干/祖细胞中相同表型细胞亚群形成的各系集落数比较,差异无显著性意义(P0.05).结论:人胎盘组织富含CD34 造血干/祖细胞,其CD34 CD38 、CD34 CD38-两个造血干/祖细胞亚群均具有增殖分化为粒细胞-单核细胞集落生成单位、红细胞爆裂型集落生成单位、混合集落生成单位的能力,并且人胎盘组织具有淋巴细胞亚群低比例和抑制性T细胞高比例的特点,使其有望成为造血干/祖细胞移植的新来源.     

脐带血重建造血潜能的母体及新生儿因素分析

脐带血作为一种备选的移植用造血干细胞,能否成功植入与输入受者体内的总有核细胞（total nucleated cells,TNC）数、CD34＋细胞数及粒-巨噬细胞集落形成单位（colony-forming unit-granulocyte-macrophage,CFU-GM）有关。本研究探讨影响脐带血造血潜能的母体及新生儿因素。按照广州脐血库标准化操作常规（SOP）,对脐带血样本进行筛选、处理、检测及冷冻,回顾性分析已保存的4615份脐带血样本的造血细胞参数及其与母体及新生儿特征的相关性。结果表明：脐带血采集量（Mean±SD：95.23±22.42ml;Median：91.85ml）与处理前TNC[Mean±SD：（1.34±0.49）×109;Median：1.25×109]及处理后TNC[Mean±SD：（1.21±0.42）×109;Median：1.14×109]、CD34＋细胞数[Mean±SD：（5.14±4.55）×106;Median：4.08×106]、CFU-GM[Mean±SD：（9.72±8.66）×105;Median：7.53×105]三者均显著相关（p〈0.001）。在供者因素中,只有婴儿出生体重与脐带血采集量及造血细胞参数均呈显著正相关（p〈0.001）,较大婴儿的脐带血在采集量、TNC、CD34＋细胞数及CFU-GM方面均呈现优势（p〈0.001）。母亲年龄与上述各项参数均无显著相关。孕龄与处理前/后TNC正相关（p〈0.001;p〈0.001）,与CD34＋细胞数呈负相关（p=0.04）,而与采集量及CFU-GM均无显著相关。剖宫产时采集的脐带血量虽然高于阴道分娩（Mean±SD：97.05ml±22.23mlvs.92.53ml±22.43ml;Median：94.08mlvs.88.82ml;p〈0.001）,但各细胞参数均低于阴道分娩（p〈0.001）。男婴脐带血的采集量和CD34＋细胞数高于女婴（Mean±SD：96.41ml±22.31mlvs.93.95ml±22.47ml;Median：93.27mlvs.90.14ml;p〈0.001）;[Mean±SD：（5.28±5.04）×106vs.（5.00±3.94）×106;Median：4.18×106vs.3.94×106;p=0.042]、但处理前TNC及处理后TNC均低于女婴[Mean±SD：（1.31±0.50）×109vs.（1.37±0.47）×109;Median：1.22×109vs.1.28×109;p〈0.001];[Mean±SD：（1.18±0.42）×109vs.（1.24±0.41）×109;Median：1.10×109vs.1.17×109;p〈0.001],二者CFU-GM的差异无统计学意义。结论：本研究数据有助于优化脐带血供者筛选及提高脐血库资源利用率。脐血库应侧重选择体重较大、阴道分娩的新生儿供者,优先处理采集量大、TNC高的脐带血样本。     

治疗用脐血干细胞的制备及初步临床应用

目的制备满足临床干细胞治疗需要的脐带血干细胞制剂,观察脐血干细胞局部移植治疗肝硬化失代偿和股骨头坏死的初步临床疗效。方法建立标准化操作规程(SOP),进行脐带血的采集、分离和检测,制备脐带血干细胞制剂进行局部移植。选择进行局部移植干细胞制剂治疗的相关疾病患者共11例,其中肝硬化9例、股骨头缺血坏死2例;年龄30—65岁,平均51岁,男9例,女2例。结果制备的脐带血干细胞制剂有核细胞计数达(3.8±1.73)×109个,均达到治疗剂量,其中CD34+细胞比率为(1.93±0.54)%,CD105+细胞比率为(97.9±4.0)%。肝硬化失代偿期患者治疗后白蛋白水平逐步升高,1个月后与治疗前相比有明显升高(P<0.05)。肝硬化和股骨头缺血坏死患者经治疗后临床症状均有好转。结论脐带血干细胞移植可为临床多种疾病的有效治疗提供一种新手段。     

胎盘组织及血液中含有丰富的造血干/祖细胞

大量的临床移植表明人脐血 (UCB)可以在造血干细胞移植的儿童中得到造血重建 ,可是在成人中脐血移植 (UCBT)效果并不理想 ,这主要是脐血中所含的细胞数及造血干 /祖细胞数有限 ,而不适宜体重较大的成人。本研究在收集脐血的同时 ,也分别收集胎盘血 (UPB)及胎盘组织 (UPT)中的细胞 ,检测有核细胞数 ,CD34(造血干 /祖细胞的表明标记 )阳性细胞 ,粒单细胞集落 (CFU GM)。结果发现 :来自于胎盘血和胎盘组织中的有核细胞数是脐血细胞的 3- 4倍 ;脐血、胎盘血及胎盘组织细胞的有核细胞数分别为 (8.3± 1.0 4 )× 10 8,(16 .33± 5 .5 4 )× 10 8和(8.0 1± 2 .6 4 )× 10 8;CD34+ 细胞分别为 (0 .77± 0 .0 1)× 10 6,(1.2 5± 0 .5 5 )× 10 6和 (4.2 1± 1.90 )× 10 6;在细胞的长期培养中 ,UPB细胞和UPT细胞能生存更长时间 ,而且这些细胞更易贴壁形成纤维样的细胞 ;冰冻前后UPT细胞活性及回收率无明显差异 ,表明胎盘细胞和脐血细胞一样适合于长期储存 ;而且 ,在UPB和UPT中含有更高比例的T淋巴细胞抑制细胞群 ,可能意味着UPB和UPT具有更强的免疫抑制功能。结论指出 ,有必要建立含有胎盘和脐血细胞的血库 ,以便为大剂量放疗及化疗后的儿童及成年病人进行造血干细胞移植 ,为重建造血创造条件