Maternal, neonatal and collection factors influencing the haematopoietic content of cord blood units

OUP accepted manuscript

Cord blood (CB) collected at birth has become a valuable stem cell source for hematopoietic stem cell transplantation (HSCT). However, the collection of umbilical cord blood always bears a risk of microbiological contamination, both in vaginal birth and in cesarean section. A total of 10 054 umbilical cord stem cell samples were successfully cryopreserved between 2010 and 2020, of which 783 (8%) samples were tested positive for bacterial contamination. Umbilical CB with a volume of less than 60 mL showed a bacterial contamination rate of 12%, and above 60 mL volume a rate of 6% was found demonstrating an inverse relationship between sample volume and contamination rate (correlation coefficient r = −0.9). The contamination rate was associated with the mode of delivery and showed a significantly higher contamination rate of 9.7% when compared with cesarean deliveries (1.4%). The 10-year period consistently shows an average contamination rate between 4% and 6% per year. It is conceivable that the inverse relationship between volume and contamination rate might be related to thinner veins although no scientific evidence has been provided so far. The lower contamination rate in cesarean sections appears to be related to the sterile operating setting. Overall, the rate of bacterial contamination varies and depends on the type of birth, the way of delivery, and probably the experience of the staff.

Prenatal selection of cord blood donors according to the estimated fetal weight percentile and new approaches; results of a prospective cohort study

BACKGROUND

Umbilical cord blood (UCB) donation is becoming inefficient and we recently proposed the estimated fetal weight percentile (EFWp) ≥60th as a predictor for a prenatal selection of donors. The aim of this study is to prospectively validate this and to identify new potential prenatal predictive parameters.

STUDY DESIGN AND METHODS

Prospective cohort study of low-risk pregnancies undergoing third trimester ultrasound, whose UCB was collected at delivery (2016-2018) and compared with a historical cohort (2013-2016, N = 869). Several ultrasound parameters (EFWp, amniotic fluid, Doppler evaluation, placental thickness) were assessed ultrasound and perinatal data were collected. The association with standard of high quality of UCB was assessed by logistic regression analysis.

RESULTS

Among 297 cases, 161 (54%) were selected according to the EFWp ≥60th for UCB units' collection. Cellular criteria for banking was achieved in 27 cases (16.8%), with an average increase of 1.7 times compared to the historical cohort (9.8%, P = .009). Selecting donors according to the 60th EFWp resulted in a higher probability of collecting clinical suitable UCB (P = .025). Among prenatal and perinatal parameters, EFWp, amniotic fluid, umbilical vein (UV) velocity, newborn weight and percentile and placental weight were significantly associated with a higher cellular content. At logistic regression analysis, significant contributors of UCB collection, were EFWp at 37-38 weeks ultrasound (OR 1.04; 95% CI: 1-1.08; P = .042) and UV velocity (OR 1.14; 95% CI: 1-1.29; P = .037).

CONCLUSION

The evaluation of the EFWp equal or above 60 and the increased UV velocity can result in higher efficiency of public UCB donation programs.

Factors associated with blood cord unit bankability: an analysis of a 15-year-long case series

Blood banking is a long and complex process requiring an accurate screening of potential donors and high-quality control systems. Previous studies in literature investigated factors potentially determining a higher cell levels with the aim of optimizing donors' selection and improving banking process. This study aims to identify factors associated with the concentration of stem cells in umbilical cord blood, so increasing the probability of bankability, focusing on the possible implications in terms of obstetric and resources management. This is a retrospective study conducted in the Obstetric Units of two Italian Hospitals in Montebelluna and Castelfranco Veneto. Study has been conducted on cord blood units banked between 1999 and 2015. Data on medical histories and clinical characteristics of mother and baby have been retrieved via a retrospective examination of medical records. A total of 869 cord blood units were studied. At multivariable analysis, in agreement with literature, birthweight and placental weight have been found to be associated with higher concentration of total nucleated cells. As additional factor, amount of fluid infused was associated with cord blood units' count. This study is the first one to clearly identify the role of fluid infusion on cord blood units' counts in addition to placental weight and delivery. Some non-modifiable features can help in predicting bankability from pre-natal aspects to factors more related with obstetric management is suggested.

Umbilical cord blood quality and quantity: Collection up to transplantation

Umbilical cord blood (UCB) is an attractive source of hematopoietic stem cells for transplantation in some blood disorders. One of the major factors that influence on transplantation fate is cord blood (CB) cell count, in addition to human leukocyte antigen similarity and CD34+ cell number. Here, we review the factors that could effect on quality and quantity of CBUs. Relevant English-language literatures were searched and retrieved from PubMed using the terms: CB, quality, collection, and transplantation. The numbers of total nucleated cells (TNCs) and CD34+ cells are good indicators of CB quality because they have been associated with engraftment; thereby, whatever the TNCs in a CB unit (CBU) are higher, more likely they led to successful engraftment. Many factors influence the quantity and quality of UCB units that collect after delivery. Some parameters are not in our hands, such as maternal and infant factors, and hence, we cannot change these. However, some other factors are in our authority, such as mode of collection, type and amount of anticoagulant, and time and temperature during collection to postthaw CBUs and freeze-and-thaw procedures. By optimizing the CB collection, we can improve the quantity and quality of UCB for storage and increase the likelihood of its use for transplantation.

Maternal lipid profiles vs. fetal growth and cord blood hematopoietic cells: weak associations in healthy Korean newborn-mother pairs

BACKGROUND

We aimed to define the maternal lipid profiles that are associated with fetal growth and cord blood (CB) hematopoietic cells in healthy Korean full-term newborns.

METHODS

A total of 608 fetal-maternal pairs were enrolled; mothers voluntarily donated CB with informed consent. We analyzed birth weight (BW) as a marker of fetal growth, and we examined total nucleated cells (TNCs) and CD34⁺ cell concentrations of CB as markers of hematopoietic progenitor cell (HPC) contents. We also analyzed maternal lipid levels and investigated their associations with BW, TNCs and CD34⁺ cells.

RESULTS

Maternal triglycerides (TG) showed a significant positive association with BW and CD34⁺ cells, and low-density lipoprotein (LDL) showed a negative association with BW and CD34⁺ cells. Though not statistically significant, higher maternal TG showed a tendency toward higher levels of TNCs. Maternal TG was independently and positively correlated with BW, and maternal LDL was independently and negatively correlated with CD34⁺ cells, although the impacts were not as strong, as indicated by small beta coefficients (0.157 and -0.226, respectively).

CONCLUSIONS

We were able to investigate the association of maternal lipid profiles with BW and CB HPCs in healthy Korean newborn-mother pairs in this study. Both BW and the HPC contents showed independent associations with maternal TG and LDL, although the effect of maternal lipid levels on fetal growth and HPCs was not strong in the normal healthy population. Because maternal lipid levels were assessed once in the healthy fetal-maternal pairs, we could not investigate those associations across pregnancy.

Estimated fetal weight percentile as a tool to predict collection of cord blood units with higher cellular content: implications for prenatal selection of cord blood donors

BACKGROUND

The need for high-cellular-content cord blood units (CBUs) for allogenic transplantation is evident to improve clinical outcomes. In our environment and with current donation programs, very few collected units meet suggested clinical thresholds, making collection programs highly inefficient. To increase the clinical conversion rate, we have assessed factors influencing the cellular content of the cord blood collection and established the estimated fetal weight percentile (EFWp) as a tool to predict which deliveries will obtain higher cellular counts.

STUDY DESIGN AND METHODS

We conducted a retrospective analysis of 11,349 collected CBUs. An analysis of diagnostic efficiency (receiver operating characteristic [ROC] curve) was performed to establish the cutoffs of several obstetric and perinatal variables from which we would obtain more than 1500 × 106 total nucleated cells and 4 × 106 CD34 cells. We then calculated the optimal EFWp cutoff to increase efficiency.

RESULTS

In the univariate analysis, factors positively and significantly associated were a greater neonatal and placental weight and longer weeks of gestation. In the multivariate analysis only neonatal and placental weight remain significant (p < 0.001). The ROC curve analysis showed that the optimal EFWp cutoff is 60, which has the maximum area under the curve. Applying this, donations meeting clinical cellular numbers will increase more than 30% with respect to not using any threshold.

CONCLUSION

The EFWp predicts the quality of the collected CBUs and can be used to make a prenatal selection of the donors, therefore increasing the efficiency of umbilical cord blood collection programs.

Associated factors of umbilical cord blood collection quality

After 30 years of hematopoietic stem cell use for various indications, umbilical cord blood is considered as an established source of cells with marrow and postmobilization peripheral blood. The limited number of cells still remains a problematic element restricting their use, especially in adults who require to be grafted with a higher cell number. Improving the quality of harvested cord blood, at least in terms of volume and amount of cells, is essential to decrease the number of discarded units. In this review, we examine several variables related to parturient, pregnancy, labor, delivery, collection, the newborn, umbilical cord, and placenta. We aim to understand the biologic mechanisms that can impact cord blood quality. This knowledge will ultimately allow targeting donors, which could provide a rich graft and improve the efficiency of the collection.

A new strategy for umbilical cord blood collection developed at the first Colombian public cord blood bank increases total nucleated cell content

BACKGROUND

The total nucleated cell dosage of umbilical cord blood (UCB) is an important factor in determining successful allogeneic hematopoietic stem cell transplantation after a minimum human leukocyte antigen donor-recipient match. The northern South American population is in need of a new-generation cord blood bank that cryopreserves only units with high total nucleated cell content, thereby increasing the likelihood of use. Colombia set up a public cord blood bank in 2014; and, as a result of its research for improving high total nucleated cell content, a new strategy for UCB collection was developed.

STUDY DESIGN AND METHODS

Data from 2933 collected and 759 cryopreserved cord blood units between 2014 and 2015 were analyzed. The correlation of donor and collection variables with cellularity was evaluated. Moreover, blood volume, cell content, CD34+ count, clonogenic capacity, and microbial contamination were assessed comparing the new method, which combines in utero and ex utero techniques, with the conventional strategies.

RESULTS

Multivariate analysis confirmed a correlation between neonatal birth weight and cell content. The new collection method increased total nucleated cell content in approximately 26% and did not alter pre-cryopreservation and post-thaw cell recovery, viability, or clonogenic ability. Furthermore, it showed a remarkably low microbial contamination rate (1.2%).

CONCLUSION

The strategy for UCB collection developed at the first Colombian public cord blood bank increases total nucleated cell content and does not affect unit quality. The existence of this bank is a remarkable breakthrough for Latin-American patients in need of this kind of transplantation.

The effect of maternal and infant factors on cord blood yield

Umbilical cord blood (CB) can be used as an alternative hematopoietic stem cell source for transplantation in hematological malignancy and blood disorders. The success of transplantation is highly related to the levels of total nucleated cell and CD34⁺ cell counts. The evaluation of optimal conditions can decrease the rate of graft rejection due to low cell count and increases the quality of CB units (CBUs) in the blood bank and the success rate of engraftment. To this end, we review the maternal and infant parameters affecting the quality and quantity of CBUs.

Predictors of high-quality cord blood units

BACKGROUND

Analysis of umbilical cord blood (UCB) transplants shows a correlation between engraftment and total number of infused cells. Thus, it is worth evaluating what maternal and neonatal characteristics and collection techniques may affect the quality of UCB units.

STUDY DESIGN AND METHODS

A cross-sectional study was performed with 7897 donors sequentially selected in three health care institutions in Brazil from October 2004 to March 2012, in which both quantitative and qualitative approaches were applied. All donors were considered suitable for cord blood collection.

RESULTS

The maternal and neonatal characteristics and techniques of collection that influenced the total number of nucleated cells (TNCs; p < 0.001) were type of delivery, newborn weight and sex, and institution of UCB collection. The TNC count was associated with gestational age (p = 0.008), type of delivery (p < 0.001), newborn sex (p < 0.001), newborn weight (p < 0.001), and UCB collection technique (p = 0.003). Center B presented the largest number of nucleated cells in its results (p < 0.001), followed by Center A (p = 0.001). Other characteristics, such as maternal age, were analyzed but were not relevant for the nucleated cell number.

CONCLUSION

This study provides elements for a model that allows an efficient selection of UCB donors, prioritizing candidates who have a better chance to lead to an optimized use of cord blood cells units.

The circadecadal rhythm of oscillation of umbilical cord blood parameters correlates with geomagnetic activity - An analysis of long-term measurements (1999-2011)

Recently, we have shown that the contents of total nucleated cells (TNCs) and CD34⁺ hematopoietic stem and progenitor cells (CD34⁺ HSPCs) as well as the cord blood volume (CBV) in umbilical cord blood (UCB) show a circadecadal (~10 years) rhythm of oscillation. This observation was based on an analysis of 17,936 cord blood donations collected during 1999-2011. The aim of the present study was to investigate whether this circadecadal rhythm of oscillation in TNCs, CD34⁺ HSPCs and CBV is related to geomagnetic activity. For the analysis, the yearly averages of TNCs, CD34⁺ HSPCs and CBV in UCB were correlated with geomagnetic activity (Dcx index). Our analysis revealed that (i) all three UCB parameters were statistically significantly correlated with the level of geomagnetic activity, (ii) CBV showed a linear correlation with the Dcx index (r = 0.5290), (iii) the number of TNCs and CD34⁺ HSPCs were quadratic inversely correlated with the Dcx index (r = -0.5343 and r = -0.7749, respectively). Furthermore, (iv) CBV and the number of TNCs were not statistically significantly correlated with the number of either modest or intense geomagnetic storms per year, but (v) the number of CD34⁺ HSPCs was statistically significantly correlated with the number of modest (r = 0.9253) as well as intense (r = 0.8683) geomagnetic storms per year. In conclusion, our study suggests that UCB parameters correlate with the state of the geomagnetic field (GMF) modulated by solar activity. Possible biophysical mechanisms underlying this observation, as well as the outcome of these findings, are discussed.

Time related variations in stem cell harvesting of umbilical cord blood

Umbilical cord blood (UCB) contains hematopoietic stem cells and multipotent mesenchymal cells useful for treatment in malignant/nonmalignant hematologic-immunologic diseases and regenerative medicine. Transplantation outcome is correlated with cord blood volume (CBV), number of total nucleated cells (TNC), CD34+ progenitor cells and colony forming units in UCB donations. Several studies have addressed the role of maternal/neonatal factors associated with the hematopoietic reconstruction potential of UCB, including: gestational age, maternal parity, newborn sex and birth weight, placental weight, labor duration and mode of delivery. Few data exist regarding as to how time influences UCB collection and banking patterns. We retrospectively analyzed 17.936 cord blood donations collected from 1999 to 2011 from Tuscany and Apulia Cord Blood Banks. Results from generalized multivariable linear mixed models showed that CBV, TNC and CD34+ cell were associated with known obstetric and neonatal parameters and showed rhythmic patterns in different time domains and frequency ranges. The present findings confirm that volume, total nucleated cells and stem cells of the UCB donations are hallmarked by rhythmic patterns in different time domains and frequency ranges and suggest that temporal rhythms in addition to known obstetric and neonatal parameters influence CBV, TNC and CD34+ cell content in UBC units.

Optimizing cord blood collections: Assessing the role of maternal and neonatal factors

BACKGROUND

As processing and cryopreservation of cord blood is time consuming and costly, it is essential to select units with optimal CD34+ cells, total nucleated cell (TNC) number and colony forming units (CFUs). These are the most important factors affecting outcome of UCB transplantation and are influenced by various maternal and neonatal factors.

AIM AND OBJECTIVES

To determine the maternal and neonatal factors affecting TNC and CD34+ cell counts in cord blood so as to aid in proper selection of cord blood units for cryopreservation.

MATERIALS AND METHODS

A total of 100 UCB units were collected from normal vaginal deliveries, processed and assessed for volume, TNC, CD34+ cell count and CFU-GM. These parameters were then analyzed to find out whether they correlated with maternal and neonatal characteristics such as mother's age, parity, gestational age, baby's birth weight, and sex.

RESULTS

The volume of CB collected significantly correlated with the TNC, CD34+ cell, and CFU-GM yields (P < 0.02). A heavier placenta (P < 0.05), and a heavier baby (P < 0.002) were associated with a significantly greater volume of CB whereas the age, parity of mother and the sex of the baby had no significant effect.

CONCLUSION

The only factors found to affect the TNC and CD34+ cell counts significantly were weight of the baby and placenta and the volume of cord blood collected. Since these factors are of prognostic significance, their analysis will aid in deciding which UCB unit should be processed and cryopreserved for UCB banking and subsequent transplantation.

The impact of fetal and maternal physiologic factors on umbilical cord blood quality as a source of stem cells in Egyptian population

BACKGROUND

Umbilical cord blood (UCB) has rapidly become a clinically useful alternative stem cell source. Many variables have been used to evaluate a UCB unit and predict transplant outcomes. The objective of this study was to measure the expression of hematopoietic stem cells in UCB and its relation to certain maternal and neonatal physiologic factors to establish optimum criteria for UCB donor selection.

STUDY DESIGN AND METHODS

Two hundred UCB units were collected from normal uncomplicated vaginal and cesarean deliveries. Total volume was noted and immediately assessed for total nucleated cell (TNC) count and CD34+ cell concentration. Assessment of maternal and neonatal variables such as mode of delivery, placental weight, baby's birthweight, and sex was made.

RESULTS

The volume of the donations ranged from 42.0 to 126 mL, the TNC count ranged from 5 × 10(9) to 28.7 × 10(9) cells/L, and CD34+ cells ranged from 0.03% to 0.62%. There was a significant positive correlation between cord blood volume and cesarean section (p = 0.01) and placental weight (p = 0.02). There was a significant positive correlation with a p value of less than 0.05 between the number of CD34+ cells and UCB volume and TNC. There was no significant difference between the variables and the TNC count.

CONCLUSION

Our study concludes that cord units collected for banking should be obtained by selecting units of larger volumes, of higher TNCs, from female babies with heavy placenta, and from babies delivered via cesarean section.

Effects of in utero cord blood collection on post-cesarean hemoglobin levels

OBJECTIVE

To assess effects of in utero cord blood collection on postoperative hemoglobin, hematocrit levels.

STUDY DESIGN

Elective cesarean deliveries in which cord blood was collected were compared with match paired elective cesarean deliveries without cord blood collection. Pre-post-operative hemoglobin and hematocrit level differences were compared between study groups with Student's t test. Multivariate regression models were used to address confounders. Correlation between volume of collected UCB and mean decrease in blood count parameters was analyzed.

RESULTS

A total of 399 cesarean deliveries during a 12 months period were included in the analysis. Mean decrease in hemoglobin levels was 1.08g/dL (SD=1.0) in UCB collected group compared to 0.84g/dL (SD=1.0) in control group (p=0.002). Mean decrease in hematocrit levels was 3.1% (SD=3.4) in cord blood collected cesarean delivery group compared to 1.9% (SD=2.4) in control group (p=0.002). Univariate analysis has shown the collected UCB volume to be uncorrelated with the change in hemoglobin levels (r=0.013). Multivariate regression models, after adjusting for birth weight, age and number of prior cesarean, have shown the UCB collection to be significantly associated with the mean decrease in blood count parameters (estimate=0.23g/dL, t=-2.23, p=0.02).

CONCLUSION

In utero UCB collection is associated with a small increase in bleeding of little clinical importance. Amount of UCB is not associated with amount of change in hemoglobin and hematocrit levels. In utero UCB collection seems to be safe for expectant mothers scheduled for low-risk cesarean delivery.

Correlation of ultrasound estimated placental volume and umbilical cord blood volume in term pregnancy

OBJECTIVE

To investigate the correlation between ultrasound measured placental volume and collected umbilical cord blood (UCB) volume in term pregnancy.

MATERIAL AND METHODS

An observational cross-sectional study of term singleton pregnant women in the labor ward at Maha Chakri Sirindhorn Medical Center was conducted. Placental thickness, height, and width were measured using two-dimensional (2D) ultrasound and calculated for placental volume using the volumetric mathematic model. After the delivery of the baby, UCB was collected and measured for its volume immediately. Then, birth weight, placental weight, and the actual placental volume were analyzed. The Pearson's correlation was used to determine the correlation between each two variables.

RESULTS

A total of 35 pregnant women were eligible for the study. The mean and standard deviation of estimated placental volume and actual placental volume were 534±180 mL and 575±118 mL, respectively. The median UCB volume was 140 mL (range 98-220 mL). The UCB volume did not have a statistically significant correlation with the estimated placental volume (correlation coefficient 0.15; p=0.37). However, the UCB volume was significantly correlated with the actual placental volume (correlation coefficient 0.62; p<0.001) and birth weight (correlation coefficient 0.38; p=0.02).

CONCLUSION

The estimated placental volume by 2D ultrasound was not significantly correlated with the UCB volume. Further studies to establish the correlation between the UCB volume and the estimated placental volume using other types of placental imaging may be needed.

CD133 allows elaborated discrimination and quantification of haematopoietic progenitor subsets in human haematopoietic stem cell transplants

The success of haematopoietic stem cell (HSC) transplantation largely depends on numbers of transplanted HSCs, which reside in the CD34(+) populations of bone marrow (BM), peripheral blood stem cells (PBSC) and umbilical cord blood (UCB). More specifically HSCs reside in the CD38(low/-) subpopulation, which cannot be objectively discriminated from mature CD34(+)  CD38(+) progenitors. Thus, better marker combinations for the quantification of more primitive haematopoietic stem and progenitor cells in transplants are required. Recently, by combining CD34 and CD133 we could clearly distinguish CD133(+)  CD34(+) multipotent and lympho-myeloid from CD133(low)  CD34(+) erythro-myeloid progenitors in UCB samples. To qualify the assessment of CD133 for routine quality control of adult HSC sources, we analysed the developmental potentials of CD133(+) and CD133(low) subpopulations in BM and PBSC. Similar to UCB, CD133 expression objectively discriminated functionally distinct subpopulations in adult HSC sources. By implementing anti-CD45RA staining, which separates multipotent (CD133(+)  CD34(+)  CD45RA(-) ) from lympho-myeloid (CD133(+)  CD34(+)  CD45RA(+) ) progenitor fractions, UCB was found to contain 2-3 times higher multipotent progenitor frequencies than BM and PBSC. To test for the consistency of CD133 expression, we compared CD133(+)  CD34(+) contents of 128 UCB samples with maternal and obstetrical factors and obtained similar correlations to related studies focusing on CD34(+) cell contents. In conclusion, implementation of anti-CD133 staining into existing routine panels will improve the quality control analyses for HSC transplants.

Factors affecting umbilical cord blood stem cell suitability for transplantation in an in utero collection program

BACKGROUND

The greatest limiting factor in the use of umbilical cord blood (UCB) for transplantations is the number of stem cells available in any given collected unit. This study examines maternal, neonatal, and obstetric factors that influence the suitability for banking and transplantation of UCB units collected in utero.

STUDY DESIGN AND METHODS

This study examined 7839 UCB units collected in utero at two hospitals from August 1, 2008, to August 31, 2011. The variables were collected from cord blood records, patient charts, delivery records, and data processed by StemCyte, Inc. (Covina, CA), our parent bank. The mean total nucleated cell (TNC) count between units selected for transplant and those banked but not selected for transplant were also compared.

RESULTS

Of the 11 variables evaluated, six had a significant influence on the acceptable banking TNC count of at least 90 × 10(7) . Of these, cord blood volume was the best predictor. The other variables that were predictors of the acceptable TNC count of significance were gestational age, infant race, parity, birthweight, and infant sex. The minimal bankable TNC count for banking is considerably lower than the mean TNC count of units actually selected for transplantation.

CONCLUSION

Maternal, neonatal, and obstetric factors can all influence the acceptability of a cord blood unit collected in utero for banking. Furthermore, units with high TNC counts are more likely to be selected for banking. Identifying these variables in potential donors can likely increase the number of adequate collections.

Toward personalized cell therapies by using stem cells: seven relevant topics for safety and success in stem cell therapy

Stem cells, both embryonic and adult, due to the potential for application in tissue regeneration have been the target of interest to the world scientific community. In fact, stem cells can be considered revolutionary in the field of medicine, especially in the treatment of a wide range of human diseases. However, caution is needed in the clinical application of such cells and this is an issue that demands more studies. This paper will discuss some controversial issues of importance for achieving cell therapy safety and success. Particularly, the following aspects of stem cell biology will be presented: methods for stem cells culture, teratogenic or tumorigenic potential, cellular dose, proliferation, senescence, karyotyping, and immunosuppressive activity.

Human placenta and chorion: potential additional sources of hematopoietic stem cells for transplantation

BACKGROUND

Hematopoietic stem cell (HSC) transplantation is an essential element of medical therapy, leading to cures of previously incurable hematological and nonhematological diseases. Many patients do not find matched donors in a timely manner, which has driven efforts to find alternative pools of transplantable HSCs. The use of umbilical cord blood (UCB) as a source of transplantable HSCs began more than two decades ago. However, the use of UCB as a reliable source of HSCs for transplantation still faces crucial challenges: the number of HSCs present in a unit of UCB is usually sufficient for younger children but not for adults, and the persistent delayed engraftment often seen can result in high rates of infection and mortality.

STUDY DESIGN AND METHODS

We propose a new approach to a solution of these problems: a potential increase of the limited number of UCB-HSCs available by harvesting HSCs contained in the placenta and the fetal chorionic membrane available at birth.

RESULTS

We investigated the presence of hematopoietic progenitors and HSCs in human placenta and chorion at different gestational ages. The characterization of these cells was performed by flow cytometry and immunolocalization, and their functional status was investigated by transplanting them into immunodeficient mice.

CONCLUSION

HSCs are present in extraembryonic tissues and could be banked in conjunction to the UCB-HSCs. This novel approach could have a large impact on the field of HSC banking and, more crucially, on the outcome of patients undergoing this treatment by greatly improving the use of life-saving hematopoietic transplants.

Associations among birth weight, placental weight, gestational period and product quality indicators of umbilical cord blood units

INTRODUCTION

Numbers of CD34+ cell and total nucleated cell (TNC) and cord blood volume are commonly used as indicators for haematopoietic potential of umbilical cord blood (UCB) units. The purpose of this study was to investigate the relationship between donor-related factors and the quality indicators of UCB.

METHODS

Obstetric and neonatal clinical laboratory data of a total of 1549 UCB units were obtained from Buddhist Tzu Chi Stem Cells Center (BTCSCC) Cord Blood Bank. A retrospective multivariate analysis was conducted to analyze the data.

RESULTS

Our results showed that birth weight had positive correlations with each of the clinical features of CD34+ cell number, TNC count and unit volume of UCB, followed by the placental weight. Longer gestational period would decrease CD34+ cell number and volume of UCB. Female baby and mode of vaginal delivery of neonates were found to have larger amount of TNC in UCB.

CONCLUSION

Our results would be helpful and beneficial in building up standard criteria for evaluating stored UCB units.

Quality-assessments of characteristics of placental/umbilical cord blood associated with maternal age- and parity-related factor

Umbilical cord blood (CB) has been widely used for unrelated allogeneic stem cell transplantation. It is important to determine the quality of CB units to avoid frequent problem of limited cell yields. However, no practical and/or optimum obstetric factors to predict them are yet available. This study analyzed the relationship between maternal/neonatal obstetric factors and the laboratory parameters of CB units to identify the optimum factors associated with a high yield of total nucleated cells (TNC). Primiparae in their early 30s may be one of the first selection criteria for CB donors to obtain higher yield of TNC.

Evaluation of volume and total nucleated cell count as cord blood selection parameters: a receiver operating characteristic curve modeling approach

The objective of the study was to evaluate the current standard practice of using volume and total nucleated cell (TNC) count for the selection of cord blood (CB) units for cryopreservation and further transplantation. Data on 794 CB units whose CD34+ cell content was determined by flow cytometry were analyzed by using a receiver operating characteristic (ROC) curve model to validate the performance of volume and TNC count for the selection of CB units with grafting purposes. The TNC count was the best parameter to identify CB units having 2 × 10(6) or more CD34+ cells, with an area under the ROC curve of 0.828 (95% confidence interval, 0.800-0.856; P < .01) and an efficiency of 75.4%. Combination of parameters (TNC/mononuclear cells [MNCs], efficiency 74.7%; TNC/volume, efficiency 68.9%; and volume/MNCs, efficiency 68.3%) did not lead to improvement in CB selection. All CB units having a TNC count of 8 × 10(8) or more had the required CD34+ cell dose for patients weighing 10 kg or less.

Effects of obstetric factors and storage temperatures on the yield of endothelial colony forming cells from umbilical cord blood

As umbilical cord blood (UCB) is a rich source of endothelial colony-forming cells (ECFC), our aim was twofold: (1) to examine potential obstetric selection criteria for achieving the highest ECFC yields from UCB units, and (2) to determine whether transient storage temperatures of fresh UCB and cryopreservation of UCB units affected ECFC yield and function. ECFC quality was assessed before and after cryopreservation by their clonogenic proliferative potential. Of the 20 factors examined, placental weight was the only statistically significant obstetric factor that predicted ECFC frequency in UCB. Studies on the effects of storage revealed that transient storage of fresh UCB at 4°C reduced ECFC yield compared with storage at 22°C, while cryopreservation of UCB MNCs significantly reduced ECFC recoveries. To our knowledge, this is the first demonstration that placental weight and temperature of storage prior to processing or culture have significant effects on ECFC frequency in UCB. Our studies further support the evidence that cryopreservation of UCB MNCs compromises ECFC recovery.

Association of HLA-A, -B and -DRB1 genotype with birthweight and CD34+ cell content: analysis of Korean newborns and their cord blood

Birthweight and the hematopoietic progenitor cell content in cord blood affect and reflect fetal development, and MHC has been reported to play an important role in intrauterine growth. In this study, we assessed HLA-A, -B and -DRB1 polymorphisms, birthweight and cord blood CD34(+) cell content in 1628 full-term healthy neonates to identify the HLA alleles that are associated with fetal growth in Koreans. HLA-A*31, B*47, B*51, DRB1*04 showed positive association and HLA-A*03, A*24, A*30, B*07, B*52, B*58, DRB1*03 showed negative association with birthweight and/or CD34(+) cell content; additionally, there was a greater association in homozygotes than heterozygotes revealed in the trend analysis of birthweight centile with candidate allele zygosity (A*24, P= 0.018; DRB1*04, P= 0.047). Among these alleles, HLA-A*24 and DRB1*03 showed significant negative association with birthweight and/or CD34(+) cell content after Bonferroni correction, suggesting a significant association of these alleles with fetal growth in late pregnancy (A*24, P= 0.002, P(c) = 0.026; DRB1*03, P < 0.001, P(c) < 0.001). Various populations should be analyzed to identify different or consistent factors among ethnicities. Furthermore, a larger scale study that includes pre-terms will aid in the comprehensive understanding of these associations.

Pre-birth selection of umbilical cord blood donors

BACKGROUND

. The fact that only a small percentage of cord blood units (CBU) stored are actually used for transplantation contributes to raising the already high costs of their processing and cryopreservation. The identification of predictors allowing the early identification of suitable CBU would allow a reduction of costs for the collection, storage and characterisation of CBU with insufficient volume or cell numbers. In our bank we have adopted a cut-off value for using CBU of 8 x 10(8) nucleated cells and a volume >or= 60 mL.

MATERIALS AND METHODS

In 365 banked CBU, we evaluated the correlation between neonatal/gestational parameters and laboratory data used to assess their quality.

RESULTS

Biparietal diameter (BPD) and abdominal circumference were significantly and positively correlated with CBU volume (r(2)=0.12, p=0.0011 and r(2)=0.092, p=0.0063, respectively). Receiver operating characteristic (ROC) analysis showed that both parameters can be used to identify CBU with insufficient volume (BPD: area under the curve 0.69, 95% CI=0.57-0.82, p=0.004; abdominal circumference: area under the curve 0.67, 95% CI=0.54-0.79, p<0.01). BPD and head circumference, but not abdominal circumference or femoral length, were positively correlated with white blood cell (WBC) count (r(2)=0.215, p=0.031, and r(2)=0.299, p=0.015, respectively). Abdominal circumference, but not BPD, head circumference or femoral length, was statistically significantly correlated with the number of CD34(+) cells in the CBU. Weight at birth and placental weight were positively correlated with WBC count, blood volume, CD34(+) cell count, total colony-forming units and burst-forming units.

CONCLUSION

. Pre-birth assessment of BPD might allow the selection of donors who would yield CBU of sufficient volume and WBC count and avoid the costs of collecting, transferring, storing and analysing CBU with a high probability of resulting unsuitable for transplantation.

Maternal and neonatal factors associated with the high yield of mononuclear low-density/CD34+ cells from placental/umbilical cord blood

Placental/umbilical cord blood (CB) contains nucleated cells and hematopoietic stem/progenitor cells (CD34(+) cells). However it is difficult to predict the number of nucleated/CD34(+) cells in each CB before cell processing. Despite many previous studies from institutes affiliated with CB banks in metropolitan areas, little information is available regarding the characteristics of CB units from other medical facilities. The purpose of the present study was to analyze the maternal/neonatal factors on the yield of cells in CB units. A total of 176 CB units were obtained from single-birth and normal vaginal deliveries. Mononuclear low-density (LD) cells were separated using Ficoll-Paque within 24 hrs after CB collection and then processed for the purification of CD34(+) cells. A multiple linear regression analysis was performed to assess the correlations between the yield of cells and maternal/neonatal factors including maternal age, gravid status, duration of labor, gestational age, neonatal height and weight, cord length, and meconium in the amniotic fluid. The total LD cells per CB unit had a weak positive correlation with the maternal age of primigravidae. The total LD cells per CB unit from the primigravidae aged > or = 25 were significantly higher than those from the primigravidae aged < or = 24. The total CD34(+) cells per CB unit from the 1-gravidae were significantly higher than those from the 2-gravidae and 3-gravidae, respectively among all donors. These results indicate that the CB units from the primigravidae aged > or = 25 are more likely to contain higher yield of LD/CD34(+) cells.

[Donors selection and retrieval of units in an umbilical cord blood bank]

BACKGROUND AND OBJECTIVE

Umbilical cord blood (UCB) contains hematopoietic stem cells that can be used as an alternative to bone marrow transplantation in certain cases. This study was designed to investigate the influence of obstetric, neonatal and collection factors on the hematopoietic content of UCB donations.

MATERIAL AND METHOD

A total of 391 consecutive maternal-neonatal pairs were evaluated during the prepartum period in the maternity ward at La Fe University Hospital. Maternal, neonatal and collection factors influencing cord blood quality measured as volume, total nucleated cells count, CD34+ cells and colony forming units were analyzed in 2,000 UCB collections.

RESULTS

32.5% of UCB potential donors were excluded, mainly due to obstetrical reasons. Among the collected units, 56% were discarded before cryopreservation, mainly due to low cell counts. In the multivariate analysis, placental weight was a predictor variable for total nucleated cells, CD34+ cells and colony forming units, while the mode of collection influenced the total nucleated cells and CD34+ cell counts.

CONCLUSIONS

The collection of UCB units before placental delivery (using the birth weight as an estimation of the placental weight) could be added to standard cord blood donors criteria in order to improve the bank efficiency.

Umbilical cord cells as a source of cardiovascular tissue engineering

There is increasing scientific evidence that human umbilical cord cells are a valuable source of adult stem cells that can be used for various implications including regenerative medicine and tissue engineering. The review describes the role of progenitor cells (mesenchymal, endothelial, prenatal) for the use in cardiovascular tissue engineering, i.e., the formation of large vessels and heart valves from umbilical cord cells. Currently used replacements in cardiovascular surgery are made of foreign materials with well known drawbacks such as thrombo-embolic complications, infection, loss of functional and biological properties, and others. Especially in the field of replacements in congenital cardiac defects, there would be a need of materials which have the advantage of optimal biological and mechanical properties. In the case of human umbilical cord cells, autologous cells can be used by minimally invasive procedures. The cells have excellent growth capacities and form a neo-matrix with excellent mechanical properties. For optimal growth and modeling, scaffolds are required with high biocompatibility and biodegradability, which allow cell attachment, ingrowth, and organization. Nutrients and waste must be easily transported and cells should be in entire contact with host's body. Finally, regenerated materials can be fully incorporated and the scaffold is completely replaced. Besides these cell and scaffold requirements, feto-maternal conditions and risk factors concerning deriving stem cells are of major interest. There are still many open questions concerning whether and how maternal conditions such as infection (viral or bacterial) or gestational age of the newborn influence stem cell harvesting and quality. If these cells will be used for the construction of replacement materials, it is clear that very strict criteria and protocols be introduced enabling the promising step from isolated cells to a therapeutic device such as a new heart valve. It is hoped that it will be only a question of time until human umbilical cord cells will be used frequently as the source of cardiovascular tissues among others in the clinical setting of treating congenital heart defects.

Optimizing Umbilical Cord Blood Collection: Impact of Obstetric Factors Versus Quality of Cord Blood Units

INTRODUCTION

The main limitation factor for wide use of umbilical cord blood units (UCBs) as a source of hematopoietic progenitors for transplantation is cell dose. International standard guidelines recommend 2 x 10(7)/kg as the minimal nucleated cell dose for UCB transplantation for adults and 3.7 x 10(7)/kg for children. Therefore it is important to the optimize donor selection and the collection method so as to achieve high cell doses. In this study our main purpose was to determine whether obstetric factors influence UCBs collected.

STUDY DESIGN

The study involved 304 UCBs collected from January to December 2004. The UCBs were collected after donor selection based on international criteria for cord blood banking. We analyzed UCB biological features such as collected volume, total nucleated cells (TNC), and CD34-positive cells, and obstetric factors.

RESULTS

First, our study showed by multivariate analysis that infant weight was the main factor that influenced biologic features of UCB collected such as total volume (P = .000), TNC (P = .000), CD34 total count (P = .003), and CFU-GM (P = .004). Placental weight > 600 g produced a better volume (P = .007) and increased TNC (P = .056). Gestational age > 39 weeks enhanced CD34% (P = .016). Regarding route of delivery, we found that cesarean section produced higher volume and reduced WBC count compared to vaginal delivery, regarding cord length, it increased TNC (P = .037). And last, we noticed that female infants increased WBC (P = .013) and CD34(+) total count (P = .019) more than male ones.

CONCLUSIONS

Our results confirm that volume and TNC are influenced by several obstetric factors, such as greater infant and placental weight, predicting a better collection.