Association of stress during delivery with increased numbers of nucleated cells and hematopoietic progenitor cells in umbilical cord blood

Nucleated red blood cell: a feasible quality parameter of cord blood units

INTRODUCTION

Umbilical cord blood is an alternative source of hematopoietic progenitor cells for bone marrow transplantation; however, it is associated with a higher graft failure rate. The presence of a high rate of nucleated red blood cells (NRBCs) seems to be related to a greater capacity for engraftment, although is also associated with fetal distress conditions. We analyzed the correlation of the NRBC with quality parameters and its association with the utilization score of a cord blood unit.

STUDY DESIGN AND METHOD

Data of 3346 units collected in a public cord blood bank from May 2010 to December 2017 were analyzed, retrospectively, to identify factors associated with an increased number of nucleated red blood cells and its correlation with the engraftment capacity measured through total nucleated cells (TNCs) and CD34 positive cells. We also evaluated the utilization score of these units and identified an NRBC cutoff associated with a higher score.

RESULTS

The median volume collected was 104 mL (42-255), the pre-processing TNC count was 144.77 × 107 (95.46-477.18), the post-processing TNC count was 119.44 × 107 (42.7-477.18), the CD34 count was 4.67 × 106 (0.31-48.01), the NRBC count was 5 (0-202) and the utilization score was 0.0228 (0.00143-0.9740). The NRBC showed a correlation with the collected volume, TNC and CD34 positive cells and a higher utilization score and the receiver operating characteristic (ROC) curve analysis identified the five NRBC/100 leukocytes cutoff that correlates better with the probability of use. No association with pathological conditions and the NRBC rate was observed.

CONCLUSIONS

The NRBC is a feasible parameter for the screening of the cord blood unit (CBU) and the minimum cutoff of five NRBC/100 leukocytes can be a strategy in conjunction with the TNC to identify better units for cord blood bank sustainability.

Effect of fetal distress on viability and yield of umbilical cord blood stem cells-a prospective comparative study

INTRODUCTION

Different factors affect the quality and viability of cord blood stem cells, and therefore the efficacy of umbilical cord stem cell transplantation. Fetal distress is one factor affecting the quantity of CD34+ cells in cord blood. This study was designed to compare the viability and yield of the umbilical cord blood stem cells of women who have undergone emergency lower segment caesarean section for fetal distress or for other causes.

MATERIALS AND METHODS

This cross-sectional analytical study was performed at a tertiary care hospital facility with a total sample size of 68: 34 participants had undergone emergency C-section for fetal distress, and 34 had undergone emergency C-section for other causes. Umbilical cord blood was collected ex-utero in a 350 mL bag with citrate-phosphate-dextrose solution with adenine. Three milliliter of blood were transferred to an ethylenediaminetetraacetic acid (EDTA) tube for cell counts and flow cytometry testing for CD34+. The chi-square test was used to compare the total mononuclear cell, CD34+, and viability between the groups.

RESULTS

The CD34+ count [mean 4.9 versus 1.1 (× 106 cells/unit)] and total nucleated cell count [mean 14.2 versus 7.5 (× 108/unit)] were significantly higher in cord blood units collected from women who delivered by C-section for fetal distress (p-value <0.05). However, the volume of umbilical cord stem cells and viability of stem cells did not vary significantly based on the presence or absence of fetal distress (p-value >0.05).

CONCLUSION

The current study shows that umbilical cord blood collected during fetal distress has a significantly higher content of stem cells and total nucleated cells than the non-fetal distress group.

[Influence of maternal and infant factors on CD34+ hematopoietic stem/progenitor cells in umbilical cord blood]

OBJECTIVE

To study the association of different maternal and infant factors with the number of total nucleated cells and CD34⁺ hematopoietic stem/progenitor cells in umbilical cord blood, and to provide a reference for reasonable selection of umbilical cord blood in the cord blood bank.

METHODS

A prospective study was performed for the umbilical cord blood samples of 130 neonates who were born in Dalian Women and Children's Medical Center from June 2019 to January 2020, with a male/female ratio of 1:1. Related perinatal information was collected, including maternal age and blood type, presence or absence of gestational diabetes or gestational hypertension, pregnancy method, mode of delivery, singleton pregnancy/twin pregnancy, body weight and sex of neonates, Apgar score after birth, and the conditions of placenta, amniotic fluid, and umbilical cord.

RESULTS

The neonates were grouped according to maternal blood type, gestational diabetes, gestational hypertension, pregnancy method, mode of delivery, singleton pregnancy/ twin pregnancy, sex of neonates, Apgar score after birth, placental morphology, meconium staining of amniotic fluid, and umbilical cord around the neck. The comparison between groups showed no significant differences in the numbers of total nucleated cells and CD34⁺ cells in umbilical cord blood (P > 0.05). Maternal age and neonatal body weight were not correlated with the number of total nucleated cells in umbilical cord blood (P > 0.05), and neonatal body weight was not correlated with the number of CD34⁺ cells (P > 0.05), while maternal age was positively correlated with the number of CD34⁺ cells (P < 0.05).

CONCLUSIONS

The number of CD34⁺ cells in umbilical cord blood increases with the increase in maternal age, and therefore, umbilical cord blood in the cord blood bank may be selected based on maternal age.

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.

Prospective associations between maternal stress during pregnancy and fasting glucose with obstetric and neonatal outcomes

OBJECTIVE

This prospective study investigated associations between maternal stress exposure and maternal psychological stress measures during pregnancy with obstetric and neonatal outcomes. We also tested whether any observed associations would be moderated by increasing glucose levels, as increased glycaemia is also associated with adverse obstetric and neonatal outcomes.

METHODS

203 women between 24 and 30 weeks gestation completed validated questionnaires assessing pregnancy-related major events and major life events, maternal perceived stress, and depression, anxiety, and stress symptoms. Glucose was measured using fasting morning blood samples. Instrumental delivery represented an obstetric outcome. Neonatal outcomes included Apgar score, large and small for gestational age weight, cord blood pH, NICU hospitalization, and neonatal hypoglycaemia.

RESULTS

Regarding the obstetric outcome, pregnancy-related major life events OR = 1.346 (1.016-1.783; p = .016) were related to more incidences of instrumental delivery. Regarding neonatal outcomes, exposure to major life events in the last 12 months was associated with lower cord blood pH values B = -0.155 (-0.059 to -0.002; p = .036) and with more incidences of hypoglycaemia OR = 0.165 (0.012-0.169; p = .04). Maternal psychological stress measures were related to more incidences of instrumental delivery OR = 1.018 (1.003-1.032; p = .013). Maternal stress perception was associated with higher cord blood pH values B = 0.155 (0-0.003; p = .046) and fewer NICU hospitalisations OR = -0.170 (-0.009 to -0.001; p = .019). Some of these associations between life events and stress perceptions with neonatal outcomes were moderated by fasting glucose levels.

CONCLUSION

Maternal pregnancy events as well as stress, depression and anxiety symptoms have a negative impact on obstetric outcomes and maternal life events are associated with negative neonatal outcomes. Higher fasting glucose levels moderate some of the relationships between stress and neonatal outcomes.

Does cesarean delivery impact infant weight gain and adiposity over the first year of life?

BACKGROUND

Potentially driven by the lack of mother-to-infant transmission of microbiota at birth, cesarean delivery has been associated with higher risk of offspring obesity. Yet, no studies have examined when delivery-mode differences in adiposity begin to emerge. In this study, we examine differences in infant weight and adiposity trajectories from birth to 12 months by delivery mode.

METHODS

From 2013 to 2015, we recruited pregnant women into the Nurture Study and followed up their 666 infants. We ascertained maternal delivery method and infant birth weight from medical records. We measured weight, length, and skinfold thicknesses (subscapular, triceps, abdominal) when infants were 3, 6, 9, and 12 months of age. The main outcome, infant weight-for-length z score, was derived based on the WHO Child Growth Standards. We used linear regression models to assess the difference at each time point and used linear mixed models to examine the growth rate for infant weight and adiposity trajectories. We controlled for maternal age, race, marital status, education level, household income, smoking status, maternal pre-pregnancy body mass index, and infant birth weight.

RESULTS

Of the 563 infants in our final sample, 179 (31.8%) were cesarean delivered. From birth to 12 months, the rate of increase in weight-for-length z score was 0.02/month (p = 0.03) greater for cesarean-delivered than vaginally-delivered infants. As a result of more rapid growth, cesarean-delivered infants had higher weight-for-length z score (0.26, 95% CI: 0.05, 0.47) and sum of subscapular and triceps (SS + TR) skinfold thickness (0.95 mm, 95% CI: 0.30, 1.60)-an indicator for overall adiposity-at 12 months, compared to vaginally-delivered infants.

CONCLUSIONS

Compared to vaginal delivery, cesarean delivery was associated with greater offspring rate of weight gain over the first year and differences in adiposity that appear as early as 3 months of age. Monitoring cesarean-delivered infants closely for excess weight gain may help guide primordial prevention of obesity later in life.

Associations of birth mode with cord blood cytokines, white blood cells, and newborn intestinal bifidobacteria

The associations of Cesarean delivery with offspring metabolic and immune-mediated diseases are believed to derive from lack of mother-to-newborn transmission of specific microbes at birth. Bifidobacterium spp., in particular, has been hypothesized to play a health-promoting role, yet little is known about how delivery mode modifies colonization of the newborn by this group of microbes. The aim of this research was to examine the presence of Bifidobacterium in meconium and in the transitional stool, and to assess cytokine levels and hematological parameters in the venous cord blood of infants born by elective, pre-labor Cesarean section vs. vaginal delivery in Southern Brazil. We recruited 89 mother-newborn pairs (23 vaginal delivery and 66 elective cesarean delivery), obtained demographic information from a structured questionnaire and clinical information from medical records. We obtained umbilical cord venous blood and meconium samples following delivery and the transitional stool (the first defecation after meconium) before discharge. We determined plasma levels of IL-1β, IL-10, IL-6, GM-CSF, IL-5, IFN-γ, TNF-α, IL-2, IL-4 and IL-8 in the cord blood, and presence of stool Bifidobacterium by real time PCR. Compared to vaginally-delivered neonates, Cesarean-delivered neonates had a lower leukocyte count (p = 0.037), lower hemoglobin (p = 0.04), and lower levels of the cytokine GM-CSF (p = 0.009) in the cord blood. Moreover, Bifidobacterium was detected less often in the transitional stool of Cesarean-delivered neonates compared to vaginally-delivered neonates (p = 0.001). The results indicate that pre-labor Cesarean birth may be associated with microbial and hematological alterations in the neonate. The clinical significance of these findings remains to be determined in larger prospective birth cohort studies.

Response of cord blood cells to environmental, hereditary and perinatal factors: A prospective birth cohort study

Background

Many studies investigating the impact of individual risk factors on cord blood immune cell counts may be biased given that cord blood composition is influenced by a multitude of factors. The aim of this study was to comprehensively investigate the relative impact of environmental, hereditary and perinatal factors on cord blood cells.

Methods

In 295 neonates from the prospective Basel-Bern Infant Lung Development Cohort, we performed complete blood counts and fluorescence-activated cell sorting scans of umbilical cord blood. The associations between risk factors and cord blood cells were assessed using multivariable linear regressions.

Results

The multivariable regression analysis showed that an increase per 10μg/m³ of the average nitrogen dioxide 14 days before birth was associated with a decrease in leukocyte (6.7%, 95% CI:-12.1,-1.0) and monocyte counts (11.6%, 95% CI:-19.6,-2.8). Maternal smoking during pregnancy was associated with significantly lower cord blood cell counts in multiple cell populations. Moreover, we observed sex differences regarding eosinophilic granulocytes and plasmacytoid dendritic cells. Finally, significantly increased numbers of cord blood cells were observed in infants exposed to perinatal stress. Cesarean section seems to play a significant role in Th1/Th2 balance.

Conclusions

Our results suggest that all three: environmental, hereditary and perinatal factors play a significant role in the composition of cord blood cells at birth, and it is important to adjust for all of these factors in cord blood studies. In particular, perinatal circumstances seem to influence immune balance, which could have far reaching consequences in the development of immune mediated diseases.

Serum concentrations of endothelial cell adhesion molecules and their shedding enzymes and early onset sepsis in newborns in Suriname

BACKGROUND

Early onset sepsis (EOS) is defined as onset of sepsis within 72 hours after birth. Leucocyte-endothelial interactions play a pivotal part in EOS pathophysiology. Endothelial cell adhesion molecules (CAMs) orchestrate these interactions and their soluble isoforms (sCAMs) are released into the vasculature by enzymes called sheddases.

PURPOSE

This study was undertaken to explore further the pathophysiology of EOS and to investigate the potential of sCAM and their sheddases as potential biomarkers for EOS.

METHODS

Stored serum aliquots were used from 71 Surinamese newborns suspected of EOS and 20 healthy newborns from an earlier study. Serum had been collected within 72 hours after birth and six (8.6%) newborns had a positive blood culture with gram-negative pathogens. Concentrations of sCAMs sP-selectin, sE-selectin, soluble vascular cell adhesion molecule-1, intercellular adhesion molecule-1 and platelet and endothelial cell adhesion molecule-1, sheddases matrix metalloproteinase-9 (MMP-9) and neutrophil elastase (NE) and sheddase antagonist tissue-inhibitor of metalloproteinases-1 (TIMP-1) were measured simultaneously with Luminex and ELISA.

RESULTS

MMP-9 and TIMP-1 levels were measured in serum of n=91 newborns and sCAMs and NE levels in serum of n=80 newborns, respectively. We found no differences in median concentrations of sCAMs, MMP-9 and TIMP-1 or NE between blood culture positive EOS, blood culture negative EOS and control groups at start of antibiotic treatment.

CONCLUSIONS

Our data indicate that serum concentrations of sCAMs and their sheddases have no clinical utility as biomarkers for EOS.

TRIAL REGISTRATION NUMBER

NCT02486783. Results.

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.

Human Umbilical Cord Blood CD45+ Pan-Hematopoietic Cells Induced a Neurotherapeutic Effect in Mice with Traumatic Brain Injury: Immunophenotyping, Comparison of Maternal and Neonatal Parameters, and Immunomodulation

Human umbilical cord blood (HUCB) transplantation has become an alternative cell therapy for hematological and oncological malignancies in the clinic and is considered for neurological disorders. The heterogeneity in the content of the different stem and progenitor cells composing HUCB mononuclear cells (MNC) may influence their engraftment and neurotherapeutic effect. We hypothesized that CD45 pan-hematopoietic marker expression is heterogeneous in MNC, and therefore, CD45⁺ subpopulation enrichment for neurotherapy may provide a tool to overcome cellular variance in different HUCB units. We employed an immunomagnetic separation method to isolate and characterize HUCB CD45⁺ pan-hematopoietic subpopulation and to investigate whether the vaginal or cesarean deliveries influence their neurotherapeutic effect in a traumatic brain injury (TBI) mouse model. Adult C57BL/6J male mice were subjected to moderate TBI and intravenously xenotransplanted with 1 × 10⁶ CD45⁺ cells derived from either vaginal or cesarean HUCB units. A large heterogeneity in the expression of CD45 marker in MNC, both in vaginal and cesarean HUCB units, was found, regardless of the number of live births. A higher expression of hematopoietic markers was found in the CD45⁺ subpopulation while low expressional levels of typical mesenchymal markers were detected. Neurotherapeutic effects, evaluated with an established neurological severity score and novel object recognition test, indicated improved functional motor and memory recovery and found independent of delivery type. Cytokine analysis in extracts of TBI brain cortices indicated an acute immunomodulatory effect by HUCB CD45⁺ subpopulation upon xenotransplantation. These results may provide insights to CD45 marker as a predictor of HUCB units' quality for neurotherapy in TBI.

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.

Hematopoietic stem cells in neonates: any differences between very preterm and term neonates?

Background

In the last decades, human full-term cord blood was extensively investigated as a potential source of hematopoietic stem and progenitor cells (HSPCs). Despite the growing interest of regenerative therapies in preterm neonates, only little is known about the biological function of HSPCs from early preterm neonates under different perinatal conditions. Therefore, we investigated the concentration, the clonogenic capacity and the influence of obstetric/perinatal complications and maternal history on HSPC subsets in preterm and term cord blood.

Methods

CD34+ HSPC subsets in UCB of 30 preterm and 30 term infants were evaluated by flow cytometry. Clonogenic assays suitable for detection of the proliferative potential of HSPCs were conducted. Furthermore, we analyzed the clonogenic potential of isolated HSPCs according to the stem cell marker CD133 and aldehyde dehydrogenase (ALDH) activity.

Results

Preterm cord blood contained a significantly higher concentration of circulating CD34+ HSPCs, especially primitive progenitors, than term cord blood. The clonogenic capacity of HSPCs was enhanced in preterm cord blood. Using univariate analysis, the number and clonogenic potential of circulating UCB HSPCs was influenced by gestational age, birth weight and maternal age. Multivariate analysis showed that main factors that significantly influenced the HSPC count were maternal age, gestational age and white blood cell count. Further, only gestational age significantly influenced the clonogenic potential of UCB HSPCs. Finally, isolated CD34+/CD133+, CD34+/CD133– and ALDH^high HSPC obtained from preterm cord blood showed a significantly higher clonogenic potential compared to term cord blood.

Conclusion

We demonstrate that preterm cord blood exhibits a higher HSPC concentration and increased clonogenic capacity compared to term neonates. These data may imply an emerging use of HSPCs in autologous stem cell therapy in preterm neonates.

Liver morphologic analysis in perinatal autopsies with intrauterine stress liver morphology in perinatal autopsies

Quantify steatosis, fibrosis, and focuses of extramedullary erythropoiesis (ER) in the liver and report it to the causes of death in the perinatal. Morphologic analysis of steatosis', percentage of fibrosis, and ER of 467 perinatal autopsies. Cases with hypoxia/perinatal anoxia and ascending infection showed higher percentage of fibrosis. The number of ER was significantly higher among premature infants and in cases with infection. Our results contribute to a better quality of perinatal care through clinical demonstration of which injuries are associated with them, what may help in early diagnosis of these alterations in children who survive.

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.

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.

Relationship between radiosensitivity of human neonatal hematopoietic stem/progenitor cells and individual maternal/neonatal obstetric factors

Hematopoietic stem/progenitor cells (HSPCs) in placental/umbilical cord blood (CB), which is neonatal peripheral blood, have increasingly been used for hematopoietic stem cell transplantations. It is likely HSPCs are sensitive to extracellular oxidative stresses, such as ionizing radiation and redox-directed chemotherapeutic agents. However, the radiosensitivity of HSPCs and neonatal hematopoietic system remains unclear. This study investigated the potential relationship between the radiosensitivity of HSPCs in CB, which was obtained from singleton and full-term deliveries, and maternal/neonatal obstetric factors. Freshly prepared CB CD34(+) cells exposed to 2 Gy X-irradiation were assayed for hematopoietic progenitor cells such as colony-forming unit-granulocyte-macrophage (CFU-GM), burst-forming unit-erythroid (BFU-E), colony-forming unit-granulocyte-erythroid-macrophage-megakaryocyte (CFU-Mix), and colony-forming unit-megakaryocyte (CFU-Meg). As a result, the neonatal weight, placental weight, CB volume, total low-density (LD) cells, and CD34(+) cells showed mutually significant positive correlations. The CB volume and total LD cells showed a significant reverse correlation with the surviving fraction of CFU-Meg. The surviving fraction of CFU-GM in spring (March-May) was significantly higher than that in autumn (September-November). The surviving fraction of CFU-Meg in the spring was significantly lower than that in the autumn. Male neonates showed a significantly higher surviving fraction of CFU-GM than female neonates. Contrarily, females showed a significantly higher surviving fraction of CFU-Meg than males. The present results suggest that the obstetric factors, such as the season of birth and neonatal gender, influence the radiosensitivity of neonatal hematopoiesis.

Perinatal asphyxia is associated with the umbilical cord nucleated red blood cell count in pre-eclamptic pregnancies

Nucleated red blood cells are commonly present in the blood of newborns. Our objective was to investigate the value of umbilical cord nucleated red blood cell (NRBC) count in predicting fetal asphyxia in pre-eclamptic women. NRBCs were counted in umbilical cord blood samples of neonates born to 43 pre-eclamptic and 25 healthy pregnant women. Pre-eclamptic women were further subgrouped based on the presence or absence of intrauterine growth restriction. The NRBC count differed significantly between pre-eclamptic women with and without intrauterine growth restriction, and controls (26.3 +/- 7.5; 17.1 +/- 6.8; and 9.9 +/- 2.7; p < 0.001). A NRBC count of 18.5 or above could predict fetal asphyxia with a sensitivity of 94.4% and a specificity of 80.0%. The umbilical cord NRBC count is effective in predicting fetal asphyxia in pre-eclamptic women.

Influence of obstetric factors on the yield of mononuclear cells, CD34+ cell count and volume of placental/umbilical cord blood

AIM

Placental/umbilical cord blood (CB) has been used increasingly not only for transplantations, but also in the field of life science research. However, little information is available on the biological characteristics of CB units collected in rural areas because no medical facilities are affiliated with CB banks. Little attention has been paid to the collection of CB units in rural areas compared to CB collected in metropolitan areas. CB is a precious source for life science research due to the recent low birth rate in Japan. Therefore, to efficiently utilize CB units, the purpose of the present study was to investigate the optimum obstetric factors associated with a higher yield of mononuclear/CD34(+) cells per CB unit.

METHODS

CB units were collected at a single hospital (Hirosaki National Hospital). A total of 126 CB units from 105 vaginal deliveries and 21 cesarean section deliveries were available for cell separation within 24 h. Mononuclear low-density (LD) cells were separated using Ficoll-Paque and then processed for CD34(+) cell enrichment using magnetic cell sorting. Associations between the maternal/neonatal factors and the yield of LD/CD34(+) cells were analyzed.

RESULTS

Despite the larger net weight of CB collected from cesarean section deliveries, the total number of LD cells collected from vaginal deliveries was significantly higher than that collected from cesarean section deliveries. The total number of LD cells per CB unit from primigravidae was significantly higher compared with that collected from from multigravidae.

CONCLUSION

CB units from vaginal deliveries of primigravidae may be more favorable because they contain a higher yield of mononuclear cells.

Quality rather than quantity: the cord blood bank dilemma

Growing inventories of cord blood units have facilitated access to umbilical cord cell transplantation for many patients lacking conventional stem cell donors. They are in principle 'off-the-shelf', 'fit-for-use', as well as safe and effective therapy products. Cellular enumeration is used as a surrogate of graft potency, and users rely on the rigorous assessment carried out in banks to avoid poor engraftment after thawing (loss of cells or poor function), when the patient's situation is critical. However, in practice, when units are selected, initially on the basis of HLA matching and cell dose assessment, their absolute quality remains uncertain. Unfortunately, quality-related issues (particularly related to viability) are not uncommon in cord blood transplantation. The reasons for potency failures are diverse, but a lack of thorough validation during critical steps of the process and of appropriate use of quality-control tools for timely detection of problematic units are significant contributors. Moreover, incongruence between different sets of standards and regulations, and lack of common quality systems between banks result in a highly heterogeneous international inventory. Therefore, this complicates the matter for the end user of the product. To ameliorate this situation, it is essential to improve quality at each of the critical manufacturing steps wherein potency can be threatened, thereby creating homogeneous inventories of units with excellent quality and quantity.

Protocols for hematopoietic stem cell expansion from umbilical cord blood

The reconstitution of adult stem cells may be a promising source for the regeneration of damaged tissues and for the reconstitution of organ dysfunction. However, there are two major limitations to the use of such cells: they are rare, and only a few types exist that can easily be isolated without harming the patient. The best studied and most widely used stem cells are of the hematopoietic lineage. Pioneering work on hematopoietic stem cell (HSC) transplantation was done in the early 1970s by ED. Thomas and colleagues. Since then HSCs have been used in allogenic and autologous transplantation settings to reconstitute blood formation after high-dose chemotherapy for various blood disorders. The cells can be easily harvested from donors, but the cell number is limited, especially when the HSCs originate from umbilical cord blood (UCB). It would be desirable to set up an ex vivo strategy to expand HSCs in order to overcome the cell dose limit, whereby the expansion would favor cell proliferation over cell differentiation. This review provides an overview of the various existing HSC expansion strategies-focusing particularly on stem cells derived from UCB-of the parameters that might affect the outcome, and of the difficulties that may occur when trying to expand such cells.

Factors modulating circulation of hematopoietic progenitor cells in cord blood and neonates

BACKGROUND

Hematopoietic progenitor cells (HPC) circulate at high levels at birth and disappear rapidly afterwards, but the underlying mechanism it is not known. The aim of this study was to assess circulating HPC in cord blood at different gestational ages and shortly after birth and concomitantly study the biologic markers involved in this phenomenon.

METHODS

All samples were analyzed for CD34(+) cells, colony-forming units (CFU) and cytokines.

RESULTS

The results obtained confirmed a slight decrease in HPC concentration during the late stage of fetal life (R(2)=0.41). After birth, CD34(+) cells showed a rapid decline from circulation: 25+/-29% at 3 h, 51+/-42% at 12 h and 80+/-48% at 60 h. CFU cleared following a similar pattern. Cord plasma showed higher concentrations of stem cell factor (SCF), fetal liver tyrosine kinase 3-ligand (FLT3l), erythrpoietin (EPO), granulocyte colony-stimulating factor (G-CSF) and interleukin-11 (IL-11) compared with an adult control. Interestingly, the EPO concentration in newborn plasma correlated with the kinetics of HPC decline after birth. Moreover, we observed an up-regulation of l-selectin and a down-regulation of CXCR4 expression in CD34(+) cells 3 h after birth.

DISCUSSION

These data combined suggest that an active homing process results in the clearance of HPC from the circulation immediately after birth.

Prenatal priming of cord blood T lymphocytes by microbiota in the maternal vagina

PROBLEM

In the vagina of women at the reproductive age, more than 170 strains of bacteria and yeasts are found. The effect of vaginal flora on neonatal T cells is yet to be investigated.

METHOD OF STUDY

We analyzed CD45RA and CD45RO expression on neonatal CD4+ T cells and cytokine production in CBMC cultures (interferon-gamma (IFN-gamma ), interleukin-4 (IL-4) and IL-12) related to vaginal bacteria isolated from a maternal vagina. We collected vaginal swabs from 36 women at the first stage of the delivery and cord blood from their newborns. IFN-gamma, IL-4, and IL-12 in stimulated CBMC were measured and the expression of CD45RA/CD45RO on CD4+ T cells was assessed.

RESULTS

We noted the difference in CD45RO CD4+ expression and IL-12 levels between the newborns whose mothers were or were not colonized with Lactobacillus in the vagina (newborns whose mothers were colonized with Lactobacillus: CD45RO-10%+/-3; IL-12-0.2 pg/mL +/- 0.05; newborns whose mothers were not colonized with Lactobacillus: CD45RO-6%+/-3; IL-12-2.0 pg/mL +/- 0.7).

CONCLUSION

Our results may indicate that lactobacilli in maternal vagina influence the development of neonatal immune system. Yet, more research is needed using specified bacterial antigens.

Early proliferation of umbilical cord blood cells from premature neonates

BACKGROUND AND OBJECTIVE

Human umbilical cord blood (UCB) is an important source of haematopoietic stem cells; however, the behaviour of progenitor cells obtained from premature and full-term neonates is still a controversy subject. Thus, the aim of this study was to evaluate cell cycle parameters and the proliferative capacity of UCB progenitor cells from premature and full-term neonates.

MATERIAL AND METHODS

Clonogenic assays were performed with methylcellulose, medium supplemented with recombinant stimulating growth factors and the colonies were scored on the seventh day and the 14th day of culture. A cell cycle study was carried out by DNA analysis using flow cytometry and 30 000 events were acquired; p107 and p130 expressions were analysed by Western blotting.

RESULTS

Cultures obtained from UCB of premature neonates showed an early growth of colony-forming unit (CFU)-burst forming unit erythroid/CFU-granulocyte, erythrocyte, macrophage and megakaryocyte (BFU-E/GEMM), and CFU-granulocyte, macrophage (GM) by the seventh day of culture (P < 0.001). Therefore, the number and morphological characteristics of these colonies were comparable with those obtained from full-term neonates, on the 14th day of culture. At the 14th day, a large amount of CFU-GM was detected in the premature group (P < 0.0032). The premature culture on the 14th day showed fibroblasts and was comparable to those of full-term neonates on the 21st day in terms of number and morphology of the colonies. DNA analysis showed that the number of cells in S-phase was also higher in premature samples when compared to full-term neonates, P < 0.0021 (0 h = 12.8 vs. 2.5%; 16 h = 10.5 vs. 5.9%; 20 h = 13.5 vs. 10.3%; 24 h = 13.8 vs. 9.1%; 48 h = 14.0 vs. 5.4%; 72 h = 20.5 vs. 8.9%; 96 h = 13.8 vs. 7.7%). The Western blotting results demonstrated that p107 and p130 cell cycle protein expressions were higher in premature cells than in full-term cells.

CONCLUSION

These results suggest that the higher capacity of proliferation and early differentiation of premature UCB might not be related only to the amount of stem/progenitor cells but also to a different timing of cell cycle entry.

[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.

Flow cytometric assessment of hematopoietic cell subsets in cryopreserved preterm and term cord blood, influence of obstetrical parameters, and availability for transplantation

OBJECTIVE

The aim of this study was to characterize the lymphocyte and the hematopoietic stem and progenitor cell (HPC) subsets of cryopreserved premature cord blood (PCB) compared to term cord blood (TCB) by flow cytometry, to study the influence of birth conditions, and to assess its availability for transplantation.

MATERIALS AND METHODS

Four-color flow cytometric analysis was performed on 43 PCB and 40 TCB cryopreserved samples using a panel of 24 different mAbs, directed against lymphoid and HPC surface markers. The CB volume was estimated by the weight of the newborn to determine the absolute MNC and CD34(+) cell content/CB sample. Clinical and obstetrical data were recovered. Statistical comparisons and a multiple regression analysis were performed.

RESULTS

No consistent differences were found in the mononuclear cell (MNC) or CD34(+) cell concentration (x10(6)/L) between PCB and TCB. The percentage of primitive HPC (CD34(+)CD38(-), CD34(+)CD38(-)CD90(-)HLA-DR(-), CD34(+)CD38(-)CD90(-)HLA-DR(+)) and primitive lymphoid progenitors (CD34(+)CD7(+), CD34(+)CD7(+)CD19(-)CD117(-)) were higher in PCB than in TCB. Correspondingly, TCB had an increased percentage of committed HPC. No sample of PCB contained >2 x 10(7) MNC/kg (and only 48% had >1 x 10(5) CD34(+) cells) for a recipient of 20 kg body wt, as the minimum threshold recommended for CB transplantation. Obstetrical factors modulated mainly lymphocyte subsets and fewer HPC subpopulations. Acute fetal distress increased CD34(+) cells, especially the immature subsets. Maternal treatment with dexamethasone and intrauterine growth retardation decreased CD3(+) cells. No other obstetrical factors played a detrimental effect on CB cells if used for transplantation.

CONCLUSION

PCB is richer in immature cells both in lymphocyte and HPC populations, and its use for transplantation, at least in special cases, should be reconsidered.

Placental/umbilical cord blood: experience of st. Eugenio Hospital collection center

BACKGROUND

Umbilical cord blood (UCB) contains stem cells and may be an alternative source to bone marrow and peripheral blood stem cells for allogeneic transplantation for the treatment of hematologic malignancies and genetic disorders. Many UCB banks have been established worldwide to quickly provide high quality materials for transplantation. Moreover, a detailed set of standards for cord blood banking have been drawn to guarantee the quality of the products.

STUDY DESIGN AND METHODS

The aim of this study was to analyze our activity between 1998 and 2001, seeking to improve the number of suitable UCB units. Written informed consent was obtained from healthy women with an uncomplicated pregnancy.

RESULTS

During the study period, we collected 1060 UCB units; 328 (31%) were banked, whereas 732 (69%) were discarded. The collections were performed in 73% vaginal deliveries and 27% of cesarean sections. The main reason for the exclusion was biological; in fact, a low number of nucleated cells and a low volume accounted for 71% of the total discarded units. Moreover, 20% of the units were discarded because of parental clinical reasons.

CONCLUSIONS

Our study shows that maternal history must be completely reviewed before labor and obstetrical factors should be considered to improve the number of UCB units.

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

BACKGROUND AND OBJECTIVES

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

MATERIAL AND METHODS

A retrospective analysis of obstetric and neonatal factors was performed from 300 cord blood donations in Valencia Cord Blood Bank. Maternal, neonatal and collection factors influencing cord blood quality measured as volume, total nucleated cell count, CD34+ cells and colony-forming units (CFU) were analysed.

RESULTS

Bigger babies produced cord blood units with larger volume, higher cells counts, CFU and CD34 cell counts. In the multivariate analysis, we found that both placental weight and mode of collection were predictor variables for total nucleated cell count, CD34 cells and CFU.

CONCLUSION

Our study concludes that cord blood units must be collected before placental delivery and that 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.

Cord blood hematopoietic progenitor cell concentration and infant sex

BACKGROUND

Characterization of cord blood facilitates understanding of the factors affecting cord blood transplant quality and improvement of transplantation results. Cord blood obtained from male and female infants has not been thoroughly characterized.

STUDY DESIGN AND METHODS

A study was performed to test the hypothesis that the cord blood hematopoietic progenitor cell content-of which the CD34+ cell and colony-forming unit (CFU) concentrations were taken as markers-would not only associate with birth weight but also with sex. The hematopoietic progenitor cell concentrations of 1999 healthy infants (47% female) were analyzed in a cord blood bank setting.

RESULTS

Male infants had significantly higher median CD34+ cell concentrations than female infants (31.8/microL vs. 30.2/microL, respectively; p = 0.03). Although the disparity in absolute concentrations was small, it was 5.3 percent. In CFU subgroup analysis, the median CFU-mixed concentration of male infants (11.1/microL) was higher than in female infants (9.9/microL; p = 0.03). The difference was more pronounced when cumulative frequencies of the CFU-mixed concentrations from cesarean section deliveries were compared. In multivariate linear regression analysis, the positive influence of male sex on the CD34+ cell concentration was significant (p < 0.05). The expected higher median nucleated cell concentration of female compared to male infants (13.9 x 10(9)/L vs. 13.3 x 10(9)/L, respectively; p = 0.0001) was mainly due to the higher neutrophil concentration of female infants (7.1 x 10(9)/L vs. 6.5 x 10(9)/L, respectively, p < 0.0001).

CONCLUSION

Cord blood hematopoietic progenitor cell concentration was higher in male infants, even after correcting for birth weight. Sex may affect the hematopoietic potential of cord blood transplants.

Impact of donor- and collection-related variables on product quality in ex utero cord blood banking

BACKGROUND

Optimizing product quality is a current focus in cord blood banking. This study evaluates the role of selected donor- and collection-related variables.

STUDY DESIGN AND METHODS

Retrospective review was performed of cord blood units (CBUs) collected ex utero between February 1, 2000, and February 28, 2002. Preprocessing volume and total nucleated cell (TNC) counts and postprocessing CD34 cell counts were used as product quality indicators.

RESULTS

Of 2084 CBUs, volume determinations and TNC counts were performed on 1628 and CD34+ counts on 1124 CBUs. Mean volume and TNC and CD34+ counts were 85.2 mL, 118.9 x 10(7), and 5.2 x 10(6), respectively. In univariate analysis, placental weight of greater than 500 g and meconium in amniotic fluid correlated with better volume and TNC and CD34+ counts. Greater than 40 weeks' gestation predicted enhanced volume and TNC count. Cesarean section, two- versus one-person collection, and not greater than 5 minutes between placental delivery and collection produced superior volume. Increased TNC count was also seen in Caucasian women, primigravidae, female newborns, and collection duration of more than 5 minutes. A time between delivery of newborn and placenta of not greater than 10 minutes predicted better volume and CD34+ count. By regression analysis, collection within not greater than 5 minutes of placental delivery produced superior volume and TNC count.

CONCLUSION

Donor selection and collection technique modifications may improve product quality. TNC count appears to be more affected by different variables than CD34+ count.

Comparison of decidual leukocytes following spontaneous vaginal delivery and elective cesarean section in uncomplicated human term pregnancy

The aim of this study was to quantify and compare leukocyte populations in term decidua basalis and parietalis obtained after spontaneous vaginal delivery (SVD) or elective cesarean section (CS) without labor. Decidua basalis and parietalis samples were obtained from placentas after SVD (n = 20) and after CS (n = 30). Following mechanical disaggregation, leukocytes were purified and stained with monoclonal antibodies. Percentages of leukocyte subclasses within the CD45(+) cell fraction and activated T cells were determined by flow cytometry. No differences were found in the percentages of CD45(+) cells or CD56(bright)CD16(-) uterine natural killer (NK) cells between decidua basalis from SVD and CS or between decidua parietalis from SVD and CS. In decidua basalis and parietalis from SVD, a significantly higher number of CD56(dim)CD16(+) NK cells was found compared to CS. In decidua basalis from SVD, there was a significantly lower percentage of CD14(+) cells and higher percentage of CD19(+) cells compared to CS. The percentage of CD3(+) T cells expressing CD25 or human leukocyte antigen (HLA)-DR was significantly decreased in decidua basalis and parietalis from SVD compared to CS. Comparison of decidua collected after SVD or CS suggests that labor is associated with dynamic changes in the distribution of decidual leukocytes, specifically NK and T cell subpopulations. In particular, the disappearance of the CD4(+)CD25(+) T cell population, which possibly contains a subpopulation of regulatory T cells, may contribute to the initiation of labor. Further investigation into factors affecting decidual leukocytes may expand our understanding of the immunological events at the maternal-fetal interface.

The immunologic profile of infants born after maternal immunoglobulin treatment and intrauterine platelet transfusions for fetal/neonatal alloimmune thrombocytopenia

OBJECTIVE

The purpose of this study was to evaluate whether maternally administered intravenous immunoglobulins (IVIG) and intrauterine platelet transfusions (IUPT) for fetal/neonatal alloimmune thrombocytopenia (FNAIT) affect the development of the fetal immune system.

STUDY DESIGN

The lymphocyte subset distribution of mononuclear cells of cord blood of 20 FNAIT newborns was analyzed by flow cytometry and compared with a control group of healthy newborns and a reference group treated with intrauterine erythrocyte transfusions (IUET) for hemolytic disease.

RESULTS

The percentage of monocytes, natural killer (NK) cells, ratios of mature and immature T cells and B cells, and resting or activated cells were not significantly different compared to the control group. In addition, the B-cell and T-cell populations showed a normal in vitro antibody production and T-cell proliferation when compared with the control group.

CONCLUSION

Antenatal treatment for FNAIT with maternal IVIG with or without IUPT is not associated with lymphocyte activation or premature maturation of the neonatal immune system.

Nucleated Red Blood Cells in Uncomplicated Prolonged Pregnancy

OBJECTIVE

Elevated counts of nucleated red blood cells (NRBCs), as well as prolongation of pregnancy, have been suggested as predictors of adverse perinatal outcome. However, the association between these 2 variables has received only minimal attention. We sought to evaluate fetal NRBCs in prolonged pregnancies.

METHODS

Umbilical cord blood was prospectively collected at delivery from 75 prolonged (at or beyond 287 days) pregnancies. One hundred and fifty term deliveries (260-286 days) served as controls. All pregnancies were accurately dated with the use of first-trimester sonography. Fetal biophysical profile testing was initiated at 40 weeks of gestation. Patients were delivered if they were in spontaneous labor or the biophysical profile was nonreassuring or by 42 weeks of gestation. Nucleated red blood cell counts were expressed per 100 white blood cells (WBC). Umbilical artery pH studies, as well as other demographic and clinical variables, were obtained.

RESULTS

Prolonged pregnancy was associated with a significantly increased incidence of induction of labor and a greater birth weight. There were no other differences between the study group and controls. The median NRBCs per 100 WBCs in prolonged pregnancy was not significantly elevated over the term values (median 3, range 0-35 versus median 3, range 0-34, respectively; P =.25). Neonatal outcome was also comparable between groups. The univariate regression analysis demonstrated a significant association between elevated NRBC counts and low arterial cord blood pH (P <.008, R = 0.175), elevated base excess (P =.02, R = 0.149), low platelet counts (P =.046, R = 0.134), and male gender (P =.028). Stepwise regression analysis revealed that low arterial cord blood pH and male gender were the only independent variables predicting elevated NRBC counts at birth.

CONCLUSION

The findings of this study suggest that elevated NRBC counts are associated with specific pregnancy complications rather than uncomplicated prolonged pregnancies in general.

Are elevated fetal nucleated red blood cell counts an indirect reflection of enhanced erythropoietin activity?

OBJECTIVE

Animal and human studies demonstrated elevated erythropoietin (EPO) levels in response to intrauterine hypoxic events. Other studies documented an association between fetal hypoxia and elevated nucleated red blood cell (NRBC) counts and have speculated that it is the elevation of EPO that results in an increase in NRBC counts. Thus, the purpose of our study was to determine the correlation between EPO levels and NRBC counts in the human fetus.

STUDY DESIGN

Data were collected prospectively between April and July of 2003. Term singleton pregnancies were eligible to participate in the study. Umbilical cord blood was collected immediately after birth for determination of fetal EPO levels and NRBC counts.

RESULTS

Forty pregnancies formed the study population. The mean gestational age at delivery was 39.5 +/- 1.2 weeks (+/-SD) and the mean birth weight was 3500 +/- 372 g. The median EPO (mU/mL) was 34 (range 13-427). The median NRBC/100 white blood cells was 10 (range 0-150). A simple regression analysis indicated that NRBC counts are significantly and positively correlated with EPO (P=.0004, R(2)=0.287).

CONCLUSION

Our results suggest a significant association between EPO and NRBC counts in term singleton fetuses. These results support the hypothesis that fetal NRBC and EPO are interrelated. However, the relatively low R(2) indicates that there are other (yet to be determined) hypoxia-derived mediators that result in an elevation of fetal NRBC counts.

Optimizing donor selection in a cord blood bank

OBJECTIVES

The main limitation factor for the wide use of umbilical cord blood (UCB) as a source of hematopoietic progenitor for transplantation is cell dose. One of the specific areas identified by some studies for improvement of UCB collection is donor selection.

METHODS

Over a 3-mth period, 391 consecutive maternal-neonatal pairs were evaluated during the pre-partum period in the maternity ward at La Fe University Hospital (Valencia) by the Cord Blood Bank staff. Reasons for discarding umbilical cord blood donors and collected UCB units at the Cord Blood Bank in Valencia have been analysed. Obstetric factors influencing TNC content of 1300 collected UCB units have been determined, in order to establish obstetric criteria for cord blood donors selection in our geographic area.

RESULTS

Only 32.5% of potential cord blood donors were refused. Among 1300 UCB collected, 506 (38.9%) were discarded before cryopreservation, mainly due to low cell counts. Multivariate analyses showed that the main significant factors influencing nucleated cell count were the weight of the placenta, sex of newborn and mode of collection.

CONCLUSIONS

Our study shows that maternal medical histories must be completely reviewed by medical staff before collection of the UCB. Obstetrical factors influence cell content of UCB and could be added to standard cord blood donor criteria in order to improve the bank efficiency.

Timing of fetal nucleated red blood cell count elevation in response to acute hypoxia

We determined the effect of an acute episode of severe hypoxia on peripheral nucleated red blood cell (RBC) counts in the fetal rat. Timed pregnant rats were randomized to a 2-hour exposure to hypoxia (placement in a chamber containing a gas mixture with 9% O2 +3% CO2 + balanced N2) or to a 2-hour exposure to a sham chamber containing room air. Two maternal animals per group underwent cesarean section immediately after the 2-hour period and then 4, 12, 24, 36, 48, and 60 h after exposure. Fetal nucleated RBC counts were compared between groups at each time interval. The nucleated RBC counts were not significantly different in the hypoxia group until 12 h (mean +/- SEM 158.0 +/- 22.4 RBC/10 high-power fields vs. 90.6 +/- 11.0; p = 0.03) and 24 h (133.2 +/- 16.0 vs. 84.1 +/- 9.0; p = 0.04) after exposure. There were no differences between groups 36, 48, and 60 h after exposure. In the near-term rat fetus, acute hypoxia was associated with a delayed but transient increase in peripheral nucleated RBC counts.

The impact of intrapartum factors on umbilical cord blood stem cell banking

AIMS

Umbilical cord blood can be used as an alternative source for related and unrelated allogeneic stem cell transplantation. This study was undertaken to determine whether intrapartum factors have an influence on the hematopoietic cell compartment of cord blood.

METHODS

Cord blood samples were obtained from 102 normal full-term deliveries for the banking of stem cells. We analyzed the influence of intrapartum factors on the count of CD34+ cells, total nucleated cells, colony forming units and total volume of collection. Fluorescence-activated cell sorting was used to measure CD34+ cell numbers. Statistical analysis was undertaken using Pearson correlation test and multiple regression analysis.

RESULTS

The higher the infants' birthweight the larger was the volume. A lower arterial umbilical pH and a larger blood volume resulted in an increased number of CD34+ cells. A large blood volume, long duration of labor, lower arterial and venous pH were correlated with more nucleated cells. A higher birthweight, larger blood volume and lower arterial pH resulted in an increased number of colony forming units.

CONCLUSIONS

Some intrapartum factors have an impact on the characteristics of collected cord blood cells. Stress during delivery may influence the number of hematopoetic cells, through altered cytokine production. This knowledge may facilitate the selection of optimal cord blood samples for unrelated banking and the early discarding of suboptimal cord blood samples thus resulting in the saving of costs related to expensive further processing.

The effect of labor on neonatal T-cell phenotype and function

With increasing interest in the role of fetal programming in child and adulthood diseases, and therefore interest in the measurement of various factors at birth, it is essential to ascertain whether the factors of interest show any gestation- or parturition-associated changes. We have investigated whether mode of delivery influenced T-cell phenotype and function (CD4+) as has been described for monocytes and neutrophils. Interferon-gamma production in response to either the mitogen phytohemagglutinin or anti-CD2/CD3/CD28 F(ab')3 was significantly reduced by neonatal mononuclear cells compared with adult cells but did not differ with mode of delivery at term (normal vaginal delivery versus elective lower-segment cesarean section). Likewise, anti-CD2/CD3/CD28-stimulated IL-2 production by the neonate was lower than adult levels but did not differ with mode of delivery. The expression of common T-cell activation markers (CD25, MHC class II, CD69, CD62L, CD11a, CD44, and CD49d) was examined. Only CD62L (L-selectin) expression was significantly different, with fewer adult T cells expressing this surface antigen compared with neonatal T cells (p < 0.0003), and significantly more T cells from lower-segment cesarean section than normal vaginal delivery were positive for CD62L (p = 0.012). sCD62L levels were significantly lower in cord plasma compared with adult plasma but did not differ with mode of delivery. Thus the phenotype and function of cord blood T cells did not differ greatly with mode of delivery, but possible differences for the marker of interest should always be assessed. Furthermore, although there was no significant difference with mode of delivery for all markers, except CD62L, the variation in the normal vaginal delivery samples, as for the adults, was greater than in the lower-segment cesarean section samples, indicating that the effects of length of labor and stress at delivery may well be relevant.

Comparison between two cord blood collection strategies

BACKGROUND AND OBJECTIVES

Collection strategy is the first step for collecting good quality cord blood (CB) units. There are two principal different techniques to collect CB from the umbilical vein: in the delivery room while the placenta is still in the uterus by midwives and obstetricians or in an adjacent room after placental delivery by CB-bank trained personnel. In this study, the benefits and disadvantages between two different CB collection strategies were evaluated in order to improve CB bank methodology.

DESIGN AND METHODS

Valencia CB bank maintains the two different collection strategies aforementioned. Before processing CB units, volume was calculated and samples were drawn for cell counts. After processing and before cryopreservation, samples for cell counts, CD34 analysis, viability, clonogenic assays and microbiology were drawn directly from the bags. We compared the efficiency of the two collection techniques.

RESULTS

Obstetric date and umbilical CB was obtained from 848 vaginal (484 collected in uterus and 364 collected ex uterus). The proportion of excluded CB units before processing was 33% for ex uterus and 25% for in uterus. The difference was statistically significant. A larger volume and a higher number of total nucleated cells, CD34+ cells and CFUs were harvested in the in uterus collection group.

INTERPRETATION AND CONCLUSIONS

Based on our findings, we conclude that the mode of collection influences the hematopoietic content of CB donations. Collection before placental delivery is the best approach to CB collection and allows optimizing CB bank methodology.

Comparison between two strategies for umbilical cord blood collection

The use of cord blood (CB) for transplantation has increased greatly in recent years. The collection strategy is the first step in collecting good-quality CB units. There are two main techniques for collecting CB from the umbilical vein: in the delivery room while the placenta is still in the uterus by midwives and obstetricians or in an adjacent room after placental delivery by CB bank trained personnel. In this study, the benefits and disadvantages between the two different CB collection strategies were evaluated, in order to improve CB bank methodology. Valencia CB bank maintains the two different collection strategies. CB was obtained from 569 vaginal and 70 caesarean deliveries and obstetrical and clinical charts were reviewed. Before processing CB units, volume was calculated and samples were drawn for cell counts. After processing and before cryopreservation samples were drawn for cell counts, CD34+cell analysis, viability, clonogenic assays and microbiology were drawn directly from the bags. We compared the efficiency of the two collection techniques. Obstetric data and umbilical CB were obtained from 569 vaginal (264 collected in utero and 305 collected ex utero) and 70 caesarean deliveries. The proportion of excluded CB units before processing was 33% for vaginal ex utero, 25% for vaginal in utero and 46% for caesarean deliveries. Differences were statistically significant. For vaginal deliveries a larger volume and a higher number of nucleated cells, percentage of CD34+ cells and colony-forming units (CFUs) were harvested in the in utero collection group. There was no statistical difference between CB collected after placental expulsion from vaginal and caesarean deliveries. Comparison between all vaginal and caesarean deliveries did not show any difference. We conclude that the mode of collection influences the haematopoietic content of CB donations. Collection before placental delivery is the best approach to CB collection and allows optimisation of CB bank methodology. Caesarean deliveries seem to contain similar progenitor content to vaginal deliveries.

Cell-free fetal DNA in the plasma of pregnant women with severe fetal growth restriction

OBJECTIVE

Although there have been reports of increased fetal nucleated erythrocytes in the blood of pregnant women who are carrying growth-restricted fetuses, there have been no reports of quantification of fetal DNA concentration in the plasma of women with fetal growth restriction. We quantified fetal DNA concentration in the plasma of pregnant women with preeclampsia and/or fetal growth restriction.

STUDY DESIGN

We examined maternal plasma from 9 pregnant women with fetal growth restriction and 9 with preeclampsia and from 20 women who were gestational age-matched normal control subjects. All women carried a male fetus. DNA was extracted from 1.5-mL plasma samples, and the DYS14 and beta-globin gene were analyzed by real-time quantitative polymerase chain reaction.

RESULTS

The concentration of fetal DNA was significantly higher in subjects with preeclampsia than in fetal growth restriction subjects and normal control subjects. Fetal DNA concentrations in fetal growth restriction subjects were similar to those of normal control subjects. The concentration of total DNA (beta-globin) was significantly higher in subjects with preeclampsia when compared with healthy control subjects.

CONCLUSION

We demonstrated that there was no increase in fetal DNA in the plasma of pregnant women with fetal growth restriction and that most fetal DNA in maternal plasma originates from trophoblasts.