Circadian and circannual variations in cord blood hematopoietic cell composition

The ALLgorithMM: How to define the hemodilution of bone marrow samples in lymphoproliferative diseases

Introduction

Minimal residual disease (MRD) is commonly assessed in bone marrow (BM) aspirate. However, sample quality can impair the MRD measurement, leading to underestimated residual cells and to false negative results. To define a reliable and reproducible method for the assessment of BM hemodilution, several flow cytometry (FC) strategies for hemodilution evaluation have been compared.

Methods

For each BM sample, cells populations with a well-known distribution in BM and peripheral blood - e.g., mast cells (MC), immature (IG) and mature granulocytes (N) – have been studied by FC and quantified alongside the BM differential count.

Results

The frequencies of cells’ populations were correlated to the IG/N ratio, highlighting a mild correlation with MCs and erythroblasts (R=0.25 and R=0.38 respectively, with p-value=0.0006 and 0.0000052), whereas no significant correlation was found with B or T-cells. The mild correlation between IG/N, erythroblasts and MCs supported the combined use of these parameters to evaluate BM hemodilution, hence the optimization of the ALLgorithMM. Once validated, the ALLgorithMM was employed to evaluate the dilution status of BM samples in the context of MRD assessment. Overall, we found that 32% of FC and 52% of Next Generation Sequencing (NGS) analyses were MRD negative in samples resulted hemodiluted (HD) or at least mildly hemodiluted (mHD).

Conclusions

The high frequency of MRD-negative results in both HD and mHD samples implies the presence of possible false negative MRD measurements, impairing the correct assessment of patients’ response to therapy and highlighs the importance to evaluate BM hemodilution.

[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.

[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.

Seasonal variation of human physiology does not influence the harvest of peripheral blood CD34+ cells from unrelated hematopoietic stem cell donors

There are many reports on factors predicting the outcome of PBSC (peripheral blood stem cell) mobilization, such as the donor's gender, age, weight, white blood cell count, platelets pre apheresis, LDH and iron status. Although there are reports of seasonal variation in the physiology of the human immune system and hematopoiesis there are no data that such differences play a role in the response to G-CSF in healthy hematopoietic stem cell donors. The response to G-CSF could also impact the collection results during different seasons. To assess the possible impact of seasonal variation we performed a retrospective, single-center analysis of mobilization and harvest of PBSC in 330 healthy unrelated donors. We found no significant differences in the number of CD34+ cells in peripheral blood after G-CSF mobilization and in collection results when all donors were analyzed. In the subgroup of male donors the number of CD34+ stem cells after G-CSF mobilization was higher than average in summer and autumn (p = 0.036), however, it did not translate into clinically relevant differences in stem cell harvest. We conclude that although there is possible seasonal variation in the response to G-CSF in male donors there is no impact on PBSC harvest in healthy unrelated donors.

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.

Reconstitution of adaptive immunity after umbilical cord blood transplantation: impact on infectious complications

In comparison with allogeneic stem cell transplantation (alloHSCT) with other stem cell sources, umbilical cord blood transplantation (UCBT) was traditionally associated with increased risk of infections, particularly during the first 3 months after transplantation. Longitudinal studies of immune monitoring reported peculiar patterns of T- and B-cell recovery in the peripheral blood of UCB recipients during the first months post-transplantation. Overall, current data suggest delayed reconstitution of naive and memory CD4⁺ and CD8⁺ T-cell pools after UCBT. This is particularly true for adult recipients and for patients who received in vivo T-cell depleting approaches before the transplantation. Such delayed T-cell recovery may increase susceptibility of UCB recipients for developing opportunistic infections and viral reactivations. Regarding B-cell recovery, UCBT was associated with accelerated B-lymphopoiesis. Recent studies also reported evidence for faster functional memory B-cell recovery in UCB recipients. In this article, we briefly review T- and B-cell reconstitution after alloHSCT, with emphasis on peculiarities observed after UCBT. We further put these data in lines with risks of infections after UCBT.

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.