Autologous umbilical cord blood transfusion

Allogeneic cord blood red blood cells: assessing cord blood unit fractionation and validation

BACKGROUND

For neonates and preterm infants, in whom a transfusion dose is low, the use of red blood cells (RBC) from cord blood appears to be feasible. Standardisation of fractionation and identification and assessment of quality control parameters for such RBC are still lacking.

MATERIALS AND METHODS

We describe the process used to obtain RBC from cord blood for transfusion purposes, including quality controls to evaluate fractionation performance and the effects of storage. The cord RBC, to which SAG-M was added, were sampled on the day of fractionation, and 7 and 14 days (end of storage) later in order to measure the complete blood count, biochemical parameters and residual white blood cells. We also assessed microbial contamination.

RESULTS

Data relative to 279 cord blood units were evaluated. The median gestational age at collection was 40 weeks (interquartile range [IQR] 39.1-40.7) and the median volume was 90 mL (IQR 81-103). Units were subjected to automated fractionation with Compomat, and packed RBC were suspended in SAG-M solution. The median volume of the SAG-M-suspended units was 31 mL (IQR 24.0-38.1) and the median haematocrit was 54.2% (IQR 49.4-59.5). The median volume after leukoreduction was 22 mL (IQR 17-28), with the volume decrease being similar in units leukoreduced before (n=75) or after (n=204) storage. The haematocrit of leukoreduced units was higher than that of buffy coat-depleted units. Storage at 2-6 °C for 14 days was accompanied by an increase of potassium levels and percentage of haemolysis. Microbial cultures were positive for 2.9% of the collected units.

DISCUSSION

Fractionation of whole cord blood can provide RBC concentrates with similar baseline characteristics as units from adults. The transfusion dose and quality of the units appear safe and suitable for clinical use in neonates, with a satisfactory haematocrit and residual white blood cell content, despite a very variable collection volume.

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.

The Use of Umbilical Cord Blood for Autologous Transfusion in Neonatal Open Heart Surgery

In the last few decades, the use of umbilical cord blood (UCB) has received increasing attention, not only as a source of stem cells, but also as a transfusion product for the treatment of anemia in the neonatal and even the adult population. This review focuses on data reports and collection efforts related to the autologous transfusion of UCB in full-term neonates with prenatally diagnosed critical congenital heart defects. This review summarizes different aspects of UCB transfusion, including indications and contraindications; the collection procedure; storage timing; and special properties of one of its constituents, fetal hemoglobin, in the setting of hypothermic cardiopulmonary bypass.

Umbilical cord blood as a source for red-blood-cell transfusion in neonatology: a systematic review

The prevention and treatment of anaemia in newborn patients made tremendous progress in the last decades. However, red-blood-cell (RBC) transfusions remain unavoidable in many neonates candidate to surgery and especially in preterm infants. In particular, anaemia occurring in neonates born at extremely low gestational age is actually severe and frequently requires transfusions. Several approaches have been explored to prevent or even to reduce the threshold and the frequency of RBC transfusions. Among these, umbilical cord blood (UCB) collection and processing to obtain RBC components for autologous or allogeneic transfusion have been extensively investigated. In this systematic review, we revised the literature concerning the use of UCB for either autologous or allogeneic transfusion purposes and we illustrated the rationale for a transfusion therapy tailored to extremely preterm neonates, based on RBC concentrates from allogeneic UCB donations.

Osmotic tolerance limits of red blood cells from umbilical cord blood

Effective methods for long-term preservation of cord red blood cells (RBCs) are needed to ensure a readily available supply of RBCs to treat fetal and neonatal anemia. Cryopreservation is a potential long-term storage strategy for maintaining the quality of cord RBCs for the use in intrauterine and neonatal transfusion. However, during cryopreservation, cells are subjected to damaging osmotic stresses during cryoprotectant addition and removal and freezing and thawing that require knowledge of osmotic tolerance limits in order to optimize the preservation process. The objective of this study was to characterize the osmotic tolerance limits of cord RBCs in conditions relevant to cryopreservation, and compare the results to the osmotic tolerance limits of adult RBCs. Osmotic tolerance limits were determined by exposing RBCs to solutions of different concentrations to induce a range of osmotic volume changes. Three treatment groups of adult and cord RBCs were tested: (1) isotonic saline, (2) 40% w/v glycerol, and (3) frozen-thawed RBCs in 40% w/v glycerol. We show that cord RBCs are more sensitive to shrinkage and swelling than adult RBCs, indicating that osmotic tolerance limits should be considered when adding and removing cryoprotectants. In addition, freezing and thawing resulted in both cord and adult RBCs becoming more sensitive to post-thaw swelling requiring that glycerol removal procedures for both cell types ensure that cell volume excursions are maintained below 1.7 times the isotonic osmotically active volume to attain good post-wash cell recovery. Our results will help inform the development of optimized cryopreservation protocol for cord RBCs.

Osmotic parameters of red blood cells from umbilical cord blood

The transfusion of red blood cells from umbilical cord blood (cord RBCs) is gathering significant interest for the treatment of fetal and neonatal anemia, due to its high content of fetal hemoglobin as well as numerous other potential benefits to fetuses and neonates. However, in order to establish a stable supply of cord RBCs for clinical use, a cryopreservation method must be developed. This, in turn, requires knowledge of the osmotic parameters of cord RBCs. Thus, the objective of this study was to characterize the osmotic parameters of cord RBCs: osmotically inactive fraction (b), hydraulic conductivity (Lp), permeability to cryoprotectant glycerol (Pglycerol), and corresponding Arrhenius activation energies (Ea). For Lp and Pglycerol determination, RBCs were analyzed using a stopped-flow system to monitor osmotically-induced RBC volume changes via intrinsic RBC hemoglobin fluorescence. Lp and Pglycerol were characterized at 4°C, 20°C, and 35°C using Jacobs and Stewart equations with the Ea calculated from the Arrhenius plot. Results indicate that cord RBCs have a larger osmotically inactive fraction compared to adult RBCs. Hydraulic conductivity and osmotic permeability to glycerol of cord RBCs differed compared to those of adult RBCs with the differences dependent on experimental conditions, such as temperature and osmolality. Compared to adult RBCs, cord RBCs had a higher Ea for Lp and a lower Ea for Pglycerol. This information regarding osmotic parameters will be used in future work to develop a protocol for cryopreserving cord RBCs.

A method to measure permeability of red blood cell membrane to water and solutes using intrinsic fluorescence

BACKGROUND

Designing effective cryopreservation procedures for cells requires knowledge of permeability of cell membrane to water and solutes. To determine cell membrane permeability, one needs to measure the rate of cell volume changes in anisotonic environment. Red blood cells (RBCs) respond very quickly to changes in extracellular solutes concentration, which complicates the use of traditional methods. Preservation of RBCs from umbilical cord blood for neonatal transfusions is currently broadly discussed in the literature, but data on osmotic permeability of cord RBCs is controversial. Therefore, alternative methods to determine osmotic membrane permeability of these cells are warranted. We describe a technique to measure rapid changes in RBC volume through changes in the intensity of RBC autofluorescence.

METHODS

To induce osmotically-driven changes in RBC volume, we rapidly mixed human RBCs with anisotonic solutions in a stopped-flow spectroscopy system and the intensity of intrinsic RBC fluorescence was measured.

RESULTS

We found that change in RBC volume cause a proportional change in the intensity of RBC autofluorescence. This phenomenon occurs due to the self-quenching of RBC hemoglobin autofluorescence at high intracellular concentrations.

CONCLUSIONS

This novel method to determine osmotic permeability of RBCs overcomes the limitations of traditional techniques and has numerous clinical applications.

Comparison of stored umbilical cord blood and adult donor blood: transfusion feasibility

Objective: This study aimed to compare the storage properties of red blood cell (RBC) concentrates of umbilical cordblood (UCB) and adult donor blood (ADB), and to evaluate the feasibility of UCB-RBC concentrate as an autologoussource for blood transfusion in very low birth weight (VLBW) preterm neonates.

Material and Methods: In all, 30 newborn (10 preterm, 20 full term) UCB and 31 ADB units were collected.RBC concentrates were stored and compared with regard to pH, potassium (K⁺), 2,3-biphosphoglycerate (2-3-BPG),adenosine tri-phosphate (ATP), plasma Hb, and bacterial contamination on d 1, 21, and 35 of storage.

Results: The K⁺ level increased with time and differed significantly between storage d 1 and 21, and between storaged 1 and 35 in both the UCB and ADB units. Initial and d 21 K⁺ levels were higher in the UCB units than in the ADBunits. The 2,3-BPG level did not differ significantly between the UCB-PRC and ADB-PRC samples. After 35 d of storageboth UCB-PRC and ADB-PRC samples exhibited significant differences from the initial free Hb, intracellular ATP, andpH values. Significant differences in intracellular ATP and pH were also observed between the UCB-PRC and ADB-PRCsamples.

Conclusion: The volume of harvested and prepared UCB-PRC can be used for some of the blood transfusions requiredduring the neonatal period and thus may decrease the number of allogeneic transfusions, especially in preterm newborns.The hematological and biochemical changes that occurred in UCB during storage were comparable with those observedin ADB, and do not pose a risk to the immature metabolism of neonates. UCB-RPC prepared and stored under standardconditions can be a safe alternative RBC source for transfusions in VLBW newborns.

Quality of red blood cells isolated from umbilical cord blood stored at room temperature

Red blood cells (RBCs) from cord blood contain fetal hemoglobin that is predominant in newborns and, therefore, may be more appropriate for neonatal transfusions than currently transfused adult RBCs. Post-collection, cord blood can be stored at room temperature for several days before it is processed for stem cells isolation, with little known about how these conditions affect currently discarded RBCs. The present study examined the effect of the duration cord blood spent at room temperature and other cord blood characteristics on cord RBC quality. RBCs were tested immediately after their isolation from cord blood using a broad panel of quality assays. No significant decrease in cord RBC quality was observed during the first 65 hours of storage at room temperature. The ratio of cord blood to anticoagulant was associated with RBC quality and needs to be optimized in future. This knowledge will assist in future development of cord RBC transfusion product.

Red blood cell transfusions in newborn infants: Revised guidelines

In general, health care professionals taking care of high risk infants in neonatal intensive care units have become more restrictive in their use of red blood cell transfusion over the past 10 years. The present statement is intended for those caring for high risk newborn infants (preterm to one month of age). The objectives of this statement are to provide guidelines to reduce the incidence of anemia in preterm and term infants, to identify strategies to decrease the need for red blood cell transfusions and to limit donor exposure in this population. Recommendations for red blood cell transfusions are included.

Prothrombin activation fragment 1 + 2 as a marker of coagulation activation in cord blood collection for banking

There have been efforts to increase the quality of cord blood (CB) collections aimed at banking and transplantation. Yet, the effect of CB collection techniques on haemostatic activation is scarcely studied, despite the unique nature of the neonatal haemostatic system. The aim of this study was to explore coagulation system and platelet (PLT) activation during CB collection at a national CB bank. At three time points over a 9-year period (in 1998, 2000 and 2006), CB collections were assessed to evaluate the collection process during bank setup and changes in procedures. Thrombin generation and PLT activation were assessed with prothrombin activation fragment 1 + 2 (F1 + 2) and PLT factor 4 (PF4), respectively. The median F1 + 2 level was 2.8 nmol L(-1) in 1998 (n = 11), 0.7 nmol L(-1) in 2000 (n = 10) and 0.7 nmol L(-1) in 2006 (n = 6), the decrease being statistically significant (1998 vs 2000, P < 0.001; 1998 vs 2006, P = 0.01). The median PF4 level was 117 IU mL(-1) in 1998 and 104 IU mL(-1) in 2000. PF4 was not measured in 2006. The level of F1 + 2 correlated with that of PF4 (n = 21; Spearman's Rho = 0.59, P = 0.006). Haemostatic activation, assessed as a part of CB bank process control, decreased from the first to the subsequent sample series. F1 + 2 may be a candidate for quality control in CB banking; however, further studies are needed to optimise the analyses and to assess the effect of haemostatic activation on CB quality.

Comparison of the Bactec 9240 and BacT/Alert blood culture systems for evaluation of placental cord blood for transfusion in neonates

The Bactec 9240 and the BacT/Alert blood culture systems were compared as a means for detection of bacterial contaminants in whole blood, concentrated red cells, and plasma preparations prepared from umbilical cord blood (UCB) samples. Ninety-two UCB units seeded with low levels of various bacteria were evaluated. In more than 50% of cases, growth was not detected in plasma using either system (P < 0.001). When concentrated red cells and whole blood were compared, the Bactec system detected bacterial growth consistently sooner than the BacT/Alert system in all seeded bacteria except Staphylococcus species in whole blood. The median lengths of time to detection (LTD) for whole blood and concentrated cells in BacT/Alert were 18.7 h and 18.5 h, respectively. The median LTD for the same blood fractions using the Bactec system were 16.05 h and 15.64 h. These differences in LTD by blood culture system and sample type were statistically significant (whole blood, P = 0.0449; concentrated cells, P = 0.0037). Based on the results of our study, we recommend the use of either concentrated red cells or whole blood for sterility testing in UCB samples. In our laboratory, the Bactec system compared to the BacT/Alert system was the superior method for rapid detection of bacterial contaminants in cord blood.

When to transfuse preterm babies

The physiological anaemia experienced by preterm babies is exacerbated by common care practices such as early clamping of the umbilical cord at birth and gradual exsanguination by phlebotomy for laboratory monitoring. The need for subsequent transfusion with red blood cells can be reduced by delaying cord clamping for 30-60 s in infants who do not require immediate resuscitation. The need for transfusions can be further reduced by limiting phlebotomy losses, providing good nutrition, and using standard guidelines for transfusion based on haemoglobin or haematocrit. What those guidelines should be is not clear. Analysis of two recent large clinical trials comparing restrictive and liberal transfusion guidelines leads to several conclusions. Restrictive transfusion guidelines may reduce the number of transfusions given, but there is no reduction in donor exposures if a single-donor transfusion programme is used. There is some evidence that more liberal transfusion guidelines may help to prevent brain injury, but information on the impact of transfusion practice on long-term outcome is lacking. Until further guidance emerges, transfusion thresholds lower than those used in the two trials should not be used, as there is no evidence that lower thresholds are safe.

Quality and stability of red cells derived from gravity-separated placental blood with a hollow-fiber system

BACKGROUND

Several studies show that donor red blood cells (RBCs) can be processed by gravity separation with a hollow-fiber filtration system. This study investigated whether fetal blood could be filtered in the same way.

STUDY DESIGN AND METHODS

Twelve newborns born after healthy pregnancies were included in the study. Placental blood was sampled with standard procedures. The sampled blood was separated with a specially designed hollow-fiber filtration system (Sangofer neonatal, Heim Group). The RBC bag contained 10 mL of saline, adenine, glucose-mannitol (SAG-M) for stabilization. After processing, the resulting RBC volume was estimated. Quality variables (blood counts, hemolysis rate) were measured before and after 35 days of storage at +4 degrees C.

RESULTS

The 12 processed RBC units had a mean volume of 62.3 +/- 13.5 mL and a mean hematocrit level of 0.56 +/- 0.06. No white blood cell contamination could be detected in any of the RBC units tested. After 35 days of storage, the hemolysis was 0.1 +/- 0.07 and the amount of free hemoglobin was 0.28 +/- 0.017 mmol per L.

CONCLUSIONS

This study shows that it is possible to process placental blood to RBCs by gravity separation with a hollow-fiber system. The quality of the RBCs thus processed was suitable for 35 days storage. The use of placental blood in the treatment of children with anemia (e.g., malaria) in the underresourced world is widely discussed. Because the separation device used here needs no additional equipment or electrical devices, it is considered to be an ideal method for use in these countries.

Prediction of transfusions in extremely low-birthweight infants in the erythropoietin era

BACKGROUND

The purpose of the present paper was to detect the clinical factors most predictive of red blood cell (RBC) transfusion in extremely low-birthweight (ELBW) infants in the recombinant human erythropoietin era.

METHODS

Between 1995 and 2000, 66 ELBW infants were admitted to a level III neonatal intensive care unit. Fifty-four of 66 infants were eligible for enrollment in the present study. Infants were treated with erythropoietin 200 IU/kg per dose s.c. twice a week with 4-6 mg/kg per day iron supplement.

RESULTS

The mean gestational age and birthweight were 26.5 +/- 2.1 weeks and 776 +/- 134 g, respectively. Ten of 54 ELBW infants (18.5%) died during the first 21 days. Eight of 10 dead infants (80.0%) and 27 of 44 surviving infants (61.4%) received one or more RBC transfusions. The overall requirement for RBC transfusions in the surviving infants was 3.0 +/- 3.2 per infant/hospital course (range: 0-9) . There were significant differences in gestational weeks, birthweight, initial hemoglobin value, 5 min Apgar score, phlebotomy loss, phlebotomy loss/birthweight, duration of mechanical ventilation, duration of oxygen supplement, and incidence of both intraventricular hemorrhage and chronic lung disease between the transfused and non-transfused group. The predictive variables, initial hemoglobin level (odds ratio [OR] 2.61; 1 g/dL), birthweight (OR 3.00; 100 g), and gestational week (OR 1.89; 1 week), were found to be most predictive for transfusion on logistic regression analysis.

CONCLUSION

ELBW infants are still the population at greatest risk for repeated blood transfusions after introduction of erythropoietin treatment. If labor develops, it is often impossible to extend the pregnancy period, therefore efforts should be made to increase hemoglobin level at birth.

Potential use of autologous umbilical cord blood red blood cells for early transfusion needs of premature infants

BACKGROUND

This prospective study investigated whether the odds of receiving a red blood cell (RBC) transfusion in premature infants can be predicted at birth and for whom of these infants harvesting of umbilical cord blood (UCB) for autologous transfusion within 30 days after birth would be worthwhile.

STUDY DESIGN AND METHODS

Characteristics were evaluated from 288 premature infants with a gestational age between 24 and 36 weeks and who were admitted to our neonatal center. In 144 (63%) of these infants UCB collection was attempted and the early transfusion needs could be compared with the amount of UCB available for transfusion.

RESULTS

Sixty-nine of 114 (61%) inborn infants with a gestational age of less than 32 weeks received one or more RBC transfusions of 10 mL per kg within 30 days after birth. Apgar score at 1 minute of less than 6 and gestational age of less than 32 weeks were independently associated with the chance of receiving a transfusion in this group. In 31 of 69 (46%) infants, at least 15 mL of UCB per kg of birth weight was collected and in 28 of 69 (41%) this would have been sufficient to cover their early transfusion needs.

CONCLUSION

The decision to collect UCB for postnatal transfusion can be made just after labor, based on Apgar score and gestational age. The collection of UCB is most effective and efficient for premature infants between 29 and 31 weeks of gestation. For infants less than 29 weeks of gestation, the technical aspects of UCB collection need improvement. This pilot study requires a prospective clinical study to evaluate the proportion of premature infants that can be fully or substantially supported with autologous UCB.

Autologous red cells derived from cord blood: collection, preparation, storage and quality controls with optimal additive storage medium (Sag-mannitol)

To investigate whether packed red cells (PRCs) prepared from autologous cord blood-packed red cells (AC-PRCs) could be used as an alternative for homologous-packed red cells (H-PRCs), we developed a system to collect and prepare AC-PRCs and determined standard storage parameters during 35 days of storage in extended storage medium (Sag-mannitol). We collected and fractionated cord blood from 390 newborns. The amount and quality of the AC-PRCs were analysed. The bacterial contamination rate was 1.84%. Twelve AC-PRCs were stored for 35 days, and standard laboratory parameters were measured at day 1 and day 35. The initial laboratory parameters of the AC-PRCs were similar to the parameters of the H-PRCs. After 35 days, the AC-PRCs displayed an increased haemolysis rate compared to H-PRCs (1.1 versus 0.2%) and also a significant decreased adenosine triphosphate value (1.2 versus 2.3 micromol L(-1)). Haemoglobin, haematocrit and pH were comparable in both groups. AC-PRCs meet the quality criteria for H-PRCs after 35 days. Utilizing a closed collection system for cord blood and an extended storage medium will increase safety and quality and facilitate the routine transfusion of autologous red cells derived from cord blood.

Autologous cord blood transfusion in an infant with a huge sacrococcygeal teratoma

We describe a case of cord blood harvest for autologous transfusion in a neonate weighing 3,992 g with a giant sacrococcygeal teratoma. The umbilical vein was pierced with an 18-gauge needle, and placental blood was withdrawn into two 50-ml syringes filled with 4 ml of citrate-phosphate-dextrose solution. Resection of the sacrococcygeal teratoma was performed on day one. During the operation the infant lost 46 ml of whole blood, more than 15% of the estimated total blood volume, and thus underwent autologous transfusion with 27.8 ml of packed red cells obtained from autologous cord blood. Consequently, she could avoid homologous blood transfusion during the hospital stay. This case highlights the safety of this procedure, with no evidence of consumption coagulopathy, hemolysis or bacterial infection.

Efficacy, recovery, and safety of RBCs from autologous placental blood: clinical experience in 52 newborns

BACKGROUND

In the present study, the efficacy, recovery, and safety of RBCs from autologous placental blood (PB-RBCs) were investigated.

STUDY DESIGN AND METHODS

A total of 52 newborns received transfusion with PB-RBCs. The number of newborns requiring no additional allogeneic RBCs was calculated. In 22 of these 52 neonates with a birth weight of 1000 to 2500 g, vital measures were performed during transfusion, and serum potassium levels were measured up to 3 days after transfusion. The results were compared with those of a matched control group given allogeneic RBC transfusions.

RESULTS

All neonates of the study group with a birth weight of less than 1000 g, but only 59 percent those with a birth weight of 1000 to 2500 g and 58 percent of those requiring surgery directly after delivery needed allogeneic transfusions in addition to PB-RBCs. The mean Hb increase after RBC transfusion of 10 mL per kg of body weight was 3 g per dL per kg of body weight in both groups; the Hb decrease was accelerated in the placental blood group (0.32 vs. 0.24 g/dL/day; p < 0.05). There were no intergroup differences in the vital parameters.

CONCLUSION

Our results show no difference in efficacy and safety between PB-RBC transfusion and allogeneic RBC transfusion. According to well-defined criteria, 40 percent of anemic neonates can be supported by autologous placental blood transfusions alone.

Obstetric predictors of placental/umbilical cord blood volume for transplantation

OBJECTIVE

Umbilical cord blood is an effective alternative to bone marrow as a source of hematopoietic stem cells in transplantation. However, the amount of donor blood and the cell content that are collected may be insufficient for engraftment in some adult recipients. This study identifies obstetric factors that affect retrievable placental cord blood volume.

STUDY DESIGN

A retrospective analysis of factors that were obtained by direct observation or medical record review that were related to harvested cord blood volume was conducted; the analysis involved 9205 deliveries from mothers who donated placental cord blood through the obstetric services of two New York City hospitals between 1993 and 1999.

RESULTS

Obstetric factors that influenced significantly the total volume of blood that was collected were route of delivery, induction of labor, presence of a nuchal cord, infant birth weight, multiple births, placental weight, and duration of labor. The length of the umbilical cord from the venipuncture site and the length of time to cord blood collection also affected the volume that was retrieved. Maternal ethnicity was associated with cord blood yield; Caucasian mothers provided larger quantities than either African American or Asian mothers.

CONCLUSION

Our results confirm that the volume of residual placental cord blood that is collected for hematopoietic stem cell transplantation is influenced by several factors, the presence of which predict the likelihood of an adequate collection. Collected volumes can be improved when a longer length of the cord is left with the placenta and when there is a shorter time between the delivery of the placenta and the collection.

Neonatal red blood cell transfusions

Red blood cell and blood product transfusion in the fetus, neonate, and premature infant are often administered with poorly defined indications and unintentional adverse consequences. Products may be altered in an effort to limit potential adverse events or may be specially selected to meet the unique needs of a specific diagnosis. One area of particular concern to neonatologists is selection blood for small volume (5-15 mL/kg) transfusions in premature infants. For infants, use of red blood cells collected in anticoagulant-additive solutions and administered in small aliquots over the shelf life of the product to decrease donor exposure has supplanted the use of fresh red blood cells with each transfusion resulting in a donor exposure. The safety of this practice has been documented and procedures established to aid a transfusion service in making these products available. Less well established are the indications for transfusion in this population; hemoglobin or Hematocrit alone are likely insufficient unless clinical findings like oxygen desaturation, apnea, and bradycardia are part of the criteria used to define transfusion need. The comorbidities that increase oxygen demands in these infants, like bronchopulmonary dysplasia and increased oxygen consumption to accommodate growth, must be part of the decision to transfuse. Noninvasive methods or assays that will reflect the unique pathophysiology of oxygen delivery and peripheral oxygen offloading are needed.

Usefulness of cord-blood harvesting for autologous transfusion in surgical newborns with antenatal diagnosis of congenital anomalies

BACKGROUND/PURPOSE

The risks of homologous transfusion and the effectiveness of predeposit autologous transfusion have been described. The authors examined the clinical usefulness of cord-blood harvesting for autologous transfusion in newborns who had congenital anomalies antenatally diagnosed that would require surgical intervention at or near the time of delivery.

METHODS

Of 112 cases of antenatal diagnosis of congenital anomalies, 50 mothers gave informed consent and enrolled in this study. Cord-blood was withdrawn immediately after clamping of the umbilical cord and was used for autologous transfusion in newborns within the first 3 days postpartum.

RESULTS

A mean of 72 +/- 54 mL of cord-blood was harvested (27 +/- 18 mL/kg). While preserving cord-blood for 3 days at 4 degrees C, no signs of clot formation or hemolysis were observed. The harvested cord-blood included plasma-free Hb ranging from 1 to 68 (13 +/- 18) mg/dL and thrombin-antithrombin III complex ranging from 2 to 273 (18 +/- 50) ng/mL. Bacteriologic examination of the stored cord-blood showed negative cultures, except for samples from 3 newborns after vaginal delivery. A mean of 46 +/- 34 mL of cord-blood was used in 26 patients for autologous transfusion. No significant complications related to cord-blood transfusion were recognized clinically.

CONCLUSIONS

Autologous cord-blood transfusion has the potential to be a useful alternative to homologous transfusion in newborns requiring surgery. Adequate collection and storage techniques for cord-blood must be developed. J Pediatr Surg 36:851-854.

Cord blood collection before and after placental delivery: levels of nucleated cells, haematopoietic progenitor cells, leukocyte subpopulations and macroscopic clots

The number of nucleated cells infused into the recipient of a cord blood (CB) transplant has emerged as the most important factor affecting the probability and speed of engraftment. At present, there is no international consensus on the procedure of CB collection in the maternity ward. In order to maximise the yield of viable cells in a CB unit, we aimed to investigate the efficiency of CB collection, with respect to the time of delivery of the placenta. We analysed stem and progenitor cells in terms of CD34+ cell content and colony-forming activities, lymphocyte subpopulations and the presence of macroscopic clots in 93 paired CB samples, collected before and after the delivery of the placenta. Our results demonstrated that the median concentrations of nucleated cells and total colony-forming unit (CFU) were significantly lower in CB collected after placenta delivery by 9.5% (P < 0.001) and 11.6% (P = 0.015), respectively, when compared to their counterparts collected before placental delivery. A reduction of granulocytes (P < 0.001), monocytes (P < 0.001) and CD19+ B lymphocytes (P = 0.031) was observed, with no significant change in the proportion of T cell subsets (CD4+, CD8+ cells) or activated T cells (CD25+, CD45RO+ cells) in samples collected after placenta delivery. The incidence of macroscopic clots was also higher in these samples (31% vs 1%, P < 0.001). The reduction of stem and progenitor cells correlated significantly with that of major cell populations, indicating a general cell loss, possibly due to clotting activities developed with time. Our study has documented strong evidence for recommending the collection of CB before the delivery of the placenta.

Cord blood as a source of autologous RBCs for transfusion to preterm infants

BACKGROUND

This prospective study was conducted to gain experience as to whether it is technically possible to produce autologous RBCs in additive solution from cord blood (CB), to optimize the blood supply for preterm infants.

STUDY DESIGN AND METHODS

CB was collected from 47 infants with a mean (+/- SD) birth weight of 1717 (+/- 699) g. Whenever possible, RBC components were prepared by standard centrifugation using a six-bag system. All samples were put in sterility testing quarantine for 5 days, and a maximum storage of 14 days from collection to transfusion was specified. The babies were given either the autologous RBCs or standard allogeneic RBC concentrates, if autologous blood was not available.

RESULTS

In 81 percent of the samples, autologous RBC components could be processed (vol, 7-87 mL; Hct, 31-82%). But within the group of extremely low birth weight infants (body weight <1000 g), a mean CB net volume of only 37 mL was collected, and the RBC preparation was successful only in exceptional cases. Three CB samples (8.6%) tested positive in sterility testing. Of the 47 infants, 21 were treated with a total of 62 allogeneic and 4 autologous RBC transfusions. Most infants with a body weight over 1400 g did not need any RBC transfusion.

CONCLUSION

The preparation of autologous RBCs from the CB of preterm infants is technically possible in principle. However, major concerns must be raised as to whether such preparations are of benefit in ensuring safe care of neonates with blood components, with respect to the high rate of bacterial contamination and the limited availability in babies with low birth weight.

Changing practices of red blood cell transfusions in infants with birth weights less than 1000 g

OBJECTIVE

Extremely low birth weight (ELBW) infants frequently undergo transfusion because they are critically ill, often need artificial ventilation, and have the highest blood sampling loss in relation to their weight. During the last decade our transfusion guidelines were changed 3 times to become more restrictive. We hypothesized that these modifications substantially decreased the number of transfusions in our ELBW infants.

METHODS

We performed a single-center analysis of 256 infants with birth weights from 500 to 999 g who were admitted from 1989 to 1997 and included 3 study periods, each starting with newly modified transfusion guidelines in April 1989, September 1991, and January 1995. We evaluated prospectively recorded clinical data and retrospective chart analysis for transfusion-related information.

RESULTS

The median number of transfusions per infant decreased from 7 in the first period to 2 in the third period, whereas donor exposure decreased from 5 to 1 and blood volume transfused decreased from 131 to 37 mL/kg birth weight (P <.01). The median venous hematocrit measured before transfusion decreased from 43% to 35% in infants who underwent ventilation and from 41% to 31% in spontaneously breathing infants. The median birth weight decreased from 870 to 740 g and the median gestational age from 27 to 25 completed weeks (P <.01). The overall survival rate was 75% and did not change. The incidences of retinopathy, intraventricular hemorrhage, and patent ductus arteriosus remained unchanged.

CONCLUSION

Over this 9-year period with increasingly restrictive transfusion guidelines, the transfusion number decreased by 71% and the donor exposure by 80% in ELBW infants without adverse clinical effects.

Low degree of regionalization and high transfusion rates in very low birthweight infants: a survey in Germany

Although anemia is common in very low birthweight (VLBW) infants, widely accepted guidelines for red blood cell transfusions are lacking. Questionnaires regarding transfusion policy in VLBW infants in 1994 were sent to 391 German pediatric departments. 208 questionnaires were returned. 51 departments reported not to admit VLBW infants. Thus, results are based on 157 completed questionnaires. 54% of the respondents admitted less than 30 VLBW infants per year and 52% of the VLBW infants were admitted to departments with less than 50 VLBW infants per year. Overall transfusion rate ranged from 0 to 100% (median 65%). This range narrowed with the departments' size indicating stricter guidelines with less variation. Indication for transfusion varied considerably depending on the infants' postnatal age and need for ventilatory support. 34% of the respondents applied directed transfusions, most frequently from the infant's father. 70% used satellite packs. 51% stored the packs up to 7 days, 10% longer than 14 days. Red cells were irradiated in 35%, and washed in 23% of the departments. Median single transfusion volume was 12 ml/kg. We conclude that regionalization of VLBW infants in Germany is far from completeness and that hospital policies for transfusion show large variety especially in small departments.

Red blood cell transfusions for preterm infants: the role of evidence-based medicine

Increasingly clinicians attempt to base decisions regarding patient management on the results of clinical studies in addition to expert opinion and their own practical experience. In this article, the author reviews the published studies available to assist clinicians to make evidence-based decisions in three topics related to small volume red blood cell (RBC) transfusions for preterm infants; namely, studies examining the effects of RBC transfusions on possible symptoms of anemia such as tachypnea, apnea or other cardiorespiratory irregularities, studies investigating the collection and transfusion of umbilical cord blood and finally studies addressing the duration of storage and use of additive solutions for RBCs for transfusion to neonates. Based on the review of these studies, guidelines for small volume RBC transfusions in preterm infants are suggested.