Jacek Rudnicki

Circulating Stem Cell Populations in Preterm Infants: Implications for the Development of Retinopathy of Prematurity

OBJECTIVE To investigate the association among different circulating stem cell (SC) populations, the levels of selected growth factors and chemokines regulating SC migration in the peripheral blood, and the incidence of retinopathy of prematurity (ROP). METHODS We evaluated 88 participants in this study: 29 preterm infants with ROP, 29 preterm infants without ROP, and 30 healthy full-term infants. Peripheral blood samples collected 10 weeks after delivery were analyzed using flow cytometry, immunofluorescence, real-time reverse transcriptase-polymerase chain reaction, and enzyme-linked immunosorbent assay. The following cell populations were analyzed: (1) lin⁻CXCR4(+)CD45⁻ (enriched in very small embryonic-like SCs), (2) lin⁻CXCR4(+)CD45(+) (enriched in hematopoietic SCs), and (3) CD34(+)CD133(+)CD144(+) (early endothelial progenitor cells) [lin indicates lineage]. The concentrations of vascular endothelial growth factor, basic fibroblast growth factor, hepatocyte growth factor, and stromal cell-derived factor 1 were measured in the plasma. RESULTS The very small embryonic-like SCs and early endothelial progenitor cells expressing neural and endothelial markers were significantly increased in the preterm infants. The number of early endothelial progenitor cells in the peripheral blood was significantly greater in the preterm infants with ROP than in the preterm infants without ROP. An accompanying increase in the concentrations of vascular endothelial growth factor and hepatocyte growth factor was found in the peripheral blood of the preterm infants with ROP. No significant associations were found between hematopoietic SCs and ROP or prematurity. CONCLUSIONS The increased number of early endothelial progenitor cells along with elevated levels of vascular endothelial growth factor and hepatocyte growth factor in preterm infants with ROP suggest that circulating vasculogenic factors may play a role in the development and progression of ROP. The increased number of very small embryonic-like SCs in preterm infants suggests that the development of immature tissues and organs, including the retina, may require a contribution of circulating SCs.

Circulating endothelial progenitor cells in premature infants: is there an association with premature birth complications?

Abstract Background: The most common morbidities in preterm infants are associated with vascular pathology. Endothelial progenitor cells (EPCs) have been implicated in repair of the vasculature, but their role in the pathogenesis of prematurity complications is not clear. Objectives: We prospectively investigated an association between the number of EPCs circulating in blood during delivery as well as 2 and 6 weeks afterwards, the level of growth factors regulating their migration/homing, and the incidence of premature birth complications. Patients and methods: The study groups consisted of 90 preterm and 52 full-term infants. Early-EPCs (CD133+CD34+CD144+) and late-EPCs (CD133–CD34+CD144+) were analysed in cord blood (CB) and peripheral blood (PB). Results: We found higher early- and late-EPC counts in the CB of premature infants compared with full-term babies. The number of circulating early- and late-EPCs was inversely associated with the Apgar score of preterm infants. A positive association between the early-EPC count and the risk of respiratory distress syndrome, retinopathy of prematurity, bronchopulmonary dysplasia, and infections was found. Nevertheless, multivariate analysis revealed that a higher number of EPCs was not an independent predictor of prematurity complications, which were directly related to lower gestational age. The EPC count in full-term infants maintained a constant, relatively low level over the 6-week follow-up, whereas the EPC population in preterm infants gradually decreased during this period. Furthermore, the number of CB late-EPCs in preterm infants positively correlated with VEGF concentration. Conclusions: EPCs may play a considerable role in vascular development in preterm infants.

Circulating hematopoietic stem cell count is a valuable predictor of prematurity complications in preterm newborns

BackgroundThe frequency of preterm labour has risen over the last few years. Hence, there is growing interest in the identification of markers that may facilitate prediction and prevention of premature birth complications. Here, we studied the association of the number of circulating stem cell populations with the incidence of complications typical of prematurity.MethodsThe study groups consisted of 90 preterm (23–36 weeks of gestational age) and 52 full-term (37–41 weeks) infants. Non-hematopoietic stem cells (non-HSCs; CD45-lin-CD184+), enriched in very small embryonic-like stem cells (VSELs), expressing pluripotent (Oct-4, Nanog), early neural (β-III-tubulin), and oligodendrocyte lineage (Olig-1) genes as well as hematopoietic stem cells (HSCs; CD45+lin-CD184+), and circulating stem/progenitor cells (CSPCs; CD133+CD34+; CD133-CD34+) in association with characteristics of prematurity and preterm morbidity were analyzed in cord blood (CB) and peripheral blood (PB) until the sixth week after delivery. Phenotype analysis was performed using flow cytometry methods. Clonogenic assays suitable for detection of human hematopoietic progenitor cells were also applied. The quantitative parameters were compared between groups by the Mann–Whitney test and between time points by the Friedman test. Fisher’s exact test was used for qualitative variables.ResultsWe found that the number of CB non-HSCs/VSELs is inversely associated with the birth weight of preterm infants. More notably, a high number of CB HSCs is strongly associated with a lower risk of prematurity complications including intraventricular hemorrhage, respiratory distress syndrome, infections, and anemia. The number of HSCs remains stable for the first six weeks of postnatal life. Besides, the number of CSPCs in CB is significantly higher in preterm infants than in full-term neonates (p < 0.0001) and extensively decreases in preterm babies during next six weeks after birth. Finally, the growth of burst-forming unit of erythrocytes (BFU-E) and colony-forming units of granulocyte-macrophage (CFU-GM) obtained from CB of premature neonates is higher than those obtained from CB of full-term infants and strongly correlates with the number of CB-derived CSPCs.ConclusionWe conclude that CB HSCs are markedly associated with the development of premature birth complications. Thus, HSCs ought to be considered as the potential target for further research as they may be relevant for predicting and controlling the morbidity of premature infants. Moreover, the observed levels of non-HSCs/VSELs circulating in CB are inversely associated with the birth weight of preterm infants, suggesting non-HSCs/VSELs might be involved in the maturation of fetal organism.

Recording of amplitude-integrated electroencephalography, oxygen saturation, pulse rate, and cerebral blood flow during massage of premature infants.

OBJECTIVE Stimulation of the nervous system plays an important role in brain function and psychomotor development of children. Massage can benefit premature infants, but has limitations. STUDY DESIGN The authors conducted a study to verify the direct effects of massage on amplitude-integrated electroencephalography (aEEG), oxygen saturation (SaO(2)), and pulse analyzed by color cerebral function monitor (CCFM) and cerebral blood flow assessed by the Doppler technique. RESULTS The amplitude of the aEEG trend during massage significantly increased. Massage also impacted the dominant frequency δ waves. Frequency significantly increased during the massage and return to baseline after treatment. SaO(2) significantly decreased during massage. In four premature infants, massage was discontinued due to desaturation below 85%. Pulse frequency during the massage decreased but remained within physiological limits of greater than 100 beats per minute in all infants. Doppler flow values in the anterior cerebral artery measured before and after massage did not show statistically significant changes. Resistance index after massage decreased, which might provide greater perfusion of the brain, but this difference was not statistically significant. CONCLUSION Use of the CCFM device allows for monitoring of three basic physiologic functions, namely aEEG, SaO(2), and pulse, and increases the safety of massage in preterm infants.

Possible counter effect in newborns of 1936A>G (I646V) polymorphism in the AKAP10 gene encoding A-kinase-anchoring protein 10.

Objective:Cyclic adenosine monophosphate/protein kinase A (PKA) is important in embryonic development. The human AKAP10 gene is polymorphic: 1936A>G results in changes to a PKA-binding domain and increased targeting to mitochondria. Previous studies found G1936 as ‘deleterious’ in adults, and this study investigates whether this holds true in preterm birth.Study Design:Study group consisted of 80 preterm newborns (PTNs) born before the 38th gestation week. Control group consisted of 123 full-term healthy newborns born after the 37th gestation week with uncomplicated pregnancies. Genomic DNA was extracted from umbilical blood and AKAP10 genotypes were identified by PCR/restriction enzyme.Result:Significant differences in frequencies of 1936A>G genotypes/alleles between both groups were found. PTNs had increased frequency (55%) of AA homozygotes (odds ratio, AA versus AG+GG: 2.63 (95% confidence interval: 1.33 to 5.20), P=0.006) after adjustments: mothers with previous PTNs, smoking, first pregnancy, first delivery and Cesarean section.Conclusion:Results suggest G1936 is preventative factor against preterm birth, in contrast with previously asserted negative effects in adults.

Does prenatal antibiotic therapy compromise the diagnosis of early-onset infection and management of the neonate?

Abstract Aim: To assess the impact of prenatal antibiotic treatment on procalcitonin (PCT) and C-reactive protein (CRP) concentrations in cord blood, and on the rate of positive neonatal blood cultures. Methods: Neonates with early-onset infection (Group A; n=46) were compared with healthy controls (Group B; n=240). We evaluated the relationship between prenatal antibiotic therapy and early-onset infection, and for interactions with antibiotic therapy in the neonate immediately after birth. Results: In the Group A antibiotics were administered significantly more often prenatally and more often to neonates just after birth. The percentage of negative blood cultures in infected neonates was higher when antibiotic treatment was instituted prenatally. Differences in cord blood PCT and CRP concentrations were significant between both groups and were independent of prenatal antibiotic treatment. Streptococcus agalactiae was the most frequent species. Conclusions: Almost one-third of neonates present with early-onset infection in spite of prenatal antibiotic therapy. Cord blood PCT and CRP measurements may be helpful in the diagnosis of infection also in cases when antibiotic therapy was started prenatally. Prenatal antibiotic administration reduced the number of positive blood cultures in neonates with early-onset infection and was associated with a greater rate of antibiotic treatment after birth in neonates without infection.

The Determination of Procalcitonin Concentration in Early-Onset Neonatal Infection: A Valuable Test Regardless of Prenatal Antibiotic Therapy

The aim of this study was to assess the clinical usefulness of blood procalcitonin (PCT) levels for the diagnosis and therapeutic monitoring of early-onset neonatal sepsis (EONS). PCT as well as C-reactive protein (CRP) levels and white blood cell (WBC) count were measured in venous blood from 57 infected and 72 uninfected neonates. Differences between groups for PCT, CRP, and WBC levels were significant. The threshold value on the receiver operating characteristic curve in the prediction of EONS was 5.33 ng/mL for PCT, 9.3 mg/L for CRP, and 14.9 × 109/L for WBC. There was no effect of antibiotic administered to the mother on PCT, CRP, and WBC levels in neonatal blood sampled before treatment of EONS. Evidently reduced PCT levels are observed after 2 days of treatment. The authors conclude that prenatal antibiotic therapy does not reduce the value of PCT levels in blood for the diagnosis of EONS.

Usefulness of estimation of blood procalcitonin concentration versus C-reactive protein concentration and white blood cell count for therapeutic monitoring of sepsis in neonates.

AIM This study was intended to assess the clinical usefulness of blood procalcitonin (PCT) concentrations for the diagnosis and therapeutic monitoring of nosocomial neonatal sepsis. MATERIAL/METHODS The enrolment criterion was sepsis clinically manifesting after three days of life. PCT concentrations were measured in venous blood from 52 infected and 88 uninfected neonates. The results were interpreted against C-reactive protein (CRP) concentrations and white blood cell counts (WBC). RESULTS Differences between the two groups in PCT and CRP concentrations were highly significant. No significant differences between the groups were noted for WBC. The threshold value on the receiver operator characteristic curve was 2.06 ng/mL for PCT (SE 75%; SP 80.68%; PPV 62.22%; NPV 88.75%; AUC 0.805), 5.0 mg/L for CRP (SE 67.44%; SP 73.68%; PPV 42.02%; NPV 88.89%; AUC 0.801), and 11.9 x109/L for WBC (SE 51.16%; SP 50.68%; PPV 23.16%; NPV 78.13%; AUC 0.484). Procalcitonin concentrations decreased 24 hours after initiation of antibiotic therapy and reverted to the control level after 5-7 days. C-reactive protein concentrations began to decline after two days of antibiotic therapy but were still higher than in the control group after 5-7 days of treatment. No significant changes in WBC during the treatment were observed. CONCLUSIONS Procalcitonin concentrations in blood appear to be of use for the diagnosis and therapeutic monitoring of nosocomial infections in neonates as this parameter demonstrates greater sensitivity and specificity than C-reactive protein. White blood cell counts appear to be of little diagnostic value in the early phase of infection or for therapeutic monitoring.

Prevalence and Forms of Congenital Anomalies in Twins Born in Pomeranian District During the Period from 1.07.1997 to 31.12.1998

The authors have analysed the frequency and structure of congenital anomalies in children born in the Pomeranian district in the period from 01.07.1997 to 31.12.1998. Among a total of 28.361 births in that area, 748 (2.64%) were affected by congenital anomalies. Among 28.361 births, 620 (2.18%) were from multiple pregnancies. 23 (3.71%) among births from multiple pregnancies were affected by congenital malformations. The prevalence rate of inborn anomalies in births from multiple pregnancy in our area were higher (3.71%) in comparison to births from singleton pregnancy (2.61%). It implies that children born from multiple pregnancy are at higher risk of developing congenital anomalies.

EEG, brain maturation, and the development of retinopathy of prematurity.

Objectives: The factors that influence the central nervous system (CNS) development can affect either the retina or the brain cortex. Immaturity of the brain cortex reflects immaturity of the retina and vice versa. The immature retina is more vulnerable than the mature retina, and is therefore more likely to develop retinopathy of prematurity (ROP). The aim of this study was to compare electroencephalographic brain maturity with ROP severity. Methods: Twenty-one prematurely born infants were divided into two groups according to the severity of ROP. The first group included 12 infants with ROP stage 3 or more and the second group included nine infants with ROP stage 2 or less. We have proposed an index of CNS maturity (M) as a percentage of interburst interval elongation compared with the norm using video-electroencephalography (vEEG). Results: The median M value was 1.07 (range = 0.43–4.44) for infants with severe ROP and −0.1 (range = −1.0 to 1.45) for infants with mild or no ROP (p = 0.000948). Conclusions: The study revealed that CNS maturation delay expressed as M value was higher among infants with severe ROP than among infants with mild or no ROP. EEG examination in prematurely born infants may prove to be a useful tool for predicting ROP development.