Neonatal anemia: pathophysiology and treatment

Early predictors of abnormal MRI patterns in asphyxiated infants: S100B protein urine levels

OBJECTIVES

The early detection and stratification of asphyxiated infants at higher risk for impaired neurodevelopment is challenging. S100B protein is a well-established biomarker of brain damage, but lacks conclusive validation according to the "gold standard" methodology for hypoxic-ischemic encephalopathy (HIE) prognostication, i.e. brain MRI. The aim of the present study was to investigate the predictive role of urinary S100B concentrations, assessed in a cohort of HIE infants receiving therapeutic hypothermia (TH), compared to brain MRI.

METHODS

Assessment of urine S100B concentrations was performed by immunoluminometric assay at first void and at 4, 8, 12, 16, 20, 24, 48, 72, 96, 108 and 120-h after birth. Neurologic evaluation, routine laboratory parameters, amplitude-integrated electroencephalography, and cerebral ultrasound were performed according to standard protocols. Brain MRI was performed at 7-10 days of life.

RESULTS

Overall, 74 HIE neonates receiving TH were included in the study. S100B correlated, already at first void, with the MRI patterns with higher concentrations in infants with the most severe MRI lesions.

CONCLUSIONS

High S100B urine levels soon after birth constitute trustable predictors of brain injury as confirmed by MRI. Results support the reliability of S100B in clinical daily practice and open the way to its inclusion in the panel of parameters used for the selection of cases suitable for TH treatment.

Perinatal presepsin assessment: a new sepsis diagnostic tool?

Perinatal sepsis constitutes a medical emergency and is still one of the major causes of mortality and morbidity. The possibility of an early diagnosis of sepsis is still debated and controversial. In particular, clinical symptoms can be hidden by the association of sepsis with other perinatal diseases and/or by therapeutic strategies performed. In this context, there is evidence that the accuracy of standard of care diagnostic parameters (i.e. blood culture, C-reactive protein, procalcitonin) can be biased by additional confounding factors (gestational age, birth-weight, acute-chronic hypoxia). Therefore, the inclusion in clinical daily practice of new biomarkers of sepsis is of utmost importance. Of a panel of biomarkers, Presepsin (P-SEP) plays an important role in the development and response of the immune system and as an early marker of sepsis both in adult and pediatric patients. Therefore, in the present review we aim to offer an overview of the role of P-SEP in the early detection of perinatal sepsis as a trustworthy marker according to actual statements of official international institutions. Future perspectives regard the possibility of a longitudinal non-invasive biological fluids P-SEP assessment thus limiting the sample stress in high risk newborns.

Perinatal asphyxia partly affects presepsin urine levels in non-infected term infants

OBJECTIVES

Standard of care sepsis biomarkers such as C-reactive protein (CRP) and procalcitonin (PCT) can be affected by several perinatal factors, among which perinatal asphyxia (PA) has a significant role. In this light, new early sepsis biomarkers such as presepsin (P-SEP) are needed to enact therapeutic strategies at a stage when clinical and laboratory patterns are still silent or unavailable. We aimed at investigating the potential effects of PA on longitudinal P-SEP urine levels.

METHODS

We conducted an observational case-control study in 76 term infants, 38 with PA and 38 controls. Standard clinical, laboratory, radiological monitoring procedures and P-SEP urine measurement were performed at four time-points (first void, 24, 48, 96 h) after birth.

RESULTS

Higher (p<0.05) CRP and PCT blood levels at T1-T3 were observed in PA than control infants whilst no differences (p>0.05, for all) at T0 were observed between groups. P-SEP urine levels were higher (p<0.05) in PA at first void and at 24 h while no differences (p>0.05) at 48 and 96 h were observed. No significant correlations were found (p>0.05) between P-SEP and urea (R=0.11) and creatinine (R=0.02) blood levels, respectively.

CONCLUSIONS

The present results, showed that PA effects on P-SEP were limited up to the first 24 h following birth in absence of any kidney function bias. Data open the way to further investigations aimed at validating P-SEP assessment in non-invasive biological fluids as a reliable tool for early EOS and LOS detection in high-risk infants.

Lipocalin-2 and calprotectin as stool biomarkers for predicting necrotizing enterocolitis in premature neonates

BACKGROUND

Necrotizing enterocolitis (NEC) is a major challenge for premature infants in neonatal intensive care units and efforts toward the search for indicators that could be used to predict the development of the disease have given limited results until now.

METHODS

In this study, stools from 132 very low birth weight infants were collected daily in the context of a multi-center prospective study aimed at investigating the potential of fecal biomarkers for NEC prediction. Eight infants (~6%) received a stage 3 NEC diagnosis. Their stools collected up to 10 days before diagnosis were included and matched with 14 non-NEC controls and tested by ELISA for the quantitation of eight biomarkers.

RESULTS

Biomarkers were evaluated in all available stool samples leading to the identification of lipocalin-2 and calprotectin as the two most reliable predicting markers over the 10-day period prior to NEC development. Pooling the data for each infant confirmed the significance of lipocalin-2 and calprotectin, individually and in combination 1 week in advance of the NEC clinical diagnosis.

CONCLUSIONS

The lipocalin-2 and calprotectin tandem represents a significant biomarker signature for predicting NEC development. Although not yet fulfilling the "perfect biomarker" criteria, it represents a first step toward it.

IMPACT

Stool biomarkers can be used to predict NEC development in very low birth weight infants more than a week before the diagnosis. LCN2 was identified as a new robust biomarker for predicting NEC development, which used in conjunction with CALPRO, allows the identification of more than half of the cases that will develop NEC in very low birth weight infants. Combining more stool markers with the LCN2/CALPRO tandem such as PGE2 can further improve the algorithm for the prediction of NEC development.

The Ca2+-Binding S100B Protein: An Important Diagnostic and Prognostic Neurobiomarker in Pediatric Laboratory Medicine

In recent decades a significant scientific effort has focused on projects regarding the use of neurobiomarkers in perinatal medicine with a view to understanding the mechanisms that interfere with physiological patterns of brain development and lead to ominous effects in several human diseases. Numerous potential neurobiomarkers have been proposed for use in monitoring high-risk fetuses and newborns, including markers of oxidative stress, neuroproteins, and vasoactive agents. Nonetheless, the use of these markers in clinical practice remains a matter of debate. Recently, the calcium-binding S100B protein has been proposed as being an ideal neurobiomarker, thanks to its simple availability and easy reproducibility, to the possibility of detecting it noninvasively in biological fluids with good reproducibility, and to the possibility of a longitudinal evaluation in relation to reference curves. The present chapter contains an overview of the most significant studies on the assessment of S100B in different biological fluids as a trophic factor and/or marker of brain damage in high-risk fetuses and newborns.

Relevance of urinary S100B protein levels as a short-term prognostic biomarker in asphyxiated infants treated with hypothermia

The initial diagnosis of neonatal hypoxic-ischemic encephalopathy is based on nervous system clinical manifestations. The use of biomarkers to monitor brain injury and evaluate neuroprotective effects allows early intervention and treatment. This study was designed to determine the short-term prognostic significance of urinary S100B calcium-binding protein (S100B) in asphyxiated newborns treated with hypothermia.An observational prospective study was conducted over a period of 5 years in 31 newborns with hypoxic-ischemic encephalopathy who received therapeutic hypothermia. The patients were divided into 2 groups: Group A (13 newborns with a normal neurological examination before discharge) and Group B (18 newborns who died during admission or had an abnormal neurologic examination before discharge). Urinary S100B was the main variable, serum S100B and neuron-specific enolase (NSE) were considered as secondary variables, and all of them were assessed on the first 3 days of life. The newborns were subsequently divided into groups with normal and abnormal electrophysiological and imaging findings.Mean urinary S100B levels were significantly higher in group B than group A on day 1 (10.58 ± 14.82 vs 4.65 ± 9.16 μg/L, P = .031) and day 2 (5.16 ± 7.63 vs 0.88 ± 2.53, P = .002). The optimal cutoff for urinary S100B on day 1 was >1.11 μg/L of (sensitivity, 100%; specificity 60%) for the prediction of neonatal death and < 0.66 μg/L (sensitivity 83% and specificity 70%) for the prediction of a normal neurological examination before discharge. It was not possible to calculate cutoffs with a similar accuracy for serum S100B or NSE. Urinary S100B on day 1 was higher in patients with abnormal magnetic resonance imaging findings (7.89 ± 8.09 vs 4.49 ± 9.14, P = .039) and abnormal positron emission tomography findings (8.60 ± 9.29 vs 4.30 ± 8.28, P = .038). There were no significant differences in S100B levels between patients with normal and abnormal electroencephalography results.Urinary S100B measured in the first days of life can predict neonatal death and short-term prognosis in asphyxiated newborns treated with hypothermia. The method is convenient, noninvasive, and has a higher sensitivity and specificity than measurement of serum S100B or NSE.

The clinical and diagnostic utility of S100B in preterm newborns

Preterm birth is still the most important cause of perinatal mortality and morbidity. Follow-up studies showed that the majority of neurological abnormalities during childhood are already present in the first week after birth. In this light, the knowledge of the timing of the insult and/or of the contributing factors is of utmost relevance in order to avoid adverse neurological outcome. Notwithstanding, the considerable advances in perinatal clinical care and monitoring, the early detection of cases at risk for brain damage is still a challenge because, when radiological pictures are still negative, brain damage may be already at a subclinical stage, with symptoms hidden by therapeutic strategies. Thus, it could be very relevant to measure quantitative parameters, such as neuroproteins, able to detect subclinical lesions at a stage when routine brain monitoring procedures are still silent. In the last decade, the assay of the brain-specific protein S100B in different biological fluids proved useful information on brain function and damage in the perinatal period. Therefore, the present study provides an overview of the most recent findings on S100B role as a reliable marker of brain development/damage in preterm high risk fetuses and newborns.

Non-invasive serum amyloid A (SAA) measurement and plasma platelets for accurate prediction of surgical intervention in severe necrotizing enterocolitis (NEC)

Objective

To evaluate the value of biomarkers to detect severe NEC.

Summary Background Data

The time point of surgery in necrotizing enterocolitis (NEC) is critical. Therefore, there is a need for markers that detect severe NEC, because clinical signs of severe NEC often develop late. This study evaluated the value of biomarkers reflecting intestinal cell damage and inflammation to detect severe NEC.

Methods

29 neonates with NEC were included. Two definitions of moderate versus severe NEC were analyzed: medical NEC (n = 12) versus surgical or fatal NEC (n = 17); and Bell stage II NEC (n = 13) versus stage III NEC (n = 16). Urinary intestinal fatty acid binding protein (I-FABP), serum amyloid A (SAA), C3a and C5a, and fecal calprotectin were measured. C-reactive protein (CRP), white blood cell count (WBC) and platelet count data were measured in blood.

Results

In both definitions of moderate versus severe NEC, urinary SAA levels were significantly higher in severe NEC. A cut-off value of 34.4 ng/ml was found in surgical NEC versus medical NEC (sensitivity, 83%; specificity, 83%; LR+, 4.88 (95% CI, 1.37–17.0); LR−, 0.20 (95% CI, 0.07–0.60)) at diagnosis of NEC and at one day prior to surgery in neonates who were operated later on. Combination of urinary SAA and platelet count increased the accuracy, with a sensitivity, 94%; specificity, 83%; LR+, 5.53 (95% CI, 1.57–20.0); and LR−, 0.07 (95% CI, 0.01–0.48).

Conclusion

Urinary SAA is an accurate marker in differentiating severe NEC from moderate NEC; particularly if combined with serum platelet count.

Elevated Activin A urine levels are predictors of intraventricular haemorrhage in preterm newborns

AIM

Intraventricular haemorrhage (IVH) is the most common variety of cerebral haemorrhage and cause of neurological disabilities in preterm newborns. We evaluated the usefulness of urine Activin A concentrations for the early detection of perinatal IVH.

METHODS

We conducted a case-control study on 100 preterm newborns (20 with IVH and 80 without IVH) in whom urine Activin A was measured at five predetermined time-points in the first 72 h after birth. IVH diagnosis and the extension of the lesion were performed by ultrasound scanning within the first 72 h and at 1 week after birth, respectively.

RESULTS

Urine Activin A in infants who developed IVH was significantly higher than in controls at all monitoring time-points (p < 0.01 for all), increasing progressively from first urination to 24 h when it reached the highest peak (p < 0.001). At a cut-off 0.08 ng/L, at the first void, Activin A sensitivity and specificity were 68.7% (CI: 41.3-89%) and 84.5% (CI: 75-91.5%).

CONCLUSION

Activin A measurements in urine soon after birth can constitute a promising tool for identifying preterm infants at risk of IVH.

Biomarkers of brain damage in preterm infants

OBJECTIVE

There is growing evidence on the usefulness of biomarkers in the early detection of preterm infants at risk for brain damage. However, among different tools Activin A, S100B protein and adrenomedullin assessment offer the possibility to investigate brain/multiorgan function and development. This could be especially useful in perinatal medicine that requires even more non-invasive techniques in order to fulfill the minimal handling in diagnostic and therapeutic strategy performance.

MATERIALS AND METHODS

The concept of Unconventional Biological Fluid (UBF: urine and saliva) is becoming even stronger and regards the assessment in non-invasive biological fluids of biochemical markers involved in the cascade of events leading to brain damage.

RESULTS

Activin A, S100B protein and adrenomedullin in UBF were increased in preterm newborns developing brain damage and/or ominous outcome.

CONCLUSIONS

The present manuscript offers an update on the usefulness of Activin A, S100B protein an adrenomedullin in UBF as brain damage markers. The findings open a new cue on the use of these markers in daily neonatal intensive care unit (NICU) activities.

Noninvasive measurement of fecal calprotectin and serum amyloid A combined with intestinal fatty acid-binding protein in necrotizing enterocolitis

BACKGROUND

Diagnosis of necrotizing enterocolitis (NEC), prevalent in premature infants, remains challenging. Enterocyte damage in NEC can be assessed by intestinal fatty acid-binding protein (I-FABP), with a sensitivity of 93% and a specificity of 90%. Numerous markers of inflammation are known, such as serum amyloid A (SAA) and fecal calprotectin.

PURPOSE

The aim of the present study was to evaluate which combination of noninvasive measurement of inflammatory markers and I-FABP improves the diagnostic accuracy in neonates suspected for NEC.

METHODS

In 62 neonates with clinical suspicion of NEC (29 with final diagnosis of NEC), urinary I-FABP, urinary SAA, and fecal calprotectin levels were determined quantitatively. Diagnostic accuracy was calculated for the combinations I-FABP-SAA and I-FABP-fecal calprotectin, using a multivariable logistic regression model.

RESULTS

The combination of SAA and I-FABP did not increase the diagnostic accuracy of I-FABP. However, the combination of fecal calprotectin and I-FABP improved accuracy significantly. The combination of urinary I-FABP and fecal calprotectin measurement produced a sensitivity of 94%, a specificity of 79%, a positive likelihood ratio of 4.48, and a negative likelihood ratio of 0.08.

CONCLUSION

The combination of noninvasive measurement of I-FABP and fecal calprotectin seems promising for diagnosing NEC at an early time point. Prospective analysis is required to confirm this finding and to evaluate better treatment strategies based on noninvasive measurement of I-FABP and calprotectin.

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.

Diagnostic accuracy of S100B urinary testing at birth in full-term asphyxiated newborns to predict neonatal death

BACKGROUND

Neonatal death in full-term infants who suffer from perinatal asphyxia (PA) is a major subject of investigation, since few tools exist to predict patients at risk of ominous outcome. We studied the possibility that urine S100B measurement may identify which PA-affected infants are at risk of early postnatal death.

METHODOLOGY/PRINCIPAL FINDINGS

In a cross-sectional study between January 1, 2001 and December 1, 2006 we measured S100B protein in urine collected from term infants (n = 132), 60 of whom suffered PA. According to their outcome at 7 days, infants with PA were subsequently classified either as asphyxiated infants complicated by hypoxic ischemic encephalopathy with no ominous outcome (HIE Group; n = 48), or as newborns who died within the first post-natal week (Ominous Outcome Group; n = 12). Routine laboratory variables, cerebral ultrasound, neurological patterns and urine concentrations of S100B protein were determined at first urination and after 24, 48 and 96 hours. The severity of illness in the first 24 hours after birth was measured using the Score for Neonatal Acute Physiology-Perinatal Extension (SNAP-PE). Urine S100B levels were higher from the first urination in the ominous outcome group than in healthy or HIE Groups (p<0.001 for all), and progressively increased. Multiple logistic regression analysis showed a significant correlation between S100B concentrations and the occurrence of neonatal death. At a cut-off >1.0 microg/L S100B had a sensitivity/specificity of 100% for predicting neonatal death.

CONCLUSIONS/SIGNIFICANCE

Increased S100B protein urine levels in term newborns suffering PA seem to suggest a higher risk of neonatal death for these infants.

Umbilical artery blood S100beta protein: a tool for the early identification of neonatal hypoxic-ischemic encephalopathy

Neuroprotective interventions in neonatal hypoxic-ischemic encephalopathy (HIE) require early indicators of brain damage to initiate therapy. In order to find a reliable, rapid, and simple method to identify infants at risk for this disorder, 40 infants with asphyxia were selected as the observation group (HIE group) and 25 normal-term infants as the control group. S100beta protein concentration and gas analysis of the umbilical cord artery blood of all infants were determined. We found that the S100beta protein levels of the HIE group (1.98 microg/L) were higher than those of the control group (1.05 microg/L, p<0.05), and there were significant differences between the mild HIE group (1.72 microg/L) and the moderate or severe HIE groups (3.61 microg/L, p<0.05). An S100beta protein concentration cutoff level of 2.02 microg/L had a sensitivity of 86.7% and a specificity of 88.0% for predicting the development of moderate or severe HIE. The blood gas parameters of umbilical artery blood, such as pH, carbon dioxide tension, and base excess, were significantly different in the HIE group compared to the control group (all p<0.001), but there were no differences between the mild HIE group and the moderate or severe HIE groups. On the basis of clinical manifestations of asphyxiated neonates, detecting the S100beta protein levels in the umbilical artery blood may be of important value in the early diagnosis and grading of HIE.

S100B protein in urine of preterm newborns with ominous outcome

Prematurity is an important cause of perinatal death, and no reliable biochemical/biophysical markers exist to identify newborns with an increased mortality risk. We aimed to use S100B concentrations in urine as an early indicator of risk of neonatal death. We did a cross-sectional study using urine obtained from 165 preterm newborns, of whom 11 suffered neonatal death within the first week, 121 displayed no overt neurologic syndrome, and 33 suffered neonatal hypoxia and intraventricular hemorrhage (IVH) but not ominous outcome. Urine S100B concentrations were determined at four time-points and corrected for gestational age by conversion to multiples of median (MoM) of healthy controls of the same gestational age. Ultrasound imaging was assessed within the first 72 h from birth. In infants that died within the first week, S100B levels in urine were already higher than controls at first urination and increased progressively between the 24 and 96-h time-points. Multiple logistic regression analysis showed a significant correlation between urine S100B protein concentrations and the occurrence of neonatal death. An S100B concentration cut-off of 12.93 MoM at first urination had a sensitivity of 100% and a specificity of 97.8% for predicting an ominous outcome. The positive predictive value was 78.6%, the negative predictive value was 100%. Measurement of urine S100B protein levels in preterm newborns could be useful to identify newborns at higher risk of neonatal death.

Measurement of transcutaneous hemoglobin concentration by noninvasive white-light spectroscopy in infants

OBJECTIVE

To compare transcutaneously spectroscopically measured hemoglobin values with venous hemoglobin values in infants.

STUDY DESIGN

Prospective study in healthy preterm and term infants who were breathing spontaneously.

RESULTS

Recordings were obtained from 85 stable infants (median gestational age at measurement: 36 weeks [range: 34-43 weeks]; median body weight: 1890 g [range: 1095-4360 g]). The spectroscopic hemoglobin values were corrected for inhomogeneous distribution of hemoglobin in the tissue. The venous and spectroscopic hemoglobin values were then compared by using the Bland-Altman method, which gave an error of <5%.

CONCLUSIONS

This pilot study could illustrate a good relation between the 2 methods for measuring hemoglobin. Larger studies are required to validate the spectroscopic method in those with conditions that affect the skin microcirculation (eg, septicemia).

Urinary S100B protein measurements: A tool for the early identification of hypoxic-ischemic encephalopathy in asphyxiated full-term infants

OBJECTIVE

Hypoxic-ischemic encephalopathy (HIE) is one of the major causes of perinatal mortality and morbidity. To date, there are no reliable methods to detect which infants will develop brain damage after asphyxia insult.

DESIGN AND SETTING

Prospective study conducted in three tertiary departments of neonatology from December 1999 to July 2002.

PARTICIPANTS

A total of 44 infants with perinatal asphyxia and 68 control infants.

INTERVENTION

Routine laboratory variables, neurologic patterns, ultrasound imaging, and urine concentrations of S100B protein were determined at nine time points.

MAIN OUTCOME MEASURES

The concentrations of S100B protein in urine were measured using an immunoluminometric assay at first urination and 4, 8, 12, 16, 20, 24, 48, and 72 hrs after birth. The results were correlated with the presence or absence of hypoxic-ischemic encephalopathy. Routine laboratory parameters and neurologic patterns were assessed at the same time as urine sampling.

RESULTS

S100B protein levels were significantly higher in samples collected at all monitoring time points from newborns with perinatal asphyxia with or without hypoxic-ischemic encephalopathy than in samples from normal infants (all p <.001). When asphyxiated infants were subdivided according to the presence of mild or absence of hypoxic-ischemic encephalopathy (group A) and of moderate or severe hypoxic-ischemic encephalopathy (group B), S100B levels were significantly higher at all the predetermined monitoring time points in group B infants than group A or control infants (all p <.001). An S100B concentration cutoff of 0.41 microg/L at first urination had a sensitivity of 91.3% and a specificity of 94.6% for predicting the development of hypoxic-ischemic encephalopathy. The sensitivity and specificity of measurements obtained from 4 to 72 hrs after birth were up to 100% and 98.8%, respectively.

CONCLUSIONS

Longitudinal S100B protein measurements in urine soon after birth are a useful tool to identify which asphyxiated infants are at risk of hypoxic-ischemic encephalopathy and its possible neurologic sequelae.

S100B protein in biological fluids: a tool for perinatal medicine

The diagnosis of perinatal insults currently relies on adequate documentation of general medical and obstetric factors and on radiologic and laboratory assessments. The measurement of brain constituents such as S100B protein may offer an alternative and direct indicator of cell damage in the nervous system when clinical and radiologic assessments are still silent and has the additional advantage of providing a quantitative indicator of the extent of brain lesions. S100B protein has been measured by several immunoassays in biological fluids (i.e., cerebrospinal fluid, blood, amniotic fluid, and urine) from fetuses and newborns at high risk of perinatal brain damage. S100B protein in biological fluids increased at an early stage when standard monitoring procedures were still silent in the study populations that later developed brain damage. S100B concentration was also significantly correlated with the extent of brain lesions. S100B protein appears to satisfy the criteria for a marker for brain injuries in perinatal medicine: (a) simple to perform measurements with good reproducibility; (b) detection in a variety of biological fluids, possibly reducing perinatal stress related to testing; (c) possible use in longitudinal monitoring because of its 1-h half-life; and (d) well-established use as an early and quantitative marker of brain lesions/damage. Finally, because of the neurotrophic role putatively played by S100B, its measurement in biological fluids at pre-/perinatal ages makes it a candidate for the laboratory evaluation of brain maturation.

Use of Hematopoietic Growth Factors in the Neonatal Intensive Care Unit

Recombinant hematopoietic growth factors have emerged as valuable treatments for a variety of medical conditions. Recently, their applications have reached the neonatal intensive care unit, where they offer new therapeutic options for problems as common as anemia of prematurity, or as catastrophic as neonatal sepsis. When facing bacterial infection, it is known that newborn infants are capable of increasing their serum G-CSF concentrations. However, their response does not reach the concentrations that adults are able to achieve, and frequently neutropenia complicates the picture of neonatal sepsis. Although Phase III clinical trials are still in progress, published animal studies, case reports, and Phase I trials suggest that neonates with a variety of neutropenias experience a rapid elevation in their blood neutrophil concentration following administration of rG-CSF, without significant adverse effects. Although many factors contribute to the development of the “anemia of prematurity,” one of the major factors is the inability of preterm infants to generate an erythropoietin (Epo) response appropriate to their degree of anemia. On the basis of this fact, administration of rEpo to preterm neonates to treat or to prevent the anemia of prematurity has been the subject of multiple clinical studies, and it is now clear that rEpo administration to this population can indeed result in lower transfusion requirements, with only occasional and mild adverse effects. Neonatal thrombocytopenia is also a frequent clinical problem, which in most patients develops without a clear underlying cause. Recent studies, quantifying circulating megakaryocyte progenitors in the peripheral blood of thrombocytopenic neonates, suggest that impaired megakaryocytopoiesis may be the main underlying mechanism of many cases of thrombocytopenia. On the basis of this finding, it is tempting to speculate that recombinant thrombopoietin, the newly discovered physiological stimulator of platelet production, will be of clinical relevance in the treatment of thrombocytopenic neonates.