Frequency, natural course, and outcome of neonatal neutropenia

Maternal inflammation regulates fetal emergency myelopoiesis

Neonates are highly susceptible to inflammation and infection. Here, we investigate how late fetal liver (FL) mouse hematopoietic stem and progenitor cells (HSPCs) respond to inflammation, testing the hypothesis that deficits in the engagement of emergency myelopoiesis (EM) pathways limit neutrophil output and contribute to perinatal neutropenia. We show that fetal HSPCs have limited production of myeloid cells at steady state and fail to activate a classical adult-like EM transcriptional program. Moreover, we find that fetal HSPCs can respond to EM-inducing inflammatory stimuli in vitro but are restricted by maternal anti-inflammatory factors, primarily interleukin-10 (IL-10), from activating EM pathways in utero. Accordingly, we demonstrate that the loss of maternal IL-10 restores EM activation in fetal HSPCs but at the cost of fetal demise. These results reveal the evolutionary trade-off inherent in maternal anti-inflammatory responses that maintain pregnancy but render the fetus unresponsive to EM activation signals and susceptible to infection.

AZU1: a new promising marker for infection in orthopedic and trauma patients?

Early and reliable detection of infection is vital for successful treatment. Serum markers such as C-reactive protein (CRP) and procalcitonin (PCT) are known to increase with a time lag. Azurocidin 1 (AZU1) has emerged as a promising marker for septic patients, but its diagnostic value in orthopedic and trauma patients remains unexplored. Between July 2020 and August 2023, all patients necessitating inpatient treatment for periprosthetic joint infection (PJI), peri-implant infection (II), soft tissue infection, chronic osteomyelitis, septic arthrodesis, bone non-union with and without infection were enrolled. Patients undergoing elective total joint arthroplasty (TJA) served as the control group. Blood samples were collected and analyzed for CRP, white blood cell count (WBC), PCT, and AZU1. Based on the inclusion and exclusion criteria 222 patients were included in the study (trauma = 38, soft tissue infection = 75, TJA = 33, PJI/II = 39, others = 37). While sensitivity and specificity were comparably high for AZU1 (0.734/0.833), CRP and PCT had higher specificity (0.542/1 and 0.431/1, respectively), and WBC a slightly higher sensitivity (0.814/0.455) for septic conditions. Taken together, the area under the curve (AUC) showed the highest accuracy for AZU1 (0.790), followed by CRP (0.776), WBC (0.641), and PCT (0.656). The Youden-Index was 0.57 for AZU1, 0.54 for CRP, 0.27 for WBC, and 0.43 for PCT. Elevated AZU1 levels effectively distinguished patients with a healthy condition from those suffering from infection. However, there is evidence suggesting that trauma may influence the release of AZU1. Additional research is needed to validate the diagnostic value of this new biomarker and further explore its potential clinical applications.

Maternal Hypertension and Early-Onset Neonatal Neutropenia

Objective: Maternal hypertension is considered a risk factor for early neonatal neutropenia. We sought to explore this relationship. Study Design: This retrospective cohort study compared initial neutrophil counts in infants born to mothers with preeclampsia with severe features (PSF) and infants born to normotensive mothers using Negative Binomial Regression (NBR) and logistic regression models. Results: Maternal hypertension negatively affected the early neonatal neutrophil count (adjusted NRB coefficient 0.4 [0.2, 0.6], p < 0.0001) but did not increase the risk of neutropenia (OR 2.07 [0.97, 4.41], p = 0.06). The initial neutrophil count and neutropenia risk were not different between PSF subgroups. Gestational age had the greatest impact on neutropenia risk (OR 0.72 [0.64, 0.81], p < 0.0001). Almost all neutropenia resolved within 48 h. Conclusion: Maternal hypertension negatively affects the early neonatal neutrophil count while not increasing the risk of neonatal neutropenia.

Maternal IL-10 restricts fetal emergency myelopoiesis

Neonates, in contrast to adults, are highly susceptible to inflammation and infection. Here we investigate how late fetal liver (FL) mouse hematopoietic stem and progenitor cells (HSPC) respond to inflammation, testing the hypothesis that deficits in engagement of emergency myelopoiesis (EM) pathways limit neutrophil output and contribute to perinatal neutropenia. We show that despite similar molecular wiring as adults, fetal HSPCs have limited production of myeloid cells at steady state and fail to activate a classical EM transcriptional program. Moreover, we find that fetal HSPCs are capable of responding to EM-inducing inflammatory stimuli in vitro , but are restricted by maternal anti-inflammatory factors, primarily interleukin-10 (IL-10), from activating EM pathways in utero . Accordingly, we demonstrate that loss of maternal IL-10 restores EM activation in fetal HSPCs but at the cost of premature parturition. These results reveal the evolutionary trade-off inherent in maternal anti-inflammatory responses that maintain pregnancy but render the fetus unresponsive to EM activation signals and susceptible to infection.

HIGHLIGHTS

The structure of the HSPC compartment is conserved from late fetal to adult life.Fetal HSPCs have diminished steady-state myeloid cell production compared to adult.Fetal HSPCs are restricted from engaging in emergency myelopoiesis by maternal IL-10.Restriction of emergency myelopoiesis may explain neutropenia in septic neonates.

eTOC BLURB

Fetal hematopoietic stem and progenitor cells are restricted from activating emergency myelopoiesis pathways by maternal IL-10, resulting in inadequate myeloid cell production in response to inflammatory challenges and contributing to neonatal neutropenia.

Study of the diagnostic criteria for hemophagocytic lymphohistiocytosis in neonatal and pediatric patients with severe sepsis or septic shock

Septic shock is a major public health concern. However, the clinical and laboratory criteria for sepsis overlap with those for hemophagocytic lymphohistiocytosis (HLH), and their differentiation can be challenging. The aim of this study was to compare HLH criteria among patients diagnosed with neonatal sepsis and childhood sepsis and to study the outcomes in patients fulfilling the diagnostic criteria for HLH. A cross-sectional study included 50 neonates and children with severe sepsis and/or septic shock. Clinical and laboratory data and HLH diagnostic criteria were studied in relation to patients outcome. Of all patients, 18% fulfilled three of the eight HLH diagnostic criteria, 2% fulfilled four criteria, and 4% fulfilled five criteria. All patients who fulfilled three or more of the criteria died. Mortality was higher in the presence of more positive HLH criteria and in pediatric age groups. However, the distributions of the HLH criteria were comparable for pediatric and neonatal patients with severe sepsis/septic shock, and their mortality rates were not significantly different when based on the criteria.

Neonatal alloimmune neutropaenia: Experience from an Australian paediatric health service

AIM

To describe the presenting features and investigation findings in infants diagnosed with neonatal alloimmune neutropaenia (NAIN) within an Australian paediatric health network. The secondary aim was to describe the management and resolution of neutropaenia in infants with NAIN.

METHODS

A retrospective cohort study was conducted at Monash Children's Hospital, Melbourne, Australia. Infants referred to the Victorian Transplantation and Immunogenetics Service for evaluation of NAIN were identified and medical records were reviewed. Descriptive statistical analysis of infants' clinical outcomes, investigation findings and management was performed.

RESULTS

Nine infants were diagnosed with NAIN between December 2004 and June 2017. Overall incidence of NAIN was around 1 per 10 000 births. Median gestational age was 38 (range 35-40) weeks and birthweight was 2920 (2300-4445) g. Median age at NAIN work-up was 7 (2-33) days. Prior to investigation for NAIN, median absolute neutrophil count was 0.2 (0.01-0.6) × 10⁹ cells/L. The post-natal ward was the source of presentation in most infants (78%). All except one infant were admitted to a neonatal unit and commenced on intravenous antibiotics (89%). Six infants were asymptomatic but received antibiotics for risk of infection (75%). Granulocyte-colony stimulating factor was administered to 44% of infants due to neutropaenia with presumed or confirmed infection. NAIN resolved at median age of 32 (6-200) days.

CONCLUSIONS

Infants with NAIN frequently presented with severe, unexpected neutropaenia without major infection. Intravenous antibiotic therapy and granulocyte-colony stimulating factor use was common in this cohort.

Usefulness of the heparin-binding protein level to diagnose sepsis and septic shock according to Sepsis-3 compared with procalcitonin and C reactive protein: a prospective cohort study in China

OBJECTIVES

Our aim was to assess the release level of heparin-binding protein (HBP) in sepsis and septic shock under the Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3).

DESIGN

Prospective cohort study.

SETTING

A general teaching hospital in China.

PARTICIPANTS

Adult infected patients with suspected sepsis and people who underwent physical examination were included. According to the health status and severity of illness, the research subjects were divided into healthy, local infection, sepsis non-shock and septic shock under Sepsis-3 definitions.

MAIN OUTCOME MEASURES

Plasma levels of HBP, procalcitonin (PCT), C reactive protein (CRP) and complete blood count were detected in all subjects. Single-factor analysis of variance was used to compare the biomarker levels of multiple groups. A receiver operating characteristic (ROC) curve was used to assess the diagnostic capacity of each marker.

RESULTS

HBP levels were significantly higher in patients with sepsis non-shock than in those with local infections (median 49.7ng/mL vs 11.8 ng/mL, p<0.01) at enrolment. Moreover, HBP levels in patients with septic shock were significantly higher than in patients with sepsis without shock (median 153.8ng/mL vs 49.7 ng/mL, p<0.01). The area under the ROC curve (AUC) of HBP (cut-off ≥28.1 ng/mL) was 0.893 for sepsis which was higher than those of PCT (0.856) for a cut-off ≥2.05 ng/mL and of CRP (0.699) for a cut-off ≥151.9 mg/L. Moreover, AUC of HBP (cut-off ≥103.5 ng/mL) was 0.760 for septic shock which was higher than the ROC curve of sequential [sepsis-related] organ failure assessment (SOFA) Score (0.656) for a cut-off ≥5.5. However, there was no significant difference between 28-d survivors (n=56) and 28-d non-survivors (n=37) with sepsis in terms of HBP value (p=0.182).

CONCLUSIONS

A high level of HBP in plasma is associated with sepsis, which might be a useful diagnostic marker in patients with suspected sepsis.

Implication of antibodies against human leukocyte antigen in simultaneous presentation of fetal and neonatal alloimmune thrombocytopenia and neutropenia

Fetal and neonatal alloimmune thrombocytopenia (FNAIT) and neonatal alloimmune neutropenia (NAN) are two rare complications of newborns caused by antibodies against paternal inherited antigens. Human platelet (HPA) and neutrophil antigens (HNA) are the common targets. Human leukocyte antigen (HLA) class I proteins are also expressed on platelets and neutrophils and anti-HLA antibodies have occasionally been implicated in these complications. We report a premature twin infant who presented with severe thrombocytopenia and neutropenia clinically compatible with FNAIT and NAN, from a mother with no identifiable HPA or HNA antibodies, but with very high levels of complement-fixing antibodies against paternal inherited HLA. These antibodies were also detected in the infant. HLA antibodies are commonly present in multiparous women who deliver healthy infants. They can, however, be cytotoxic and cause clinical complications after blood products transfusion (TRALI and becoming refractory to platelets transfusion) and after organ transplantation (allogeneic organ rejection).

Severe congenital autoimmune neutropenia in preterm monozygotic twins: case series and literature review

The presence of high levels of neutrophil associated immunoglobulins (NAIG) in the serum of newborns with neutropenia and their mothers is usually associated with the diagnosis of allo-immune neonatal neutropenia (AINN). We describe a set of otherwise healthy late preterm monozygotic twins who presented with an isolated severe neonatal neutropenia on the first day of life. Flow cytometry for neutrophil antibody screen for both twins detected elevated levels of NAIG with normal serum levels of allo anti-neutrophil antibody (allo-NAB). Maternal serum did not contain either NAIG or allo-NAB. Also, the NAIG immunoglobulin M (IgM) levels were markedly increased in both twins if compared to the increase in the NAIG immunoglobulin G (IgG). Both twins showed very good response to a short course treatment with granulocyte colony stimulating factor (G-CSF), they remained clinically well until 12 months of age. We suggest that this case may be an early presentation of autoimmune neutropenia of infancy. This case study is the earliest report of autoimmune neutropenia of infancy in preterm monozygotic twins.

Role of Early Onset Neutropenia in Development of Candidemia in Premature Infants

BACKGROUND

The aim of the study was to assess the effect of early-onset neutropenia (EON) on the development of candidemia in premature infants and evaluate other risk factors.

MATERIALS AND METHODS

This prospective study was carried out in a neonatal intensive care unit of Cairo University Hospital. Fifty neutropenic premature infants were matched to 50 non-neutropenics. Subjects were then regrouped into candidemics and non-candidemics to study other risk factors such as central venous catheters, mechanical ventilation, parenteral nutrition, drugs as corticosteroids and others. Candidemia was assessed by Bactec and then seminested polymerase chain reaction for culture negatives.

RESULTS

Candidemia developed in 28 neutropenic preterms and in 8 non-neutropenics (odds ratio  = 6.68, 95% confidence interval = 2.61-17.1, p <0.001). Risk factors for invasive fungal infection in univariate analysis included bacterial septicemia, mechanical ventilation, parenteral nutrition and steroid therapy. Independent predictors of candidemia in multivariate regression analysis included EON, mechanical ventilation and steroid therapy.

CONCLUSION

EON is an independent risk factor for candidemia in premature infants.

How I manage children with neutropenia

Neutropenia, usually defined as a blood neutrophil count <1·5 × 10⁹ /l, is a common medical problem for children and adults. There are many causes for neutropenia, and at each stage in life the clinical pattern of causes and consequences differs significantly. I recommend utilizing the age of the child and clinical observations for the preliminary diagnosis and primary management. In premature infants, neutropenia is quite common and contributes to the risk of sepsis with necrotizing enterocolitis. At birth and for the first few months of life, neutropenia is often attributable to isoimmune or alloimmune mechanisms and predisposes to the risk of severe bacterial infections. Thereafter when a child is discovered to have neutropenia, often associated with relatively minor symptoms, it is usually attributed to autoimmune disorder or viral infection. The congenital neutropenia syndromes are usually recognized when there are recurrent infections, the neutropenia is severe and there are congenital anomalies suggesting a genetic disorder. This review focuses on the key clinical finding and laboratory tests for diagnosis with commentaries on treatment, particularly the use of granulocyte colony-stimulating factor to treat childhood neutropenia.

Effectiveness of Granulocyte Colony-Stimulating Factor in Hospitalized Infants with Neutropenia

Objective The objective of this study was to determine the time to hematologic recovery and the incidence of secondary sepsis and mortality among neutropenic infants treated or not treated with granulocyte colony-stimulating factor (G-CSF). Study Design We identified all neutropenic infants discharged from 348 neonatal intensive care units from 1997 to 2012. Neutropenia was defined as an absolute neutrophil count ≤ 1,500/µL for ≥ 1 day during the first 120 days of life. Incidence of secondary sepsis and mortality and number of days required to reach an absolute neutrophil count > 1,500/µL for infants exposed to G-CSF were compared with those of unexposed infants. Results We identified 30,705 neutropenic infants, including 2,142 infants (7%) treated with G-CSF. Treated infants had a shorter adjusted time to hematologic recovery (hazard ratio: 1.36, 95% confidence interval [CI]: 1.30-1.44) and higher adjusted odds of secondary sepsis (odds ratio [OR]: 1.50, 95% CI: 1.20-1.87), death (OR: 1.33, 95% CI: 1.05-1.68), and the combined outcome of sepsis or death (OR: 1.41, 95% CI: 1.19-1.67) at day 14 compared with untreated infants. These differences persisted at day 28. Conclusion G-CSF treatment decreased the time to hematologic recovery but was associated with increased odds of secondary sepsis and mortality in neutropenic infants. G-CSF should not routinely be used for infants with neutropenia.

Similar but not the same: Differential diagnosis of HLH and sepsis

Differential diagnosis of hemophagocytic lymphohistiocytosis (HLH; hemophagocytic syndrome) and sepsis is critically important because the life-saving aggressive immunosuppressive treatment, required in the effective HLH therapy, is absent in sepsis guidelines. Moreover, HLH may be complicated by sepsis. Hyperinflammation, present in both states, gives an overlapping clinical picture including fever and performance status deterioration. The aim of this review is to provide aid in this challenging diagnostic process. Analysis of clinical features and laboratory results in multiple groups of patients (both adult and pediatric) with either HLH or sepsis allows to propose criteria differentiating these two conditions. The diagnosis of HLH is supported by hyperferritinemia, splenomegaly, marked cytopenias, hypofibrinogenemia, low CRP, characteristic cytokine profile and, only in adults, hypertriglyceridemia. In the presence of these parameters (especially the most characteristic hyperferritinemia), the other HLH criteria should be assessed. Genetic analyses can reveal familial HLH. Hemophagocytosis is neither specific nor sensitive for HLH.

Hematologic Aspects of Early and Late-Onset Sepsis in Preterm Infants

This article reviews and updates the state of the art on the hematologic aspects related to neonatal sepsis in preterm neonates in the neonatal intensive care unit and overviews all hematologic changes occurring during neonatal infections and their implications both as diagnostic and prognostic parameters to guide clinicians at the patients' bedside.

Is umbilical cord milking always an advantage?

OBJECTIVE

The role of cord milking as an alternative to delayed cord clamping is an area that requires more research. Purpose of this clinical trial was to investigate the impact of umbilical cord milking on the absolute neutrophil counts (ANCs) and the neutropenia frequency of preterm infants.

METHODS

Fifty-eight pregnant women were randomly assigned to one of the umbilical cord milking and control groups. A total of 54 preterm infants (gestational age ≤ 32 weeks) were enrolled into the study. The umbilical cords of 25 infants were clamped immediately after birth, and in 29 infants, umbilical cord milking was performed first.

RESULTS

The ANCs were statistically significantly lower in the cord milking group compared with the control group on days 1, 3 and 7. The frequency of neutropenia was higher in the cord milking group compared with the control group.

CONCLUSION

In our study, ANCs were lower in the cord milking group and the frequency of neutropenia was higher. Umbilical cord milking plays a role on the ANCs of preterm infants.

Efficacy of recombinant human granulocyte colony stimulating factor in very-low-birth-weight infants with early neutropenia

BACKGROUND/PURPOSE

Neutropenia is a risk factor for nosocomial infections (NI) in very-low-birth-weight (VLBW) infants. Although recombinant human granulocyte colony stimulating factor (rhG-CSF) increases the neutrophil counts in neutropenic VLBW infants, its long-term efficacy for early neutropenia (EN) remains unknown.

METHODS

In this case-controlled study, charts of VLBW recipients of rhG-CSF for EN (total neutrophil count <1.5 × 10(9)/L during first 7 days) were reviewed and compared to gestational age, total neutrophil count, and birth weight matched infants unexposed to rhG-CSF.

RESULTS

Twenty-seven infants were identified in each group. Mortality and morbidity did not differ between the two groups. Rate of NI (16/27 vs. 4/27, p = 0.002, odds ratio = 8.36) as well as the total number of episodes of NI (22 vs. 4, p = 0.007) were higher in rhG-CSF (+) group than in the rhG-CSF (-) group.

CONCLUSION

Our experience does not show benefit in empirical use of rhG-CSF in preventing NI in VLBW infants with EN.

Therapeutic hypothermia delays the C-reactive protein response and suppresses white blood cell and platelet count in infants with neonatal encephalopathy

BACKGROUND

Therapeutic hypothermia (HT) delays the cytokine response in infants with neonatal encephalopathy (NE).

OBJECTIVE

To determine if HT delayed the C-reactive protein (CRP) response and altered white blood cell (WBC), neutrophil and platelet count course during the first week of life in infants with NE.

DESIGN

Retrospective cohort study.

SETTING

Regional neonatal intensive care unit, UK.

PATIENTS

104 term infants with NE (38 normothermia (NT) and 66 HT) born between 1998 and 2010. Infants not exposed to prenatal sepsis risk factors were classified as group 'A' and exposed infants to group 'B'. CRP >10 mg/L was defined as significant response.

MAIN OUTCOME MEASURES

Time to CRP >10 mg/L, peak CRP, WBC, neutrophil and platelet count.

RESULTS

Blood cultures were negative in all the infants. In babies who had CRP response, HT delayed time to CRP >10 mg/L (median (95% CI): group A, HT: 36 h (28.3 to 48.0); NT: 24 h (0.0 to 24.0); p=0.001; group B, HT: 30 h (15.2 to 56.8); NT: 12 h (0.0 to 24.0); p=0.009) and time to peak CRP (median (95% CI): group A, HT: 60 h (60.0 to 72.0); NT: 36 h (0.0 to 48.0); p=0.001; group B, HT: 84 h (62.1 to 120.0); NT: 24 h (0.0 to 36.0); p=0.001). Compared with NT, HT was associated with reduction in slope of CRP elevation by 0.5 (95% CI 0.04 to 0.97), WBC by 2.18×10(9)/L (95% CI 0.002 to 4.35) and platelet count by 32.3×10(9)/L (95% CI 2.75 to 61.8) independent of exposure to sepsis risk, meconium aspiration and severity of asphyxia.

CONCLUSIONS

Therapeutic hypothermia delayed the initiation of CRP and its peak response, and depressed the WBC and platelet count compared with NT.

Management and outcome of 35 cases with foetal/neonatal alloimmune neutropenia

AIM

The aim of this study was to provide an overview of foetal/neonatal alloimmune neutropenia (FNAIN), together with advice on the clinical management.

METHODS

Neutrophil serology in the Netherlands is centralised at Sanquin Diagnostic Services. We examined FNAIN cases between January 1, 1991, and July 1, 2013, to determine the number of cases diagnosed, the relationship with human neutrophil antigen (HNA) antibody, the clinical presentation and therapeutic interventions.

RESULTS

We identified 35 FNAIN cases. The detected HNA antibodies were as follows: anti-HNA-1a (n = 7), anti-HNA-1b (n = 12), anti-HNA-1c (n = 2), anti-HNA-2 (n = 8), anti-HNA-3a (n = 1), anti-HNA-5a (n = 1) and anti-FcγRIIIb (n = 4). No infections were diagnosed in 14 neonates, and the other 21 neonates suffered from omphalitis (n = 6), urinary tract infection (n = 1), candida mucositis (n = 1), fever of unknown origin (n = 6) and sepsis (n = 7, 20%). Parity, gestational age, birthweight, neutrophil counts and antibody specificity were not significantly different for cases with, and without, infections. All the infected children were treated with antibiotics. No children died.

CONCLUSION

More than half (21) of the 35 cases of FNAIN presented with infections and most implicated were HNA-1a, HNA-1b and HNA-2. Treatment with antibiotics seemed adequate. A neonatal neutropenia workflow model for use in neonatal intensive care units is presented.

Role of G-CSF GM-CSF in the management of infections in preterm newborns: an update

Neutropenia (definable as an absolute granulocyte count <1,000/μL in neonates) is a relatively frequent condition in small for gestational age and/or low birth weight neonates. Colony stimulating factors (CSF), namely granulocyte- (G-CSF) and granulocyte-macrophage- (GM-CSF) CSF, have been proposed for prophylaxis and therapy of severe infections in this condition. Available data do not support the use of these substances for prophylaxis of infections in the presence of neutropenia. On the contrary, there might be space for their use, mainly for G-CSF, in case of severe infectious complications in severely neutropenic neonates (absolute polymorphonuclear neutrophil count <500/μL) and/or in the presence of specific hematological diseases causing neutropenia.

Neutropenia in the newborn

PURPOSE OF REVIEW

The aim is to review normal blood neutrophil concentrations and the clinical approach to neutropenia in the neonatal period. A literature search on neonatal neutropenia was performed using the databases PubMed, EMBASE, and Scopus, and the electronic archive of abstracts presented at the annual meetings of the Pediatric Academic Societies.

RECENT FINDINGS

The review summarizes current knowledge on the causes of neutropenia in premature and critically ill neonates, focusing on common causes such as maternal hypertension, neonatal sepsis, twin-twin transfusion, alloimmunization, and hemolytic disease. The article provides a rational approach to diagnosis and treatment of neonatal neutropenia, including current evidence on the role of recombinant hematopoietic growth factors.

SUMMARY

Neutrophil counts should be carefully evaluated in premature and critically ill neonates. Although neutropenia is usually benign and runs a self-limited course in most neonates, it can be prolonged, and it constitutes a serious deficiency in antimicrobial defense in some infants.

Alloimmune neonatal neutropenia in Croatia during the 1998-2008 period

PROBLEM

The aim of this study was to estimate the incidence of the disease and to analyze laboratory data of 23 newborns undergoing serologic testing for alloimmune neonatal neutropenia (ANN) during the 1998-2008 period in Croatia.

METHOD OF STUDY

Laboratory data on 23 newborns undergoing serologic testing for ANN during the 1998-2008 period and epidemiologic data on the number of live births in Croatia were analyzed. Laboratory testing for ANN included serologic screening of maternal and neonatal sera and granulocytes (neutrophils) by immunofluorescence (IF) method. The monoclonal antibody immobilization of neutrophil antigens (MAINA) was employed to determine anti-HNA antibody specificity.

RESULTS

Anti-HNA antibodies were detected in seven (54%) of 13 cases of serologically positive ANN. Only anti-HLA class I antibodies were demonstrated in four (31%) of 13 cases In the 2007-2008 period of prospective data collection, the number of serologically verified ANN cases was one case per 17,323 live births. Results of the prospective study conducted at Maternity Ward, Department of Gynecology and Obstetrics, Sestre milosrdnice University Hospital Center yielded the ANN incidence of one case per 2843 live births.

CONCLUSION

Monitoring of neutrophil count in neonatal blood and serologic testing for ANN in case of isolated neutropenia in the newborn contributed considerably to timely detection of ANN.

DESCRIPTORS

Neonatal alloimmune neutropenia-incidence, serologic diagnosis, antineutrophil antibodies, anti-HNA, anti-HLA class I, Croatia.

Late-onset neutropenia: defining limits of neutrophil count in very low birth weight infants

OBJECTIVE

To evaluate the incidence, onset, duration, characteristics and importance of late-onset neutropenia (defined as absolute neutrophil count<1500 μl(-1) at 3 weeks of age or later) in a group of very low birth weight (VLBW) infants.

STUDY DESIGN

Routine complete blood cell counts (CBCs) obtained from VLBW infants over a period of 7 years were gathered retrospectively, including those of newborns with weekly CBCs taken over a duration of at least 3 weeks. Data were obtained from between January 2003 and December 2009.

RESULT

CBCs of 399 newborns were included. Values were obtained from birth to 36 weeks of postnatal age. Late-onset neutropenia was observed in 259 cases (65%). Neutropenic infants had a mean of 0.5 weeks lower gestational age. Late-onset neutropenia was more frequent in children with intraventricular hemorrhage but not in patients who received erythropoietin. The median age of neutropenia onset was 7 weeks in extremely low birth weight infants and 6 weeks in VLBW infants. The fifth percentile of neutrophils between weeks 3 and 4 was 1280 μl(-1) and between weeks 13 and 15 was 500 μl(-1). The average duration was 2 weeks with normalized values after 18 weeks.

CONCLUSION

A neutrophil count <1500 μl(-1) after the third week of life is frequently observed in VLBW infants and should not be used as a lower reference limit. The fifth percentile varies according to postnatal age from around 1300 μl(-1) in week 4 of life, decreasing to a nadir of 500 μl(-1) between 3 and 4 months of age. Values normalize in the first year of life.

Medical decision support using machine learning for early detection of late-onset neonatal sepsis

OBJECTIVE

The objective was to develop non-invasive predictive models for late-onset neonatal sepsis from off-the-shelf medical data and electronic medical records (EMR).

DESIGN

The data used in this study are from 299 infants admitted to the neonatal intensive care unit in the Monroe Carell Jr. Children's Hospital at Vanderbilt and evaluated for late-onset sepsis. Gold standard diagnostic labels (sepsis negative, culture positive sepsis, culture negative/clinical sepsis) were assigned based on all the laboratory, clinical and microbiology data available in EMR. Only data that were available up to 12 h after phlebotomy for blood culture testing were used to build predictive models using machine learning (ML) algorithms.

MEASUREMENT

We compared sensitivity, specificity, positive predictive value and negative predictive value of sepsis treatment of physicians with the predictions of models generated by ML algorithms.

RESULTS

The treatment sensitivity of all the nine ML algorithms and specificity of eight out of the nine ML algorithms tested exceeded that of the physician when culture-negative sepsis was included. When culture-negative sepsis was excluded both sensitivity and specificity exceeded that of the physician for all the ML algorithms. The top three predictive variables were the hematocrit or packed cell volume, chorioamnionitis and respiratory rate.

CONCLUSIONS

Predictive models developed from off-the-shelf and EMR data using ML algorithms exceeded the treatment sensitivity and treatment specificity of clinicians. A prospective study is warranted to assess the clinical utility of the ML algorithms in improving the accuracy of antibiotic use in the management of neonatal sepsis.

Evaluation of neutropenia and neutrophilia in preterm infants

OBJECTIVE

Neutrophil counts are used routinely as part of the sepsis evaluation in newborn infants. In this article, we review the normal blood neutrophil concentrations and the clinical approach to neutropenia and neutrophilia in the neonatal period.

METHODS

A literature search was performed using the databases PubMed, EMBASE, and Scopus, and the electronic archive of abstracts presented at the annual meetings of the Pediatric Academic Societies.

RESULTS

Neutropenia and neutrophilia are documented frequently in premature infants. Neutropenia can be seen in up to 8% of all infants admitted to neonatal intensive care. Neutrophilia is even more common, reported in up to 40% of all preterm infants.

CONCLUSIONS

Neutrophil counts should be carefully evaluated in premature neonates. Maternal and perinatal history, physical examination, and a limited laboratory assessment is usually adequate for making a diagnosis in most infants.

Granulocyte-colony stimulating factor for hematopoietic stem cell donation from healthy female donors during pregnancy and lactation: what do we know?

BACKGROUND Hematopoietic growth factors (HGFs) are mostly used as supportive measures to reduce infectious complications associated with neutropenia. Over the past decade, the use of HGFs became a common method for mobilizing human CD34+ stem cells, either for autologous or allogeneic transplantation. However, since their introduction the long-term safety of the procedure has become a major focus of discussion and research. Most information refers to healthy normal donors and data concerning pregnant and lactating women are scarce. The clinical question, which is the core of this review, is whether stem cell donation, preceded by administration of granulocyte-colony stimulating factor (G-CSF) for mobilization, is a safe procedure for pregnant donors. METHODS Literature searches were performed in Pubmed for English language articles published before the end of May 2012, focusing on G-CSF administration during pregnancy, lactation and hematopoietic stem cell donation. Searches included animal and human studies. RESULTS Data from animals (n = 15 studies) and women (n = 46 studies) indicate that G-CSF crosses the placenta, stimulates fetal granulopoiesis, improves neonatal survival mostly for very immature infants, promotes trophoblast growth and placental metabolism and has an anti-abortive role. Granulocyte macrophage-CSF is a key cytokine in the maternal immune tolerance towards the implanted embryo and exerts protective long-term programming effects to preimplantation embryos. The available data suggest that probably CSFs should not be administered during the time of most active organogenesis (first trimester), except perhaps for the first week during which implantation takes place. Provided CSF is administered during the second and third trimesters, it appears to be safe, and pregnant women receiving the CSF treatment can become hematopoietic stem cell donors. There are also risks related to the anesthesia, which is required for the bone marrow aspiration. During lactation, there should be a period of at least 3 days to allow for clearance of CSF from milk before resuming breast feeding. With regard to teratogenicity or leukaemogenity, in non-pregnant or non-lactating women reports show that CSF administration is associated with a risk for leukemia; however, this risk is not higher compared with the control population. CONCLUSIONS The information available to date indicates that administration of CSF in general, and G-CSF in particular, is safe and healthy pregnant women can serve as donors of either bone marrow or peripheral blood stem cells. However, the clinical experience is rather limited and therefore until more data become available, G-CSF should not be used during pregnancy and lactation when other therapeutic options, instead of stem cell transplantation, are available.

Effect of early postnatal neutropenia in very low birth weight infants born to mothers with pregnancy-induced hypertension

Purpose

In this study, we aimed to investigate the perinatal clinical conditions of very low birth weight (VLBW) infants born to mothers with pregnancy-induced hypertension (PIH) focusing on the effects of early postnatal neutropenia.

Methods

We reviewed the medical records of 191 VLBW infants who were born at Konyang University Hospital, between March 2003 and May 2011. We retrospectively analyzed the clinical characteristics of the infants and their mothers and compared the incidence of perinatal diseases and mortality of the infants according to the presence or absence of maternal PIH and neutropenia on the first postnatal day.

Results

Infants born to mothers with PIH showed an increased incidence of neutropenia on the first postnatal day (47.4%), cesarean delivery, and intrauterine growth restriction. When the infants born to mothers with PIH showed neutropenia on the first postnatal day, their incidence of respiratory distress syndrome (RDS) was increased (P=0.031); however, the difference was not found to be significant through logistic regression analysis. In all the VLBW infants, neutropenia on the first postnatal day was correlated with the development of RDS. The incidence of the other perinatal diseases involving sepsis and mortality did not significantly differ according to the presence or absence of neutropenia in infants born to mothers with PIH.

Conclusion

In VLBW infants born to mothers with PIH, the incidence of neutropenia on the first postnatal day was increased and it was not significantly correlated with the development of perinatal diseases involving RDS, sepsis, and mortality.

Neonatal alloimmune neutropenia: still a diagnostic and therapeutical challenge

OBJECTIVE

To describe a case of neonatal alloimmune neutropenia (NAN), a very rare disease of the newborn and the first ever reported in our neonatal intensive care unit, with emphasis in its management and outcome.

DESCRIPTION

We report a case of NAN due to anti-human neutrophil antigen-1b alloimmunization in a 29-week preterm admitted to our neonatal intensive care unit. In this case, the neutropenia was severe and persisted for almost 2 months. There was a good response to the administration of intravenous immunoglobulin.

COMMENTS

NAN is caused by maternal production of neutrophil-specific alloantibodies in response to antigens from paternal heritage present on the newborn neutrophiles. The course of the disease is usually mild and self-limiting. The optimal therapy is yet a debate, with some authors finding the use of intravenous immunoglobulin effective, prophylactic antibiotic therapy or recombinant human granulocyte colony-stimulating factor.

Elevated plasma levels of heparin-binding protein in intensive care unit patients with severe sepsis and septic shock

INTRODUCTION

Rapid detection of, and optimized treatment for, severe sepsis and septic shock is crucial for successful outcome. Heparin-binding protein (HBP), a potent inducer of increased vascular permeability, is a potentially useful biomarker for predicting outcome in patients with severe infections. Our aim was to study the systemic release and dynamics of HBP in the plasma of patients with severe sepsis and septic shock in the ICU.

METHODS

A prospective study was conducted of two patient cohorts treated in the ICU at Karolinska University Hospital Huddinge in Sweden. A total of 179 patients was included, of whom 151 had sepsis (126 with septic shock and 25 patients with severe sepsis) and 28 a non-septic critical condition. Blood samples were collected at five time points during six days after admission.

RESULTS

HBP levels were significantly higher in the sepsis group as compared to the control group. At admission to the ICU, a plasma HBP concentration of ≥ 15 ng/mL and/or a HBP (ng/mL)/white blood cell count (109/L) ratio of >2 was found in 87.2% and 50.0% of critically ill patients with sepsis and non-septic illness, respectively. A lactate level of >2.5 mmol/L was detected in 64.9% and 56.0% of the same patient groups. Both in the sepsis group (n = 151) and in the whole group (n = 179), plasma HBP concentrations at admission and in the last measured sample within the 144 hour study period were significantly higher among 28-day non-survivors as compared to survivors and in the sepsis group, an elevated HBP-level at baseline was associated with an increased case-fatality rate at 28 days.

CONCLUSIONS

Plasma HBP levels were significantly higher in patients with severe sepsis or septic shock compared to patients with a non-septic illness in the ICU. HBP was associated with severity of disease and an elevated HBP at admission was associated with an increased risk of death. HBP that rises over time may identify patients with a deteriorating prognosis. Thus, repeated HBP measurement in the ICU may help monitor treatment and predict outcome in patients with severe infections.

Neonatal neutropenia: what diagnostic evaluation is needed and when is treatment recommended?

Neutropenia is a relatively frequent finding in the neonatal intensive care unit, particularly in very low birth weight neonates during the first week of life. Healthy term and preterm neonates have blood neutrophil counts within the same basic range as adults, but their neutrophil function, and their neutrophil kinetics during infection, differ considerably from those of adults. Neutrophil function of neonates, particularly preterm neonates, is less robust than that of adults and might also contribute to the increase in propensity to infection. In premature infants, early-onset neutropenia is correlated with sepsis, maternal hypertension, intrauterine growth restriction, severe asphyxia, and periventricular haemorrhage, and might be associated with an increase in the incidence of early-onset sepsis, nosocomial infection, and Candida colonisation. Some varieties of neutropenia in the NICU are very common and others are extremely rare. The most common causes of neutropenia in the NICU have an underlying cause that is often evident, and require little diagnostic evaluation. Unlike, persistent neutropenia should prompt evaluation even if it is of moderate severity. The laboratory tests to consider are those that provide a specific diagnosis. The first tests that should be ordered are a blood film, a complete blood count on the mother, and, if her blood neutrophil concentration is normal, maternal neutrophil antigen typing and an anti-neutrophil antibody screen. A bone marrow biopsy can be useful in cases with prolonged, unusual, or refractory neutropenia. Various treatments have been proposed as means of enhancing neutrophil production and function in preterm infants. Both recombinant granulocyte stimulating factor and recombinant granulocyte macrophage-colony-stimulating factor have been tried with variable success. Intravenous immunoglobulin, corticosteroids, granulocyte transfusions, and gamma interferon did not show a clear adequate beneficial role for the therapy of neonatal neutropenia.

Chemokines plasma levels in preterm newborns of preeclamptic mothers

Information on leukocyte activation in newborn infants of preeclamptic mothers is scarce. IL-8 and GRO-α are the main pro-inflammatory cytokines involved in leukocyte activation. The objective was to evaluate IL-8 and GRO-α plasma levels in preterm newborns infants of preeclamptic mothers. Newborns with gestational age<36 weeks and birth weight<2000 g were included and divided: non-preeclamptic (n=64) and preeclamptic groups (n=55). Exclusion criteria were major congenital malformations, inborn errors of metabolism or chromosomal anomalies, congenital infections, death in delivery room, and maternal chronic hypertension without preeclampsia. IL-8 and GRO-α were measured by enzyme immunoassay in the first 48 h. Groups were similar in birth weight, gestational age, Apgar scores at 5 min, sepsis, RDS, mechanical ventilation, TPN, NEC, intraventricular hemorrhage and death. The preeclamptic group had more neutropenia, SGA, cesarean section, and less rupture of membranes>18 h. IL-8 was higher in the non-preeclamptic [157.1 pg/mL (86.4-261.3) and 26.54 pg/mL (3.6-87.2) p<0.001]. GRO-α levels were similar in both groups [229.5 pg/mL (116.6-321.3) and 185.5 pg/mL (63.9-306.7) p=0.236]. After multiple regression analysis only absence of preeclampsia was associated with high IL-8 levels. Our data suggest that leukocyte activation may be impaired in infants of preeclamptic mothers.

Neonatal erythema multiforme: a case report

Erythema multiforme (EM) is an extremely rare condition in infancy. To the best of our knowledge, there have been only three cases of neonatal EM described in the literature, and no such cases have been reported in Korea. A preterm neonate born at 35 weeks and six days of gestation presented with multiple annular erythematous patches with a targetoid shape over his entire body at 36 days of age (corrected age of 7 days). He had no systemic symptoms except for transient mild fever. No triggering factor except for hepatitis B and BCG vaccination was found. Neutropenia was noted upon laboratory analysis. Skin biopsy specimens showed findings suggestive of erythema multiforme. The skin lesions improved rapidly upon administration of intravenous methylprednisolone; however, neutropenia continued for a much longer period. The significance of neutropenia with respect to the development of EM was not clarified. There has been no recurrence of skin lesions over a one-year follow-up period.

Sepsis and neutropenia in very low birth weight infants delivered of mothers with preeclampsia

OBJECTIVE

To study the association between maternal preeclampsia and neonatal sepsis in very low birth weight newborns.

STUDY DESIGN

We studied all infants with birth weights between 500 g and 1500 g who were admitted to 6 neonatal intensive care units of the Brazilian Network on Neonatal Research for 2 years. Exclusion criteria were major malformations, death in the delivery room, and maternal chronic hypertension. Absolute neutrophil count was performed in the first 72 hours of life.

RESULTS

A total of 911 very low birth weight infants (preeclampsia, 308; non-preeclampsia, 603) were included. The preeclampsia group had significantly higher gestational age, more cesarean deliveries, antenatal steroid, central catheters, total parenteral nutrition, and neutropenia, and less rupture of membranes>18 hours and mechanical ventilation. Both groups had similar incidences of early sepsis (4.6% and 4.2% in preeclampsia and non-preeclampsia groups, respectively) and late sepsis (24% and 22.1% in preeclampsia and non- preeclampsia groups, respectively). Vaginal delivery and neutropenia were associated with multiple logistic regressions with early sepsis, and mechanical ventilation, central catheter, and total parenteral nutrition were associated with late sepsis. Death was associated with neutropenia in very preterm infants.

CONCLUSIONS

Preeclampsia did not increase neonatal sepsis in very low birth weight infants, and death was associated with neutropenia in very preterm infants.

Number of sites of perinatal Candida colonization and neutropenia are associated with nosocomial candidemia in the neonatal intensive care unit patient

OBJECTIVES

To determine the role of perinatally acquired Candida colonization to invasive Candida infection (candidemia) and to assess risk factors associated with Candida colonization and candidemia in neonatal intensive care unit patients.

DESIGN

Retrospective case-control study.

SETTING

Neonatal intensive care unit of a teaching hospital.

PATIENTS

A total of 39 of 3219 (1.2%) who were positive for Candida colonization at birth were compared with 117 noncolonized controls.

INTERVENTIONS

Routine surveillance cultures for Candida of skin and meconium were performed at admission. All neonates with Candida colonization at birth during a 10-yr period were identified. Each case was matched to place of birth and date of admission with three noncolonized controls.

MEASUREMENTS AND MAIN RESULTS

Perinatal and neonatal variables were collected. Blood or skin culture was obtained when signs of sepsis or dermatitis were present. Patients with Candida colonization were compared with their noncolonized controls, whereas in this cohort, patients with candidemia were compared with those without by multivariate analysis. Vaginal candidiasis (odds ratio [OR] 15.8, 95% confidence interval [CI] 2.63, 94.77), birth weight below 1000 g (OR 8.1, 95% CI 1.22, 52.26), and vaginal delivery (OR 7.08, 95% CI 1.17, 42.70) were associated with Candida colonization. An increased risk for nosocomial candidemia was independently associated with the number of sites of Candida colonization (OR 24.02, 95% CI 1.89, 304), early neonatal neutropenia (OR 7.15, 95% CI 0.98, 80.95) and illness severity (clinical risk index for babies [CRIB]) score at day 1 (OR 1.38, 95%CI 1.065, 1.811).

CONCLUSIONS

Maternal vaginal candidiasis and vaginal birth are risk factors for neonatal colonization. When controlling for illness severity, the number of sites colonized with Candida at birth contributes to neonatal nosocomial candidemia. Early neutropenia increases the risk further. These findings offer opportunities for prevention of Candida infection in neonatal intensive care unit patients.

A multicenter, randomized, placebo-controlled trial of prophylactic recombinant granulocyte-colony stimulating factor in preterm neonates with neutropenia

OBJECTIVE

To test the hypothesis that prophylactic treatment of neutropenic premature neonates with recombinant granulocyte-colony stimulating factor (rG-CSF) would reduce the incidence of nosocomial infections (NIs).

STUDY DESIGN

A total of 25 neonatal intensive care units participated in this multicenter, randomized, double-blind, placebo-controlled trial. Premature infants of gestational age (GA) <or= 32 weeks were included if they had a peripheral blood count showing < 1500 neutrophils/mm(3) for at least 24 hours during the first 3 weeks of life. A total of 200 infants received either rG-CSF (10 microg/kg/day) or placebo for 3 days. Primary outcome was survival free of infection for 4 weeks after treatment, assessed in an intention-to-treat analysis.

RESULTS

A total of 102 infants received rG-CSF (mean GA, 29.2 weeks), and 98 received placebo (mean GA, 29.1 weeks). Survival free of confirmed infection for 4 weeks after treatment was 74/102 in the rG-CSF group and 66/98 in the placebo group (P = .42). However, during 2 weeks, there was a significant difference between groups (86/102 vs 70/98; P = .028).

CONCLUSIONS

In this population, prophylactic rG-CSF did not significantly increase survival free of infection at 4 weeks after treatment. The transient effect observed at 2 weeks in the most immature infants should be evaluated further.

Is thrombocytopenia suggestive of organism-specific response in neonatal sepsis?

BACKGROUND

It is controversial whether thrombocytopenia is suggestive of one (or more) causative agents of neonatal sepsis: a low platelet count has been related in turn to Gram-positive, Gram-negative or fungal sepsis.

METHODS

A retrospective, cohort study on 514 very low-birthweight (VLBW) neonates admitted over a 9 year period to a large tertiary neonatal intensive care unit (NICU) in Italy was carried out. Through database search, data on platelet counts, sepsis, clinical course, and microbiological culture were collected and analyzed. Statistical analysis was performed to look for significant association between thrombocytopenia and sepsis caused by different (Gram-positive, Gram-negative or fungal) organisms.

RESULTS

Sepsis diagnosed on microbiological criteria occurred in 197 of 514 VLBW neonates (38.3%), and thrombocytopenia (at least one finding of platelet count <80,000/mm(3)) was detected in 34 (17.2%) of the 197 septic infants. Thrombocytopenia occurred in 10 of 51 neonates with fungal sepsis (19.6%), and in 24 of 146 with bacterial sepsis (16.4%; P = 0.37). The difference was not significant when clustering for sepsis caused by Gram-positive (nine thrombocytopenic of 51 with Gram-positive sepsis, 17.6%; P = 0.40) and Gram-negative organisms (15/95, 15.7%; P = 0.22), or when considering only coagulase-negative Staphylococcus sepsis (6/37, 16.2%; P = 0.25).

CONCLUSIONS

In contrast with previous reports, thrombocytopenia might not be an organism-specific marker of sepsis. Caution should be maintained in relating a low platelet count to any infectious agent (or group of agents) in preterm VLBW neonates.

Early neutropenia is not associated with an increased rate of nosocomial infection in very low-birth-weight infants

BACKGROUND

Evidence is contradictory whether very low-birth-weight (VLBW, birth weight <1500 g) infants with early neutropenia (NP), especially those born to mothers with preeclampsia experience a greater incidence of nosocomial infection (NI).

OBJECTIVE

To investigate whether NP within the first 7 days of life is a risk factor for NI in VLBW infants.

METHODS

Over a 42-month period, we identified all VLBW infants born at <or=34 weeks gestation who survived for more than 72 h. Infants who had no evidence of early infection, who had at least one complete blood count performed in the first week of life, and who were not given prophylactic recombinant human granulocyte colony-stimulating factor (rhG-CSF) were included in this retrospective study. Early NP was defined as an absolute neutrophil count less than 1500 per microl at any time during the first week of life. NI was defined as the culture of a bacterial or fungal pathogen from a sterile body fluid that was obtained after 72 h of life in an infant with one or more clinical signs of infection.

RESULTS

A total of 338 VLBW infants were reviewed. Of those, 51 infants were excluded because of death or onset of an infection before 72 h of age, lack of a complete blood count in the first week of life or treatment with rhG-CSF. Of the remaining 287 infants, NI occurred in 11 of 77 (14.3%) infants with early NP compared to 42 of 210 (20.0%) infants without early NP (P=0.31). Infants who developed NI were smaller and less mature, had lower Apgar scores, were more frequently instrumented with central lines and required a longer duration of parenteral nutrition compared to infants without NI. Infants with NI also had a higher mortality and a greater incidence of necrotizing enterocolitis, severe intraventricular hemorrhage and threshold retinopathy of prematurity. However, using stepwise multivariate logistic regression analysis, only the duration of parenteral nutrition and gestational age were significant risk factors for NI.

CONCLUSION

Our data do not support the hypothesis that early NP increases the risk for NI in VLBW infants.

Caecal ligation and puncture in the rat mimics the pathophysiological changes in human sepsis and causes multi-organ dysfunction

Sepsis is a major clinical challenge that is associated with encephalopathy and multi-organ dysfunction. Current therapeutic interventions are relatively ineffective and the development of novel treatments is hampered by the lack of a well-characterised animal model. Therefore, the behavioural, metabolic, physiological and histological changes resulting from 'through and through' caecal ligation and puncture (CLP) in the rat were investigated to determine its suitability as an animal model of human sepsis. CLP resulted in bacteraemia, characterised by the presence of multiple enteric species within 18-20 h. Locomotor activity was reduced within 4 h of CLP and this reduction increased with time. Pyrexia was evident 4-5 h after CLP and was followed by hypothermia beginning 17 h after intervention. CLP resulted in reduced white blood cell and platelet counts and an increased neutrophil: lymphocyte ratio within 18-20 h. It also resulted in decreased blood glucose, but not lactate levels. CLP caused histopathological changes in the cerebral cortex, liver, lungs and vascular system indicative of multi-organ dysfunction. Therefore, CLP in the rat mimics the cardinal clinical features of human sepsis and the subsequent development of multi-organ dysfunction. It appears to be the best available animal model currently available, in which to investigate the underlying pathophysiology of sepsis and identify therapeutic targets.

Early-onset neutropenia is a risk factor for Candida colonization in very low-birth-weight neonates

Neutropenia is a major risk factor for bacterial colonization and sepsis in preterm neonates in the neonatal intensive care unit (NICU), but little is known about its relationships with candidal colonization (CC) in these settings. We performed a case-control study on neonates with birth weight of <1500 g admitted to our NICU during a 7-year period (1996-2003, N = 585). Through database search, infants with early-onset neutropenia (EON) (n = 68, group A) were identified and 1:1 matched with controls without EON (n = 68, group B). Microbiologic data from weekly surveillance cultures were examined to determine the presence and intensity of CC. Groups A and B were similar clinically and demographically. All group A neonates recovered from EON before the 8th day of life. Incidence of CC in the 1st month of life (at least 1 site) was significantly higher in group A (61.8% versus 35.3%, P = 0.002) and was not modified by treatment with recombinant granulocyte colony-stimulating factor. The same was true of CC intensity, expressed as the number of sites affected (P = 0.002). Incidence of candidal sepsis, mortality rates, and relative frequencies of the various subspecies of Candida among the isolates did not significantly differ between the 2 groups. In conclusion, EON in preterm neonates is a significant, independent risk factor for CC. Larger, prospective, adequately powered studies should verify whether increased CC related to neutropenia may translate into a similar increased occurrence of candidal sepsis in these settings.

Low blood neutrophil concentrations among extremely low birth weight neonates: data from a multihospital health-care system

OBJECTIVE

A blood neutrophil concentration < 1000/microl has been reported to occur in about 8% of neonatal intensive care unit (NICU) patients, at some time during their hospital stay. However, the incidence of this finding among extremely low birth weight (ELBW) neonates (< 1000 g birth weight) is not known. Using data from four NICU's in one health-care system, we sought to estimate the incidence, timing, causes, severity and duration of neutrophil counts < 1000/microl among ELBW neonates. We also tabulated the treatments used for this condition and associations with mortality.

METHODS

We performed an historic cohort analysis of all ELBW neonates born during the 36-month period, 1 July 2002 to 30 June 2005, cared for in the four Intermountain Healthcare level III NICU's.

RESULTS

Three hundred and thirty-eight ELBW neonates were the subjects of the analysis. Complete blood cell counts (CBCs) were obtained in all (range, 1 to 123 CBCs/patient). Thirty-eight percent (128/338) had one or more neutrophil counts < 1000/microl. In 57% the low neutrophil count persisted for < 24 h; in 43% it persisted for 1 to 7.5 days. Most of the cases (74%) were detected during the first 3 days of life. Twenty-two percent of cases were not detected until after the first week. Low neutrophil counts were more common among the smallest patients, with a 63% incidence in those < or = 500 g, 44% in those 501 to 600 g and 34% in those 801 to 999 g. When low neutrophil counts were recognized during the first 3 days of life, the patients were typically either small for gestational age (SGA; weight < 10th percentile for gestational age) or born after pregnancy-induced hypertension (PIH) (68%), or had early-onset bacterial infection (6%). When recognized after the first 3 days, the patients typically had necrotizing enterocolitis (31%) or a nosocomial bacterial infection (19%). Alloimmune mechanisms were not tested for in any of the cases. No cause for the low counts was identified among 35% of the neutropenic patients. Intravenous immunoglobulins was administered to 28% of cases, and 100% of these were given according to our written guidelines. Recombinant granulocyte-colony stimulating factor was administered to 13% of cases, and 69% of these were given according to guidelines. Neither the presence of low neutrophil counts nor the severity (lowest recorded count) correlated with mortality rate, except in proven early-onset sepsis.

CONCLUSIONS

We observed low neutrophil counts among ELBW neonates at a rate five times that reported in the general NICU population. Most cases were present in the first days of life and occurred in SGA neonates or those with PIH. In over 1/3, no cause was discovered. We maintain that more consistency is needed in evaluating and treating neutropenia among ELBW neonates.

Can neutrophil responses in very low birth weight infants predict the organisms responsible for late-onset bacterial or fungal sepsis?

OBJECTIVE

To examine neutrophil counts and various neutrophil indices in preterm very low birth weight (VLBW) newborn infants (birth weight <1500 g) with culture-proven late-onset sepsis to determine whether the neutrophil responses could predict the responsible infectious agent.

STUDY DESIGN

Neutrophil parameters were examined during episodes of culture-proven sepsis in a cohort of 1026 VLBW infants, born over a 6-year period and admitted to two different neonatal intensive care units. Revised reference ranges of Mouzinho et al. for circulating neutrophil counts in VLBW infants were used to define the abnormal neutrophil indices.

RESULTS

One hundred sixty-two of 1026 (15.8%) VLBW infants had blood culture-proven late-onset infection. Infections included Gram-positive bacteria (113/162, 70%), Gram-negative bacteria (30/162, 18%) and fungi (19/162, 12%). Of the 162 sepsis episodes, only nine (5.5%) were associated with neutropenia (absolute total neutrophil (ATN) <1100/mm3). Six of the 30 (20%) infants with Gram-negative bacterial sepsis were neutropenic compared to 2.6% infants with Gram-positive bacterial sepsis and none with fungal sepsis (odds ratio: 11; 95% confidence interval: 2.6, 47.3). Neutrophil counts and various neutrophil indices were similar in infants with late-onset Gram-positive bacterial and fungal sepsis; but total white blood cells, and ATN count were significantly lower (P = 0.004 and 0.001, respectively) in infants with late-onset Gram-negative bacterial sepsis.

CONCLUSIONS

In VLBW infants, common organisms causing infection have different effects on neutrophil responses. Occurrence of neutropenia during evaluation of sepsis in sick VLBW infants is more common with Gram-negative bacterial infection.

Fungal and bacterial sepsis and threshold ROP in preterm very low birth weight neonates

OBJECTIVE

To determine whether an association exists between either fungal or bacterial sepsis and retinopathy of prematurity (ROP).

STUDY DESIGN

Retrospective cohort study on all neonates with birth weight <1500 g admitted to a large Italian third Level Neonatal Intensive Care Unit in the years 1997-2001 and screened for ROP. Univariate analysis and multiple logistic regression were used to detect significant associations with ROP (all grades and threshold) in neonates with birth weight<1000 g (extremely low birth weight (ELBW)) and 1000-1500 g.

RESULTS

Among 301 enrolled neonates, ROP (all grades), threshold ROP, fungal and bacterial sepsis occurred in 31.9, 12.9, 11.6 and 40.5% of the infants, respectively. At multivariate analysis, only gestational age (P=0.03), colonization by Candida non-albicans spp (P=0.03) and fungal sepsis (P=0.03) were independent predictors of threshold ROP, and only in ELBW neonates.

CONCLUSIONS

Fungal (but not bacterial) sepsis is significantly and independently associated with ROP, but only in ELBW neonates and only with threshold ROP.

The hematologic system as a marker of organ dysfunction in sepsis

Sepsis with acute organ dysfunction (severe sepsis) results from a systemic proinflammatory and procoagulant response to infection. Organ dysfunction in the patient with sepsis is associated with increased mortality. Although most organs have discrete anatomical boundaries and carry out unified functions, the hematologic system is poorly circumscribed and serves several unrelated functions. This review addresses the hematologic changes associated with sepsis and provides a framework for prompt diagnosis and rational drug therapy. Data sources used include published research and review articles in the English language related to hematologic alterations in animal models of sepsis and in critically ill patients. Hematologic changes are present in virtually every patient with severe sepsis. Leukocytosis, anemia, thrombocytopenia, and activation of the coagulation cascade are the most common abnormalities. Despite theoretical advantages of using granulocyte colony-stimulating factor to enhance leukocyte function and/or circulating numbers, large clinical trials with these growth factors are lacking. Recent studies support a reduction in the red blood cell transfusion threshold and the use of erythropoietin treatment to reduce transfusion requirements. Treatment of thrombocytopenia depends on the cause and clinical context but may include platelet transfusions and discontinuation of heparin or other inciting drugs. The use of activated protein C may provide a survival benefit in subsets of patients with severe sepsis. The hematologic system should not be overlooked when assessing a patient with severe sepsis. A thorough clinical evaluation and panel of laboratory tests that relate to this organ system should be as much a part of the work-up as taking the patient's blood pressure, monitoring renal function, or measuring liver enzymes.

Late-onset neutropenia in very low birthweight infants

AIM

To evaluate the incidence and duration of late-onset neutropenia (defined as an absolute neutrophil count (ANC) <1500 mm(-3) at a postnatal age of >3 wk) in a population of infants with birthweight <2000 g, and to determine whether copper deficiency, a possible cause of both anemia and neutropenia, may be associated with this complication.

METHODS

Complete blood cell count and differential were assessed in 247 low (LBW) and very low birthweight (VLBW) infants who were discharged after 3 wk of life. In neutropenic infants plasma copper and ceruloplasmin levels were also measured.

RESULTS

Late-onset neutropenia was detected in 11 out of 147 VLBW infants (7.5%) and in 7 out of 127 LBW infants (5.5%). A neutrophil count of <1000 mm(-3) was observed in 14 infants (5.1%). A significantly lower gestational age was found in neutropenic infants compared with non-neutropenic infants. In neutropenic infants ANCs were significantly correlated with hemoglobin and hematocrit. In addition, a significant negative correlation was found between neutrophil and reticulocyte counts. Plasma copper concentration was significantly correlated with birthweight. Oral copper sulfate was administered to infants with plasma copper concentration <50 microg dl(-1), and did not seem to affect ANC, hemoglobin, hematocrit or reticulocyte counts.

CONCLUSION

Late-onset neutropenia appears to be a benign condition that is not associated with any particular complication and does not require specific treatment. Reference ranges after the early neonatal period and during the first few months of life in LBW and VLBW infants should probably be set at lower values.

Immune-mediated neutropenia in the neonate

Alloimmune neonatal neutropenia, neonatal autoimmune neutropenia and autoimmune neutropenia of infancy have remained nebulous entities with difficulties in both clinical and laboratory identification. These disorders are reviewed in this article.