Oxidative stress in the choroid plexus contributes to blood-cerebrospinal fluid barrier disruption during sepsis development.

BACKGROUND: The choroid plexus (CP), main component of blood-cerebrospinal fluid barrier (BCSFB), protects the brain from peripheral inflammation similar to the blood-brain barrier. Thus, CP is considered a critical target site of oxidative damage, which in sepsis oxidative stress is likely to be a major step in the development of brain damage. Functional alterations in CP may be associated with sepsis-induced brain injury. However, there is no description on the mechanisms associated with BCSFB disruption during sepsis development. MATERIALS AND METHODS: To test this hypothesis, we examined time-dependent oxidative stress markers in CP and permeability of BCSFB in rats submitted to polymicrobial sepsis by cecal ligation and puncture (CLP) or sham surgery (control). We assessed albumin cerebrospinal fluid/plasma concentration quotient (Qalb), an index of BCSFB dysfunction and in CP samples, the oxidative damage in lipids, proteins, antioxidant enzymes and nitrite/nitrate (N/N) concentration in 12, 24 and 48 h after CLP. RESULTS: The increase of BCSFB permeability is time-related to the increase of N/N concentration, oxidative damage to lipid and proteins, and decrease of antioxidant enzyme superoxide dismutase activity at 12 h in the CP; and decrease of catalase activity in 12 and 24 h. CONCLUSIONS: In experimental sepsis the BCSFB dysfunction occurs and oxidative stress seems to be a major step in this dysfunction.

Lipooligosaccharide Structures of Invasive and Carrier Isolates of Neisseria meningitidis Are Correlated with Pathogenicity and Carriage.

The degree of phosphorylation and phosphoethanolaminylation of lipid A on neisserial lipooligosaccharide (LOS), a major cell-surface antigen, can be correlated with inflammatory potential and the ability to induce immune tolerance in vitro. On the oligosaccharide of the LOS, the presence of phosphoethanolamine and sialic acid substituents can be correlated with in vitro serum resistance. In this study, we analyzed the structure of the LOS from 40 invasive isolates and 25 isolates from carriers of Neisseria meningitidis without disease. Invasive strains were classified as groups 1-3 that caused meningitis, septicemia without meningitis, and septicemia with meningitis, respectively. Intact LOS was analyzed by high resolution matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Prominent peaks for lipid A fragment ions with three phosphates and one phosphoethanolamine were detected in all LOS analyzed. LOS from groups 2 and 3 had less abundant ions for highly phosphorylated lipid A forms and induced less TNF-α in THP-1 monocytic cells compared with LOS from group 1. Lipid A from all invasive strains was hexaacylated, whereas lipid A of 6/25 carrier strains was pentaacylated. There were fewer O-acetyl groups and more phosphoethanolamine and sialic acid substitutions on the oligosaccharide from invasive compared with carrier isolates. Bioinformatic and genomic analysis of LOS biosynthetic genes indicated significant skewing to specific alleles, dependent on the disease outcome. Our results suggest that variable LOS structures have multifaceted effects on homeostatic innate immune responses that have critical impact on the pathophysiology of meningococcal infections.

Comparison of diagnostic clinical samples and environmental sampling for enterovirus and parechovirus surveillance in Scotland, 2010 to 2012.

Human enteroviruses (EV) and parechoviruses (HPeV) within the family Picornaviridae are the most common causes of viral central nervous system (CNS)-associated infections including meningitis and neonatal sepsis-like disease. The frequencies of EV and HPeV types identified in clinical specimens collected in Scotland over an eight-year period were compared to those identified in sewage surveillance established in Edinburgh. Of the 35 different EV types belonging to four EV species (A to D) and the four HPeV types detected in this study, HPeV3 was identified as the most prevalent picornavirus in cerebrospinal fluid samples, followed by species B EV. Interestingly, over half of EV and all HPeV CNS-associated infections were observed in young infants (younger than three months). Detection of species A EV including coxsackievirus A6 and EV71 in clinical samples and sewage indicates that these viruses are already widely circulating in Scotland. Furthermore, species C EV were frequently identified EV in sewage screening but they were not present in any of 606 EV-positive clinical samples studied, indicating their likely lower pathogenicity. Picornavirus surveillance is important not only for monitoring the changing epidemiology of these infections but also for the rapid identification of spread of emerging EV and/or HPeV types.

[Proteasomes and their role in the extracellular space].

The presented review concerns the intracellular proteasome and their possible functions. The ubiquitin-proteasome system (UPS) is responsible for the common regulated proteolysis in the cell. 26S proteasome is a central proteolytic unit of UPS and is a multisubunit protein complex consisting of a core catalytic complex, called 20S proteasome, capped at one or both ends by 19S regulatory complex. Proteasomes have been shown in the extracellular space: in alveolar and cerebrospinal fluids, blood plasma. Extracellular proteasomes are intact intracellular particles that exhibit three types of specific peptidase activity. Extracellular proteasomes have been detected in both healthy people and patients with different diseases. Its concentration has been found to be increased in patients suffering from autoimmune diseases, malignant tumors, trauma or sepsis and to correlate with the disease progression, which has both diagnostic and prognostic value.

Variation in lumbar punctures for early onset neonatal sepsis: a nationally representative serial cross-sectional analysis, 2003-2009.

BACKGROUND: Whether lumbar punctures (LPs) should be performed routinely for term newborns suspected of having early onset neonatal sepsis (EONS) is subject to debate. It is unclear whether variations in performance of LPs for EONS may be associated with patient, hospital, insurance or regional factors. Our objective was to identify characteristics associated with the practice of performing LPs for suspected EONS in a nationally representative sample. METHODS: Utilizing data from the 2003, 2006 and 2009 Kids' Inpatient Database (KID) compiled by the Agency for Healthcare Research and Quality, we examined the frequency and characteristics of term, normal-birth weight newborns receiving an LP for EONS. Survey-weighting was applied for national estimates and used in chi squared and multivariable regression analysis. RESULTS: In 2009, there were 13,694 discharges for term newborns that underwent LPs for apparent EONS. Newborns having LPs performed were more likely to be covered by Medicaid vs. private insurance (51.9 vs. 45.1 percent; p < 0.001), be born in urban vs. rural hospitals (94.8 vs. 87.3 percent; p < 0.001), teaching vs. non-teaching (60.8 vs. 43.1 percent; p < 0.001) and children's hospitals vs. non-children's (23.0 vs. 11.2 percent; p < 0.001). Lastly, newborns having LPs performed were disproportionately born in the Northeast census region (p = 0.03). In multi-year adjusted analysis, infants with Medicaid coverage, and those born in urban or teaching hospitals, consistently had higher odds of having an LP performed. CONCLUSIONS: We found pronounced variation in LPs performed for EONS, even when adjusting for clinical conditions that would prompt LPs. These findings indicate practice variations in newborn care that merit further examination and explanation.

Maternal markers for detecting early-onset neonatal infection and chorioamnionitis in cases of premature rupture of membranes at or after 34 weeks of gestation: a two-center prospective study.

BACKGROUND: Accurate prediction of infection, including maternal chorioamnionitis and early-onset neonatal infection, remains a critical challenge in cases of preterm rupture of membranes and may influence obstetrical management. The aim of our study was to investigate the predictive value for early-onset neonatal infection and maternal histological and clinical chorioamnionitis of maternal biological markers in routine use at or after 34 weeks of gestation in women with premature rupture of membranes. METHODS: We conducted a two-center prospective study of all women admitted for premature rupture of membranes at or after 34 weeks of gestation. The association of C-reactive protein, white blood cell count, vaginal sample bacteriological results, and a prediction model at admission, for early-onset neonatal infection and maternal chorioamnionitis were analyzed by comparing areas under the receiver operating characteristic curves and specificity. RESULTS: The study included 399 women. In all, 4.3% of the newborns had an early-onset neonatal infection and 5.3% of the women had clinical chorioamnionitis. Histological chorioamnionitis was detected on 10.8% of 297 placentas tested. White blood cell counts and C-reactive protein concentrations were significantly associated with early-onset neonatal infection and included in a prediction model. The area under the receiver operating characteristic curve of this model was 0.82 (95% CI [0.72, 0.92]) and of C-reactive protein, 0.80 (95% CI [0.68, 0.92]) (p = 1.0). Specificity was significantly higher for C-reactive protein than for the prediction model (48% and 43% respectively, p < 0.05). C-reactive protein was associated with clinical and histological chorioamnionitis, with areas under the receiver operating characteristic curve of 0.61 (95% CI [0.48, 0.74]) and 0.62 (95% CI [0.47, 0.74]), respectively. CONCLUSIONS: The concentration of C-reactive protein at admission for premature rupture of membranes is the most accurate infectious marker for prediction of early-onset neonatal infection in routine use with a sensitivity > 90%. A useful next step would be a randomized prospective study of management strategy comparing CRP at admission with active management to assess whether this more individualized care is a safe alternative strategy in women with premature rupture of membranes at or after 34 weeks.

Persistent hyperammonia and altered concentrations of urea cycle metabolites in a 5-day swine experiment of sepsis.

We measured plasma and cerebrospinal fluid (CSF) metabolite concentrations in a 5-day porcine sepsis model of fecal peritonitis. The objectives were: (i) to verify whether the expected pathways that had emerged in previous studies pertain only to the early inflammatory response or persist for the subsequent days; (ii) to identify metabolic derangements that arise later; (iii) to verify whether CSF metabolite concentrations were altered and if these alterations were similar to those in the blood or delayed. We observed an early response to inflammation and cytokine storms with alterations in lipid and glucose metabolism. The arginine/asymmetric dimethylarginine (ADMA) and phenylalanine/tyrosine balances changed 24 h after resuscitation in plasma, and later in CSF. There was a rise in ammonia concentration, with altered concentrations of metabolites in the urea cycle. Whether persistent derangement of these pathways have a role not only on short-term outcomes but also on longer-term comorbidities, such as septic encephalopathy, should be addressed in further studies.

Characteristics and Outcomes of Neonates With Blood Stream Infection Due to Listeria monocytogenes.

BACKGROUND: Infection due to Listeria monocytogenes (LM) is rare in neonates; thus, its clinical presentation and outcomes are not commonly reported, especially in low- and middle-income countries. In 2017, South Africa had an outbreak due to LM. OBJECTIVE: To determine demographic characteristics, clinical and laboratory findings and outcomes of all neonates infected with LM during the outbreak period. METHODS: This is a retrospective analytic study. Clinical and laboratory records of neonates admitted at Chris Hani Baragwanath Academic Hospital from January 2017 to May 2018 with positive blood and cerebrospinal fluid culture with LM were reviewed for demographic characteristics, clinical presentation, ancillary laboratory test results and outcomes at hospital discharge. RESULTS: There were 42 neonates with positive cultures due to LM. Thirty-four (81%) were born preterm. Mode of delivery was vaginal in 78.6% and 31.0% were HIV exposed. All patients presented within the first 6 days of life as an early-onset disease. Common clinical presentation was respiratory depression (52.4%) and respiratory distress (38.1%) with 69% requiring invasive or noninvasive respiratory support. Common abnormal laboratory findings were high C-reactive protein (77.1%) followed by leukopenia (23.8%). Fourteen patients (40%) had features of meningitis based on blood and cerebrospinal fluid findings (4 culture proven). There were 11 deaths at hospital discharge, giving a mortality rate of 26.2%. CONCLUSIONS: The majority of neonates infected with LM were born preterm, raising the possibility that LM itself may have been responsible for preterm labor. All presented in the first 6 days of life and most presented with respiratory distress or depression. A high proportion had meningitis, and there was a high-mortality overall.

Sepsis associated encephalopathy studied by MRI and cerebral spinal fluid S100B measurement.

The pathogenesis of sepsis associated encephalopathy (SAE) is not yet clear: the blood-brain barrier (BBB) disruption has been indicated among the possible causative mechanisms. S100B, a calcium binding protein, originates in the central nervous system but it can be also produced by extra-cerebral sources; it is passively released from damaged glial cells and neurons; it has limited passage through the BBB. We aimed to demonstrate BBB damage as part of the pathogenesis of SAE by cerebral spinal fluid (CSF) and serum S100B measurements and by magnetic resonance imaging (MRI). This paper describes four septic patients in whom SAE was clinically evident, who underwent MRI and S100B measurement. We have not found any evidence of CSF-S100B increase. Serum S100B increase was found in three out of four patients. MRI did not identify images attributable to BBB disruption but vasogenic edema, probably caused by an alteration of autoregulation, was diagnosed. S100B does not increase in CSF of septic patients; S100B increase in serum may be due to extracerebral sources and does not prove any injury of BBB. MRI can exclude other cerebral pathologies causing brain dysfunction but is not specific of SAE. BBB damage may be numbered among the contributors of SAE, which aetiology is certainly multifactorial: an interplay between the toxic mediators involved in sepsis and the indirect effects of hyperthermia, hypossia and hypoperfusion.

[Sepsis-associated Guillain-Barré syndrome]. / Das Sepsis-assoziierte Guillain-Barré-Syndrom.

This article reports on the case of a multiple trauma patient, who was admitted to the intensive care unit with haemorrhagic shock and severe hypoxaemia. Following posttraumatic septic shock the patient developed quadriplegia 3 weeks after admittance. After having excluded any traumatic and cerebral origins, an analysis of the cerebrospinal fluid was performed and revealed a"dissociation albuminocytologique". This finding in association with limb quadriplegia led to the diagnosis of Guillain-Barré syndrome. Therapy with high-dose i.v. immunoglobulins led to a complete recovery.

Prospective research of human parechovirus and cytokines in cerebrospinal fluid of young children less than one year with sepsis-like illness: Comparison with enterovirus.

BACKGROUND: Human parechovirus (PeV) and enterovirus are important pathogens that cause viral infection and aseptic meningitis in young children. We aimed to investigate the rate of HPeV and enterovirus detection, and to characterize cytokine profiles in the cerebrospinal fluid (CSF) of young infants with sepsis-like illness or meningitis/encephalitis. STUDY DESIGN: This was a prospective cohort study. CSF samples were collected from 90 infants less than 1 year of age. PeV and enterovirus detection was performed using reverse transcription polymerase chain reaction. Fifteen cytokines in the CSF were measured simultaneously by using multiplex immunoassays. RESULTS: PeV (PeV-group) and enterovirus (EV-group) were detected in 10 (11.1%) and 12 (13.3%) CSF samples, respectively. Other aseptic meningitis (AM-group) was diagnosed in 22 (24.4%) patients. Forty-six (51.1%) patients exhibited non-central nervous system infection (Ngroup). The PeV-group had the lowest CSF leukocyte (2.1 ± 3.5/mm3, p=0.022) and blood leukocyte (7,953 ± 4,583/mm3, p=0.046) count and Creactive protein levels (0.2 ± 0.1 mg/dL, p=0.036), than did those in the EV- and AM-groups. CSF leukocyte count and protein levels were not significantly different between the PeV- and N-groups. The levels of interleukin (IL)-1ß, IL-5, IL-6, IL-12, and IL-17 were higher in the EVgroup; conversely, IL-2, IL-4, IL-7, and IL-13 were higher in the PeVgroup. CONCLUSIONS: Examinations to detect PeV in the CSF may help identify the etiological basis of undiagnosed febrile illness in young children. Significant differences in CSF and blood laboratory findings were observed between PeV- and enterovirus-infected children.

Identifying genes associated with invasive disease in S. pneumoniae by applying a machine learning approach to whole genome sequence typing data.

Streptococcus pneumoniae, a normal commensal of the upper respiratory tract, is a major public health concern, responsible for substantial global morbidity and mortality due to pneumonia, meningitis and sepsis. Why some pneumococci invade the bloodstream or CSF (so-called invasive pneumococcal disease; IPD) is uncertain. In this study we identify genes associated with IPD. We transform whole genome sequence (WGS) data into a sequence typing scheme, while avoiding the caveat of using an arbitrary genome as a reference by substituting it with a constructed pangenome. We then employ a random forest machine-learning algorithm on the transformed data, and find 43 genes consistently associated with IPD across three geographically distinct WGS data sets of pneumococcal carriage isolates. Of the genes we identified as associated with IPD, we find 23 genes previously shown to be directly relevant to IPD, as well as 18 uncharacterized genes. We suggest that these uncharacterized genes identified by us are also likely to be relevant for IPD.

Role of beta-2-microglobulin as a biomarker in very preterm and extremely preterm infants with CNS inflammation.

BACKGROUND: Premature infants are at risk for severe sepsis and meningitis, both infections associated with high mortality and morbidity. Cerebro-spinal fluid (CSF) culture is the gold standard method for meningitis diagnosis, but interpretation of biochemical parameters of CSF is essential at the moment of the analysis in order to start the appropriate treatment. The main objective of this study was to determine whether levels of CSF beta-2-microglobulin (B2M) were elevated in preterm infants with CNS infections or other inflammatory processes, and to establish if there were differences in B2M concentrations amongst various inflammatory settings (sepsis, meningitis, and progressive post-hemorrhagic ventricular dilatation (PHVD)). METHODS: This is a retrospective study of all very preterm and extremely preterm infants (< 32 weeks of gestation) admitted to our NICU between 2012 and 2017. All those who underwent a lumbar puncture during their stay as part of a sepsis work-up or PHVD were considered for inclusion. CSF biochemical parameters and B2M were tested in all of the patients. RESULTS: Fifty-nine patients were included in the study. In patients with CNS infections, the median value of B2M was 8.69 mg/L (3.92-18.5). B2M levels above 3.92 mg/L showed greater sensitivity and specificity than leukocyte levels in discriminating between patients with CNS infections or other inflammatory processes and those without CNS inflammation. CONCLUSIONS: In this population, CSF B2M proved to be an effective biomarker to discriminate between patients with CNS infections and other inflammatory processes and those without CNS inflammation.

Pitfalls in the diagnosis of meningitis in neonates and young infants: the role of lumbar puncture.

Meningitis occurs frequently in neonates and can lead to a number of acute, severe complications and long-term disabilities. An early diagnosis of neonatal meningitis is essential to reduce mortality and to improve outcomes. Initial clinical signs of meningitis are often subtle and frequently overlap with those of sepsis, and current haematologic tests do not distinguish sepsis from meningitis. Thus, lumbar puncture (LP) remains the gold standard for the diagnosis of meningitis in infants, and this procedure is recommended in clinical guidelines. Nevertheless, in clinical practice, LP is frequently deferred or omitted due to concerns regarding hypothetical adverse events or limited experience of the performer. Future studies should assess whether a combination of clinical findings and select haematologic tests at disease onset can identify those neonates with the highest risk of meningitis who should undergo LP. Furthermore, clinicians should be convinced that the actual benefits of an early diagnosis of meningitis far outweigh the hypothetical risks associated with LP.

The Protective Effects and the Involved Mechanisms of Tanshinone IIA on Sepsis-Induced Brain Damage in Mice.

To evaluate the protective effect of tanshinone IIA on sepsis using a mouse model as well as to preliminarily explore the mechanism behind its application. The mouse model of sepsis was established using the cecal ligation and puncture (CLP) method. Eighty mice were randomly divided into four groups: Sham operation group (Sham group), model group (CLP group), tanshinone IIA group (DS group), and dexamethasone group (DEX group). ELISA method was used to detect the levels of TNF-α and IL-6 in the hippocampal tissue of mouse. Western blot method was used to detect the expression levels of PSD-95, SYP, and Iba-1 in the hippocampus tissue. Immunohistochemistry was used to detect the expression level and distribution of astrocytes (GFAP antibody). Morris water maze test was used to determine the ability of learning and memory in mice. Tanshinone IIA could improve the postoperative survival and 7-day survival rate in the septic mice after operation, which shortens the escape latency and increases the number of crossing platform in the septic mice. It also reduces the expression of TNF-α, IL-6, and Iba-1 in the peripheral blood/hippocampus and the number of astrocytes in hippocampal CA3 area after 7 days of sepsis in mice. However, tanshinone IIA increases the expression levels of SYP and PSD-95 in the hippocampus of septic mice on the seventh day after operation. Tanshinone IIA has a protective effect on the nerve of septic mice, and its mechanism may be related to the anti-inflammatory effects of the peripheral and hippocampal parts as well as inhibiting the over-activation of astrocytes and microglia.

Human parechoviruses as an important viral cause of sepsislike illness and meningitis in young children.

BACKGROUND: Enteroviruses (EVs) belong to the family Picornaviridae and are a well-known cause of neonatal sepsis and viral meningitis. Human parechoviruses (HPeVs) type 1 and 2, previously named echovirus 22 and 23, have been associated with mild gastrointestinal or respiratory symptoms in young children. Six HPeV genotypes are currently known, of which HPeV3 is associated with neonatal sepsis and meningitis. METHODS: Cerebrospinal fluid samples from children aged <5 years previously tested by EV-specific polymerase chain reaction (PCR) during 2004-2006 were selected (N= 761). Samples from 716 of those children were available for retrospective testing by HPeV-specific real-time PCR. The prevalence of EV and HPeV in these samples was compared. Data on clinical presentation of children infected with HPeV were retrospectively documented. RESULTS: HPeV was found in cerebrospinal fluid samples from 33 (4.6%) of the children. Yearly prevalence of HPeV in cerebrospinal fluid varied remarkably: 8.2% in 2004, 0.4% in 2005, and 5.7% in 2006. EV was detected in 14% (108 of 761 samples), with no variation in yearly prevalence. Children with HPeV in cerebrospinal fluid presented with clinical symptoms of sepsislike illness and meningitis, which led to hospitalization and antibiotic treatment. CONCLUSION: EV-specific PCRs do not detect HPeVs. The addition of an HPeV-specific PCR has led to a 31% increase in detection of a viral cause of neonatal sepsis or central nervous system symptoms in children aged <5 years. HPeV can be considered to be the second cause of viral sepsis and meningitis in young children, and rapid identification of HPeV by PCR could contribute to shorter duration of both antibiotic use and hospital stay.

Neutrophils in cerebrospinal fluid without pleocytosis.

Neutrophils in cerebrospinal fluid (CSF) samples are commonly considered a pathological feature; however, there is little information on the frequency and significance of these cells in CSF samples without pleocytosis. Therefore, the frequency and possible clinical significance of neutrophils in CSF was investigated. In a retrospective study comprising 1556 consecutive CSF samples, cytologies and patient records were reviewed. Five hundred thirty-eight CSF samples without pleocytosis were identified. Neutrophils were detected in 35.5% of these samples. The presence of neutrophils was associated with sepsis (P < 0.01), recent epileptic seizure (P < 0.0001), and blood contamination (P < 0.01). Amongst patients without CSF pleocytosis, CNS infections were not more frequent if neutrophils were present. Neutrophils are frequently observed in CSF with normal leukocyte counts. As sepsis but not CNS infection occurred more frequently in these patients, we conclude that in the absence of CSF pleocytosis, neutrophils are not indicative of CNS infections.

Cerebrospinal fluid values in very low birth weight infants with suspected sepsis at different ages.

OBJECTIVES: Lumbar puncture can be an essential part of the septic work-up in premature infants who are at risk for sepsis and meningitis. Cerebrospinal fluid (CSF) values for cell counts, protein concentrations, and glucose concentrations in children and full-term infants are well established. CSF values in premature infants, however, have not been well studied. We sought to determine CSF values in very low birth weight premature infants at different ages (birth, postmenstrual age, and postnatal age). DESIGN: Medical records of all very low birth weight premature infants with suspected sepsis who were admitted to our neonatal intensive care unit between 1991 and 2005 were reviewed. Infants were excluded if they had evidence of intraventricular hemorrhage, sepsis/meningitis, or major congenital abnormalities or had a traumatic lumbar puncture. SETTING: Neonatal intensive care unit. PATIENTS: Patients were 455 infants who underwent lumbar puncture. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Medical records of 455 infants who underwent 648 lumbar punctures were reviewed. Of these, 243 infants met our inclusion criteria, and 88 patients underwent lumbar puncture only at birth. Patients' mean gestational age and birth weight were 28.8 +/- 2.6 wks and 1080 +/- 279 g, respectively. There were no correlations between gestational age and CSF white blood cell (WBC) count or between gestational age and CSF protein concentrations at birth. CSF WBC count remained unchanged at different postmenstrual ages. However, CSF protein concentration decreased with advancing postmenstrual age (Spearman's rho correlation coefficient, r = -.29; p < .01), and both CSF WBC count and CSF protein concentration decreased with advancing postnatal age (Spearman's rho correlation coefficient, r = -.319 and r = -.376, respectively; p < .01). A subgroup analysis revealed differences in CSF WBC count and CSF protein concentrations between infants who had a lumbar puncture at birth, at 2 wks, and at 3 wks of life at the same postmenstrual age. CONCLUSIONS: In very low birth weight premature infants, CSF WBC count and CSF protein concentrations vary with advancing postnatal and postmenstrual ages.

High thrombopoietin concentrations in the cerebrospinal fluid of neonates with sepsis and intraventricular hemorrhage may contribute to brain damage.

Thrombopoietin (TPO) and its receptor (TPOR) are expressed in the central nervous system (CNS). Although TPO shares significant homology with various neurotrophins, recent data indicate a proapoptotic function of TPO in the CNS. In this study, TPO concentrations were analyzed in the cerebrospinal fluid (CSF) of neonates. Human neuroblastoma-derived SH-SY5Y cells were established to elucidate the effects of inflammation and hypoxia on neuronal Tpo expression. TPO was detectable in the CSF of 6 of 15 neonates with bacterial infection/sepsis (median 140, range 2-613 pg/mL), 5 of 9 neonates with posthemorrhagic hydrocephalus (median 31, range 1.4-469 pg/mL), 3 of 4 neonates with posthemorrhagic hydrocephalus plus bacterial infection/sepsis or meningitis (median 97, range 6-397 pg/mL), but not in controls ( n = 3). Neither the presence of detectable TPO nor its level in the CSF significantly correlated with any clinical or laboratory parameter. In SH-SY5Y cells, TPO and TPOR expression was detected by RT-PCR and Western blot analysis. In vitro, interleukin-6 (IL-6) did not significantly change Tpo gene expression. In contrast, Tpo mRNA expression significantly decreased under hypoxia, whereas erythropoietin (EPO) mRNA expression increased. In conclusion, our data provide evidence that in neuronal cells, TPO production is regulated by different mechanisms than in hepatocytes.