A Phase Ib Trial of Personalized Neoantigen Therapy Plus Anti-PD-1 in Patients with Advanced Melanoma, Non-small Cell Lung Cancer, or Bladder Cancer.

Neoantigens arise from mutations in cancer cells and are important targets of T cell-mediated anti-tumor immunity. Here, we report the first open-label, phase Ib clinical trial of a personalized neoantigen-based vaccine, NEO-PV-01, in combination with PD-1 blockade in patients with advanced melanoma, non-small cell lung cancer, or bladder cancer. This analysis of 82 patients demonstrated that the regimen was safe, with no treatment-related serious adverse events observed. De novo neoantigen-specific CD4+ and CD8+ T cell responses were observed post-vaccination in all of the patients. The vaccine-induced T cells had a cytotoxic phenotype and were capable of trafficking to the tumor and mediating cell killing. In addition, epitope spread to neoantigens not included in the vaccine was detected post-vaccination. These data support the safety and immunogenicity of this regimen in patients with advanced solid tumors (Clinicaltrials.gov: NCT02897765).

NEDD4L intramolecular interactions regulate its auto and substrate NaV1.5 ubiquitination.

NEDD4L is a HECT-type E3 ligase that catalyzes the addition of ubiquitin to intracellular substrates such as the cardiac voltage-gated sodium channel, NaV1.5. The intramolecular interactions of NEDD4L regulate its enzymatic activity which is essential for proteostasis. For NaV1.5, this process is critical as alterations in Na+ current is involved in cardiac diseases including arrhythmias and heart failure. In this study, we perform extensive biochemical and functional analyses that implicate the C2 domain and the first WW-linker (1,2-linker) in the autoregulatory mechanism of NEDD4L. Through in vitro and electrophysiological experiments, the NEDD4L 1,2-linker was determined to be important in substrate ubiquitination of NaV1.5. We establish the preferred sites of ubiquitination of NEDD4L to be in the second WW-linker (2,3-linker). Interestingly, NEDD4L ubiquitinates the cytoplasmic linker between the first and second transmembrane domains of the channel (DI-DII) of NaV1.5. Moreover, we design a genetically encoded modulator of Nav1.5 that achieves Na+ current reduction using the NEDD4L HECT domain as cargo of a NaV1.5-binding nanobody. These investigations elucidate the mechanisms regulating the NEDD4 family and furnish a new molecular framework for understanding NaV1.5 ubiquitination.

Sepsis Huddles in the Neonatal Intensive Care Unit: A Retrospective Cohort Study of Late-onset Infection Recognition and Severity Assessment.

OBJECTIVE: To analyze relationships between provider-documented signs prompting sepsis evaluations, assessments of illness severity, and late-onset infection (LOI). STUDY DESIGN: Retrospective cohort study of all infants receiving a sepsis huddle in conjunction with a LOI evaluation. Participants were ≥3 days old and admitted to a level IV neonatal intensive care unit (NICU) from September 2018 through May 2021. Data were extracted from standardized sepsis huddle notes in the electronic health record, including clinical signs prompting LOI evaluations, illness severity assessments (from least to most severe: green, yellow, and red), and management plans. To analyze relationships of sepsis huddle characteristics with the detection of culture-confirmed LOI (bacteremia, urinary tract infection, or meningitis), we utilized diagnostic test statistics, area under the receiver-operator characteristic analyses, and multivariable logistic regression. RESULTS: We identified 1209 eligible sepsis huddles among 604 infants. There were 111 culture-confirmed LOI episodes (9% of all huddles). Twelve clinical signs of infection poorly distinguished infants with and without LOI, with sensitivity for each ranging from 2% to 36% and area under the receiver-operator characteristic ranging 0.49-0.53. Multivariable logistic regression identified increasing odds of infection with higher perceived illness severity at the time of sepsis huddle, adjusted for gestational age and receipt of intensive care supports. CONCLUSIONS: Clinical signs prompting sepsis huddles were nonspecific and not predictive of concurrent LOI. Higher perceived illness severity was associated with presence of infection, despite some misclassification based on objective criteria. In level IV NICUs, antimicrobial stewardship through development of criteria for antibiotic noninitiation may be challenging, as presenting signs of LOI are similar among infants with and without confirmed infection.

Effect of Minimization of Early Blood Sampling Losses Among Extremely Premature Neonates: A Randomized Clinical Trial.

OBJECTIVE: To evaluate the effect of blood sampling stewardship on transfusion requirements among infants born extremely preterm. STUDY DESIGN: In this single-center, randomized controlled trial (RCT), infants born at <28 weeks of gestation and birth weight of <1000 g were randomized at 24 hours of age to two different blood sampling approaches: restricted sampling (RS) vs conventional sampling (CS). The stewardship intervention in the RS group included targeted reduction in blood sampling volume and frequency and point of care testing methods in the first 6 weeks after birth. Both groups received early recombinant erythropoietin from day three of age. Primary outcome was the rate of early red blood cell (RBC) transfusions in the first six postnatal weeks. RESULTS: A total of 102 infants (mean gestational age: 26 weeks; birth weight: 756 g) were enrolled. Fidelity to the sampling protocol was achieved in 95% of the infants. Sampling losses in the first 6 weeks were significantly lower in the RS group (16.8 ml/kg vs 23.6 ml/kg, P < .001). The RS group had a significantly lower rate of early postnatal RBC transfusions (41% vs 73%, RR: 0.56 [0.39-0.81], P = .001). The hazard of needing a transfusion during neonatal intensive care unit (NICU) stay was reduced by 55% by RS. Mortality and neonatal morbidities were similar between the two groups. CONCLUSION: Minimization of blood sampling losses by approximately one-third in the first 6 weeks after birth leads to substantial reduction in the early red blood cell transfusion rate in infants born extremely preterm and weighing <1000 g at birth. TRIAL REGISTRATION: http://www.ctri.nic.in (CTRI/2020/01/022  964).

PI3 kinase signals BCR-dependent mature B cell survival.

Previous work has shown that mature B cells depend upon survival signals delivered to the cells by their antigen receptor (BCR). To identify the molecular nature of this survival signal, we have developed a genetic approach in which ablation of the BCR is combined with the activation of specific, BCR dependent signaling cascades in mature B cells in vivo. Using this system, we provide evidence that the survival of BCR deficient mature B cells can be rescued by a single signaling pathway downstream of the BCR, namely PI3K signaling, with the FOXO1 transcription factor playing a central role.

Development of high-affinity nanobodies specific for NaV1.4 and NaV1.5 voltage-gated sodium channel isoforms.

Voltage-gated sodium channels, NaVs, are responsible for the rapid rise of action potentials in excitable tissues. NaV channel mutations have been implicated in several human genetic diseases, such as hypokalemic periodic paralysis, myotonia, and long-QT and Brugada syndromes. Here, we generated high-affinity anti-NaV nanobodies (Nbs), Nb17 and Nb82, that recognize the NaV1.4 (skeletal muscle) and NaV1.5 (cardiac muscle) channel isoforms. These Nbs were raised in llama (Lama glama) and selected from a phage display library for high affinity to the C-terminal (CT) region of NaV1.4. The Nbs were expressed in Escherichia coli, purified, and biophysically characterized. Development of high-affinity Nbs specifically targeting a given human NaV isoform has been challenging because they usually show undesired crossreactivity for different NaV isoforms. Our results show, however, that Nb17 and Nb82 recognize the CTNaV1.4 or CTNaV1.5 over other CTNav isoforms. Kinetic experiments by biolayer interferometry determined that Nb17 and Nb82 bind to the CTNaV1.4 and CTNaV1.5 with high affinity (KD ∼ 40-60 nM). In addition, as proof of concept, we show that Nb82 could detect NaV1.4 and NaV1.5 channels in mammalian cells and tissues by Western blot. Furthermore, human embryonic kidney cells expressing holo NaV1.5 channels demonstrated a robust FRET-binding efficiency for Nb17 and Nb82. Our work lays the foundation for developing Nbs as anti-NaV reagents to capture NaVs from cell lysates and as molecular visualization agents for NaVs.

Efficacy and Safety of Two Different Flow Rates of Nasal High-Flow Therapy in Preterm Neonates ≥28 Weeks of Gestation: A Randomized Controlled Trial.

OBJECTIVE: The study aimed to compare the efficacy and safety of two different nasal high-flow rates for primary respiratory support in preterm neonates STUDY DESIGN: In this single-center, double-blinded randomized controlled trial, preterm neonates ≥28 weeks of gestation with respiratory distress from birth were randomized to treatment with either increased nasal flow therapy (8-10 L/min) or standard nasal flow therapy (5-7 L/min). The primary outcome of nasal high-flow therapy failure was a composite outcome defined as the need for higher respiratory support (continuous positive airway pressure [CPAP] or mechanical ventilation) or surfactant therapy. RESULTS: A total of 212 neonates were enrolled. Nasal high-flow failure rate in the increased flow group was similar to the standard flow group (22 vs. 29%, relative risk = 0.81 [95% confidence interval: 0.57-1.15]). However, nasal flow rate escalation was significantly more common in the standard flow group (64 vs. 43%, p = 0.004). None of the infants in the increased flow group developed air leak syndromes. CONCLUSION: Higher nasal flow rate (8-10 L/min) when compared with lower nasal flow rate of 5 to 7 L/min did not reduce the need for higher respiratory support (CPAP/mechanical ventilation) or surfactant therapy in moderately and late preterm neonates. However, initial flow rates of 5 L/min were not optimal for most preterm infants receiving primary nasal flow therapy. KEY POINTS: · Use of high nasal flows (8-10 L/min) did not reduce the need for higher respiratory support in moderately and late preterm infants.. · Nasal flow rate of 5 L/min was not optimal for most preterms with respiratory distress from birth.. · Careful patient selection and optimized flow settings could enhance nasal flow success in neonates..

Acute Kidney Injury Associated with Late-Onset Neonatal Sepsis: A Matched Cohort Study.

OBJECTIVES: To determine incidence and severity of acute kidney injury (AKI) within 7 days of sepsis evaluation and to assess AKI duration and the association between AKI and 30-day mortality. STUDY DESIGN: Retrospective, matched cohort study in a single-center level IV neonatal intensive care unit. Eligible infants underwent sepsis evaluations at ≥72 hours of age during calendar years 2013-2018. Exposed infants (cases) were those with culture-proven sepsis and antimicrobial duration ≥5 days. Nonexposed infants (controls) were matched 1:1 to exposed infants based on gestational and corrected gestational age, and had negative sepsis evaluations with antibiotic durations <48 hours. AKI was defined by modified neonatal Kidney Disease Improving Global Outcomes criteria. Statistical analysis included Mann-Whitney and χ2 tests, multivariable logistic regression, and Kaplan-Meier time-to-event analysis. RESULTS: Among 203 episodes of late-onset sepsis, 40 (20%) developed AKI within 7 days after evaluation, and among 193 episodes with negative cultures, 16 (8%) resulted in AKI (P = .001). Episodes of sepsis also led to greater AKI severity, compared with nonseptic episodes (P = .007). The timing of AKI onset and AKI duration did not differ between groups. Sepsis was associated with increased odds of developing AKI (aOR, 3.0; 95% CI, 1.5-6.2; P = .002). AKI was associated with increased 30-day mortality (aOR, 4.5; 95% CI, 1.3-15.6; P = .017). CONCLUSIONS: Infants with late-onset sepsis had increased odds of AKI and greater AKI severity within 7 days of sepsis evaluation, compared with age-matched infants without sepsis. AKI was independently associated with increased 30-day mortality. Strategies to mitigate AKI in critically ill neonates with sepsis may improve outcomes.

Effects of blood sampling stewardship and erythropoietin administration in extremely low birth weight infants-a quality improvement non-controlled before-and-after retrospective study.

The majority of extremely low birth weight (ELBW) neonates receive red blood cell (RBC) transfusions; at least 50% receive multiple transfusions. Anemia care bundles could be the most effective approach to reduce transfusion rates. We conducted a quality improvement non-controlled before-and-after retrospective study involving 345 ELBW infants admitted over a 5-year period in two consecutive epochs before and after implementation of an anemia care bundle in January 2017. Bundle components included (a) prophylactic subcutaneous erythropoietin twice each week (600 IU/kg/week) from day 7 through 8 weeks of age and (b) blood sampling stewardship in the first five postnatal weeks. Early postnatal blood sampling losses were significantly reduced following the implementation of the care bundle (21.2 ml/kg vs 25 ml/kg, P < 0.001). We found a 50% reduction in the rate of multiple RBC transfusions (adjusted RR 0.45, 95% CI: 0.34-0.59) and a reduced odds of necrotizing enterocolitis (NEC) (4% vs 10%, adjusted OR 0.38 (95% CI: 0.15-0.78)) among infants that received the anemia care bundle (n = 182 infants). The overall transfusion rate, number and volume of transfusions, and multiple donor exposures were also significantly reduced.Conclusion: The combination of extended subcutaneous erythropoietin administration and reduced early postnatal blood sampling was associated with a significant reduction in the rate of multiple erythrocyte transfusions and NEC in ELBW neonates. What is known: • The majority of extremely low birth weight neonates continue to require blood transfusions despite advances in standardized transfusion practices; at least 50% require multiple transfusions. • Anemia care bundles, employing a combination of anemia prevention strategies, can effectively reduce the RBC transfusion rates in ELBW infants. What is new: • A combination of extended subcutaneous erythropoietin supplementation and blood sampling stewardship practices reduced the rate of multiple RBC transfusions in ELBW neonates by 50%. • Implementation of the anemia care bundle was associated with a significant reduction in the rates of necrotizing enterocolitis.

Performance of Pediatric Systemic Inflammatory Response Syndrome and Organ Dysfunction Criteria in Late-Onset Sepsis in a Quaternary Neonatal Intensive Care Unit: A Case-Control Study.

OBJECTIVES: To evaluate accuracy of systemic inflammatory response syndrome (SIRS) criteria in identifying culture-proven late-onset neonatal sepsis and to assess prevalence of organ dysfunction and its relationship with SIRS criteria. STUDY DESIGN: This was a retrospective case-control study of patients in the Children's Hospital of Philadelphia level IV neonatal intensive care unit undergoing sepsis evaluations (concurrent blood culture and antibiotics). During calendar years 2016-2017, 77 case and 77 control sepsis evaluations were identified. Cases included infants who had sepsis evaluations with positive blood cultures and antibiotic duration ≥7 days. Controls were matched by gestational and postmenstrual age, and had sepsis evaluations with negative blood cultures and antibiotic duration ≤48 hours. SIRS criteria were determined at time of sepsis evaluation, and organ dysfunction evaluated in the 72 hours following sepsis evaluation. Statistical analysis included descriptive statistics, Mann-Whitney tests, and χ2 (Fisher exact) tests. RESULTS: At time of sepsis evaluation, 42% of cases and 26% of controls met SIRS criteria. Among infants of ≤37 weeks postmenstrual age, SIRS criteria were met in only 17% of sepsis evaluations (4 of 23 in both cases and controls). Test characteristics for SIRS at diagnosis of culture-proven sepsis included sensitivity 42% and specificity 74%. Cases had higher rates of new organ dysfunction within 72 hours (40% vs 21%); however, 58% of cases developing organ dysfunction did not meet SIRS criteria at time of sepsis evaluation. Of 6 deaths (all cases with organ dysfunction), 2 did not meet SIRS criteria at sepsis evaluation. CONCLUSIONS: SIRS criteria did not accurately identify culture-proven late-onset sepsis, with poorest accuracy in preterm infants. SIRS criteria did not predict later organ dysfunction or mortality.

Surviving Sepsis in a Referral Neonatal Intensive Care Unit: Association between Time to Antibiotic Administration and In-Hospital Outcomes.

OBJECTIVE: To determine if time to antibiotic administration is associated with mortality and in-hospital outcomes in a neonatal intensive care unit (NICU) population. STUDY DESIGN: We conducted a prospective evaluation of infants with suspected sepsis between September 2014 and February 2018; sepsis was defined as clinical concern prompting blood culture collection and antibiotic administration. Time to antibiotic administration was calculated from time of sepsis identification, defined as the order time of either blood culture or an antibiotic, to time of first antibiotic administration. We used linear models with generalized estimating equations to determine the association between time to antibiotic administration and mortality, ventilator-free and inotrope-free days, and NICU length of stay in patients with culture-proven sepsis. RESULTS: Among 1946 sepsis evaluations, we identified 128 episodes of culture-proven sepsis in 113 infants. Among them, prolonged time to antibiotic administration was associated with significantly increased risk of mortality at 14 days (OR, 1.47; 95% CI, 1.15-1.87) and 30 days (OR, 1.47; 95% CI, 1.11-1.94) as well as fewer inotrope-free days (incidence rate ratio, 0.91; 95% CI, 0.84-0.98). No significant associations with ventilator-free days or NICU length of stay were demonstrated. CONCLUSIONS: Among infants with sepsis, delayed time to antibiotic administration was an independent risk factor for death and prolonged cardiovascular dysfunction. Further study is needed to define optimal timing of antimicrobial administration in high-risk NICU populations.

Lymphoproliferative disease and autoimmunity in mice with increased miR-17-92 expression in lymphocytes.

The genomic region encoding the miR-17-92 microRNA (miRNA) cluster is often amplified in lymphoma and other cancers, and cancer cells carrying this amplification have higher expression of miRNA in this cluster. Retroviral expression of miR-17-92 accelerates c-Myc-induced lymphoma development, but precisely how higher expression of miR-17-92 promotes lymphomagenesis remains unclear. Here we generated mice with higher expression of miR-17-92 in lymphocytes. These mice developed lymphoproliferative disease and autoimmunity and died prematurely. Lymphocytes from these mice showed more proliferation and less activation-induced cell death. The miR-17-92 miRNA suppressed expression of the tumor suppressor PTEN and the proapoptotic protein Bim. This mechanism probably contributed to the lymphoproliferative disease and autoimmunity of miR-17-92-transgenic mice and contributes to lymphoma development in patients with amplifications of the miR-17-92 coding region.

Derivation of a metabolic signature associated with bacterial meningitis in infants.

BACKGROUND: Diagnosis of bacterial meningitis (BM) is challenging in newborn infants. Presently, biomarkers of BM have limited diagnostic accuracy. Analysis of cerebrospinal fluid (CSF) metabolites may be a useful diagnostic tool in BM. METHODS: In a nested case-control study, we examined >400 metabolites in CSF of uninfected infants and infants with culture-confirmed BM using gas and liquid chromatography mass spectrometry. Preterm and full-term infants in a Level III or IV Neonatal Intensive Care Unit were prospectively enrolled when evaluated for serious bacterial infection. RESULTS: Over 200 CSF metabolites significantly differed in uninfected infants and infants with BM. Using machine learning, we found that as few as 6 metabolites distinguished infants with BM from uninfected infants in this pilot cohort. Further analysis demonstrated three metabolites associated with Group B Streptococcal meningitis. CONCLUSIONS: We report the first comprehensive metabolic analysis of CSF in infants with BM. In our pilot cohort, we derived a metabolic signature that predicted the presence or absence of BM, irrespective of gestational age, postnatal age, sex, race and ethnicity, presence of neurosurgical hardware, white blood cell count in CSF, and red blood cell contamination in CSF. Metabolic analysis may aid diagnosis of BM and facilitate clinical decision-making in infants. IMPACT: In a pilot cohort, metabolites in cerebrospinal fluid distinguished infants with bacterial meningitis from uninfected infants.We report the first comprehensive metabolic analysis of cerebrospinal fluid in infants with bacterial meningitis.Our findings may be used to improve diagnosis of bacterial meningitis and to offer mechanistic insights into the pathophysiology of bacterial meningitis in infants.

Effect of Umbilical Cord Blood Sampling versus Admission Blood Sampling on Requirement of Blood Transfusion in Extremely Preterm Infants: A Randomized Controlled Trial.

OBJECTIVE: To evaluate the effect of blood sampling from the placental end of the umbilical cord compared with initial blood sampling from neonates, on the need for first packed red blood cell transfusion in extremely preterm infants. We hypothesized that cord blood sampling could delay the time to first blood transfusion. STUDY DESIGN: In this single-center, assessor blind, randomized controlled trial, we included extremely low birth weight neonates <28 weeks of gestational age at birth. Five milliliter of blood for initial laboratory investigations was collected either from the placental end of the umbilical cord (study group) or from the neonate upon neonatal intensive care unit admission (control group). Both groups received similar anemia prevention strategies. The primary outcome was the time (in days) to the first packed red blood cell transfusion, and was compared using survival analysis. RESULTS: Eighty neonates were enrolled. The time to first transfusion was significantly delayed in the cord sampling group (30 vs 14 days, hazard ratio: 0.44, [95% CI 0.27-0.72], P < .001). Fewer neonates in the cord sampling group were transfused in the first 28 days of life (30% vs 75%, P < .001). Overall transfusion requirements and other clinical outcomes were similar in the groups. CONCLUSIONS: Initial blood sampling from placental end of umbilical cord, when combined with anemia prevention strategies, significantly prolonged the time to first transfusion and reduced the need for early transfusions among extremely premature neonates. TRIAL REGISTRATION: Ctri.nic.in/ (CTRI/2017/04/008320).

The B-cell antigen receptor integrates adaptive and innate immune signals.

B cells respond to antigens by engagement of their B-cell antigen receptor (BCR) and of coreceptors through which signals from helper T cells or pathogen-associated molecular patterns are delivered. We show that the proliferative response of B cells to the latter stimuli is controlled by BCR-dependent activation of phosphoinositidyl 3-kinase (PI-3K) signaling. Glycogen synthase kinase 3ß and Foxo1 are two PI-3K-regulated targets that play important roles, but to different extents, depending on the specific mitogen. These results suggest a model for integrating signals from the innate and the adaptive immune systems in the control of the B-cell immune response.

Functional characterization of solute carrier (SLC) 26/sulfate permease (SulP) proteins in membrane mimetic systems.

Solute carrier (SLC) 26 or sulfate permease (SulP) anion transporters, belong to a phylogenetically ancient family of secondary active transporters. Members of the family are involved in several human genetic diseases and cell physiological processes. Despite their importance, the substrates for transport by this family of proteins have been poorly characterized. In this study, recombinant StmYchM/DauA, a SulP from Salmonella typhimurium was purified to homogeneity and functionally characterized. StmYchM/DauA was found to be a dimer in solution as determined by size exclusion chromatography coupled to multiple angle light scattering. We report a functional characterization of the SulP proteins in two membrane mimetic systems and reveal a dual nature of anionic substrates for SulP. StmYchM/DauA functionally incorporated into nanodiscs could bind fumarate with millimolar affinities (KD = 4.6 ± 0.29 mM) as detected by intrinsic tryptophan fluorescence quench studies. In contrast, electrophysiological experiments performed in reconstituted liposomes indicate a strong bicarbonate transport in the presence of chloride but no detectable electrogenic fumarate transport. We hence suggest that while SulP acts as an electrogenic bicarbonate transporter, fumarate may serve as substrate under different conditions indicating multiple functions of SulP.

Systematic Review and Meta-analysis: Gene Association Studies in Neonatal Sepsis.

Background Association studies of various gene variants in neonatal sepsis show conflicting results. Objective We performed a systematic review of candidate gene association studies in neonatal sepsis to provide pooled estimates of risk for selected gene variants. Methods We performed a search using MeSH terms "infection," "sepsis," "infant," "genetic variation," "polymorphism," and "genetic association studies." We included studies evaluating associations between neonatal sepsis and genetic variants (2000-2015). We excluded case reports/series, commentaries, narrative reviews, and nonhuman research. We assessed quality of studies using STREGA guidelines. Following estimation of odds ratios (ORs), data were pooled using random effects models. Results Twenty eight of 1,404 identified studies were included. Meta-analyses were performed for interleukin (IL)-6, tumor necrosis factor-α (TNF-α), and IL-10 as these gene variants were tested in multiple studies. TNF-α 308GG genotype demonstrated trends toward increased sepsis risk in the primary analysis of culture-proven sepsis (OR 1.18, 95% confidence interval [CI] 0.97-1.44). IL-10 1082GG genotype was associated with lower sepsis odds in very low-birth-weight (VLBW) infants (OR 0.51, 95% CI 0.29-0.91). Conclusion We uncovered an association between IL-10 1082 gene variation and sepsis in VLBW infants but did not identify associations between neonatal sepsis and TNF-α 308 or IL-6 gene variation. Larger cohort replication studies are required to validate these findings.

Cerebrospinal fluid cytokines in the diagnosis of bacterial meningitis in infants.

BACKGROUND: Bacterial meningitis poses diagnostic challenges in infants. Antibiotic pretreatment and low bacterial density diminish cerebrospinal fluid (CSF) culture yield, while laboratory parameters do not reliably identify bacterial meningitis. Pro and anti-inflammatory cytokines are elevated in bacterial meningitis and may be useful diagnostic adjuncts when CSF cultures are negative. METHODS: In a prospective cohort study of infants, we used cytometric bead arrays to measure tumor necrosis factor alpha (TNF-α), interleukin 1 (IL-1), IL-6, IL-8, IL-10, and IL-12 in CSF. Receiver operating characteristic (ROC) analyses and Principal component analysis (PCA) were used to determine cytokine combinations that identified bacterial meningitis. RESULTS: Six hundred and eighty four infants < 6 mo were included; 11 had culture-proven bacterial meningitis. IL-6 and IL-10 were the individual cytokines possessing greatest accuracy in diagnosis of culture proven bacterial meningitis (ROC analyses; area under the concentration-time curve (AUC) 0.91; 0.9103 respectively), and performed as well as, or better than combinations identified using ROC and PCA. CSF cytokines were highly correlated with each other and with CSF white blood cell count (WBC) counts in infants with meningitis. A subset of antibiotic pretreated culture-negative subjects demonstrated cytokine patterns similar to culture positive subjects. CONCLUSION: CSF cytokine levels may aid diagnosis of bacterial meningitis, and facilitate decision-making regarding treatment for culture negative meningitis.