CSF inflammatory markers differ in gram-positive versus gram-negative shunt infections

Complications of ventriculoperitoneal shunts: Infection and exposure in hydrocephalus patients: A case series

Background

Ventriculoperitoneal shunt (VPS) is an effective intervention for managing hydrocephalus; however, various complications may arise, one of which is infection due to shunt exposure. In this study, we report the incidence, risk factors, clinical presentation, and management strategies of four cases of shunt exposure in patients with hydrocephalus.

Case Description

The first case involves a 1-year-10-month-old female who underwent her initial VPS placement at 7 months old due to hydrocephalus. The second case is a 3-month-old female who had a VPS placed at 20 days old for obstructive hydrocephalus and ventriculomegaly secondary to toxoplasmosis. The third case is a 15-year-old female who received a VPS due to a cerebral abscess with a prior history of tuberculous meningoencephalopathy. The fourth case is a 38-year-old male who underwent VPS placement for hydrocephalus. Two years post-intervention, the fourth patient was diagnosed with VPS exposure and subsequently underwent shunt removal.

Conclusion

The identification of risk factors and clinical symptoms in patients, supported by ancillary examinations such as cerebrospinal fluid analysis, can predict the incidence of VPS infections. Bacterial VPS infections can be managed with appropriate antibiotics tailored to the specific bacterial species. However, in certain cases, surgical removal of the VPS may be considered as a measure to eradicate infectious pathogens.

Paediatric ventriculoperitoneal shunt failures: 12-year experience from a Singapore children's hospital

PURPOSE

Cerebrospinal fluid (CSF) shunt failures in children are devastating. The primary aims of this study are to, firstly, review our institutional series of ventriculoperitoneal shunt (VPS) insertions and identify factors associated with shunt failure.

METHODS

This is a single-institution, retrospective study conducted over a 12-year period. All patients under 18 years old with VPS inserted were included. Variables of interest such as patient characteristics, hydrocephalus aetiology, shunt implant details, and outcomes were subjected to statistical analyses.

RESULTS

A total of 214 VPS patients were selected for this study. The mean age at VPS insertion was 6 months with a mean follow-up duration of 44 months. The most common type of hydrocephalus was obstructive (n = 142, 66.4%), and the most frequent aetiology was tumour-related (n = 66, 30.8%). The 30-day shunt failure rate was 9.3%: 9 infections (4.2%), 7 occlusions (3.3%), and 4 others (1.9%). After multivariable analysis, only recent central nervous system (CNS) infection prior to VPS insertion remained significant (OR 15.4 (1.3-175), p = 0.028).

CONCLUSION

This is the first, large-scale local study focused on the shunt failure in Singaporean children. Significant findings in our study demonstrate that recently treated CNS infection is a factor associated with 30-day shunt failure while the values of CSF constituents were not contributory.

Serial Neuroendoscopic Lavage for the Treatment of Elevated Cerebrospinal Fluid Protein Levels in Infants with Gram-Negative Rod Ventriculitis

INTRODUCTION

Gram-negative rod (GNR) bacterial ventriculitis is a rare complication of shunt-dependent hydrocephalus, often requiring an extended and invasive treatment course. Accumulation of purulent material, as well as empyema and septation formation, limits circulation of antibiotics and infection clearance. Supplementation of standard care with neuroendoscopic-guided intraventricular lavage with lactated Ringer solution and fenestration of septations may facilitate infection clearance and simplify the eventual shunt construct required. Here, the utility of serial lavage for ventriculitis is described in a population of shunt-dependent neonates and infants at high risk for morbidity and mortality.

METHODS

Five infants with shunt-dependent hydrocephalus and subsequent GNR ventriculitis were treated with standard care measures with the addition of serial neuroendoscopic lavage. A retrospective chart review was performed to collect patient characteristics, shunt dependency, and shunt revisions within a year of ventriculitis resolution.

RESULTS

Patients demonstrated a mean 74% decrease in cerebrospinal fluid (CSF) protein following each neuroendoscopic lavage and trended toward a shorter time to infection clearance in comparison to previously published literature. Patients required 0-2 shunt revisions at 1-year follow-up following hospitalization for shunt-related ventriculitis (mean 0.8 +/- 0.8).

CONCLUSIONS

Serial neuroendoscopic lavage is an effective technique, used alone or in combination with fenestration of septations, to reduce the CSF protein and bacterial load in the treatment of ventriculitis, decreasing time until eradication of infection. Serial lavage may reduce the risk of future shunt malfunction, simplify the future shunt construct, and decrease duration of infection.

Bacteria commonly associated with central nervous system catheter infections elicit distinct CSF proteome signatures

Background

Cerebrospinal fluid (CSF) shunt infection is a common and devastating complication of the treatment of hydrocephalus. Timely and accurate diagnosis is essential as these infections can lead to long-term neurologic consequences including seizures, decreased intelligence quotient (IQ) and impaired school performance in children. Currently the diagnosis of shunt infection relies on bacterial culture; however, culture is not always accurate since these infections are frequently caused by bacteria capable of forming biofilms, such as Staphylococcus epidermidis, Cutibacterium acnes, and Pseudomonas aeruginosa resulting in few planktonic bacteria detectable in the CSF. Therefore, there is a critical need to identify a new rapid, and accurate method for diagnosis of CSF shunt infection with broad bacterial species coverage to improve the long-term outcomes of children suffering from these infections.

Methods

To investigate potential biomarkers that would discriminate S. epidermidis, C. acnes and P. aeruginosa central nervous system (CNS) catheter infection we leveraged our previously published rat model of CNS catheter infection to perform serial CSF sampling to characterize the CSF proteome during these infections compared to sterile catheter placement.

Results

P. aeruginosa infection demonstrated a far greater number of differentially expressed proteins when compared to S. epidermidis and C. acnes infection and sterile catheters, and these changes persisted throughout the 56-day time course. S. epidermidis demonstrated an intermediate number of differentially expressed proteins, primarily at early time points that dissipated over the course of infection. C. acnes induced the least amount of change in the CSF proteome when compared to the other pathogens.

Conclusions

Despite the differences in the CSF proteome with each organism compared to sterile injury, several proteins were common across all bacterial species, especially at day 5 post-infection, which are candidate diagnostic biomarkers.

Inflammatory Markers Combined With Metalloproteinase-9, Neopterin, and S100B Concentrations May Indicate the Pathogenesis of Central Nervous System Diseases in Children

The identification of central nervous system inflammation etiology leads to adjusted therapy. We analyzed the potential inflammatory and neuro-axonal damage markers in children. Our target was to correlate the findings with a disease's course or a sequalae risk and assess their clinical usefulness. The study included 96 children with symptoms of central nervous system inflammation who underwent diagnostics. The research group involved 24 children with autoimmune disorders and 31 with neuroinfection. The control group included patients with both etiologies excluded. We analyzed the results of routine laboratory tests together with chosen serum (neopterin, interleukin [IL]-1β, IL-6) and CSF (metalloproteinase [MMP]-9, S100B protein) markers. In the whole cohort, CSF MMP-9 correlated with CSF cytosis and serum IL-6 and CRP. In the undivided neuroinflammatory group, CSF S100B correlated with serum IL-6 and IgM concentrations. CSF cytosis was associated with CSF MMP-9 and serum neopterin levels. Among the infective patients, IL-6 was linked with increased CSF MMP-9. We conclude that astroglial protein S100B, neopterin, and cytokine concentrations may enable predicting long-term consequences, whereas CSF MMP-9 concentration may reflect the actual central nervous system injury regardless of etiology.

Cerebrospinal Fluid Shunt Infections in Children: Do Hematologic and Cerebrospinal Fluid White Cells Examinations Correlate With the Type of Infection?

BACKGROUND

Cerebrospinal fluid (CSF) shunt infections in children represent an increasing problem in clinical practice. However, comprehensive clinical, laboratory and microbiologic data are scarce in pediatric age.

METHODS

We conducted a 10-year retrospective study to (1) analyze clinical, laboratory and microbiologic parameters associated with infections in children; (2) analyze results according to the type of catheter (medicated or not), type of infection (first or relapses), type of hydrocephalus (acquired and congenital), presence or not of bacteriemia; (3) describe antibiotic susceptibilities and their evolution during the study period.

RESULTS

Eighty-seven children with shunt infection and 61 children with mechanical shunt malfunction were enrolled. Fever, vomit, leukocytosis and elevated C-reactive protein were more frequent in the infected group (P < 0.001), while neurologic symptoms developed more frequently in the noninfected group (10.3% vs. 27.87%; P = 0.006). Local signs of inflammation and abdomen distension were similarly reported in the 2 groups. Children with medicated shunts had lower cell count in the CSF (12/mm3) compared with those with nonmedicated shunts (380/mm3; P < 0.0001). Gram-negative bacteria were more common in the not-medicated catheters (90.91% vs. 50% of cultures; P = 0.04). Gram-negative bacteria were identified in 50.67% of CSF cultures, Gram-positive bacteria in 53.33% and fungi were observed in 5.33%. Sixteen children (18.4%) had also a positive blood culture. Enterococci isolation was associated with relapsed infections (37.50% vs. 15.25%; P = 0.05).

CONCLUSIONS

Our study shows that the diagnosis and management of children with shunt infections are challenging. Prospective studies with a comprehensive approach focusing on patient, medical, microbiologic and surgical risk factors for first infection are urgently needed.

Post-neurosurgical meningitis; gram negative bacilli vs. gram positive cocci

Background

Post-neurosurgical meningitis is a significant cause of mortality and morbidity. In this study we aimed to compare the differences of clinical, laboratory features and outcomes between the post-neurosurgical meningitis caused by gram-negative bacilli (GNB) and gram-positive cocci (GPC).

Methods

Cases of post-neurosurgical meningitis (with positive CSF culture) were included. After classifying patients as GNB and GPC groups, clinical and paraclinical data were compared.

Results

Out of 2667 neurosurgical patients, CSF culture was positive in 45 patients. 25 (54.3%) were GNB, 19 (41.3%) GPC. The most common microorganisms were Klebsiella pneumoniae (n=14, 31.1%), Coagulase negative staphylococcus (n=8, 17.8%), Staphylococcus aureus (n=6, 13.3%), Acinetobacter baumannii (n=4, 8.9%), Pseudomonas aeruginosa (n=2, 4.4%), and Escherichia coli (n=2, 4.4%). There were no correlation between CSF Leakage, Surgical site appearance, presence of drain, Age and GCS between two groups (P=0.11, P=0.28, P=0.06, P=0.86, P=0.11 respectively). The only different laboratory indexes were ESR (86.8 mm/h vs. 59.5 mm/h, P=0.01) and PCT (13.1 ng/ml vs. 0.8 ng/ml, P=0.02) which were higher in GNB cases. 20% (n=5) of patients with GNB meningitis received preoperative corticosteroid, while none of GPC cases received (P=0.03). The median length of hospitalization for GNB and GPC cases was 56 and 44.4 days respectively (P=0.3).

Conclusion

The GNB antibiotic coverage should be designed more carefully in post-neurosurgical meningitis especially in patients with recent corticosteroid therapy and elevated ESR and procalcitonin.

Age-Dependent Microglial Response to Systemic Infection

Inflammation is part of the aging process, and the inflammatory innate immune response is more exacerbated in older individuals when compared to younger individuals. Similarly, there is a difference in the response to systemic infection that varies with age. In a recent article by Hoogland et al., the authors studied the microglial response to systemic infection in young (2 months) and middle-aged mice (13–14 months) that were challenged with live Escherichia coli to investigate whether the pro- and anti-inflammatory responses mounted by microglia after systemic infection varies with age. Here, we comment on this study and its implications on how inflammation in the brain varies with age.

Cutibacterium acnes Central Nervous System Catheter Infection Induces Long-Term Changes in the Cerebrospinal Fluid Proteome

Cutibacterium acnes is the third most common cause of cerebrospinal fluid (CSF) shunt infection and is likely underdiagnosed due to the difficulty in culturing this pathogen. Shunt infections lead to grave neurologic morbidity for patients especially when there is a delay in diagnosis. Currently, the gold standard for identifying CSF shunt infections is microbiologic culture. However, C. acnes infection often results in falsely negative cultures; therefore, new diagnostic methods are needed. To investigate potential CSF biomarkers of C. acnes CSF shunt infection we adapted a rat model of CSF catheter infection to C. acnes. We found elevated levels of interleukin-1β (IL-1β), IL-6, chemokine ligand 2, and IL-10 in the CSF and brain tissues of animals implanted with C. acnes-infected catheters compared to sterile controls at day 1 postinfection. This coincided with modest increases in neutrophils in the CSF and, to a greater extent, in the brain tissues of animals with C. acnes infection, which closely mirrors the clinical findings in patients with C. acnes shunt infection. Mass spectrometry revealed that the CSF proteome is altered during C. acnes shunt infection and changes over the course of disease, typified at day 1 postinfection by an acute-phase and pathogen neutralization response evolving to a response consistent with wound resolution at day 28 compared to a sterile catheter placement. Collectively, these results demonstrate that it is possible to distinguish C. acnes infection from sterile postoperative inflammation and that CSF proteins could be useful in a diagnostic strategy for this pathogen that is difficult to diagnose.

Toll-like receptor linked cytokine profiles in cerebrospinal fluid discriminate neurological infection from sterile inflammation

Rapid determination of an infective aetiology causing neurological inflammation in the cerebrospinal fluid can be challenging in clinical practice. Post-surgical nosocomial infection is difficult to diagnose accurately, as it occurs on a background of altered cerebrospinal fluid composition due to the underlying pathologies and surgical procedures involved. There is additional diagnostic difficulty after external ventricular drain or ventriculoperitoneal shunt surgery, as infection is often caused by pathogens growing as biofilms, which may fail to elicit a significant inflammatory response and are challenging to identify by microbiological culture. Despite much research effort, a single sensitive and specific cerebrospinal fluid biomarker has yet to be defined which reliably distinguishes infective from non-infective inflammation. As a result, many patients with suspected infection are treated empirically with broad-spectrum antibiotics in the absence of definitive diagnostic criteria. To begin to address these issues, we examined cerebrospinal fluid taken at the point of clinical equipoise to diagnose cerebrospinal fluid infection in 14 consecutive neurosurgical patients showing signs of inflammatory complications. Using the guidelines of the Infectious Diseases Society of America, six cases were subsequently characterized as infected and eight as sterile inflammation. Twenty-four contemporaneous patients with idiopathic intracranial hypertension or normal pressure hydrocephalus were included as non-inflamed controls. We measured 182 immune and neurological biomarkers in each sample and used pathway analysis to elucidate the biological underpinnings of any biomarker changes. Increased levels of the inflammatory cytokine interleukin-6 and interleukin-6-related mediators such as oncostatin M were excellent indicators of inflammation. However, interleukin-6 levels alone could not distinguish between bacterially infected and uninfected patients. Within the patient cohort with neurological inflammation, a pattern of raised interleukin-17, interleukin-12p40/p70 and interleukin-23 levels delineated nosocomial bacteriological infection from background neuroinflammation. Pathway analysis showed that the observed immune signatures could be explained through a common generic inflammatory response marked by interleukin-6 in both nosocomial and non-infectious inflammation, overlaid with a toll-like receptor-associated and bacterial peptidoglycan-triggered interleukin-17 pathway response that occurred exclusively during infection. This is the first demonstration of a pathway dependent cerebrospinal fluid biomarker differentiation distinguishing nosocomial infection from background neuroinflammation. It is especially relevant to the commonly encountered pathologies in clinical practice, such as subarachnoid haemorrhage and post-cranial neurosurgery. While requiring confirmation in a larger cohort, the current data indicate the potential utility of cerebrospinal fluid biomarker strategies to identify differential initiation of a common downstream interleukin-6 pathway to diagnose nosocomial infection in this challenging clinical cohort.

Neutrophil peptide-1 promotes the repair of sciatic nerve injury through the expression of proteins related to nerve regeneration

Objectives Small-molecule polypeptide neutrophil peptide 1 (NP-1) was reported to promote the regeneration of the sciatic nerve after denervation, but the mechanisms underlying this effect of NP-1 are unclear. Here, we established a Sprague-Dawley rat model of crush injury to study the effect of a single intermuscular injection of NP-1 on the repair of injured peripheral nerves and elucidate the possible underlying mechanism.Methods 39 rats were randomly selected to join this study and divided into the blank control group (normal group, n=9), experimental group (NP-1 group, n=15), and negative control group (NS group, n=15). The dynamic expression of cytokines in different groups of nerve tissues during Wallerian degeneration was observed using protein chips at different time points after injury. Recovery of injured nerves was determined based on the general condition, local gross morphology of the nerve suture site, sciatic nerve function index, neuroelectrophysiology, and osmic acid staining at 6 weeks after the surgery. The recovery of effector function was determined based on wet weight, hematoxylin-eosin staining, modified Gomori staining, and nicotinamide adenine dinucleotide-tetrazolium reductase staining at 6 weeks after the surgery.Results It was found that a single topical administration of NP-1 promoted sciatic nerve regeneration after crush injury and affected the expression of proteins related to neurotrophy, inflammation, cell chemotaxis, and cell generation pathways.

Association of the FilmArray Meningitis/Encephalitis Panel With Clinical Management

OBJECTIVES

To determine the association of the use of the multiplex assay meningitis/encephalitis panel with clinical management of suspected meningitis.

METHODS

A cross-sectional study was conducted with children 0 to 18 years of age who received a lumbar puncture within 48 hours of admission for an infectious workup. Patient demographic and presenting information, laboratory studies, and medication administration were collected. The primary measure was length of stay (LOS) with secondary measures: time on antibiotics, time to narrowing antibiotics, and acyclovir doses. LOS and antibiotic times were stratified for outcomes occurring before 36 hours. Logistic regression analysis was used to account for potential confounding factors associated with both the primary and secondary outcomes. A value of P < .05 was considered statistically significant.

RESULTS

Meningitis panel use was associated with a higher likelihood of a patient LOS <36 hours (P = .04; odds ratio = 1.7; 95% confidence interval [CI]: 1.03-2.87), a time to narrowing antibiotics <36 hours (P = .008; odds ratio = 1.89; 95% CI: 1.18-2.87), and doses of acyclovir (P < .001; incidence rate ratio = 0.37; 95% CI: 0.26-0.53). When controlling for potential confounding factors, these associations persisted.

CONCLUSIONS

Use of the meningitis panel was associated with a decreased LOS, time to narrowing of antibiotics, and fewer acyclovir doses. This likely is a result of the rapid turnaround time as compared with cerebrospinal fluid cultures. Additional studies to examine the outcomes related to this change in management are warranted.

Identification of Potential Cerebrospinal Fluid Biomarkers To Discriminate between Infection and Sterile Inflammation in a Rat Model of Staphylococcus epidermidis Catheter Infection

Staphylococcus epidermidis cerebrospinal fluid (CSF) shunt infection is a common complication of hydrocephalus treatment, creating grave neurological consequences for patients, especially when diagnosis is delayed. The current method of diagnosis relies on microbiological culture; however, awaiting culture results may cause treatment delays, or culture may fail to identify infection altogether, so newer methods are needed.

Staphylococcus epidermidis cerebrospinal fluid (CSF) shunt infection is a common complication of hydrocephalus treatment, creating grave neurological consequences for patients, especially when diagnosis is delayed. The current method of diagnosis relies on microbiological culture; however, awaiting culture results may cause treatment delays, or culture may fail to identify infection altogether, so newer methods are needed. To investigate potential CSF biomarkers of S. epidermidis shunt infection, we developed a rat model allowing for serial CSF sampling. We found elevated levels of interleukin-10 (IL-10), IL-1β, chemokine ligand 2 (CCL2), and CCL3 in the CSF of animals implanted with S. epidermidis-infected catheters compared to sterile controls at day 1 postinfection. Along with increased chemokine and cytokine expression early in infection, neutrophil influx was significantly increased in the CSF of animals with infected catheters, suggesting that coupling leukocyte counts with inflammatory mediators may differentiate infection from sterile inflammation. Mass spectrometry analysis revealed that the CSF proteome in sterile animals was similar to that in infected animals at day 1; however, by day 5 postinfection, there was an increase in the number of differently expressed proteins in the CSF of infected compared to sterile groups. The expansion of the proteome at day 5 postinfection was interesting, as bacterial burdens began to decline by this point, yet the CSF proteome data indicated that the host response remained active, especially with regard to the complement cascade. Collectively, these results provide potential biomarkers to distinguish S. epidermidis infection from sterile postoperative inflammation.