Individual responsiveness of macrophage migration inhibitory factor predicts long-term cognitive impairment after bacterial meningitis.

BACKGROUND: Patients with pneumococcal meningitis are at risk for death and neurological sequelae including cognitive impairment. Functional genetic polymorphisms of macrophage migration inhibitory factor (MIF) alleles have shown to predict mortality of pneumococcal meningitis. METHODS: We investigated whether MIF concentrations during the acute phase of disease were predictive for death in a nationwide prospective cohort study. Subsequently, we studied whether individual ex vivo MIF response years after meningitis was associated with the development of cognitive impairment. RESULTS: We found that in the acute illness of pneumococcal meningitis, higher plasma MIF concentrations were predictive for mortality (p = 0.009). Cognitive impairment, examined 1-5 years after meningitis, was present in 11 of 79 patients after pneumococcal meningitis (14%), as compared to 1 of 63 (2%) in controls, and was consistently associated with individual variability in MIF production by peripheral blood mononuclear cells after ex vivo stimulation with various infectious stimuli. CONCLUSIONS: Our study confirms the role of MIF in poor disease outcome of pneumococcal meningitis. Inter-individual differences in MIF production were associated with long-term cognitive impairment years after pneumococcal meningitis. The present study provides evidence that MIF mediates long-term cognitive impairment in bacterial meningitis survivors and suggests a potential role for MIF as a target of immune-modulating adjunctive therapy.

Clinical significance of Epstein-Barr virus in the cerebrospinal fluid of immunocompetent patients.

INTRODUCTION: Polymerase chain reaction (PCR)-based testing of cerebrospinal fluid (CSF) samples has greatly facilitated the diagnosis of central nervous system (CNS) infections. However, the clinical significance of Epstein-Barr virus (EBV) DNA in CSF of individuals with suspected CNS infection remains unclear. We wanted to gain a better understanding of EBV as an infectious agent in immunocompetent patients with CNS disorders. METHODS: We identified cases of EBV-associated CNS infections and reviewed their clinical and laboratory characteristics. The study population was drawn from patients with EBV PCR positivity in CSF who visited Pusan National University Hospital between 2010 and 2019. RESULTS: Of the 780 CSF samples examined during the 10-year study period, 42 (5.4 %) were positive for EBV DNA; 9 of the patients (21.4 %) were diagnosed with non-CNS infectious diseases, such as optic neuritis, Guillain-Barré syndrome, and idiopathic intracranial hypotension, and the other 33 cases were classified as CNS infections (22 as encephalitis and 11 as meningitis). Intensive care unit admission (13/33 patients, 39.3 %) and presence of severe neurological sequelae at discharge (8/33 patients, 24.2 %) were relatively frequent. In 10 patients (30.3 %), the following pathogens were detected in CSF in addition to EBV: varicella-zoster virus (n = 3), cytomegalovirus (n = 2), herpes simplex virus 1 (n = 1), herpes simplex virus 2 (n = 1), Streptococcus pneumomiae (n = 2), and Enterococcus faecalis (n = 1). The EBV-only group (n = 23) and the co-infection group (n = 10) did not differ in age, gender, laboratory data, results of brain imaging studies, clinical manifestations, or prognosis; however, the co-infected patients had higher CSF protein levels. CONCLUSION: EBV DNA in CSF is occasionally found in the immunocompetent population; the virus was commonly associated with encephalitis and poor prognosis, and frequently found together with other microbes in CSF.

MeningiSSS: A New Predictive Score to Support Decision on Invasive Procedures to Monitor or Manage the Intracerebral Pressure in Children with Bacterial Meningitis.

BACKGROUND: Knowing the individual child's risk is highly useful when deciding on treatment strategies, especially when deciding on invasive procedures. In this study, we aimed to develop a new predictive score for children with bacterial meningitis and compare this with existing predictive scores and individual risk factors. METHODS: We developed the Meningitis Swedish Survival Score (MeningiSSS) based on a previous systematic review of risk factors. From this, we selected risk factors identified in moderate-to-high-quality studies that could be assessed at admission to the hospital. Using data acquired from medical records of 101 children with bacterial meningitis, we tested the overall capabilities of the MeningiSSS compared with four existing predictive scores using a receiver operating characteristic curve (ROC) analysis to assert the area under the curve (AUC). Finally, we tested all predictive scores at their cut-off levels using a Chi-square test. As outcome, we used a small number of predefined outcomes; in-hospital mortality, 30-day mortality, occurrence of neurological disabilities at discharge defined as Pediatric Cerebral Performance Category Scale category two to five, any type of complications occurring during the hospital stay, use of intensive care, and use of invasive procedures to monitor or manage the intracerebral pressure. RESULTS: For identifying children later undergoing invasive procedures to monitor or manage the intracerebral pressure, the MeningiSSS excelled in the ROC-analysis (AUC = 0.90) and also was the only predictive score able to identify all cases at its cut-off level (25 vs 0%, p < 0.01). For intensive care, the MeningiSSS (AUC = 0.79) and the Simple Luanda Scale (AUC = 0.75) had the best results in the ROC-analysis, whereas others performed less well (AUC ≤ 0.65). Finally, while none of the scores' results were significantly associated with complications, an elevated score on the MeningiSSS (AUC = 0.70), Niklasson Scale (AUC = 0.72), and the Herson-Todd Scale (AUC = 0.79) was all associated with death. CONCLUSIONS: The MeningiSSS outperformed existing predictive scores at identifying children later having to undergo invasive procedures to monitor or manage the intracerebral pressure in children with bacterial meningitis. Our results need further external validation before use in clinical practice. Thus, the MeningiSSS could potentially be helpful when making difficult decisions concerning intracerebral pressure management.

Competence-induced protein Ccs4 facilitates pneumococcal invasion into brain tissue and virulence in meningitis.

Streptococcus pneumoniae is a major pathogen that causes pneumonia, sepsis, and meningitis. The candidate combox site 4 (ccs4) gene has been reported to be a pneumococcal competence-induced gene. Such genes are involved in development of S. pneumoniae competence and virulence, though the functions of ccs4 remain unknown. In the present study, the role of Ccs4 in the pathogenesis of pneumococcal meningitis was examined. We initially constructed a ccs4 deletion mutant and complement strains, then examined their association with and invasion into human brain microvascular endothelial cells. Wild-type and Ccs4-complemented strains exhibited significantly higher rates of association and invasion as compared to the ccs4 mutant strain. Deletion of ccs4 did not change bacterial growth activity or expression of NanA and CbpA, known brain endothelial pneumococcal adhesins. Next, mice were infected either intravenously or intranasally with pneumococcal strains. In the intranasal infection model, survival rates were comparable between wild-type strain-infected and ccs4 mutant strain-infected mice, while the ccs4 mutant strain exhibited a lower level of virulence in the intravenous infection model. In addition, at 24 hours after intravenous infection, the bacterial burden in blood was comparable between the wild-type and ccs4 mutant strain-infected mice, whereas the wild-type strain-infected mice showed a significantly higher bacterial burden in the brain. These results suggest that Ccs4 contributes to pneumococcal invasion of host brain tissues and functions as a virulence factor.

Resveratrol Acts Anti-Inflammatory and Neuroprotective in an Infant Rat Model of Pneumococcal Meningitis by Modulating the Hippocampal miRNome.

Resveratrol (RSV) is anti-inflammatory and neuroprotective, cross the blood-brain barrier (BBB) and has a safe profile. Besides, RSV modulates the expression of some miRNAs related to neurological disorders. Thus, we hypothesized that RSV can be neuroprotective in pneumococcal meningitis by modulating the global microRNA expression profile (miRNome). Eleven-day old rats were intracysternally infected with S. pneumoniae (~ 2 × 106 c.f.u.) and were orally administered with RSV (50 mg/kg) or vehicle in pre-treatment (before infection) or post-treatment schedules (3 and 18 h p.i.). At 24 h p.i., animals were euthanized and apoptotic cells were counted in the hippocampal dentate gyrus of the right brain hemispheres. The hippocampi from left hemispheres were used for cytokines and chemokines multiplex assay and miRNome profiling with TaqMan OpenArray Rodent MicroRNA. Infected rats treated with RSV had lower apoptotic scores and IL-1ß, CCL2, and CCL3 levels when compared to the infected group receiving placebo. Seven miRNAs were down regulated, and 18 were up regulated by pneumococcal acute meningitis. Thirty-seven miRNAs were down regulated, and three were up regulated (hsa-miR-15b-5p, hsa-miR-25-3p, hsa-miR-125b-5p) by the interaction between meningitis and RSV. Pathway enriched analysis revealed that meningitis and RSV modulate the expression of miRNAs targeting critical pathways related to the pathophysiology of bacterial meningitis. Nevertheless, hsa-miR-25-3p and hsa-miR-125b-5p target the transcription factor TEF-1, for which there are binding sites in Il-1ß, Ccl2, and Ccl3 genes. RSV is anti-inflammatory and neuroprotective in an infant rat model of pneumococcal meningitis and these positive effects involve the modulation of the hippocampal miRNome.

Pneumococcal meningitis with normal cerebrospinal biochemistry and no pneumococci at microscopy, mimicking a stroke: a case report.

BACKGROUND: Bacterial meningitis commonly presents with symptoms such as headache, impaired consciousness, neck stiffness, and fever. In most cases, cerebrospinal fluid analysis will yield white cell counts >100/mm3. Atypical presentations occur, especially in the very young or very elderly and the immunocompromised. We report an unusual case of pneumococcal meningitis in a healthy 78-year-old Danish woman who presented with clinical features mimicking a stroke with normal cerebrospinal fluid parameters and without microscopic evidence of bacteria. CASE PRESENTATION: The patient was admitted after being found unconscious on her bed. Upon admittance, she was considered confused, with a temperature of 39.4 °C and slight neutrophilic leukocytosis, but no neck stiffness. A neurological examination revealed bilateral horizontal nystagmus, unstable eye movements, and suspected right-sided gaze paralysis. Cerebrospinal fluid analysis revealed normal parameters, and the microscopy result was negative for bacteria. The most likely diagnosis was considered to be stroke with concomitant infection. However, cerebrospinal fluid and blood cultures subsequently were rapidly positive for pneumococci. Neither immunodeficiency nor blood contamination was considered a likely cause of this discrepancy. CONCLUSIONS: This case emphasizes the need to consider a multidisciplinary approach and empirical meningitis treatment until diagnostic results from microbiological cultures are obtained.

Mannose-binding lectin-associated serine protease 2 (MASP-2) contributes to poor disease outcome in humans and mice with pneumococcal meningitis.

BACKGROUND: Pneumococcal meningitis is the most common and severe form of bacterial meningitis. Fatality rates are substantial, and long-term sequelae develop in about half of survivors. Disease outcome has been related to the severity of the pro-inflammatory response in the subarachnoid space. The complement system, which mediates key inflammatory processes, has been implicated as a modulator of pneumococcal meningitis disease severity in animal studies. METHODS: We investigated mannose-binding lectin-associated serine protease (MASP-2) levels in cerebrospinal fluid (CSF) samples derived from the diagnostic lumbar puncture, which was available for 307 of 792 pneumococcal meningitis episodes included in our prospective nationwide cohort study (39%), and the association between these levels and clinical outcome. Subsequently, we studied the role of MASP-2 in our experimental pneumococcal meningitis mouse model using Masp2 -/- mice and evaluated the potential of adjuvant treatment with MASP-2-specific monoclonal antibodies in wild-type (WT) mice. RESULTS: MASP-2 levels in cerebrospinal fluid of patients with bacterial meningitis were correlated with poor functional outcome. Consistent with these human data, Masp2-deficient mice with pneumococcal meningitis had lower cytokine levels and increased survival compared to WT mice. Adjuvant treatment with MASP-2-specific monoclonal antibodies led to reduced complement activation and decreased disease severity. CONCLUSIONS: MASP-2 contributes to poor disease outcome in human and mice with pneumococcal meningitis. MASP-2-specific monoclonal antibodies can be used to attenuate the inflammatory response in pneumococcal meningitis.

The Early Adaptive Immune Response in the Pathophysiological Process of Pneumococcal Meningitis.

BACKGROUND: The adaptive immune system has been considered to play a minimal role in the early host response during bacterial meningitis. METHODS: We investigated the progression and outcome of pneumococcal meningitis in Rag1-/- mice lacking functional B and T cells by assessing overall and symptom-free survival, bacteriological and histological studies, as well as flow cytometry and measurements of proinflammatory mediators. RESULTS: The intracerebral injection of S. pneumoniae D39 induced the recruitment of B and T cells (CD4+, γδ and natural killer) into the brain of wild-type mice. Mice with no functional B and T cells developed clinical symptoms and succumbed to the infection earlier than the wild-type group. In the CNS, Rag1-/- mice showed lower levels of interleukin 1ß, reduced microglial proliferation, and impaired granulocyte recruitment with an earlier spread of pneumococci into the bloodstream, compared with wild-type mice. Lack of B and T cells resulted in a severe impairment of bacterial clearance in blood, spleen, and liver and an exaggerated systemic inflammatory response. CONCLUSIONS: B and T cells are important effector cells delaying the spread of pneumococci from the brain to the systemic circulation and shaping the immune response, thereby prolonging the survival of the host in the absence of antibiotic treatment.

Depression-Like Adult Behaviors may be a Long-Term Result of Experimental Pneumococcal Meningitis in Wistar Rats Infants.

Pneumococcal meningitis is a life-threatening infection of the central nervous system (CNS) with a high mortality rate. In addition to causing severe neurological sequelae infectious diseases of the CNS can play a significant role in the pathogenesis of neuropsychiatric disorders. In this study infant Wistar rats, postnatal day 11, received intracerebroventricular (i.c.v.) either artificial cerebrospinal fluid (CSF) or a Streptococcus pneumoniae suspension to a concentration of 1 × 106 colony-forming units (CFU). 18 h later animals received antibiotic treatment as usual during 7 days. On postnatal day 46, the animals received imipramine intraperitoneal (i.p.) or sterile NaCl during 14 days (postnatal days 46-60). Then, on postnatal days 59-60 we evaluated the consumption of sweet food (an index of anhedonia). On postnatal day 60 the animals were submitted to the forced swimming task. 60 min after this task the animals were decapitated and the blood was collected to evaluate adrenocorticotropic hormone (ACTH) and corticosterone. Immediately after blood collection the hippocampus was removed to evaluate brain-derived neurotropic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF). The meningitis group exhibited depressive-like behavior as evidenced by decreased sucrose intake and increased immobility time in the forced swimming task, and BDNF and GDNF decrease in the hippocampus. ACTH levels were increased in the blood. Imipramine treatment reversed depressive-like behaviors, re-established hippocampal BDNF and GDNF expression, and normalized ACTH levels in the blood. Here we demonstrate that meningitis during early life period can trigger depressive-like behavior in adult life of rats.

Clinical findings and management of patients with meningitis with an emphasis on Haemophilus influenzae meningitis in rural Tanzania.

INTRODUCTION: The spectrum of meningitis pathogens differs depending on the age of patients and the geographic region, amongst other. Although meningitis vaccination programs have led to the reduction of incidence rates, an imbalance between low- and high-income countries still exists. METHODS: In a hospital-based study in rural northern Tanzania, we consecutively recruited patients with confirmed meningitis and described their clinical and laboratory characteristics. RESULTS: A total of 136 patients with meningitis were included. Fever (85%), meningism (63%) and impairment of consciousness (33%) were the most frequent clinical symptoms/signs. Nearly 10% of all patients tested were positive for malaria. The majority of the patients with bacterial meningitis (39%), especially those under 5years of age, were confirmed to be infected with Haemophilus influenzae (26%), Streptococcus pneumoniae (19%) and Neisseria meningitidis (15%). Haemophilus influenzae represented the dominant causative organism in children under 2years of age. CONCLUSION: Our study emphasizes the importance of recognizing warning symptoms like fever, meningism and impairment of consciousness, implementing laboratory tests to determine responsible pathogens and evaluating differential diagnoses in patients with meningitis in sub-Saharan Africa. It also shows that Haemophilus influenza meningitis is still an important cause for meningitis in the young, most probabaly due to lack of appropriate vaccination coverage.

Antibody-induced neutrophil depletion prior to the onset of pneumococcal meningitis influences long-term neurological complications in mice.

During pneumococcal meningitis, clearance of bacteria by recruited neutrophils is crucial for host protection. However, these innate immune mechanisms are often insufficient and treatment with antibiotics is necessary to prevent death. Despite this antibiotic treatment, approximately half of all survivors suffer lifelong neurological problems. There is growing evidence indicating the harmful effects of neutrophils on CNS integrity. Therefore, the present study investigated the roles of neutrophils in the acute inflammatory response and the resulting long-term neuropsychological effects in murine pneumococcal meningitis. Long-term behavioural and cognitive functions in mice were measured using an automated IntelliCage system. Neutrophil depletion with antibody 1A8 as adjunctive therapy was shown to remarkably impair survival in meningitic C57BL/6J mice despite antibiotic (ceftriaxone) treatment. This was accompanied by increased bacterial load in the cerebrospinal fluid (CSF) and an increase in IL-1ß, but decrease in TNF, within the CSF at 20h after bacterial inoculation. In the longer term, the surviving neutrophil-depleted post-meningitic (PM) mice displayed reduced diurnal hypolocomotion compared to PM mice treated with an isotype antibody. However, they showed nocturnal hyperactivity, and greater learning impairment in a patrolling task that is believed to depend upon an intact hippocampus. The data thus demonstrate two important mechanisms: 1. Neutrophil extravasation into the CNS during pneumococcal meningitis influences the pro-inflammatory response and is central to control of the bacterial load, an increase in which may lead to death. 2. Neutrophil-mediated changes in the acute inflammatory response modulate the neuropsychological sequelae in mice that survive pneumococcal meningitis.

Autosplenectomy Causing Catastrophic Pneumococcal Meningitis in a Patient with Lupus/Antiphospholipid Antibody Syndrome.

We present the case ofa26-year-old female who presented to the hospital with pneumococcal meningitis. A review of her records showed atrophic spleen, and a hypercoagulable workup was positive for Systemic Lupus Erythematous (SLE)/Antiphospholipid Antibody Syndrome (APS). An autosplenectomy from thrombotic occlusion of the splenic artery made her susceptible to pneumococcal meningitis. Autoimmune conditions, particularly SLE and APS, are important causes of hypercoagulable states in a young population, and earlier detection of these conditions and appropriate treatment helps to decrease morbidity and mortality among these patients.

Progressively Recovering Auditory Brainstem Response in a Cochlear-implanted Child After Meningitis: A Case Report.

OBJECTIVE: I describe the case of an 8-year-old boy who developed meningitis several years after implantation and how electrically evoked auditory brainstem response (EABR) is used in the assessment of his hearing performance after recovery. PATIENT: An 8-year-old boy stopped using both his cochlear implants because of streptococcal meningitis accompanied with acute otitis media on the left ear. After recovery his hearing was quickly restored on the right ear, but he complained of not hearing well on the left ear. INTERVENTION: Diagnostic. MAIN OUTCOME MEASURE: EABRs were measured on both ears 2 months after meningitis offset. Testing was repeated on the left ear 12 and 18 months after the first session. Responses were evoked by apical, mid-array, and basal electrodes. RESULTS: At initial testing EABRs were normal on the right ear. They were absent on the left ear for the apical electrode and present but with delayed wave latencies for the middle and basal electrodes. At the second and third sessions, EABRs were present for all electrodes and wave eV latencies were shorter. The stimulus level needed to evoke an EABR was considerably reduced on all electrodes from the first to the third session. There was good agreement between these findings and the subjective feedback from the patient. CONCLUSION: EABR provided valuable information throughout the patient's hearing recovery. Its use should be considered in difficult patients, especially those who cannot give feedback.

Folic acid prevented cognitive impairment in experimental pneumococcal meningitis.

Streptococcus pneumoniae is a common cause of bacterial meningitis, with a high mortality rate and neurological sequelae. In contrast, folic acid plays an important role in neuroplasticity and the preservation of neuronal integrity. In the present study, we evaluated the influence of folic acid on memory, oxidative damage, enzymatic defence, and brain-derived neurotrophic factor (BDNF) expression in experimental pneumococcal meningitis. In animals that received folic acid at a dose of 10 or 50 mg, there was a reduction in both crossing and rearing during an open-field task compared with the training session, demonstrating habituation memory. During a step-down inhibitory avoidance task, there was a difference between the training and the test sessions, demonstrating aversive memory. In the hippocampus, BDNF expression decreased in the meningitis group; however, adjuvant treatment with 10 mg of folic acid increased BDNF expression, decreased lipid peroxidation, protein carbonylation, nitrate/nitrite levels, and myeloperoxidase activity and increased superoxide dismutase activity. In frontal cortex adjuvant treatment with 10 mg of folic acid decreased lipid peroxidation and protein carbonylation. There is substantial interest in the role of folic acid and related pathways in nervous system function and in folic acid's potential therapeutic effects. Here, adjuvant treatment with vitamin B9 prevented memory impairment in experimental pneumococcal meningitis.

Interleukin-18 deficiency and its long-term behavioural and cognitive impacts in a murine model of pneumococcal meningitis.

Pneumococcal meningitis often results in death or neurological sequelae, but the underlying pathogenetic mechanisms remain poorly understood. In C57BL/6J mice subjected to intracerebroventricular (icv) challenge with Streptococcus pneumoniae, the chemokine CCL2 and cytokines interferon-γ, interleukin (IL)-1ß, IL-6 and tumour necrosis factor were prominently expressed in the brain during the acute phase of the disease. The upregulation of these immune mediators was markedly diminished in IL-18-deficient mice. Uninfected IL-18(-/-) mice exhibited decreases in anxiety phenotype and licking behaviour, and an increase in behavioural habituation, in an automated monitoring system (the IntelliCage). Without antibiotic intervention, a majority of IL-18(+/+) mice developed irreversible disease after icv S. pneumoniae but this was significantly improved by deleting IL-18 gene function. IL-18(+/+) mice cured of pneumococcal meningitis with four doses of ceftriaxone, initiated at 20 h post-inoculation, showed enduring sequelae. These included abnormal behavioural phenotypes featuring diurnal hypoactivity and nocturnal hyperactivity, light phobia and disrupted cognitive function. While the hyperactive phenotype was absent in the corresponding IL-18(-/-) survivors, cognitive impairments and behavioural deficits were still present. Overall, the results suggest that the high levels of cytokines and/or chemokines released after pneumococcal challenge provoked a series of pathological events, ultimately causing acute death. Furthermore, since only a subset of behavioural phenotypes were ameliorated in the pneumococcus-infected IL-18(-/-) mice, the pathological pathways causing mortality may be, at least in part, distinct from those leading to long-term neurological sequelae.

Vitamin B6 reduces hippocampal apoptosis in experimental pneumococcal meningitis.

BACKGROUND: Bacterial meningitis caused by Streptococcus pneumoniae leads to death in up to 30% of patients and leaves up to half of the survivors with neurological sequelae. The inflammatory host reaction initiates the induction of the kynurenine pathway and contributes to hippocampal apoptosis, a form of brain damage that is associated with learning and memory deficits in experimental paradigms. Vitamin B6 is an enzymatic cofactor in the kynurenine pathway and may thus limit the accumulation of neurotoxic metabolites and preserve the cellular energy status. The aim of this study in a pneumococcal meningitis model was to investigate the effect of vitamin B6 on hippocampal apoptosis by histomorphology, by transcriptomics and by measurement of cellular nicotine amide adenine dinucleotide content. METHODS AND RESULTS: Eleven day old Wistar rats were infected with 1x10(6) cfu/ml of S. pneumoniae and randomized for treatment with vitamin B6 or saline as controls. Vitamin B6 led to a significant (p > 0.02) reduction of hippocampal apoptosis. According to functional annotation based clustering, vitamin B6 led to down-regulation of genes involved in processes of inflammatory response, while genes encoding for processes related to circadian rhythm, neuronal signaling and apoptotic cell death were mostly up-regulated. CONCLUSIONS: Our results provide evidence that attenuation of apoptosis by vitamin B6 is multi-factorial including down-modulation of inflammation, up-regulation of the neuroprotective brain-derived neurotrophic factor and prevention of the exhaustion of cellular energy stores. The neuroprotective effect identifies vitamin B6 as a potential target for the development of strategies to attenuate brain injury in bacterial meningitis.

Role of oxidative stress in the pathophysiology of pneumococcal meningitis.

Pneumococcal meningitis is a life-threatening disease characterized by an acute purulent infection affecting the pia mater, the arachnoid, and the subarachnoid spaces. Streptococcus pneumoniae crosses the blood-brain barrier (BBB) by both transcellular traversal and disruption of the intraepithelial tight junctions to allow intercellular traversal. During multiplication, pneumococci release their bacterial products, which are highly immunogenic and may lead to an increased inflammatory response in the host. Thus, these compounds are recognized by antigen-presenting cells through the binding of toll-like receptors. These receptors induce the activation of myeloid differentiation factor 88 (MyD88), which interacts with various protein kinases, including IL-1 receptor-associated kinase-4 (IRAK4), which is phosphorylated and dissociated from MyD88. These products also interact with tumor necrosis factor receptor-associated factor 6 dependent signaling pathway (TRAF6). This cascade provides a link to NF- κ B-inducing kinase, resulting in the nuclear translocation of NF- κ B leading to the production of cytokines, chemokines, and other proinflammatory molecules in response to bacterial stimuli. Consequently, polymorphonuclear cells are attracted from the bloodstream and then activated, releasing large amounts of NO(•), O2(•), and H2O2. This formation generates oxidative and nitrosative stress, subsequently, lipid peroxidation, mitochondrial damage, and BBB breakdown, which contributes to cell injury during pneumococcal meningitis.

Educational achievement and economic self-sufficiency in adults after childhood bacterial meningitis.

IMPORTANCE: To our knowledge, no previous study has examined functioning in adult life among persons who had bacterial meningitis in childhood. OBJECTIVE: To study educational achievement and economic self-sufficiency in adults diagnosed as having bacterial meningitis in childhood. DESIGN, SETTING, AND PARTICIPANTS: Nationwide population-based cohort study using national registries of Danish-born children diagnosed as having meningococcal, pneumococcal, or Haemophilus influenzae meningitis in the period 1977-2007 (n=2784 patients). Comparison cohorts from the same population individually matched on age and sex were identified, as were siblings of all study participants. End of study period was 2010. MAIN OUTCOMES AND MEASURES: Cumulative incidences of completed vocational education, high school education, higher education, time to first full year of economic self-sufficiency, and receipt of disability pension and differences in these outcomes at age 35 years among meningitis patients, comparison cohorts, and siblings. RESULTS: By age 35 years, among persons who had a history of childhood meningococcal (n=1338), pneumococcal (n=455), and H. influenzae (n=991) meningitis, an estimated 11.0% (41.5% vs 52.5%; 95% CI, 7.3%-14.7%), 10.2% (42.6% vs 52.8%; 95% CI, 3.8%-16.6%), and 5.5% (47.7% vs 53.2%; 95% CI, 1.9%-9.1%) fewer persons, respectively, had completed high school and 7.9% (29.3% vs 37.2%; 95% CI, 1.6%-14.2%), 8.9% (28.1% vs 37.0%; 95% CI, 0.6%-17.2%), and 6.5% (33.5% vs 40.0%; 95% CI, 1.4%-11.6%) fewer had attained a higher education compared with individuals from the comparison cohort. Siblings of meningococcal meningitis patients also had lower educational achievements, while educational achievements of siblings of pneumococcal and H. influenzae meningitis patients did not differ substantially from those in the general population. At end of follow-up, 3.8% (90.3% vs 94.1%; 95% CI, 1.1%-6.5%), 10.6% (84.0% vs 94.6%; 95% CI, 5.1%-16.1%), and 4.3% (90.6% vs 94.9%; 95% CI, 2.0%-6.6%) fewer meningococcal, pneumococcal, and H. influenzae meningitis patients were economically self-sufficient and 1.5% (3.7% vs 2.3%; 95% CI, -0.2% to 3.2%), 8.7% (10.0% vs 1.3%; 95% CI, 5.0%-12.4%), and 3.7% (6.2% vs 2.5%; 95% CI, 1.6%-5.8%) more received disability pension compared with individuals from the comparison cohort. CONCLUSIONS AND RELEVANCE: In a Danish population, bacterial meningitis in childhood was associated with lower educational achievement and economic self-sufficiency in adult life. This association may apply particularly to pneumococcal and H. influenzae meningitis, whereas for meningococcal meningitis the lower educational achievement may be family-related.

Cannabidiol reduces host immune response and prevents cognitive impairments in Wistar rats submitted to pneumococcal meningitis.

Pneumococcal meningitis is a life-threatening disease characterized by an acute infection affecting the pia matter, arachnoid and subarachnoid space. The intense inflammatory response is associated with a significant mortality rate and neurologic sequelae, such as, seizures, sensory-motor deficits and impairment of learning and memory. The aim of this study was to evaluate the effects of acute and extended administration of cannabidiol on pro-inflammatory cytokines and behavioral parameters in adult Wistar rats submitted to pneumococcal meningitis. Male Wistar rats underwent a cisterna magna tap and received either 10µl of sterile saline as a placebo or an equivalent volume of S. pneumoniae suspension. Rats subjected to meningitis were treated by intraperitoneal injection with cannabidiol (2.5, 5, or 10mg/kg once or daily for 9 days after meningitis induction) or a placebo. Six hours after meningitis induction, the rats that received one dose were killed and the hippocampus and frontal cortex were obtained to assess cytokines/chemokine and brain-derived neurotrophic factor levels. On the 10th day, the rats were submitted to the inhibitory avoidance task. After the task, the animals were killed and samples from the hippocampus and frontal cortex were obtained. The extended administration of cannabidiol at different doses reduced the TNF-α level in frontal cortex. Prolonged treatment with canabidiol, 10mg/kg, prevented memory impairment in rats with pneumococcal meningitis. Although descriptive, our results demonstrate that cannabidiol has anti-inflammatory effects in pneumococcal meningitis and prevents cognitive sequel.