Molecular diagnostics in cerebrospinal fluid for the diagnosis of central nervous system infections.

SUMMARYCentral nervous system (CNS) infections can be caused by various pathogens, including bacteria, viruses, fungi, and parasites. Molecular diagnostic methods are pivotal for identifying the different causative pathogens of these infections in clinical settings. The efficacy and specificity of these methods can vary per pathogen involved, and in a substantial part of patients, no pathogen is identified in the cerebrospinal fluid (CSF). Over recent decades, various molecular methodologies have been developed and applied to patients with CNS infections. This review provides an overview of the accuracy of nucleic acid amplification methods in CSF for a diverse range of pathogens, examines the potential value of multiplex PCR panels, and explores the broad-range bacterial and fungal PCR/sequencing panels. In addition, it evaluates innovative molecular approaches to enhance the diagnosis of CNS infections.

Human Listeriosis.

Listeria monocytogenes is a Gram-positive facultative intracellular pathogen that can cause severe invasive infections upon ingestion with contaminated food. Clinically, listerial disease, or listeriosis, most often presents as bacteremia, meningitis or meningoencephalitis, and pregnancy-associated infections manifesting as miscarriage or neonatal sepsis. Invasive listeriosis is life-threatening and a main cause of foodborne illness leading to hospital admissions in Western countries. Sources of contamination can be identified through international surveillance systems for foodborne bacteria and strains' genetic data sharing. Large-scale whole genome studies have increased our knowledge on the diversity and evolution of L. monocytogenes, while recent pathophysiological investigations have improved our mechanistic understanding of listeriosis. In this article, we present an overview of human listeriosis with particular focus on relevant features of the causative bacterium, epidemiology, risk groups, pathogenesis, clinical manifestations, and treatment and prevention.

Immunothrombosis in Acute Ischemic Stroke.

Ischemic stroke is one of the leading causes of disability and mortality worldwide. Thrombosis is the main pathological process of stroke and is therefore an important therapeutic target in stroke prevention. In recent years, with the development of endovascular treatment and therefore retrieving the thrombus for further investigation, evidence is accumulating that immune cells are inextricably linked to stroke pathogenesis. Circulating immune cells have been found to induce immunothrombosis, and they actively participate in the formation of the thrombus by promoting platelet recruitment and thrombin activation. Additionally, the formation of thromboinflammation leads to increased instability of atherosclerotic plaques. We review the concepts of stroke immunothrombosis and thromboinflammation and the effect of immune cells on vessel recanalization and patient outcome. In addition, we elaborate on the possible mechanism of immune cells being activated and participating in thrombosis in ischemic stroke.

Otitis in Patients With Community-Acquired Bacterial Meningitis: A Nationwide Prospective Cohort Study.

BACKGROUND: Otitis is commonly associated with community-acquired bacterial meningitis, but the role of ear surgery as treatment is debated. In this study, we investigated the impact of otitis and ear surgery on outcome of adults with community-acquired bacterial meningitis. METHODS: We analyzed episodes of adults with community-acquired bacterial meningitis from a nationwide prospective cohort study in the Netherlands, between March 2006 and July 2021. RESULTS: A total of 2548 episodes of community-acquired bacterial meningitis were evaluated. Otitis was present in 696 episodes (27%). In these patients the primary causative pathogen was Streptococcus pneumoniae (615 of 696 [88%]), followed by Streptococcus pyogenes (5%) and Haemophilus influenzae (4%). In 519 of 632 otitis episodes (82%) an ear-nose-throat specialist was consulted, and surgery was performed in 287 of 519 (55%). The types of surgery performed were myringotomy with ventilation tube insertion in 110 of 287 episodes (38%), mastoidectomy in 103 of 287 (36%), and myringotomy alone in 74 of 287 (26%). Unfavorable outcome occurred in 210 of 696 episodes (30%) and in 65 of 696 episodes was fatal (9%). Otitis was associated with a favorable outcome in a multivariable analysis (odds ratio 0.74; 95% confidence interval [CI] .59-.92; P = .008). There was no association between outcome and ear surgery. CONCLUSIONS: Otitis is a common focus of infection in community-acquired bacterial meningitis in adults, with S. pneumoniae being the most common causative pathogen. Presence of otitis is associated with a favorable outcome. Ear surgery's impact on the outcome of otogenic meningitis patients remains uncertain.

Metoclopramide to Prevent Pneumonia in Patients With Stroke and a Nasogastric Tube: Data From the PRECIOUS Trial.

BACKGROUND: A randomized trial suggested that treatment with metoclopramide reduces the risk of pneumonia in patients with acute stroke and a nasogastric tube. We assessed whether this finding could be replicated in a post hoc analysis of the randomized PRECIOUS trial (Prevention of Complications to Improve Outcome in Elderly Patients With Acute Stroke). METHODS: PRECIOUS was an international, 3×2 partial-factorial, randomized controlled, open-label clinical trial with blinded outcome assessment assessing preventive treatment with metoclopramide, paracetamol, and ceftriaxone in patients aged ≥66 years with acute ischemic stroke or intracerebral hemorrhage and a National Institutes of Health Stroke Scale score ≥6. In the present study, we analyzed patients who had a nasogastric tube within 24 hours after randomization. Patients who were allocated to metoclopramide (10 mg TID) were compared with patients who were not. Treatment was started within 24 hours after symptom onset and continued for 4 days or until discharge if earlier. The primary outcome was pneumonia in the first week after stroke. The score on the modified Rankin Scale after 90 days was a secondary outcome and analyzed with ordinal logistic regression. RESULTS: From April 2016 through June 2022, a total of 1493 patients were enrolled with 1376 included in this analysis, of whom 1185 (86%) had ischemic stroke and 191 (14%) had intracerebral hemorrhage. The first day after randomization, 329 (23.9%) patients had a nasogastric tube, of whom 156 were allocated to metoclopramide and 173 to standard care. Metoclopramide was not associated with a reduction of pneumonia (41.0% versus 35.8%; adjusted odds ratio, 1.35 [95% CI, 0.79-2.30]) or with poor functional outcome (adjusted odds ratio, 1.07 [95% CI, 0.71-1.61]). CONCLUSIONS: In patients with stroke who had a nasogastric tube shortly after stroke onset, metoclopramide for 4 days did not reduce pneumonia or have an effect on the functional outcome.

Noncompressive myelopathy in acute community-acquired bacterial meningitis: Report of seven cases and review of literature.

BACKGROUND AND PURPOSE: Bacterial meningitis is a severe disease with high rates of complications and unfavorable outcome. Complications involving the spinal cord are rarely reported. METHODS: Cases of noncompressive myelopathy were identified from a nationwide cohort study of adults with community-acquired bacterial meningitis in the Netherlands. The American Spinal Injury Association Impairment Scale was used to classify the severity of spinal cord dysfunction. Subsequently, we reviewed the literature on noncompressive myelopathy as a complication of bacterial meningitis. RESULTS: Noncompressive myelopathy was reported in seven of 3047 episodes of community-acquired bacterial meningitis (0.2%). The median age of these patients was 51 years (range = 17-77). Causative pathogens were Streptococcus pneumoniae in three, Streptococcus agalactiae in two, and Neisseria meningitidis and Haemophilus influenzae both in one. Paresis of legs (n = 6) or arms and legs (n = 1) was the presenting symptom, occurring after a median duration of 9 days after admission (range = 2-28). Spinal magnetic resonance imaging showed T2-weighted abnormalities of the spinal cord in six of seven patients. Improvement of spinal cord function during admission was noted in four of seven patients. The literature review yielded 15 additional cases. Among patients from our cohort and the literature, there was no significant association between immunosuppressive therapy and subsequent improvement of spinal cord function (5/8 patients with immunosuppressive therapy [63%] vs. 5/14 without immunosuppressive therapy [36%], p = 0.44). CONCLUSIONS: Noncompressive myelopathy is an uncommon but severe complication of bacterial meningitis. Improvement after diagnosis is expected, but all patients had persistent neurological deficits.

Patient-reported daily functioning after SARS-CoV-2 vaccinations in autoimmune neuromuscular diseases.

BACKGROUND AND PURPOSE: There are concerns for safety regarding SARS-CoV-2 vaccines for patients with autoimmune neuromuscular disease. We compared daily functioning using disease-specific patient-reported outcome measures (PROMs) before and after SARS-CoV-2 vaccinations. METHODS: In this substudy of a prospective observational cohort study (Target-to-B!), patients with myasthenia gravis (MG), chronic inflammatory demyelinating polyneuropathy (CIDP), multifocal motor neuropathy (MMN), and idiopathic inflammatory myopathy (IIM) vaccinated against SARS-CoV-2 were included. Surveys of daily functioning (Myasthenia Gravis Activities of Daily Living, Inflammatory Rasch-Built Overall Disability Scale, Multifocal Motor Neuropathy Rasch-Built Overall Disability Scale, and Health Assessment Questionnaire-Disability Index) were sent before first vaccination and every 60 days thereafter for up to 12 months. Regression models were constructed to assess differences in PROM scores related to vaccination, compared to scores unrelated to vaccination. We also assessed the proportion of patients with deterioration of at least the minimal clinically important difference (MCID) between before first vaccination and 60 days thereafter. RESULTS: We included 325 patients (median age = 59 years, interquartile range = 47-67, 156 [48%] female sex), of whom 137 (42%) had MG, 79 (24%) had CIDP, 43 (13%) had MMN, and 66 (20%) had IIM. PROM scores related to vaccination did not differ from scores unrelated to vaccination. In paired PROMs, MCID for deterioration was observed in three of 49 (6%) MG patients, of whom none reported a treatment change. In CIDP, MCID for deterioration was observed in eight of 29 patients (28%), of whom two of eight (25%) reported a treatment change. CONCLUSIONS: SARS-CoV-2 vaccination had no effect on daily functioning in patients with autoimmune neuromuscular diseases, confirming its safety in these patients.

Effect of the COVID-19 pandemic on clinical characteristics and outcomes of adult pneumococcal meningitis patients - a Dutch prospective nationwide cohort study.

PURPOSE: To investigate clinical characteristics and outcomes of patients with pneumococcal meningitis during the COVID-19 pandemic. METHODS: In a Dutch prospective cohort, risk factors and clinical characteristics of pneumococcal meningitis episodes occurring during the COVID-19 pandemic (starting March 2020) were compared with those from baseline and the time afterwards. Outcomes were compared with an age-adjusted logistic regression model. RESULTS: We included 1,699 patients in 2006-2020, 50 patients in 2020-2021, and 182 patients in 2021-2023. After March 2020 relatively more alcoholism was reported (2006-2020, 6.1%; 2020-2021, 18%; 2021-2023, 9.7%; P = 0.002) and otitis-sinusitis was less frequently reported (2006-2020, 45%; 2020-2021, 22%; 2021-2023, 47%; P = 0.006). Other parameters, i.e. age, sex, symptom duration or initial C-reactive protein level, remained unaffected. Compared to baseline, lumbar punctures were more frequently delayed (on admission day, 2006-2020, 89%; 2020-2021, 74%; 2021-2022, 86%; P = 0.002) and outcomes were worse ('good recovery', 2020-2021, OR 0.5, 95% CI 0.3-0.8). CONCLUSION: During the COVID-19 pandemic, we observed worse outcomes in patients with pneumococcal meningitis. This may be explained by differing adherence to restrictions according to risk groups or by reduced health care quality.

Granulocytes in cerebrospinal fluid of adults suspected of a central nervous system infection: a prospective study of diagnostic accuracy.

PURPOSE: Cerebrospinal fluid (CSF) granulocytes are associated with bacterial meningitis, but information on its diagnostic value is limited and primarily based on retrospective studies. Therefore, we assessed the diagnostic accuracy of CSF granulocytes. METHODS: We analyzed CSF granulocytes (index test) from all consecutive patients in two prospective cohort studies in the Netherlands. Both studies included patients ≥ 16 years, suspected of a central nervous system (CNS) infection, who underwent a diagnostic lumbar puncture. All episodes with elevated CSF leukocytes (≥ 5 cells per mm3) were selected and categorized by clinical diagnosis (reference standard). RESULTS: Of 1261 episodes, 625 (50%) had elevated CSF leukocytes and 541 (87%) were included. 117 of 541 (22%) were diagnosed with bacterial meningitis, 144 (27%) with viral meningoencephalitis, 49 (9%) with other CNS infections, 76 (14%) with CNS autoimmune disorders, 93 (17%) with other neurological diseases and 62 (11%) with systemic diseases. The area under the curve to discriminate bacterial meningitis from other diagnoses was 0.97 (95% confidence interval [CI] 0.95-0.98) for CSF granulocyte count and 0.93 (95% CI 0.91-0.96) for CSF granulocyte percentage. CSF granulocyte predominance occurred in all diagnostic categories. A cutoff at 50% CSF granulocytes gave a sensitivity of 94% (95% CI 90-98), specificity of 80% (95% CI 76-84), negative predictive value of 98% (95% CI 97-99) and positive predictive value of 57% (95% CI 52-62). CONCLUSION: CSF granulocytes have a high diagnostic accuracy for bacterial meningitis in patients suspected of a CNS infection. CSF granulocyte predominance occurred in all diagnostic categories, limiting its value in clinical practice.

Heterogeneity of treatment effect of vilobelimab in COVID-19: a secondary analysis of a randomised controlled trial.

In a phase 3 trial (PANAMO, NCT04333420), vilobelimab, a complement 5a (C5a) inhibitor, reduced 28-day mortality in mechanically ventilated COVID-19 patients. This post hoc analysis of 368 patients aimed to explore treatment heterogeneity through unsupervised learning. All available clinical variables at baseline were used as input. Treatment heterogeneity was assessed using latent class analysis (LCA), Ward's hierarchical clustering (HC) and the adjudication to previously described clinical sepsis phenotypes. The primary outcome was 28-day mortality. For LCA, a 2-class latent model was deemed most suitable. In the LCA model, 82 (22%) patients were assigned to class 1 and 286 (78%) to class 2. Class 1 was defined by more severely ill patients with significantly higher mortality. In an adjusted logistic regression, no heterogeneity of treatment effect (HTE) between classes was observed (p = 0.998). For HC, no significant classes were found (p = 0.669). Using the previously described clinical sepsis subtypes, 41 patients (11%) were adjudicated subtype alpha (α), 17 (5%) beta (ß), 112 (30%) delta (δ) and 198 (54%) gamma (γ). HTE was observed between clinical subtypes (p = 0.001) with improved 28-day mortality after treatment with vilobelimab for the δ subtype (OR = 0.17, 95% CI 0.07-0.40, p < 0.001). No signal for harm of treatment with vilobelimab was observed in any class or clinical subtype. Overall, treatment effect with vilobelimab was consistent across different classes and subtypes, except for the δ subtype, suggesting potential additional benefit for the most severely ill patients.

Pericytes are protective in experimental pneumococcal meningitis through regulating leukocyte infiltration and blood-brain barrier function.

BACKGROUND: Brain pericytes participate in the regulation of cerebral blood flow and the maintenance of blood-brain barrier integrity. Because of their perivascular localization, their receptor repertoire, and their potential ability to respond to inflammatory and infectious stimuli by producing various cytokines and chemokines, these cells are also thought to play an active role in the immune response to brain infections. This assumption is mainly supported by in vitro studies, investigations in in vivo disease models are largely missing. Here, we analysed the role of brain pericytes in pneumococcal meningitis, in vitro and in vivo in two animal models of pneumococcal meningitis. METHODS: Primary murine and human pericytes were stimulated with increasing concentrations of different serotypes of Streptococcus pneumoniae in the presence or absence of Toll-like receptor inhibitors and their cell viability and cytokine production were monitored. To gain insight into the role of pericytes in brain infection in vivo, we performed studies in a zebrafish embryo model of pneumococcal meningitis in which pericytes were pharmacologically depleted. Furthermore, we analyzed the impact of genetically induced pericyte ablation on disease progression, intracranial complications, and brain inflammation in an adult mouse model of this disease. RESULTS: Both murine and human pericytes reacted to pneumococcal exposure with the release of selected cytokines. This cytokine release is pneumolysin-dependent, TLR-dependent in murine (but not human) pericytes and can be significantly increased by macrophage-derived IL-1b. Pharmacological depletion of pericytes in zebrafish embryos resulted in increased cerebral edema and mortality due to pneumococcal meningitis. Correspondingly, in an adult mouse meningitis model, a more pronounced blood-brain barrier disruption and leukocyte infiltration, resulting in an unfavorable disease course, was observed following genetic pericyte ablation. The degree of leukocyte infiltration positively correlated with an upregulation of chemokine expression in the brains of pericyte-depleted mice. CONCLUSIONS: Our findings show that pericytes play a protective role in pneumococcal meningitis by impeding leukocyte migration and preventing blood-brain barrier breaching. Thus, preserving the integrity of the pericyte population has the potential as a new therapeutic strategy in pneumococcal meningitis.

Sex and Gender Differences in Bacterial Infections.

There is a growing awareness of the importance of sex and gender in medicine and research. Women typically have stronger immune responses to self and foreign antigens than men, resulting in sex-based differences in autoimmunity and infectious diseases. In both animals and humans, males are generally more susceptible than females to bacterial infections. At the same time, gender differences in health-seeking behavior, quality of health care, and adherence to treatment recommendations have been reported. This review explores our current understanding of differences between males and females in bacterial diseases. We describe how genetic, immunological, hormonal, and anatomical factors interact to influence sex-based differences in pathophysiology, epidemiology, clinical presentation, disease severity, and prognosis, and how gender roles affect the behavior of patients and providers in the health care system.

Pneumococcal Meningitis in Adults: A Prospective Nationwide Cohort Study Over a 20-year Period.

BACKGROUND: The epidemiology and treatment of pneumococcal meningitis has changed with the implementation of conjugate vaccines and the introduction of adjunctive dexamethasone therapy. METHODS: We analyzed episodes of community-acquired pneumococcal meningitis in adults (≥16 years) in the Netherlands, identified by the National Reference Laboratory for Bacterial Meningitis or treating physician between October 1, 1998, and April 1, 2002, and between January 1, 2006, and July 1, 2018. We studied incidence, pneumococcal serotypes, and clinical features. Predictors for unfavorable outcome (Glasgow Outcome Scale score 1-4) were identified in a multivariable logistic regression model. Two physicians independently categorized causes of death as neurological or systemic. RESULTS: There were 1816 episodes in 1783 patients. The incidence of 7- and 10-7-valent pneumococcal conjugate vaccine serotypes decreased (from 0.42 to 0.06, P = .001; from 0.12 to 0.03 episodes per 100 000 population per year, P = .014). Incidence of nonvaccine serotypes increased (from 0.45 to 0.68, P = .005). The use of adjunctive treatment with dexamethasone increased and was administered in 85% of patients in 2018. In-hospital death occurred in 363 episodes (20%) and unfavorable outcome in 772 episodes (43%). Delayed cerebral thrombosis occurred in 29 patients (2%), of whom 15 patients (52%) died. Adjunctive dexamethasone therapy was associated with favorable outcome (adjusted odds ratio 2.27, P < .001), individual pneumococcal serotypes were not. CONCLUSION: Implementation of conjugate vaccines and adjunctive dexamethasone therapy have changed the incidence and outcome of pneumococcal meningitis in adults over the last two decades. Despite recent advances pneumococcal meningitis remains associated with a residual high rate of mortality and morbidity.

Temporal Profile of Pneumonia After Stroke.

BACKGROUND AND PURPOSE: The occurrence of pneumonia after stroke is associated with a higher risk of poor outcome or death. We assessed the temporal profile of pneumonia after stroke and its association with poor outcome at several time points to identify the most optimal period for testing pneumonia prevention strategies. METHODS: We analyzed individual patient data stored in the VISTA (Virtual International Stroke Trials Archive) from randomized acute stroke trials with an inclusion window up to 24 hours after stroke onset and assessed the occurrence of pneumonia in the first 90 days after stroke. Adjusted odds ratios and hazard ratios were calculated for the association between pneumonia and poor outcome and death by means of logistic and Cox proportional hazard regression, respectively, at different times of follow-up. RESULTS: Of 10 821 patients, 1017 (9.4%) had a total of 1076 pneumonias. Six hundred eighty-nine (64.0%) pneumonias occurred in the first week after stroke. The peak incidence was on the third day and the median time of onset was 4.0 days after stroke (interquartile range, 2-12). The presence of a pneumonia was associated with an increased risk of poor outcome (adjusted odds ratio, 4.8 [95% CI, 3.8-6.1]) or death (adjusted hazard ratio, 4.1 [95% CI, 3.7-4.6]). These associations were present throughout the 90 days of follow-up. CONCLUSIONS: Two out of 3 pneumonias in the first 3 months after stroke occur in the first week, with a peak incidence on the third day. The most optimal period to assess pneumonia prevention strategies is the first 4 days after stroke. However, pneumonia occurring later was also associated with poor functional outcome or death.

Prematurity Modifies the Risk of Long-term Neurodevelopmental Impairments After Invasive Group B Streptococcus Infections During Infancy in Denmark and the Netherlands.

BACKGROUND: Preterm birth and neonatal infections are both associated with mortality and long-term neurodevelopmental impairments (NDIs). We examined whether the effect of invasive group B Streptococcus disease (iGBS) on mortality and long-term NDI differs for preterm and term infants, and whether co-occurrence of iGBS and prematurity leads to worse outcome. METHODS: Nationwide cohort studies of children with a history of iGBS were conducted using Danish and Dutch medical databases. Comparison cohorts of children without iGBS were matched on birth year/month, sex, and gestational age. Effects of iGBS on all-cause mortality and NDI were analyzed using Cox proportional hazards and logistic regression. Effect modification by prematurity was evaluated on additive and multiplicative scales. RESULTS: We identified 487 preterm and 1642 term children with a history of iGBS and 21 172 matched comparators. Dutch preterm children exposed to iGBS had the highest mortality rate by 3 months of age (671/1000 [95% CI, 412-929/1000] person-years). Approximately 30% of this mortality rate could be due to the common effect of iGBS and prematurity. Preterm children with iGBS had the highest NDI risk (8.8% in Denmark, 9.0% in the Netherlands). Of this NDI risk 36% (Denmark) and 60% (the Netherlands) might be due to the combined effect of iGBS and prematurity. CONCLUSIONS: Prematurity is associated with iGBS development. Our study shows that it also negatively impacts outcomes of children who survive iGBS. Preterm infants would benefit from additional approaches to prevent maternal GBS colonization, as this decreases risk of both preterm birth and iGBS.

Community-acquired bacterial meningitis.

Progress has been made in the prevention and treatment of community-acquired bacterial meningitis during the past three decades but the burden of the disease remains high globally. Conjugate vaccines against the three most common causative pathogens (Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae) have reduced the incidence of disease, but with the replacement by non-vaccine pneumococcal serotypes and the emergence of bacterial strains with reduced susceptibility to antimicrobial treatment, meningitis continues to pose a major health challenge worldwide. In patients presenting with bacterial meningitis, typical clinical characteristics (such as the classic triad of neck stiffness, fever, and an altered mental status) might be absent and cerebrospinal fluid examination for biochemistry, microscopy, culture, and PCR to identify bacterial DNA are essential for the diagnosis. Multiplex PCR point-of-care panels in cerebrospinal fluid show promise in accelerating the diagnosis, but diagnostic accuracy studies to justify routine implementation are scarce and randomised, controlled studies are absent. Early administration of antimicrobial treatment (within 1 hour of presentation) improves outcomes and needs to be adjusted according to local emergence of drug resistance. Adjunctive dexamethasone treatment has proven efficacy beyond the neonatal age but only in patients from high-income countries. Further progress can be expected from implementing preventive measures, especially the development of new vaccines, implementation of hospital protocols aimed at early treatment, and new treatments targeting checkpoints of the inflammatory cascade.

Microglial cell response in α7 nicotinic acetylcholine receptor-deficient mice after systemic infection with Escherichia coli.

BACKGROUND: Development of neurodegeneration in older people has been associated with microglial cell activation triggered by systemic infection. We hypothesize that α7 nicotinic acetylcholine receptor (α7nAChR) plays an important role in regulation of this process. METHODS: 8- to 10-week-old male wild-type (WT) and α7nAChR knock-out (α7nAChR-/-) mice were intraperitoneally inoculated with live Escherichia (E.) coli or saline. After inoculation, all mice were treated with ceftriaxone (an antimicrobial drug) at 12 and 24 h and killed at 2 or 3 days. The microglial response was characterized by immunohistochemical staining with an ionized calcium-binding adaptor molecule 1 (Iba-1) antibody and flow cytometry. To quantify inflammatory response, mRNA expression of pro- and anti-inflammatory mediators was measured in brain and spleen. RESULTS: We observed no differences in Iba-1 positive cell number or morphology and flow cytometry (CD11b, CD45 and CD14) of microglial cells between WT and α7nAChR-/- mice after systemic infection. Infected α7nAChR-/- mice showed significantly higher mRNA expression in brain for tumor necrosis factor alpha (TNF-α) at day 2 and 3, interleukin 6 (IL-6) at day 2 and monocyte chemotactic protein 1 (MCP-1) and suppressor of cytokine signaling 1 (SOCS1) at day 3, there was significantly lower mRNA expression in brain for mitogen-activated protein kinase 1 (MAPK1) at day 2 and 3, high-mobility group 1 (HMGB-1) and CD11b at day 2, and deubiquitinase protein A20 (A20) at day 3 compared to infected WT mice. INTERPRETATION: Loss of function of α7nAChR during systemic infection led to an increased expression of TNF-α and IL-6 in brain after systemic infection with E. coli, but not to distinct differences in microglial cell number or morphological activation of microglia.

Anti-C5a antibody vilobelimab treatment and the effect on biomarkers of inflammation and coagulation in patients with severe COVID-19: a substudy of the phase 2 PANAMO trial.

We recently reported in the phase 3 PANAMO trial that selectively blocking complement 5a (C5a) with vilobelimab led to improved survival in critically ill COVID-19 patients. C5a is an important contributor to the innate immune system and can also activate the coagulation system. High C5a levels have been reported in severely ill COVID-19 patients and correlate with disease severity and mortality. Previously, we assessed the potential benefit and safety of vilobelimab in severe COVID-19 patients. In the current substudy of the phase 2 PANAMO trial, we aim to explore the effects of vilobelimab on various biomarkers of inflammation and coagulation. Between March 31 and April 24, 2020, 17 patients with severe COVID-19 pneumonia were enrolled in an exploratory, open-label, randomised phase 2 trial. Blood markers of complement, endothelial activation, epithelial barrier disruption, inflammation, neutrophil activation, neutrophil extracellular trap (NET) formation and coagulopathy were measured using enzyme-linked immunosorbent assay (ELISA) or utilizing the Luminex platform. During the first 15 days after inclusion, change in biomarker concentrations between the two groups were modelled with linear mixed-effects models with spatial splines and compared. Eight patients were randomized to vilobelimab treatment plus best supportive care (BSC) and nine patients were randomized to BSC only. A significant decrease over time was seen in the vilobelimab plus BSC group for C5a compared to the BSC only group (p < 0.001). ADAMTS13 levels decreased over time in the BSC only group compared to the vilobelimab plus BSC group (p < 0.01) and interleukin-8 (IL-8) levels were statistically more suppressed in the vilobelimab plus BSC group compared to the BSC group (p = 0.03). Our preliminary results show that C5a inhibition decreases the inflammatory response and hypercoagulability, which likely explains the beneficial effect of vilobelimab in severe COVID-19 patients. Validation of these results in a larger sample size is warranted.

Clinical characteristics and outcome of neurosarcoidosis-associated myelitis: A retrospective cohort study and review of the literature.

BACKGROUND AND PURPOSE: Neurosarcoidosis can affect all parts of the nervous system of which myelitis is relatively frequent. The aim of this study was to describe clinical characteristics, treatment and prognosis of patients with myelitis attributable to neurosarcoidosis. METHODS: We performed a retrospective cohort study and a systematic review and meta-analysis of neurosarcoidosis-associated myelitis. RESULTS: Myelitis was identified in 41 of 153 (27%) neurosarcoidosis patients seen at our clinic from 2015 to 2020. Classification of neurosarcoidosis was definite in three (7%), probable in 29 (71%) and possible in nine patients (22%). The median (interquartile range) age at onset was 49 (41-53) years and 20 of the patients were female (49%). The presenting symptoms included muscle weakness in 31 of 41 patients (78%), sensory loss in 35 (88%) and micturition abnormalities in 30 (75%). Spinal magnetic resonance imaging showed longitudinally extensive myelitis in 27 of 36 patients (75%) and cerebrospinal fluid examination showed an elevated leukocyte count in 21 patients (81%). Initial treatment consisted of glucocorticoids in 38 of 41 patients (93%), with additional methotrexate or azathioprine in 21 of 41 patients (51%) and infliximab in 10 of 41 patients (24%). Treatment led to remission, improvement or stabilization of disease in 37 of 39 patients (95%). Despite treatment, 18 of 30 patients (60%) could not walk independently at the end of follow-up (median 36 months). A review of the literature published between 2000 and 2020 identified 215 patients with comparable clinical characteristics and results of ancillary investigations. CONCLUSION: Sarcoidosis-associated myelitis is observed in 27% of neurosarcoidosis patients. Although treatment often led to a decrease in disease activity, residual neurological deficits leading to loss of ambulation occurred frequently.

Subarachnoid Hemorrhage in Bacterial Meningitis Patients.

INTRODUCTION: Subarachnoid hemorrhage (SAH) has been described as an uncommon complication of community-acquired bacterial meningitis. However, the incidence, clinical course, and outcome are unclear. METHODS: We assessed the clinical characteristics, incidence, and clinical outcome of patients with SAH complicating bacterial meningitis in a prospective nationwide cohort study from 2006 to 2018 in the Netherlands. Patients were identified through the Netherlands Reference Laboratory for Bacterial Meningitis, which receives around 90% of CSF isolates of all Dutch patients with bacterial meningitis, or after direct report by the treating physician. RESULTS: SAH was diagnosed in 22 of 2,306 episodes (0.9%), of which 7 (32%) were diagnosed upon admission and 15 (68%) during admission. All patients showed clinical deterioration before SAH was diagnosed: altered mental status in 18 of 22 patients (82%), focal neurological symptoms in 2 (9%) and, new-onset fever with severe tachycardia in 1 (5%). Acute onset of headache was not reported in any of the patients. Distribution of blood was diffuse in the subarachnoid space in 7 patients (32%), multifocal in 8 patients (36%), and focal in 7 patients (32%) of 22 patients. In 6 patients (27%), CT angiography, MR angiography, or digital subtraction angiography was performed, showing a mycotic aneurysm in 1 patient (5%) and vasculitis in 1 patient (5%). Presence of SAH in bacterial meningitis patients was associated with a poor prognosis assessed at discharge: 12 of 22 patients with SAH died (54%) compared to 361 of 2,257 (16%, p < 0.001) without SAH, and 19 of 22 had an unfavorable outcome (86%) compared to 831 of 2,257 (37%, p < 0.001). CONCLUSION: SAH is an uncommon complication in bacterial meningitis and is associated with high case fatality and morbidity.