The relationship between the laboratory diagnosis of Lyme neuroborreliosis and climate factors in Kalmar County Sweden - an overview between 2008 and 2019.

The purpose of this study was to describe the epidemiology of Lyme neuroborreliosis (LNB) in Kalmar County, in southern Sweden, between 2008 and 2019, and to analyse the relationship between the LNB incidence and climate factors. Data containing cerebrospinal fluid (CSF) cell counts and borrelia CSF/serum antibody index results was received from the departments of clinical chemistry and microbiology at Kalmar County hospital. For this study, we defined LNB as a case with a positive borrelia antibody CSF/serum index and CSF leukocytes > 5 × 106/L. Climate data including mean temperature, humidity and precipitation covering Kalmar County was collected from the Swedish Meteorological and Hydrological Institute. A total of 5051 paired serum-CSF samples from 4835 patients were investigated of which 251 laboratory LNB cases were found. The average annual LNB incidence in Kalmar County 2008-2019 was 8.8 cases per 100,000 inhabitants. Positive relationships were observed between mean temperature and LNB incidence (p < 0.001) as well as precipitation and LNB incidence (p = 0.003), both with a one calendar month delay. The results suggest an association between climate factors such as mean temperature and precipitation and LNB incidence, presumably through increased/decreased human-tick interactions. This calls for increased awareness of LNB in both the short perspective after periods of warmth and heavy precipitation as well as in a longer perspective in relation to possible climate change. Further studies with larger study groups, covering other geographical areas and over longer periods of time are needed to confirm these findings.

Cerebrospinal fluid oligoclonal bands in Neuroborreliosis are specific for Borrelia burgdorferi.

BACKGROUND: Cerebrospinal fluid (CSF) oligoclonal bands (OCB) occur in chronic or post-acute phase of inflammatory diseases of the central nervous system. OBJECTIVE: To determine whether CSF OCB in patients with neuroborreliosis (NB) are specific for borrelia burgdorferi senso lato. METHODS: We performed isoelectric focusing followed by immunoblotting in CSF of 10 NB patients and 11 controls (7 patients with multiple sclerosis, 2 patients with neuromyelitis optica spectrum disease, 1 patient with dementia and 1 patient with monoclonal gammopathy). Immunoblotting was performed using an uncoated as well as a borrelia antigen pre-coated nitrocellulose membrane (NCM). OCB were counted by visual inspection and photometric analysis. OCB were compared between uncoated und pre-coated NCM both in the NB and control group. For validation purposes inter-assay precision was determined by calculating the coefficient of variation (CV). RESULTS: Borrelia-specific OCB were found in the CSF of 9 NB patients and in none of the control subjects resulting in a sensitivity of 90% and a specificity of 100%. Number of NB specific OCB were 11±7 bands by photometric analyses compared to 9±5 bands by visual inspection. Validation experiments revealed an inconsistent inter-assay precision between visual and photometric analyses (NB uncoated: visual 28% versus photometric 14%, control subject uncoated: visual 16% versus photometric 24%). CONCLUSIONS: In CSF samples with positive OCB, Borrelia-specific bands were detected in almost all NB patients and in none of the control subjects. Inconsistent inter-assay precision may be explained by a poor comparability of visual and photometric approach.

Neutrophils and Neutrophil Extracellular Traps Regulate Immune Responses in Health and Disease.

Neutrophils are first responders of antimicrobial host defense and sterile inflammation, and therefore, play important roles during health and disease [...].

Complement activation in individuals with previous subclinical Lyme borreliosis and patients with previous Lyme neuroborreliosis.

Lyme borreliosis (LB) is caused by Borrelia burgdorferi and infection may lead to not only a large variety of clinical manifestations but also a subclinical outcome. The aim of the present study was to investigate if there is a constitutional difference in complement activation between individuals with previous subclinical Lyme borreliosis (SB) and patients previously diagnosed with Lyme neuroborreliosis (LNB).Lepirudin plasma for activation studies was collected from 60 SB individuals and from 22 patients pre-diagnosed with LNB. The plasma was incubated with live Borrelia spirochetes of two strains (complement sensitive B. garinii Lu59 and complement resistant B. afzelii ACA1).Complement factor C3 was measured in non-activated lepirudin plasma with immune-nephelometry and C3a and sC5b-9 generated during complement activation were measured by enzyme-linked immunosorbent assay.We found that the complement sensitive Lu59 induced higher complement activation than the complement resistant ACA1 when measuring activation products C3a and sC5b-9 in SB and LNB patients, p < 0.0001. No significant difference was found between SB and LNB patients in systemic levels of C3. Furthermore, SB individuals generated a higher activation of C3 cleavage to C3a (C3a/C3 ratio) than LNB patients after activation with ACA1, p < 0.001, but no significant differences were found in response to Lu59. In conclusion, Lu59 induced higher complement activation than ACA1 and individuals with previous SB showed increased generation of C3a compared with patients with previous LNB. In our study population, this mechanism could lead to less elimination of spirochetes in LNB patients and thereby be a factor contributing to the clinical outcome.

Prospective comparison of two enzyme-linked immunosorbent spot assays for the diagnosis of Lyme neuroborreliosis.

Commercial cellular tests are used to diagnose Lyme borreliosis (LB), but studies on their clinical validation are lacking. This study evaluated the utility of an in-house and a commercial enzyme-linked immunosorbent spot (ELISpot) assay for the diagnosis of Lyme neuroborreliosis (LNB). Prospectively, peripheral blood mononuclear cells (PBMCs) were isolated from patients and controls and analysed using an in-house Borrelia ELISpot assay and the commercial LymeSpot assay. B. burgdorferi B31 whole cell lysate and a mixture of outer surface proteins were used to stimulate the PBMCs and the numbers of interferon-gamma-secreting T cells were measured. Results were evaluated using receiver operating characteristic (ROC) curve analysis. Eighteen active and 12 treated LNB patients, 10 healthy individuals treated for an early (mostly cutaneous) manifestation of LB in the past and 47 untreated healthy individuals were included. Both assays showed a poor diagnostic performance with sensitivities, specificities, positive and negative predictive values ranging from 44.4-66.7%, 42.0-72.5%, 21.8-33.3% and 80.5-87.0%, respectively. The LymeSpot assay performed equally poorly when the calculation method of the manufacturer was used. Both the in-house and the LymeSpot assay are unable to diagnose active LNB or to monitor antibiotic treatment success.

Beyond LNB: Real life data on occurrence and extent of CSF CXCL13 in neuroinflammatory diseases.

To evaluate occurrence and extent of CSF CXCL13 elevations beyond Lyme neuroborreliosis, we investigated CXCL13 in an unselected patient cohort with neuroinflammatory disease. From March 2016 to March 2017, 180 in-patients with CSF pleocytosis were categorized into following groups: pyogenic CNS infections, aseptic meningoencephalitis, neuroimmunological diseases, and reactive pleocytosis. We provide evidence that CXCL13 elevation occurs at variable extent in the majority of neuroinflammatory diseases. The exact role of CXCL13 in CSF is elusive, but the broad occurrence in neuroinflammation points at CNS immune activation, which is not exclusive for LNB.

Neutrophil Extracellular Traps (NETs) in the Cerebrospinal Fluid Samples from Children and Adults with Central Nervous System Infections.

Neutrophils operate as part of the innate defence in the skin and may eliminate the Borrelia spirochaete via phagocytosis, oxidative bursts, and hydrolytic enzymes. However, their importance in Lyme neuroborreliosis (LNB) is unclear. Neutrophil extracellular trap (NET) formation, which is associated with the production of reactive oxygen species, involves the extrusion of the neutrophil DNA to form traps that incapacitate bacteria and immobilise viruses. Meanwhile, NET formation has recently been studied in pneumococcal meningitis, the role of NETs in other central nervous system (CNS) infections has previously not been studied. Here, cerebrospinal fluid (CSF) samples from clinically well-characterised children (N = 111) and adults (N = 64) with LNB and other CNS infections were analysed for NETs (DNA/myeloperoxidase complexes) and elastase activity. NETs were detected more frequently in the children than the adults (p = 0.01). NET presence was associated with higher CSF levels of CXCL1 (p < 0.001), CXCL6 (p = 0.007), CXCL8 (p = 0.003), CXCL10 (p < 0.001), MMP-9 (p = 0.002), TNF (p = 0.02), IL-6 (p < 0.001), and IL-17A (p = 0.03). NETs were associated with fever (p = 0.002) and correlated with polynuclear pleocytosis (rs = 0.53, p < 0.0001). We show that neutrophil activation and active NET formation occur in the CSF samples of children and adults with CNS infections, mainly caused by Borrelia and neurotropic viruses. The role of NETs in the early phase of viral/bacterial CNS infections warrants further investigation.

Neutrophil extracellular traps in the central nervous system hinder bacterial clearance during pneumococcal meningitis.

Neutrophils are crucial mediators of host defense that are recruited to the central nervous system (CNS) in large numbers during acute bacterial meningitis caused by Streptococcus pneumoniae. Neutrophils release neutrophil extracellular traps (NETs) during infections to trap and kill bacteria. Intact NETs are fibrous structures composed of decondensed DNA and neutrophil-derived antimicrobial proteins. Here we show NETs in the cerebrospinal fluid (CSF) of patients with pneumococcal meningitis, and their absence in other forms of meningitis with neutrophil influx into the CSF caused by viruses, Borrelia and subarachnoid hemorrhage. In a rat model of meningitis, a clinical strain of pneumococci induced NET formation in the CSF. Disrupting NETs using DNase I significantly reduces bacterial load, demonstrating that NETs contribute to pneumococcal meningitis pathogenesis in vivo. We conclude that NETs in the CNS reduce bacterial clearance and degrading NETs using DNase I may have significant therapeutic implications.

Immunoblot reactivity at follow-up in treated patients with Lyme neuroborreliosis and healthy controls.

About 5-20% of the general population in endemic areas have seroprevalence for anti-borrelial antibodies. Previous studies have shown a high rate of 25-97% of persisting anti-borrelial antibodies in patients with treated Lyme neuroborreliosis (LNB) at follow-up. These studies used immunoblots with antigens from whole-cell sonicates, which could be less specific than modern recombinant antigens. We assessed the seroprevalence of anti-borrelial antibodies in serum from patients with definite LNB and healthy controls with a line immunoblot using highly specific recombinant antigens. We retrospectively identified patients with treated definite LNB who were treated at the Medical Center-University of Freiburg. Serum from LNB patients at a mean follow-up period of 4.9 years (SD: 3.3) and serum from healthy controls were assessed for anti-borrelial antibodies with a line immunoblot with recombinant antigens. A total of 45 patients with definite LNB and 40 healthy controls were included. Ten LNB patients (22.7%) had persisting antibodies (IgG and/or IgM) in serum at follow-up. Serum samples from six healthy controls (15%) were positive for anti-borrelial antibodies (IgG and or IgM). Prevalence of positive IgM or IgG antibodies showed no statistically significant difference between LNB patients at follow-up and healthy controls (IgM p = 0.32, IgG p = 0.54). Immunoblot reactivity patterns at follow-up in LNB patients did not have statistically significant differences from healthy controls. The discrepancy regarding earlier studies reporting higher amounts of LNB patients with persisting antibodies could be due to a higher specificity of the antigens used in recombinant immunoblots compared to other immunoblots (e.g., whole-cell sonicates). The results of our study should be replicated in a larger prospective multi-center study.

Case report: persistently seronegative neuroborreliosis in an immunocompromised patient.

BACKGROUND: Infection with Borrelia burgdorferi sensu lato complex (B. b. sl) spirochetes can cause Lyme borreliosis, manifesting as localized infection (e.g. erythema migrans) or disseminated disease (e.g. Lyme neuroborreliosis). Generally, patients with disseminated Lyme borreliosis will produce an antibody response several weeks post-infection. So far, no case of neuroborreliosis has been described with persistently negative serology one month after infection. CASE PRESENTATION: We present a patient with a history of Mantle cell lymphoma and treatment with R-CHOP (rituximab, doxorubicine, vincristine, cyclofosfamide, prednisone), with a meningo-encephalitis, who was treated for a suspected lymphoma relapse. However, no malignant cells or other signs of malignancy were found, and microbial tests did not reveal any clues, including Borrelia serology. He did not recall being bitten by ticks, and a Borrelia PCR on CSF was negative. After spontaneous improvement of symptoms, he was discharged without definite diagnosis. Several weeks later, he was readmitted with a relapse of symptoms of meningo-encephalitis. This time however, a Borrelia PCR on CSF was positive, confirmed by two independent laboratories, and the patient received ceftriaxone upon which he partially recovered. Interestingly, during the diagnostic process of this exceptionally difficult case, a variety of different serological assays for Borrelia antibodies remained negative. Only P41 (flagellin) IgG was detected by blot and the Liaison IgG became equivocal 2 months after initial testing. CONCLUSIONS: To the best of our knowledge this is the first case of neuroborreliosis that is seronegative on repeated sera and multiple test modalities. This unique case demonstrates the difficulty to diagnose neuroborreliosis in severely immunocompromised patients. In this case, a delay in diagnosis was caused by broad differential diagnosis, an absent known history of tick bites, negative serology and the low sensitivity of PCR on CSF. Therefore, awareness of the diagnostic limitations to detect Borrelia infection in this specific patient category is warranted.

Serologic Evidence of Tick-Borne Encephalitis Virus Infection in a Patient with Suspected Lyme Disease in Japan.

Tick-borne encephalitis (TBE) is widely prevalent on the Eurasian continent, including Japan, but four cases of TBE have been reported in Japan. To inspect unconfirmed TBE cases in Japan, we conducted a retrospective seroepidemiological study of a total of 158 samples from 81 meningoencephalitis patients suspected as Lyme disease. Two serum samples from one patient showed neutralizing antibodies against TBE virus. The patient with severe and progressive encephalitis had a history of tick bite in Hokkaido in 2012. These results demonstrated that tick-borne encephalitis virus (TBEV) case was actually unconfirmed in Japan. Further seroepidemiological surveys are required to identify unconfirmed TBEV infections to consider the pros and cons of introducing specific countermeasures including vaccination in Japan.

Diagnostic value of cerebrospinal fluid CXCL13 for acute Lyme neuroborreliosis. A systematic review and meta-analysis.

OBJECTIVES: The utility of cerebrospinal fluid (CSF) CXCL13 for diagnosis of acute Lyme neuroborreliosis (LNB) has been debated and the test is not yet routinely performed. This study's aim was to evaluate its overall diagnostic accuracy through meta-analysis. METHODS: Electronic searches in PubMed MEDLINE and Web of Science were performed to identify relevant articles published before January 2018. A summary receiver operating characteristic curve and an optimal cut-off were estimated modelling multiple cut-offs. Publication bias was evaluated using a funnel plot and the associated regression test. RESULTS: A total of 18 studies involving 618 individuals with acute LNB and 2326 individuals with other neurological disorders meeting the eligibility criteria were identified. The pooled sensitivity for CSF CXCL13 was 89% (95% CI 85%-93%) and the pooled specificity was 96% (95% CI 92%-98%), using the identified optimal cut-off value of 162 pg/mL. There was marked heterogeneity between studies, caused by differences in the designs of the study populations and age distribution. The optimal cut-off in the seven studies with a cross-sectional design was 91 pg/mL (sensitivity 96%, 95% CI 92%-98%; specificity 94%, 95% CI 86%-97%) and in the 11 case-control studies it was 164 pg/mL (sensitivity 85%, 95% CI 78%-91%; specificity 95%, 95% CI 90%-98%). CSF CXCL13 values above the optimal cut-off level (determined in this meta-analysis) were also detectable in some other central nervous system disorders, namely neurosyphilis and central nervous system lymphoma. CONCLUSIONS: Our meta-analysis shows that CSF CXCL13 has the potential to become a useful adjunct in the diagnosis of acute LNB.

CXCL13 concentrations in cerebrospinal fluid of patients with Lyme neuroborreliosis and other neurological disorders determined by Luminex and ELISA.

The aims of the study were to determine and compare the concentration of CXCL13 in cerebrospinal fluid (CSF) of patients with Lyme neuroborreliosis (LNB) and various other neurological disorders applying a Luminex based assay and ELISA, and to find factors associated with CXCL13 concentration. CSF samples obtained from four clinically well-defined groups of patients (proven LNB, suspected LNB, tick-borne encephalitis (TBE), and aseptic meningitis/meningoencephalitis other than TBE) - 25 samples per group - were analyzed. The performance of the Luminex recomBead CXCL13 assay (Microgen, Neuried, Germany) and ELISA (Euroimmun, Lübeck, Germany) was assessed by receiver operating characteristics. CXCL13 cut-off values were presented as functions of CSF lymphocyte/monocyte counts. Demographic variables, CSF findings, and history of erythema migrans were assessed as possible predictors for CXCL13 CSF concentrations by a general linear model. The calculated cut-off values determined by the maximum of the Youden index were >131 pg/mL for recomBead and >259 pg/mL for the ELISA. RecomBead showed a sensitivity of 88% (68.8-97.5%) and a specificity of 94% (83.5-98.7%). For the ELISA the corresponding values were 84% (63.9-95.5%) and 98% (89.4-99.9%). The CXCL13 concentration positively correlated with CSF lymphocyte/monocyte count and Borrelia-specific intrathecal antibody index (p < 0.05). High CXCL13 concentrations were only found in the group with proven LNB. CXCL13 levels above cut-off value were established in some patients with viral meningitis/meningoencephalitis but were not detected in patients with suspected LNB without pleocytosis. Applying a linearized cut-off of the CXCL13 concentration in the CSF which is dependent on the CSF cell count is a novel approach in the laboratory diagnosis of LNB.

Subclinical Lyme borreliosis is common in south-eastern Sweden and may be distinguished from Lyme neuroborreliosis by sex, age and specific immune marker patterns.

BACKGROUND: Determinants of a subclinical course of Lyme borreliosis (LB) remain largely unknown. The aim of this study was to assess the extent, sex and age profiles of subclinical Borrelia seroconversion in a LB endemic area in Sweden and to map blood cellular Borrelia-specific immune marker patterns in individuals with a previous subclinical LB course compared with patients previously diagnosed with Lyme neuroborreliosis (LNB). METHODS: A large group of 1113 healthy blood donors was screened for multiple IgG anti-Borrelia antibodies and asked to complete a health inquiry regarding previous LB. A group of subjects with anti-Borrelia-specific IgG antibodies but no previous history of LB (subclinical LB, n = 60) was identified together with 22 cases of previous LNB. Whole Borrelia spirochetes, strains B. afzelii ACA1 and B. garinii Ip90, were used for ex vivo whole blood stimulations, whereas outer surface protein enriched fractions of the same strains were used for stimulation of peripheral blood mononuclear cells (PBMCs). An extensive panel of immune markers was analysed in the supernatants after stimulation using multiplex bead arrays, and Borrelia-specific secretion was determined by subtracting the spontaneous secretion. RESULTS: A total of 125/1113 blood donors reported previous clinical LB. In contrast, 66 donors denied previous LB but showed multiple IgG anti-Borrelia antibodies; these were defined as subclinical subjects, of whom 60 were available for further studies. The subclinical subjects consisted of significantly more men and had a younger age compared with the LNB patients (p ≤ 0.01). Discriminant analysis revealed a distinct pattern of sex, age and PBMC B. garinii-specific levels of IL-10, IL-17A and CCL20 discriminating subclinical subjects from LNB patients. CONCLUSIONS: This study confirms that subclinical Borrelia seroconversion is common in south-eastern Sweden. The findings further suggest that male sex, younger age together with B. gariniii induced levels of IL-10, IL-17A and CCL20 may be associated with a subclinical course.

Cerebrospinal fluid Lyme multiplex assay results are not diagnostic in horses with neuroborreliosis.

BACKGROUND: The accuracy of the Lyme multiplex assay for the diagnosis of neuroborreliosis in horses is unknown. HYPOTHESIS/OBJECTIVES: To describe Lyme multiplex results in horses with a postmortem diagnosis of neuroborreliosis. The hypothesis was that paired serum and cerebrospinal fluid (CSF) results and a CSF : serum ratio would allow differentiation of horses with neuroborreliosis from those with other neurologic diseases. ANIMALS: Ninety horses that had neurologic examinations, serum and CSF Lyme multiplex analyses, and postmortem examination of the nervous system performed. METHODS: Retrospective study. Data collected included signalment, ante- and postmortem diagnoses, and serum and CSF Lyme multiplex results. The CSF : serum ratio was calculated by dividing CSF median fluorescent intensity (MFI) by serum MFI for each result. RESULTS: Ten horses had a final diagnosis of neuroborreliosis, 70 were diagnosed with other neurologic diseases, and 10 had no neurologic disease. Not all horses with neuroborreliosis had positive results: 4/10 had at least 1 positive serum result, 5/10 had at least 1 positive CSF result, and 3/10 had at least 1 CSF result 4-fold higher than the corresponding serum result. Results were similar for the 70 horses with other neurologic diseases: 53% had at least 1 positive serum result, 50% had at least 1 positive CSF result, and 16% had at least 1 CSF result 4-fold higher than the corresponding serum result. CONCLUSIONS AND CLINICAL IMPORTANCE: Positive Lyme multiplex results were common in horses with neurologic diseases and did not adequately differentiate horses with neuroborreliosis from horses with other disorders.

Autoimmunity against a glycolytic enzyme as a possible cause for persistent symptoms in Lyme disease.

Some patients with a history of Borrelia burgdorferi infection develop a chronic symptomatology characterized by cognitive deficits, fatigue, and pain, despite antibiotic treatment. The pathogenic mechanism that underlines this condition, referred to as post-treatment Lyme disease syndrome (PTLDS), is currently unknown. A debate exists about whether PTLDS is due to persistent infection or to post-infectious damages in the immune system and the nervous system. We present the case of a patient with evidence of exposure to Borrelia burgdorferi sl and a long history of debilitating fatigue, cognitive abnormalities and autonomic nervous system issues. The patient had a positive Western blot for anti-basal ganglia antibodies, and the autoantigen has been identified as γ enolase, the neuron-specific isoenzyme of the glycolytic enzyme enolase. Assuming Borrelia own surface exposed enolase as the source of this autoantibody, through a mechanism of molecular mimicry, and given the absence of sera reactivity to α enolase, a bioinformatical analysis was carried out to identify a possible cross-reactive conformational B cell epitope, shared by Borrelia enolase and γ enolase, but not by α enolase. Taken that evidence, we hypothesize that this autoantibody interferes with glycolysis in neuronal cells, as the physiological basis for chronic symptoms in at least some cases of PTLDS. Studies investigating on the anti-γ enolase and anti-Borrelia enolase antibodies in PTLDS are needed to confirm our hypotheses.

Neuroimmunomodulators in Neuroborreliosis and Lyme Encephalopathy.

Background: Lyme encephalopathy, characterized by nonspecific neurobehavioral symptoms including mild cognitive difficulties, may occur in patients with systemic Lyme disease and is often mistakenly attributed to central nervous system (CNS) infection. Identical symptoms occur in many inflammatory states, possibly reflecting the effect of systemic immune mediators on the CNS. Methods: Multiplex immunoassays were used to measure serum and cerebrospinal fluid (CSF) cytokines in patients with or without Lyme disease to determine if there are specific markers of active CNS infection (neuroborreliosis), or systemic inflammatory mediators associated with neurobehavioral syndromes. Results: CSF CXCL13 levels were elevated dramatically in confirmed neuroborreliosis (n = 8), less so in possible neuroborreliosis (n = 11) and other neuroinflammatory conditions (n = 44). Patients with Lyme (n = 63) or non-Lyme (n = 8) encephalopathy had normal CSF findings, but had elevated serum levels of interleukins 7, 17A, and 17F, thymic stromal lymphopoietin and macrophage inflammatory protein-α. Conclusions: CSF CXCL13 is a sensitive and specific marker of neuroborreliosis in individuals with Borrelia-specific intrathecal antibody production. However, it does not distinguish individuals strongly suspected of having neuroborreliosis, but lacking confirmatory intrathecal antibodies, from those with other neuroinflammatory conditions. Patients with mild cognitive symptoms occurring during acute Lyme disease, and/or after appropriate treatment, have normal CSF but elevated serum levels of T-helper 17 markers and T-cell growth factors, which are also elevated in patients without Lyme disease but with similar symptoms. In the absence of CSF abnormalities, neurobehavioral symptoms appear to be associated with systemic inflammation, not CNS infection or inflammation, and are not specific to Lyme disease.

Pediatric stroke related to Lyme neuroborreliosis: Data from the Swiss NeuroPaediatric Stroke Registry and literature review.

BACKGROUND: Cerebrovascular complications of Lyme neuroborreliosis (LNB) are poorly documented in the paediatric population. METHODS: We performed a retrospective analysis from prospectively registered cases of acute ischemic stroke (AIS) from the Swiss NeuroPaediatric Stroke Registry (SNPSR) from 2000 to 2015. Only cases with serologically confirmed LNB were included. In addition, a literature review on paediatric stroke cases secondary to Lyme neuroborreliosis in the same time frame was performed. RESULTS: 4 children out of 229 children with arterial ischemic childhood stroke and serologically confirmed LNB were identified in the SNPSR giving a global incidence of 1.7%. Median age was 9.9 years. A prior history of tick bites or erythema migrans (EM) was reported in two cases. Clinical presenting signs were suggestive of acute cerebellar/brainstem dysfunction. On imaging, three children demonstrated a stroke in the distribution of the posterior inferior cerebellar artery. The remaining fourth child had a "stroke-like" picture with scattered white matter lesions and a multifocal vasculitis with prominent basilar artery involvement. Lymphocytic pleocytosis as well as intrathecal synthesis of Borrelia burgdorferi antibodies were typical biological features. Acute intravenous third generation cephalosporins proved to be effective with rapid improvement in all patients. No child had recurrent stroke. Data from the literature concerning eight patients gave similar results, with prominent posterior circulation stroke, multifocal vasculitis and abnormal CSF as distinctive features. CONCLUSIONS: Lyme Neuroborreliosis accounts for a small proportion of paediatric stroke even in an endemic country. The strong predilection towards posterior cerebral circulation with clinical occurrence of brainstem signs associated with meningeal symptoms and CSF lymphocytosis are suggestive features that should rapidly point to the diagnosis. This can be confirmed by appropriate serological testing in the serum and CSF. Clinicians must be aware of this rare neurological complication of Lyme disease that demands specific antibiotic treatment.

Characteristics and Clinical Outcome of Lyme Neuroborreliosis in a High Endemic Area, 1995-2014: A Retrospective Cohort Study in Denmark.

BACKGROUND: Despite a well-described symptomatology, treatment delay and sequelae are common in patients with Lyme neuroborreliosis (LNB). The aim of this study was to contribute to the knowledge about the symptomatology and epidemiology of LNB. METHODS: We conducted a retrospective study of all LNB cases verified by a positive Borrelia intrathecal antibody index test performed at the Department of Microbiology, Odense University Hospital, Denmark, from 1995 through 2014. RESULTS: The study included 431 patients; 126 were children. The mean incidence was 4.7 per 100 000 inhabitants per year. The median delay from neurological symptom debut to first hospital contact was 20 days and significantly longer for patients with symptom debut in the winter/early spring. The most common clinical symptoms were painful radiculitis (65.9%), cranial nerve palsy (43.4%), and headache (28.3%). A total of 30.6% were seen in >1 hospital department, and 85.6% were admitted during their course of treatment. Serum Borrelia immunoglobulin M and immunoglobulin G at the time of positive Borrelia intrathecal antibody index test were negative in 67 patients (15.5%). We found a median treatment delay of 24 days, with no improvement in our 20-year study period. Residual symptoms following treatment were found in 28.1% of patients, and risk of residual symptoms was significantly associated with delay from symptom debut to initiation of treatment. CONCLUSIONS: The association between treatment delay and residual symptoms and the lack of improvement in treatment delay during the study period highlight the need for standardized diagnostic routines and a better follow-up for LNB patients. Our findings disprove that all patients with LNB develop positive serum Borrelia antibodies within 6 weeks after infection.

Borrelia burgdorferi basic membrane protein A could induce chemokine production in murine microglia cell line BV2.

Lyme neuroborreliosis is a nervous system infectious disease caused by Borrelia burgdorferi (B. burgdorferi). It has been demonstrated that cytokines induced by B. burgdorferi are related to Lyme neuroborreliosis. Microglia is known as a key player in the immune responses that occur within the central nervous system. In response to inflammation, it will be activated and generate cytokines and chemokines. Experiments in vitro cells have showed that B. Burgdorferi membrane protein A (BmpA), a major immunogen of B. Burgdorferi, could induce Lyme arthritis and stimulate human and murine lymphocytes to produce inflammatory cytokines. In our study, the murine microglia BV2 cell line was used as a cell model to explore the stimulating effects of recombinant BmpA (rBmpA); Chemokine chip, ELISA and QPCR technology were used to measure the production of chemokines from microglial cells stimulated by rBmpA. Compared with the negative control group, CXCL2, CCL22, and CCL5 concentrations in the cell supernatant increased significantly after the rBmpA stimulation; the concentration of these chemokines increased with rBmpA concentration increasing; the mRNA expression levels of chemokines (CXCL2, CCL22, and CCL5) in murine BV2 cells increased significantly with 10 µg/mL and 20 µg/mL rBmpA stimulation; CXCL13 was not change after the rBmpA stimulation. Our study shows that chemokines, such as CXCL2, CCL22, and CCL5 were up-regulated by the rBmpA in the BV2 cells. The production of chemokines in Lyme neuroborreliosis may be mainly from microglia cells and the rBmpA may be closely related with the development of Lyme neuroborreliosis.