Lyme neuroborreliosis

Basic Analysis of the Cerebrospinal Fluid: An Important Framework for Laboratory Diagnostics of the Impairment of the Central Nervous System

Laboratory analysis of basic cerebrospinal fluid (CSF) parameters is considered as essential for any CSF evaluation. It can provide rapidly very valuable information about the status of the central nervous system (CNS). Our retrospective study evaluated parameters of basic CSF analysis in cases of either infectious or non-infectious CNS involvement. Neutrophils are effector cells of innate immunity. Predominance of neutrophils was found in 98.2% of patients with purulent inflammation in CNS. Lymphocytes are cellular substrate of adaptive immunity. We found their predominance in 94.8% of patients with multiple sclerosis (MS), 66.7% of patients with tick-borne encephalitis (TBE), 92.2% of patients with neuroborreliosis, 83.3% of patients with inflammatory response with oxidative burst of macrophages in CNS and 75.0% of patients with malignant infiltration of meninges (MIM). The simultaneous assessment of aerobic and anaerobic metabolism in CSF using the coefficient of energy balance (KEB) allows us to specify the type of inflammation in CNS. We found predominantly aerobic metabolism (KEB > 28.0) in 100.0% CSF of patients with normal CSF findings and in 92.8% CSF of patients with MS. Predominant faintly anaerobic metabolism (28.0 > KEB > 20.0) in CSF was found in 71.8% patients with TBE and in 64.7% patients with neuroborreliosis. Strong anaerobic metabolism (KEB < 10.0) was found in the CSF of 99.1% patients with purulent inflammation, 100.0% patients with inflammatory response with oxidative burst of macrophages and in 80.6% patients with MIM. Joint evaluation of basic CSF parameters provides sufficient information about the immune response in the CSF compartment for rapid and reliable diagnosis of CNS involvement.

Rare case of acute transverse myelitis associated with Lyme neuroborreliosis

Acute transverse myelitis is a neurological disorder that leads to acute spinal cord injury due to inflammation caused by autoimmune disorders or by parainfectious etiologies. Among the many different infectious causes of transverse myelitis, one of the rare ones is Lyme disease. Here we describe a case of a 62 year old male who presents with bilateral paresthesia and weakness. MRI imaging of the cervical and thoracic spine led to the initial diagnosis of cervical cord edema leading to the symptoms associated transverse myelitis. However further workup of different infectious causes lead to positive Lyme titers with positive confirmatory ELISA testing. Initiation of Lyme disease treatment with IV ceftriaxone led to the gradual resolution of the symptoms.

Endogenous and Borrowed Proteolytic Activity in the Borrelia

The Borrelia spp. are tick-borne pathogenic spirochetes that include the agents of Lyme disease and relapsing fever. As part of their life cycle, the spirochetes traffic between the tick vector and the vertebrate host, which requires significant physiological changes and remodeling of their outer membranes and proteome. This crucial proteome resculpting is carried out by a diverse set of proteases, adaptor proteins, and related chaperones. Despite its small genome, Borrelia burgdorferi has dedicated a large percentage of its genome to proteolysis, including a full complement of ATP-dependent proteases. Energy-driven proteolysis appears to be an important physiological feature of this dual-life-cycle bacterium. The proteolytic arsenal of Borrelia is strategically deployed for disposal of proteins no longer required as they move from one stage to another or are transferred from one host to another. Likewise, the Borrelia spp. are systemic organisms that need to break down and move through host tissues and barriers, and so their unique proteolytic resources, both endogenous and borrowed, make movement more feasible. Both the Lyme disease and relapsing fever Borrelia spp. bind plasminogen as well as numerous components of the mammalian plasminogen-activating system. This recruitment capacity endows the spirochetes with a borrowed proteolytic competency that can lead to increased invasiveness.

Peripheral neuropathy due to neuroborreliosis: Insensitivity for CXCL13 as early diagnostic marker

The case of a 69-year-old woman with peripheral neuropathy caused by Lyme neuroborreliosis (LNB) in an endemic region in Eastern Austria is reported. The patient had noticed transient numbness of her left leg. On initial examination, she had patchy sensory disturbances of the left lower leg, but ancillary examinations of nerve conduction and cerebrospinal fluid (CSF), including the B-cell chemokine CXCL13, were normal. A re-tap performed 54 days later, following clinical progression with foot drop, widespread lower leg paresthesia, and pain, revealed an increased cell count, autochthonous IgM production, synthesis of Borrelia-specific IgM, and elevated CXCL13. Neurophysiological examinations disclosed an incomplete conduction block, mixed axonal and demyelinating sensorimotor neuropathy, and subacute neurogenic damage of muscles innervated by the peroneal nerve. This case study presents rare evidence of very early diagnostic findings in peripheral neuropathy caused by LNB. These are characterized by insensitivity of CXCL13 in CSF to aid earlier diagnosis and the development of an intrathecal immune response against Borrelia at a later stage. These findings reinforce the need for a re-tap to confirm the diagnosis and facilitate appropriate treatment in this rare manifestation of LNB.

Environmental toxins and Alzheimer's disease progression

Alzheimer's disease (AD) is the most common form of dementia, which causes progressive memory loss and cognitive decline. Effective strategies to treat or prevent remains one of the most challenging undertakings in the medical field. AD is a complex and multifactorial disease that involves several risk factors. Aging and genetic factors both play important roles in the onset of the AD, however; certain environmental factors have been reported to increase the risk of AD. Chronic exposure to toxins has been seen as an environmental factor that may increase the risk of developing a neurodegenerative disease such as AD. Exposure to metals and biotoxins produced by bacteria, molds, and viruses may contribute to the cognitive decline and pathophysiology associated with AD. Toxins may contribute to the pathology of the disease through various mechanisms such as deposition of amyloid-beta (Aβ) plaques and tangles in the brain, induction of apoptosis, inflammation, or oxidative damage. Here, we will review how toxins affect brain physiology with a focus on mechanisms by which toxins may contribute to the development and progression of AD. A better understanding of these mechanisms may help contribute towards the development of an effective strategy to slow the progression of AD.

Possible Lyme Carditis with Sick Sinus Syndrome

Borrelia burgdorferi (B. burgdorferi) is a spirochete bacterium that is transmitted via the Ixodes tick. Infection results in Lyme disease with possible cardiac manifestations, which is also known as Lyme carditis. Patients can present with bradycardia due to rapidly fluctuating atrioventricular block (AVB), which is the hallmark of Lyme carditis. However, we present a rare case of sick sinus syndrome (SSS) without AVB in a 47-year-old man with Lyme disease. He initially presented with a headache and subsequently developed new onset bradycardia and a right cranial nerve (CN) VI palsy with diplopia. B. burgdorferi enzyme-linked immunosorbent assay (ELISA) screen and IgM western blot were positive. He was admitted to the intensive care unit. Electrocardiography (EKG) indicated a heart rate in the high 30 s beats per minute (BPM) with several pauses, but no AVB was present. The patient responded well to therapy, and was discharged with an outpatient regimen of doxycycline. Lyme carditis should be considered in patients who develop new onset bradycardia and live in endemic areas.

Lyme Neuroborreliosis: Clinical Outcomes, Controversy, Pathogenesis, and Polymicrobial Infections

Lyme borreliosis is the object of numerous misconceptions. In this review, we revisit the fundamental manifestations of neuroborreliosis (meningitis, cranial neuritis, and radiculoneuritis), as these have withstood the test of time. We also discuss other manifestations that are less frequent. Stroke, as a manifestation of Lyme neuroborreliosis, is considered in the context of other infections. The summary of the literature regarding clinical outcomes of neuroborreliosis leads to its controversies. We also include new information on pathogenesis and on the polymicrobial nature of tick-borne diseases. In this way, we update the review that we wrote in this journal in 1995. ANN NEUROL 2019;85:21-31.

Lyme Neuroborreliosis - The Mystifying Pitfall: "Neuropathology and Current Therapeutics"

Lyme's Disease (LD) is a severe, rapidly growing, broad spectrum chronic infection caused by the bacterium 'Borrelia (B.) burgdorferi', which can be easily transmitted through the bite of certain species of ticks. The prevalence of LD is swiftly mounting in the present scenario in many countries from species to species. Although Lyme's infection is now detectable via serologic examination of early and late Lyme neuroborreliosis (LNB), the management of persistent symptoms is still fraught with quora of doubt and debate. LD is a multisystem spirochete which results after the dissemination of B. burgdorferi from a dermal inoculation site after a tick bite. Lyme's infection can easily get transmitted to the central nervous system and develop various neurological symptoms due to inflammation and an autoimmune response from body may lead to life-threatening "Lyme Borreliosis". The neurological symptoms are well mixed in presentation, late and confusing to get differentiated easily from other diseases. The use of antibiotics in post Lyme infection with neurological complications is still a topic of debate. Babesiosisstates, and human ehrlichiosis' the two other diseases, are associated with the same ticks that spread the LD. However, the prevalence of diagnosed human cases is usually much lower than that of actual cases of LD due to misdiagnosis, late diagnosis or undiagnosis at y such lateral neuroinfection stage after the tick bite. The current review focuses on the molecular neuropathology and current advancements in LD. There are very few patents or discoveries made on borrelia infection, drawing attention towards more focused and targeted research for the cure.

Lyme Meningoradiculitis: Case Reports and Literature Review

The clinical manifestations of Lyme disease are protean. The meningoradiculitis is a common and well-recognized complication of neuroborreliosis but can be easily misdiagnosed without a high degree of clinical suspicion, mainly if the tick bite is not present in the medical history. We report two cases of Lyme meningoradiculitis with excellent outcome after appropriate antibiotic therapy. In an endemic area in case of neurological manifestations suggestive for neuroborreliosis the serological testing for B. burgdorferi in serum and cerebrospinal fluid is imperative for the correct diagnosis.

Magnetic resonance imaging of infectious meningitis and ventriculitis in adults

Magnetic resonance imaging findings of meningitis are usually nonspecific with respect to the causative pathogen because the brain response to these insults is similar in most cases. In this article, we will use a few representative cases to describe the characteristic magnetic resonance findings of meningitis and its complications, including ventriculitis.

Interaction of spirochetes with the host fibrinolytic system and potential roles in pathogenesis

The pathogenic spirochetes Borrelia burgdorferi, B. hermsii, B. recurrentis, Treponema denticola and Leptospira spp. are the etiologic agents of Lyme disease, relapsing fever, periodontitis and leptospirosis, respectively. Lyme borreliosis is a multi-systemic disorder and the most prevalent tick-borne disease in the northern hemisphere. Tick-borne relapsing fever is persistent in endemic areas worldwide, representing a significant burden in some African regions. Periodontal disease, a chronic inflammatory disorder that often leads to tooth loss, is caused by several potential pathogens found in the oral cavity including T. denticola. Leptospirosis is considered the most widespread zoonosis, and the predominant human disease in tropical, undeveloped regions. What these diseases have in common is that they are a significant burden to healthcare costs in the absence of prophylactic measures. This review addresses the interaction of these spirochetes with the fibrinolytic system, plasminogen (Plg) binding to the surface of bacteria and the generation of plasmin (Pla) on their surface. The consequences on host-pathogen interactions when the spirochetes are endowed with this proteolytic activity are discussed on the basis of the results reported in the literature. Spirochetes equipped with Pla activity have been shown to degrade extracellular matrix (ECM) components, in addition to digesting fibrin, facilitating bacterial invasion and dissemination. Pla generation triggers the induction of matrix metalloproteases (MMPs) in a cascade of events that enhances the proteolytic capacity of the spirochetes. These activities in concert with the interference exerted by the Plg/Pla on the complement system - helping the bacteria to evade the immune system - should illuminate our understanding of the mechanisms involved in host infection.

Multiple sclerosis: diagnosis, differential diagnosis, and clinical presentation

The diagnosis of multiple sclerosis (MS) is based on demonstrating evidence of inflammatory-demyelinating injury within the central nervous system that is disseminated in both time and space. Diagnosis is made through a combination of the clinical history, neurologic examination, magnetic resonance imaging and the exclusion of other diagnostic possibilities. Other so-called "paraclinical" tests, including the examination of the cerebrospinal fluid, the recording of evoked potentials, urodynamic studies of bladder function, and ocular coherence tomography, may be helpful in establishing the diagnosis for individual patients, but are often unnecessary. Differential diagnosis in MS must be guided by clinical presentation and neurologic localization. While the list of conditions that can mimic MS clinically or radiologically is long, in clinical practice there are few conditions that truly mimic MS on both fronts. A positive test for a putative MS "mimic" does not unto itself exclude the diagnosis of MS. Typical symptoms of MS include discrete episodes ("attacks" or "relapses") of numbness, tingling, weakness, vision loss, gait impairment, incoordination, imbalance, and bladder dysfunction. In between attacks, patients tend to be stable, but may experience fatigue and heat sensitivity. Some MS patients go on to experience, or only experience, an insidious worsening of neurologic function and accumulation of disability ("progression") that is not associated with discrete relapse activity. Progression accounts for most of the long-term disability in MS. Diagnostic criteria for MS have evolved over the past several decades, with each revision impacting the apparent prevalence and prognosis of the disorder - the result has been to encourage earlier diagnosis without compromising accuracy.

Chronic or late lyme neuroborreliosis: analysis of evidence compared to chronic or late neurosyphilis

Whether spirochetes persist in affected host tissues and cause the late/chronic manifestations of neurosyphilis was the subject of long-lasting debate. Detection of Treponema pallidum in the brains of patients with general paresis established a direct link between persisting infection and tertiary manifestations of neurosyphilis. Today, the same question is in the center of debate with respect to Lyme disease. The goal of this review was to compare the established pathological features of neurosyphilis with those available for Lyme neuroborreliosis. If the main tertiary forms of neurosyphilis also occur in Lyme neuroborreliosis and Borrelia burgdorferi can be detected in brain lesions would indicate that the spirochete is responsible for the neuropsychiatric manifestations of late/chronic Lyme neuroborreliosis. The substantial amounts of data available in the literature show that the major forms of late/chronic Lyme neuroborreliosis (meningovascular and meningoencephalitis) are clinically and pathologically confirmed. Borrelia burgdorferi was detected in association with tertiary brain lesions and cultivated from the affected brain or cerebrospinal fluid. The accumulated data also indicate that Borrelia burgdorferi is able to evade from destruction by the host immune reactions, persist in host tissues and sustain chronic infection and inflammation. These observations represent evidences that Borrelia burgdorferi in an analogous way to Treponema pallidum is responsible for the chronic/late manifestations of Lyme neuroborreliosis.Late Lyme neuroborreliosis is accepted by all existing guidelines in Europe, US and Canada. The terms chronic and late are synonymous and both define tertiary neurosyphilis or tertiary Lyme neuroborreliosis. The use of chronic and late Lyme neuroborreliosis as different entities is inaccurate and can be confusing. Further pathological investigations and the detection of spirochetes in infected tissues and body fluids are strongly needed.

Peripheral nervous system manifestations of lyme borreliosis

Lyme disease is a tick-borne illness that has protean neurologic manifestations involving both the central and peripheral nervous system. The peripheral nervous system manifestations of Lyme borreliosis can be divided chronologically into acute and chronic forms. Within weeks after disease onset, approximately 15% of untreated patients develop an acute Lyme meningoradiculoneuritis with headache, fever, radicular pain, weakness, and sensory loss, often associated with cranial neuropathy, usually facial palsy. Cerebrospinal fluid typically shows lymphocytic pleocytosis, high protein, and normal glucose. Diagnosis is made by recognition of characteristic clinical features with a history of preceding exposure and confirmed by serologic evidence of exposure to B. burgdorferi or by antibody or PCR evidence of cerebrospinal fluid infection. Months to years after onset, rare patients may develop chronic polyradiculoneuropathy presenting with sensory symptoms or radicular pain. Diagnosis is confirmed by a history of exposure, previous systemic or acute neurologic manifestations of Lyme borreliosis, and serologic evidence of infection. Pathology of acute or chronic Lyme radiculoneuropathy reveals axonal degeneration with perivascular mononuclear infiltration. Eradication of the organism can be achieved with 2 to 4 weeks of ceftriaxone for both acute and chronic Lyme neuroborreliosis. Isolated facial palsy without evidence of cerebrospinal fluid infection can be treated with oral antibiotics such as doxycycline. Prognosis after therapy is good, but neurologic recovery is slower for chronic than acute Lyme radiculoneuropathy.

Cytotoxic mechanisms may play a role in the local immune response in the central nervous system in neuroborreliosis

Aiming to investigate the role of cytotoxic mechanisms in neuroborreliosis (NB), the cytokines IL-2, IL-7, IL-10, IL-12p70, IL-15, GM-CSF and the Th17-cytokine IL-17 were analyzed in cerebrospinal fluid (CSF) and plasma from NB-patients. NB-patients showed increased levels in CSF compared to controls of all analyzed cytokines except IL-15 but not in plasma. Blood lymphocytes from three NB-patients showed functional cytotoxicity in response to autologous Borrelia-infected macrophages. The findings support a role for cytotoxic mechanisms in the local immune response in NB and in addition suggest an increase of IL-17.

Evaluation of brain tissue or cerebrospinal fluid with broadly reactive polymerase chain reaction for Ehrlichia, Anaplasma, spotted fever group Rickettsia, Bartonella, and Borrelia species in canine neurological diseases (109 cases)

BACKGROUND

Vector-transmitted microorganisms in the genera Ehrlichia, Anaplasma, Rickettsia, Bartonella, and Borrelia are commonly suspected in dogs with meningoencephalomyelitis (MEM), but the prevalence of these pathogens in brain tissue and cerebrospinal fluid (CSF) of dogs with MEM is unknown.

HYPOTHESIS/OBJECTIVES

To determine if DNA from these genera is present in brain tissue and CSF of dogs with MEM, including those with meningoencephalitis of unknown etiology (MUE) and histopathologically confirmed cases of granulomatous (GME) and necrotizing meningoencephalomyelitis (NME).

ANIMALS

Hundred and nine dogs examined for neurological signs at 3 university referral hospitals.

METHODS

Brain tissue and CSF were collected prospectively from dogs with neurological disease and evaluated by broadly reactive polymerase chain reaction (PCR) for Ehrlichia, Anaplasma, Spotted Fever Group Rickettsia, Bartonella, and Borrelia species. Medical records were evaluated retrospectively to identify MEM and control cases.

RESULTS

Seventy-five cases of MUE, GME, or NME, including brain tissue from 31 and CSF from 44 cases, were evaluated. Brain tissue from 4 cases and inflammatory CSF from 30 cases with infectious, neoplastic, compressive, vascular, or malformative disease were evaluated as controls. Pathogen nucleic acids were detected in 1 of 109 cases evaluated. Specifically, Bartonella vinsonii subsp. berkhoffii DNA was amplified from 1/6 dogs with histopathologically confirmed GME.

CONCLUSION AND CLINICAL IMPORTANCE

The results of this investigation suggest that microorganisms in the genera Ehrlichia, Anaplasma, Rickettsia, and Borrelia are unlikely to be directly associated with canine MEM in the geographic regions evaluated. The role of Bartonella in the pathogenesis of GME warrants further investigation.

Bactericidal action of a complement-independent antibody against relapsing fever Borrelia resides in its variable region

A single chain variable fragment (scFv) of CB515, a complement-independent bactericidal monoclonal IgM against a relapsing fever Borrelia, was constructed to investigate the region wherein the unique bactericidal function resides. Monomeric CB515 scFv (26 kDa) was capable of binding its Ag on whole organisms and by immunoblot. This binding was shown to be species and serotype-specific to the 19 kDa variable small protein, recognized by its parent monoclonal IgM. A dose-dependent bactericidal effect of the CB515 scFv was detected by direct enumeration of spirochetes. Spirochetes incubated with the CB515 scFv before inoculation into mice grew into escape mutants, whereas spirochetes incubated with an irrelevant scFv developed as the original infecting serotype. This bactericidal effect, as seen at the ultrastructural level, was due to disruption of the outer membrane and to severe membrane blebbing eventually progressing to lysis. These results indicate that the variable region of CB515 is responsible for this bactericidal activity and that the constant region of the Ab is dispensable.

Lyme meningoradiculitis: prospective evaluation of biological diagnosis methods

The symptoms of Lyme meningoradiculitis and the value of biological examinations in an endemic area were determined in a prospective study in which data were collected on all patients consecutively hospitalised for Lyme meningoradiculitis at our institution during an 18-month period. Specific antibody titres in the serum and cerebrospinal fluid (CSF) were determined by Vidas enzyme-linked-immunosorbent-assay (IgG + IgM), Dade-Behring enzyme immunoassay (EIA) (IgM; IgG) and Western blot analysis (IgG). We also searched for Borrelia burgdorferi in the CSF by PCR analysis and following culture on a specific medium. A control group was recruited, consisting of 16 consecutive patients who had been referred during the same period with suspected but not confirmed Lyme meningoradiculitis. Eleven patients were included. Borrelia EIA of the serum revealed that 40% of the patients had both elevated specific IgM titres and intrathecal synthesis of specific IgG; 40% of the patients was negative for IgM but had isolated intrathecal synthesis of IgG; 20% of the patients had elevated specific IgM titres without intrathecal synthesis of IgG. PCR analysis and the CSF culture were positive in one case only (B. garinii). The results of this study highlight the importance of systematic serological testing for B. burgdorferi in the CSF in the case of early neuroborreliosis suspicion, even in the absence of IgM serum antibodies, which was the case in 40% of the patients in the present study. Nevertheless, intrathecal anti-B. burgdorferi IgG synthesis, which remains the "gold standard" for the diagnosis of neuroborreliosis, was not detectable in 20% of the patients for whom diagnosis was subsequently confirmed by demonstration of specific serum IgM.

Avellis syndrome due to borreliosis

Avellis syndrome is a rare form of alternating hemiparesis that is usually because of atherosclerosis. We report a 67-year-old man who developed paresthesiae of the left arm, dysphagia and dysphonia. The clinical picture, magnetic resonance imaging and cerebrospinal fluid findings were consistent with Avellis syndrome caused by brain stem arteritis because of late stage Borrelia burgdorferi infection, an extremely unusual aetiology for Avellis syndrome; this may well be the first such instance. It may be unrecognized in elderly patients with other risk factors for cerebrovascular disease.

Reciprocal upregulation of urokinase plasminogen activator and its inhibitor, PAI-2, by Borrelia burgdorferi affects bacterial penetration and host-inflammatory response

The mammalian plasminogen activation system (PAS) is a complex system involved in multiple physiological and pathological processes. Borrelia burgdorferi interacts with certain components of the PAS. Here we further investigate this interaction to determine its effect on bacterial dissemination and host cell migration in vitro. We show that stimulation of monocytic cells with B. burgdorferi induces the transient production and secretion of urokinase plasminogen activator (uPA), shortly followed by its physiological inhibitor, plasminogen activator inhibitor-2 (PAI-2). Mono Mac 6 (MM6) cells as well as peripheral blood monocytes enhanced transmigration of B. burgdorferi across a barrier coated with fibronectin mediated by uPA. Moreover, the induction of PAI-2 or the addition of recombinant PAI-2 did not have a significant effect on the uPA-potentiated transmigration of B. burgdorferi. In contrast, the induction of PAI-2 by B. burgdorferi resulted in significantly diminished invasion by monocytic cells across a reconstituted basement membrane (matrigel), which could be partially restored by treatment with purified uPA. These results show that the PAS plays a twofold role in the pathogenesis of B. burgdorferi infection, both by enhancing bacterial dissemination and by diminishing host-cell inflammatory migration.

Persistent brain infection and disease reactivation in relapsing fever borreliosis

Relapsing fever, an infection caused by Borrelia spirochetes, is generally considered a transient, self-limiting disease in humans. The present study reveals that murine infection by Borrelia duttonii can be reactivated after an extended time as a silent infection in the brain, with no bacteria appearing in the blood and spirochete load comparable to the numbers in an infected tick. The host cerebral gene expression pattern is indistinguishable from that of uninfected animals, indicating that persistent bacteria are not recognized by the immune system nor cause noticeable tissue damage. Silent infection can be reactivated by immunosuppression, inducing spirochetemia comparable to that of initial densities. B. duttonii has never been found in any host except man and the tick vector. We therefore propose the brain to be a possible natural reservoir of the spirochete. The view of relapsing fever as an acute disease should be extended to include in some cases prolonged persistence, a feature characteristic of the related spirochetal infections Lyme disease and syphilis.

Heterozygous Arg753Gln polymorphism of human TLR-2 impairs immune activation by Borrelia burgdorferi and protects from late stage Lyme disease

Lyme disease (LD) is caused by Borrelia burgdorferi and displays different stages, including localized, early disseminated, and persistent infection, all of which are associated with profound inflammatory reactions in the host. Induction of proinflammatory cytokines by B. burgdorferi is mainly mediated by outer surface proteins interacting with TLR-2/TLR-1 heterodimers. In this study, we show that TNF-alpha induction by Borrelia lysate was impaired in heterozygous TLR-2 knockout mice, while reactivity to lipoteichoic acid, another TLR-2 ligand signaling via TLR-2/TLR-6 heterodimers, was unaffected. Blood from individuals heterozygous for the TLR-2 polymorphism Arg753Gln was tested for cytokine release upon stimulation with Borrelia lysate, and induction of TNF-alpha and IFN-gamma was significantly lower as compared with individuals not exhibiting this variation. Overexpression of TLR-2 carrying the Arg753Gln polymorphism in HEK 293 cells led to a significantly stronger impairment of activation by TLR-2/TLR-1 ligands as compared with TLR-2/TLR-6 ligands. To study whether heterozygosity for the Arg753Gln variant of TLR-2 influenced susceptibility for LD, we analyzed 155 patients for this polymorphism. The Arg753Gln variant occurs at a significantly lower frequency in LD patients as compared with matched controls (5.8 vs 13.5%, odds ratio 0.393, 95% confidence interval 0.17-0.89, p = 0.033), with an even more pronounced difference when late stage disease was observed (2.3 vs 12.5%, odds ratio 0.163, 95% confidence interval 0.04-0.76, p = 0.018). These data suggest that Arg753Gln may protect from the development of late stage LD due to a reduced signaling via TLR-2/TLR-1.

Painful hallucinations and somatic delusions in a patient with the possible diagnosis of neuroborreliosis

Neuroborreliosis has become the most frequently recognized tick-borne infection of the nervous system in Europe and the United States. In addition to dermatological, cardiac, articular, and neurologic manifestations, psychiatric disorders such as depression, panic attacks, and schizophrenia-like psychosis can also arise. We report on a 61-year-old woman who developed a severe pain syndrome following several tick bites. She was diagnosed with neuroborreliosis; she received various courses of antibiotics over several years, but without any clinical improvement in her condition. Her eventual admission to a psychiatric ward due to mental symptoms and neuroleptic treatment led to a dramatic improvement of her pain symptoms. However, increasing delusions disclosed a psychotic episode, which ceased over time. We discuss therapeutic difficulties and psychiatric complications in the absence of a clear-cut diagnosis of neuroborreliosis. Although this patient might have suffered from late-onset schizophrenia with painful hallucinations right from the start of her disease, the case highlights psychiatric complications that might be associated with neuroborreliosis.

Murine microglia are effective phagocytes for Borrelia burgdorferi

Lyme disease is a multi-systemic infection that causes diverse neurologic dysfunction collectively known as neuroborreliosis. In the murine model of Lyme disease, Borrelia burgdorferi are seldom found in the nervous system indicating that the spirochetes are rapidly cleared from the brain and peripheral nerves. In the present study, we examined the interaction between microglia and B. burgdorferi. Murine microglia are efficient phagocytes and are capable of ingesting and killing spirochetes with or without opsonization.

Pathogenesis of Lyme neuroborreliosis: mitogen-activated protein kinases Erk1, Erk2, and p38 in the response of astrocytes to Borrelia burgdorferi lipoproteins

Lyme borreliosis, which is prevalent both in the US and in Europe, is an infectious disease that may cause local inflammation in numerous organs. We have hypothesized that, as with some neurodegenerative diseases, the pathogenesis of the neurocognitive deficiencies associated with Lyme neuroborreliosis of the central nervous system also has an inflammatory component. Dysregulated production of pro-inflammatory cytokines such as IL-6 and TNF-alpha can lead to neuronal damage. Mitogen-activated protein kinases (MAPK) play a key role in the regulation of neuronal development, growth, and survival, as well as that of pro-inflammatory cytokine production. As a model, we explored the possibility that MAPK-mediated lipoprotein-induced apoptosis and gliosis of rhesus monkey astrocytes stimulated in vitro. Lipoproteins are the key inflammatory molecule type of Borrelia burgdorferi, the spirochete that causes Lyme disease, and we had previously shown that lipoprotein-induced TNF-alpha production in astrocytes caused astrocyte apoptosis, and IL-6 enhanced proliferation of these cells. Lipoproteins readily activated p38 and Erk1/2 MAPK, thus enlisting these pathways among the kinase pathways that spirochetes may address as they invade the central nervous system. We also investigated whether specific inhibition of p38 and Erk1/2 MAPK would inhibit TNF-alpha and IL-6 production and thus astrocyte apoptosis, and proliferation, respectively. Lipoprotein-stimulated IL-6 production was unaffected by the MAPK inhibitors. In contrast, inhibition of both p38 and Erk1/2 significantly diminished TNF-alpha production, and totally abrogated production of this cytokine when both MAPK pathways were inhibited simultaneously. MAPK inhibition thus may be considered as a strategy to control inflammation and apoptosis in Lyme neuroborreliosis.

Histopathological Studies of Experimental Lyme Disease in the Dog

Experimental borrelia infection was induced in 62 specific--pathogen-free beagle dogs by exposure to Ixodes scapularis ticks harbouring the spirochaete Borrelia burgdorferi. Clinical signs of Lyme disease occurred in 39/62 dogs, the remaining 23 being subclinically infected. Clinical signs consisted of one to six episodes of transitory lameness with joint swelling and pain, most commonly affecting the elbow or shoulder joints. The polymerase chain reaction and culture demonstrated that the dogs remained infected for up to 581 days. At necropsy, gross findings consisted of lymphadenopathy in the area of tick attachment. Microscopical changes consisted of effusive fibrinosuppurative inflammation or nonsuppurative inflammation, or both, affecting synovial membranes, joint capsules and associated tendon sheaths. Plasma cells dominated areas of chronic inflammation, with CD3(+) T cells being present in lesser numbers. Microscopical signs of arthritis were polyarticular and more widespread than indicated by clinical signs, and most of the subclinically affected animals also had synovitis. In areas of tick attachment to the skin, hyperkeratosis and a mixture of suppurative and nonsuppurative dermatitis were encountered. Lymphadenopathy in superficial lymph nodes resulted from follicular and parafollicular hyperplasia. In 14/62 dogs, lymphoplasmacytic periarteritis and perineuritis were noted, resembling lesions found in human Lyme disease and syphilis, in which an underlying microangiopathy has been proposed.

The versatile roles of antibodies in Borrelia infections

Antibodies are the primary weapons of the mammalian immune system that are used against the tick-borne borreliae, the causative agents of relapsing fever and Lyme disease worldwide. Some antibody responses have 'traditional' functions, whereas others are more versatile and have novel functions and modes of action. At a time when the multiple functions of antibodies are being increasingly recognized and passive immunization is being revived as therapy for infectious and other diseases, the versatile nature of the antibody response to the borreliae fits well with this antibody renaissance.

Severe neuroborreliosis: The benefit of prolonged high-dose combination of antimicrobial agents with steroids--an illustrative case

Neuroborreliosis frequently occurs in endemic areas, whereas encephalomyelitis is uncommon. Treatment consists classically of 2 to 4 weeks of recommended antimicrobial agents with a generally good outcome. A severe case is reported combining an encephalomyelitis with an axonal polyneuropathy. Clinical improvement was observed only with the use of prolonged high dose of 2 antimicrobial agents combined with steroids.

Borrelia burgdorferi, host-derived proteases, and the blood-brain barrier

Neurological manifestations of Lyme disease in humans are attributed in part to penetration of the blood-brain barrier (BBB) and invasion of the central nervous system (CNS) by Borrelia burgdorferi. However, how the spirochetes cross the BBB remains an unresolved issue. We examined the traversal of B. burgdorferi across the human BBB and systemic endothelial cell barriers using in vitro model systems constructed of human brain microvascular endothelial cells (BMEC) and EA.hy 926, a human umbilical vein endothelial cell (HUVEC) line grown on Costar Transwell inserts. These studies showed that B. burgdorferi differentially crosses human BMEC and HUVEC and that the human BMEC form a barrier to traversal. During the transmigration by the spirochetes, it was found that the integrity of the endothelial cell monolayers was maintained, as assessed by transendothelial electrical resistance measurements at the end of the experimental period, and that B. burgdorferi appeared to bind human BMEC by their tips near or at cell borders, suggesting a paracellular route of transmigration. Importantly, traversal of B. burgdorferi across human BMEC induces the expression of plasminogen activators, plasminogen activator receptors, and matrix metalloproteinases. Thus, the fibrinolytic system linked by an activation cascade may lead to focal and transient degradation of tight junction proteins that allows B. burgdorferi to invade the CNS.

Sciatica, disk herniation, and neuroborreliosis. A report of four cases

We report four cases of sciatica in patients with same-level disk herniation confirmed by computed tomography and a final diagnosis of acute radiculitis caused by Borrelia burgdorferi, with a favorable response to ceftriaxone therapy. The neurological manifestations of Lyme disease are protean, and a potential contribution of concomitant disk disease to sciatica can lead to diagnostic wanderings. Disk lesions and infectious conditions that can cause sciatica are discussed. Whether a favorable response to antibiotic therapy should be taken as proof of B. burgdorferi radiculitis deserves discussion. In practice, in a patient with clinical manifestations suggesting disk-related nerve root pain and residing or having traveled to an endemic area, B. burgdorferi infection should be looked for, as both etiologies can coexist.

Neuropathie sensitive ataxiante et maladie de Lyme

INTRODUCTION

The clinical spectrum of peripheral neuropathies in Lyme disease is very wide. We report a case which was revealed by an ataxic sensory neuropathy.

OBSERVATION

A 77-year-old patient presented with a subacute ataxic sensory neuropathy which occurred 2 weeks after a skin lesion involving the right lower limb. He fully recovered after specific antibiotic treatment. EMG was suggestive of a predominantly axonal neuropathy. Diagnosis of Lyme disease was assessed by progressive elevation of serum antibodies, demonstration of a lymphocytic meningitis and intrathecal synthesis of antibodies.

CONCLUSION

Lyme disease may be added to the list of diseases which may induce subacute sensory neuropathies.

Generation of a complement-independent bactericidal IgM against a relapsing fever Borrelia

The spirochetemia of relapsing fever in mice is cleared by a complement-independent, polyclonal IgM response with reactivity to two prominent Ags of 20 and 35 kDa. In this study, we have dissected the polyclonal IgM Ab response against a relapsing fever spirochete to determine the specificity of its complement-independent bactericidal properties. Our experimental approach selectively generated an IgM murine mAb from the early specific immune response to a variable outer membrane protein. This IgM is bactericidal in the absence of complement and is part of the polyclonal Ab response that mediates the clearance of this bacterium from the blood. Purified monoclonal IgM caused direct structural damage to the outer membrane of the spirochete, in the absence of complement, and protected both B cell- and C5-deficient mice from challenge when administered passively. The direct, complement-independent, bactericidal activity of Abs is a critical mechanism of host defense against infection.

Phenotypes indicating cytolytic properties of Borrelia-specific interferon-gamma secreting cells in chronic Lyme neuroborreliosis

The immuno-pathogenetic mechanisms underlying chronic Lyme neuroborreliosis are mainly unknown. Human Borrelia burgdorferi (Bb) infection is associated with Bb-specific secretion of interferon-gamma (IFN-gamma), which may be important for the elimination of Bb, but this may also cause tissue injury. In order to increase the understanding of the pathogenic mechanisms in chronic neuroborreliosis, we investigated which cell types that secrete IFN-gamma. Blood mononuclear cells from 13 patients with neuroborreliosis and/or acrodermatitis chronicum atrophicans were stimulated with Bb antigen and the phenotypes of the induced IFN-gamma-secreting cells were analyzed with three different approaches. Cells expressing CD8 or TCRgammadelta, which both have cytolytic properties, were the main phenotypes of IFN-gamma-secreting cells, indicating that tissue injury in chronic neuroborreliosis may be mediated by cytotoxic cells.

The urokinase receptor can be induced by Borrelia burgdorferi through receptors of the innate immune system

Monocytic cells exposed to Borrelia burgdorferi, through unknown receptors, overexpress the urokinase receptor (uPAR), a key mediator of the plasminogen activation system. We show that combined blockade of CD14 and TLR2 causes a significant inhibition of B. burgdorferi-induced uPAR in Mono Mac 6 (MM6) cells. Other pattern recognition receptors tested (CD11b/CD18, the mannose receptor, and the N-formyl-methionyl-leucyl-phenylalanine receptor) did not have demonstrated roles in B. burgdorferi-mediated uPAR induction. We dissected the result for CD14 andTLR2 by investigating the singular contributions of each. Independent functional blockade of CD14 or TLR2 failed to inhibit B. burgdorferi-mediated uPAR induction. 1,25-Dihydroxyvitamin D(3) differentiation of MM6 cells increased CD14 expression 12-fold but did not augment B. burgdorferi-mediated uPAR expression. Peritoneal exudate macrophages (PEM) from CD14- or TLR2-deficient mice were not defective in B. burgdorferi-mediated synthesis of uPAR mRNA and protein. Increased uPAR mRNA or protein or both were apparent in PEM from transgenic and control mice, even at a ratio of one Borrelia spirochete per cell. We conclude that signaling for the uPAR response, as mediated by B. burgdorferi, proceeds with CD14 and TLR2 as partial contributors. That part under control of CD14 and TLR2 represents a new link between the host plasminogen activation and innate immunity systems.

5-y Follow-up study of patients with neuroborreliosis

The objective of this follow-up study was to determine the long-term outcome of strictly classified cases of neuroborreliosis treated with antibiotics. A 1-y prospective population-based survey of Lyme borreliosis was conducted in southern Sweden between 1992 and 1993. A total of 349 identified cases with suspected neuroborreliosis were followed up 5 y later. Medical records were reviewed and all participants filled in a questionnaire. Of those patients classified with definite neuroborreliosis, 114/130 completed the follow-up, of whom 111 had completed the initial antibiotic treatment. Of the 114 patients followed up, 86 (75%) had recovered completely and 70 (61%) had recovered within 6 months. Residual neurological symptoms, such as facial palsy, concentration disorder, paresthesia and/or neuropathy, were reported by 28/114 patients. No significant differences between different antibiotic treatments were observed in terms of the occurrence of sequelae. To conclude, we found that 25% (95% confidence interval 17-33%) of the patients suffered from residual neurological symptoms 5 y post-treatment. However, the clinical outcome of treated neuroborreliosis is favorable as only 14/114 (12%) patients had sequelae that influenced their daily activities post-treatment. Early diagnosis and treatment would seem to be of great importance in order to avoid such sequelae.

Inflammation in the central nervous system: the role for dendritic cells

Dendritic cells (DCs) are a subclass of antigen-presenting cells critical in the initiation and regulation of adaptive immunity against pathogens and tumors, as well as in the triggering of autoimmunity. Recent studies have provided important knowledge regarding distribution of DCs in the central nervous system (CNS) and their role in intrathecal immune responses. DCs are present in normal meninges, choroid plexus, and cerebrospinal fluid, but absent from the normal brain parenchyma. Inflammation is accompanied by recruitment and/or development of DCs in the affected brain tissue. DCs present in different compartments of the CNS are likely to play a role in the defence against CNS infections, and also may contribute to relapses/chronicity of CNS inflammation and to break-down of tolerance to CNS autoantigens. CNS DCs can therefore be viewed as a future therapeutic target in chronic inflammatory diseases such as multiple sclerosis.

Antibodies and T-cell reactivity to Borrelia burgdorferi in an asymptomatic population: a study of healthy blood donors in an inland town district in the south-east of Sweden

To address the issue of whether Borrelia infection can be asymptomatic, blood donors with no history of borreliosis (n = 408) were screened for antibodies against Borrelia burgdorferi. Seropositive individuals (n = 17) were further investigated with respect to Borrelia-specific T-cell reactivity, using an interferon-gamma ELISPOT assay. Anti-Borrelia antibodies as well as Borrelia-specific T-cell responses were evident in 9 asymptomatic donors, strongly supporting a current or previous asymptomatic Borrelia infection.

Neurologic aspects of Lyme disease

Lyme disease has emerged as a major infection with frequent neurologic manifestations. These manifestations probably reflect several predominantly indirect pathogenetic mechanisms and involve host, vector, and organism factors. With early diagnosis and appropriate antibiotic treatment, patients do well. Because culture is not reliable, diagnosis has relied on positive serology to document exposure. Serology should improve as second-generation assays become available. Although there is a preventive vaccine based on the lipoprotein OspA, newer vaccines in development may prove more desirable. Lyme disease provides a valuable model to study how infectious pathogens cause neurologic disease.