Oligoclonal Borrelia burgdorferi-specific IgG antibodies in cerebrospinal fluid in Lyme neuroborreliosis

Neurofilament Light in Cerebrospinal Fluid is Associated With Disease Staging in European Lyme Neuroborreliosis

Background

Drivers of differences in disease presentation and symptom duration in Lyme neuroborreliosis (LNB) are currently unknown.

Objectives

We hypothesized that neurofilament light (NfL) in cerebrospinal fluid (CSF) would predict disease location and sequelae in a historic LNB cohort.

Design

Using a cross-sectional design and archived CSF samples from 185 patients diagnosed with LNB, we evaluated the content of NfL in the total cohort and in a subgroup of 84 patients with available clinical and paraclinical information.

Methods

Individuals were categorized according to disease location: a. Central nervous system (CNS) with stroke (N=3), b. CNS without stroke (N=11), c. Peripheral nervous system (PNS) with cranial nerve palsy (CNP) (N=40) d. PNS without CNP (N=30). Patients with hospital follow-up more than 6 months after completed antibiotic therapy were categorized as having LNB associated sequelae (N=15).

Results

At diagnosis concentration of NfL exceeded the upper reference level in 60% (105/185), especially among individuals above 30 years. Age-adjusted NfL was not found to be associated with symptom duration. Age-adjusted NfL was significantly higher among individuals with CNS involvement. Category a. (stroke) had significantly higher NfL concentrations in CSF compared to all other categories, category b. (CNS involvement without stroke) had significantly higher values compared to the categories of PNS involvement. We found no significant difference between the categories with PNS involvement (with or without CNP). Significantly higher NfL was found among patients with follow-up in hospital setting.

Conclusion

Comparison of NfL concentrations between the 4 groups of LNB disease manifestations based on clinical information revealed a hierarchy of neuron damage according to disease location and suggested evolving mechanisms with accelerated injury especially when disease is complicated by stroke. Higher values of NfL among patients with need of follow-up in hospital setting suggest NfL could be useful to identify rehabilitative needs.

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.

A case of chronic progressive lyme encephalitis as a manifestation of late lyme neuroborreliosis

A 54-year-old female living in Europe presented with gait ataxia, dizziness, and bilateral hearing loss. Magnetic resonance imaging (MRI) revealed non-specific white matter changes. The patient’s condition gradually deteriorated over two years without diagnosis. The patient continued to decline cognitively and neurologically with worsening ataxia and upper motor neuron signs. Repeat MRI showed worsening white matter changes. Lumbar puncture, not previously done, showed positive Lyme testing. Treatment with intravenous ceftriaxone resulted in marked neurological improvement. Four years after symptom, the patient has short-term memory deficits and chronic fatigue, but is otherwise neurologically, cognitively, and functionally intact. Follow up MRI findings remain largely unchanged. Because cases of intraparenchymal or encephalopathic neuroborreliosis in America are lacking, so are treatment options. We present a rare case and discuss our experience with antibiotic treatment. This case lends evidence to define optimal treatment of this disease, imperative for hastening neurological recovery.

Nervous system Lyme disease

Lyme disease, the multisystem infectious disease caused by the tick-borne spirochete Borrelia burgdorferi involves the nervous system in 10-15% of affected individuals. Manifestations include lymphocytic meningitis, cranial neuritis, radiculoneuritis, and mononeuropathy multiplex. Encephalopathy, identical to that seen in many systemic inflammatory diseases, can occur during active systemic infection. It is not specific to Lyme disease and only rarely is evidence of nervous system infection. Diagnosis of systemic disease is based on demonstration of specific antibodies in peripheral blood by means of two-tier testing with an ELISA and Western blot. Central nervous system infection often results in specific antibody production in the CSF, demonstrable by comparing spinal fluid to blood serologies. Treatment is straightforward and curative in most instances. Many patients can be treated effectively with oral antibiotics such as doxycycline; in severe CNS infection parenteral treatment with ceftriaxone or other similar agents is highly effective. Treatment should usually be for 2 to at most 4 weeks. Longer treatment adds no therapeutic benefit but does add substantial risk.

Diagnostic biomarkers in multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the CNS and comprises a heterogeneous spectrum of disease subtypes. The distinctive variability of clinical presentations, histopathologic and immunologic patterns, as well as neuroradiologic phenotypes in MS poses a diagnostic challenge to the attending physician and claims a more differentiated typing of MS patients by diagnostic biomarkers in order to anticipate the expected disease course and to stratify patients for specifically tailored therapies. In this paper, the major biomarkers presently recommended in the diagnosis of MS are reviewed, including magnetic resonance imaging, the analysis of cerebrospinal fluid parameters and the diagnostic relevance of antibodies to aquaporin-4 water channels and myelin antigens.

Lyme neuroborreliosis

Lyme neuroborreliosis (LNB) designates the nervous system disorders caused by the tick-borne spirochete Borrelia burgdorferi (Bb). The clinical syndromes are usually distinct and are classified as early and the rare late or chronic LNB. Early LNB occurs 3-6 weeks after infection most frequently as a lymphocytic meningoradiculoneuritis (LMR). Symptoms are mainly due to a painful sensory radiculitis and a multifocal motor radiculo-neuritis. Fifty percent have cranial nerve involvement predominantly uni- or bilateral facial nerve palsies. Meningitic symptoms occur primarily in children. Nerve biopsies, autopsies, animal models, and nerve conduction studies showed that the pathology is a lymphocytic perineuritis leading to multisegmental axonal injury of nerve roots, spinal ganglia, and distal nerve segments. Due to meningeal and root inflammation cerebrospinal fluid (CSF) shows lymphocytic inflammation. The only evidence that Bb causes peripheral neuropathy without CSF inflammation is seen in patients with acrodermatitis chronica atrophicans (ACA), a chronic dermatoborreliosis. In the rare chronic or late LNB the pathology and thus the clinical presentation is primarily due to chronic meningitis and meningovascular CNS involvement, whereas the peripheral nervous system is not primarily affected. In early and late LNB the diagnosis is based on a characteristic clinical appearance and CSF inflammation with Bb-specific intrathecal antibody production. Both conditions, but not the ACA-associated neuropathy, respond to antibiotic therapy.

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.

Can ELISPOT Be Applied to A Clinical Setting as A Diagnostic Utility for Neuroborreliosis?

The aim of this prospective study was to investigate the diagnostic performance of Borrelia (Bb)-induced interferon (IFN)-γ secretion detected by ELISPOT modified to be feasible for clinical laboratories as a supplementary test to the laboratory diagnosis of Lyme neuroborreliosis (LNB) in an endemic setting. Between 2002 and 2004, patients with symptoms of suspected clinical LNB were included in a study conducted on the Åland islands in the Finnish archipelago, which is a hyper-endemic area for Lyme borreliosis (LB). Fourteen patients with confirmed LNB and 103 patients with non-LNB were included, and the numbers of spontaneous and Bb-induced IFN-γ-secreting cells were assayed by the ELISPOT test. The ELISPOT assay showed a weak diagnostic performance with a sensitivity of 36% and a specificity of 82%. The findings in this study show that this ELISPOT-assay modified to be feasible in clinical routine laboratories is not useful as a supplementary diagnostic tool in the laboratory diagnosis of patients with clinically suspected LNB.

Varicella-zoster virus (VZV) glycoprotein E is a serological antigen for detection of intrathecal antibodies to VZV in central nervous system infections, without cross-reaction to herpes simplex virus 1

Herpes simplex virus 1 (HSV-1) and varicella-zoster virus (VZV) cause serious central nervous system (CNS) diseases that are diagnosed with PCR using samples of cerebrospinal fluid (CSF) and, during later stages of such infections, with assays of intrathecal IgG antibody production. However, serological diagnoses have been hampered by cross-reactions between HSV-1 and VZV IgG antibodies and are commonly reported in patients with herpes simplex encephalitis (HSE). In this study we have evaluated VZV glycoprotein E (gE) as a new antigen for serological diagnosis of VZV-induced CNS infections. Paired samples of CSF and serum from 29 patients with clinical diagnosis of VZV CNS infection (n = 15) or HSE (n = 14), all confirmed by PCR, were analyzed. VZV gE and whole VZV were compared as antigens in enzyme-linked immunosorbent assays (ELISAs) for serological assays in which the CSF/serum sample pairs were diluted to identical IgG concentrations. With the gE antigen, none of the HSE patients showed intrathecal IgG antibodies against VZV, compared to those shown by 11/14 patients using whole-VZV antigen (P < 0.001). In the patients with VZV infections, significantly higher CSF/serum optical density (OD) ratios were found in the VZV patients using the VZV gE antigen compared to those found using the whole-VZV antigen (P = 0.001). These results show that gE is a sensitive antigen for serological diagnosis of VZV infections in the CNS and that this antigen was devoid of cross-reactivity to HSV-1 IgG in patients with HSE. We therefore propose that VZV gE can be used for serological discrimination of CNS infections caused by VZV and HSV-1.

Biomarkers of inflammatory and auto-immune central nervous system disorders

PURPOSE OF REVIEW

Inflammatory and auto-immune disorders of the central nervous system are a heterogeneous group of disorders. Many of these disorders are potentially treatable with immune therapies that can reduce disability or prevent death. We review the clinical value of biomarkers which can aid in the diagnosis of paediatric inflammatory and auto-immune central nervous system (CNS) disorders.

RECENT FINDINGS

This review will first describe the clinical usefulness of nonspecific biomarkers of CNS inflammation such as cerebrospinal fluid neopterin and oligoclonal bands. Neopterin is produced by immune and neuronal cells after stimulation by interferon species and is increased in a broad range of inflammatory and auto-immune CNS disorders. Oligoclonal bands represent clonal production of immunoglobulin G in the CNS and are present in demyelinating, auto-immune, and infectious CNS disorders. In addition, we will review new advances in the immunogenetic investigation of familial auto-inflammatory disorders such as Aicardi-Goutières syndrome and Chronic Infantile Neurologic Cutaneous Articular syndrome. Finally, we will review the clinical utility of auto-antibodies in CNS disorders, with specific focus on auto-antibodies that bind to cell surface proteins such as N-methyl-D-asparate receptor, voltage-gated potassium channels, myelin oligodendrocyte glycoprotein, and aquaporin-4.

SUMMARY

These biomarkers are increasingly important in the recognition and treatment of inflammatory and auto-immune CNS disorders. Like many biomarkers in paediatric practice, it is essential to interpret the findings in the context of the patient history and examination.

Lyme optic neuritis

Lyme optic neuritis (ON) is a rare disease and only a few cases have been reported. We describe two cases of isolated Lyme ON, one with recurrence 9 months after the appearance of initial symptoms. Diagnosis criteria for multiple sclerosis and neuromyelitis optica were not met. The etiological diagnosis was based on European case definition criteria for neuroborreliosis. Both patients had positive serum and cerebrospinal fluid serology, a positive intrathecal anti-Borrelia antibody index, and a good outcome on ceftriaxone. Specific diagnosis of Lyme ON is important since improvement of visual acuity is possible with specific antibiotherapy, even after many months.

B cells and antibodies in MS

Increasing research activities on humoral immune responses involved in the immunopathogenesis of multiple sclerosis (MS) led to a revival of the importance of B cells and antibodies in MS. B cells seem now to play various immunopathogenetic roles in the initiation and propagation of inflammatory demyelinating processes at different disease stages of MS. The biological activities of antibodies in MS is, in general, still less known, although it emerges that antibodies are specifically involved in demyelination or, at least, mirror tissue destruction in the central nervous system. Finally, there is growing evidence that treatments, which specifically target B cells and/or antibodies, are effective in MS and its variants neuromyelitis optica (NMO). This chapter therefore aims to summarize the present knowledge and to outline future directions about the role of B cells and antibodies in research and therapy of MS and NMO.

Pathogen specificity and autoimmunity are distinct features of antigen-driven immune responses in neuroborreliosis

Neuroborreliosis (NB) is a chronic infectious disease of the central nervous system (CNS) caused by a tick-borne spirochete, Borrelia burgdorferi. In addition to direct effects of the causative infectious agent, additional immunity-mediated mechanisms are thought to play a role in the CNS pathology of NB. In order to further understand the involvement of humoral immune mechanisms in NB, we dissected the intrathecal antibody responses down to the single-plasma-cell level. Starting with single-cell reverse transcription-PCR of fluorescence-activated cell sorter-sorted cerebrospinal fluid plasma cells from an NB patient, we identified expanded clones and resurrected the antigen specificity of their secreted antibodies through recombinant expression of the correctly paired immunoglobulin heavy- and light-chain genes as monoclonal antibodies (MAbs). As expected, we found specificity for the causative infectious agent, B. burgdorferi, among the clonally expanded plasma cell (cePC)-derived MAbs. However, from an independent cePC of the same patient, we could derive MAbs specific for human CNS myelin, without detectable cross-reactivity with B. burgdorferi antigens. While reactivity against B. burgdorferi is a known feature of humoral immune responses in NB, we show (i) that immune responses specific for self antigens may be a distinct feature of CNS infections independent of pathogen reactivity and (ii) that humoral autoimmunity in NB (since found in cePC) is the result of a truly antigen-driven immune response. Our findings indicate that in NB mechanisms may be at play that induce distinct immune responses specific for pathogen and self antigens independent from "molecular mimicry."

Microbiological and serological diagnosis of Lyme borreliosis

In Europe, Lyme borreliosis is caused by Borrelia burgdorferi sensu stricto, B. afzelii, B. garinii and the recently described species B. spielmanii. For the development of diagnostic tools, the heterogeneity of the causative agents must be considered. The serological diagnosis should follow the principle of a two-step procedure: a sensitive enzyme-linked immunosorbent analysis as the first step, followed by immunoblot (IgM and IgG) if reactive. The sensitivity and standardization of immunoblots have been enhanced by the use of recombinant antigens instead of whole cell lysates. Improved sensitivity has resulted from the use of recombinant proteins primarily expressed in vivo (e.g. VlsE) and the combination of homologous proteins from different strains (e.g. DbpA). At present, detection rates for serum antibodies are 20-50% in localized, 70-90% in disseminated early and nearly 100% in late disease. Detection of the borreliae by culture or PCR should be confined to specific indications. The best results are obtained from skin biopsies (50-70% with culture or PCR) and synovial tissue or fluid (50-70% with PCR). Cerebrospinal fluid is positive in only 10-30%. Methods that are not recommended for diagnostic purposes include antigen tests in body fluids, PCR of urine and lymphocyte transformation tests.

Serologic proteome analysis of Borrelia burgdorferi membrane-associated proteins

Lyme disease, a global health concern, is caused by infection with Borrelia burgdorferi, B. afzelii, or B. garinii. The spirochete responsible for the disease in the United States is B. burgdorferi and is spread by the bite of an infected Ixodes tick. We utilized multiple two-dimensional gel techniques combined with proteomics to reveal the full humoral immune response of mice and Lyme patients to membrane-associated proteins isolated from Borrelia burgdorferi. Our studies indicated that a subset of immunogenic membrane-associated proteins (some new and some previously identified) was recognized by mice experimentally infected with Borrelia burgdorferi either by low-dose needle inoculation or by tick infestation. Moreover, the majority of these immunogenic membrane-associated proteins were recognized by sera from patients diagnosed with early-disseminated Lyme disease. These included RevA, ErpA, ErpP, DbpA, BmpA, FtsZ, ErpB, LA7, OppA I, OppA II, OppA IV, FlhF, BBA64, BBA66, and BB0323. Some immunogens (i.e., BBI36/38) were more reactive with sera from mice than Lyme patients, while additional membrane proteins (i.e., FlaB, P66, LA7, and Hsp90) were recognized more strongly with sera from patients diagnosed with early-localized, early-disseminated, or late (chronic)-stage Lyme disease. We were able to examine the humoral response in Lyme patients in a temporal fashion and to identify the majority of immunoreactive proteins as the disease progresses from early to late stages. This serologic proteome analysis enabled the identification of novel membrane-associated proteins that may serve as new diagnostic markers and, more importantly, as second-generation vaccine candidates for protection against Lyme disease.

Antibodies as biological markers for pathophysiological processes in MS

Multiple sclerosis (MS), the most important human inflammatory demyelinating disease of the central nervous system, is characterized by various clinical disease courses, inhomogeneous and unpredictable therapeutic effects, heterogenous genetic backgrounds and immunopathogenetic subtypes as demonstrated by neuropathology. Because of this heterogeneity of MS, a subtyping of our patients by genetical, clinical, neuroradiological, and neuroimmunological parameters will be necessary in the future. Therefore the importance of identifying biological markers for MS has evolved over the past years. Evidence for a possible role of antibodies as biological markers for MS comes from several studies indicating that intrathecal antibody production and the dominance of B cells are associated with a more progressive disease course. In this review we will give an overview on the current status and potential applicability of antibodies as biological markers for the diagnosis, classification, disease activity and prediction of clinical courses in MS. We will therefore summarize the findings on autoantibodies to myelin and nonmyelin antigens and on viral antigens in MS. We believe that antibodies serving as biomarkers will help to establish a differential therapeutic concept in MS, which will allow to treat individuals selectively according to their pathogenetic subtype and disease status.

Diagnostic utility of Borrelia burgdorferi cerebrospinal fluid polymerase chain reaction in children with Lyme meningitis

BACKGROUND

Cerebrospinal fluid (CSF) laboratory tests are frequently collected to help differentiate Lyme meningitis from other causes of aseptic meningitis. Previous studies using Lyme CSF polymerase chain reaction (PCR) have yielded varied results (sensitivity between 10 and 90%). No studies have specifically examined the diagnostic utility of Lyme CSF-PCR in North American children with Lyme meningitis.

METHODS

Retrospective chart review of children presenting to a children's hospital in a Lyme-endemic region between October 1999 and September 2004. Patients were included if they had both Lyme serology and Lyme CSF-PCR performed during the same hospital encounter and had documented meningitis. Patients were considered to have Lyme meningitis if they had meningitis and met CDC criteria for Lyme disease. The Lyme CSF-PCR assay amplified a Borrelia burgdorferi DNA flagellin gene sequence.

RESULTS

Of 108 patients with meningitis who qualified for the study, 20 patients met criteria for Lyme meningitis and 88 were classified as aseptic meningitis. Positive Lyme CSF-PCR was found in 1 patient (1 of 20, 5%) with Lyme meningitis and one patient classified as aseptic meningitis (1 of 88, 1%). Lyme CSF-PCR had a sensitivity of 5% and a specificity of 99%. The only Lyme meningitis patient with positive Lyme CSF-PCR had the highest CSF white blood cell count and CSF protein values compared with the other Lyme meningitis patients.

CONCLUSIONS

This is the first study to evaluate Lyme CSF-PCR exclusively in North American children. This commercially available laboratory test is not generally helpful for identifying Lyme meningitis because of its low sensitivity.

Research opportunities on human neuroborreliosis

A workshop, sponsored by the National Institutes of Health, was convened in September 2001 to evaluate the current knowledge in neurological Lyme disease. The meeting was centered into discussion of both clinical and basic aspects of the disease. Participants included researchers from the fields of infectious diseases, neurology, rheumatology, autoimmunity and basic immunology, largely but not exclusively focused on Lyme disease. This report summarizes the presentations made at the meeting.

Epidemiology and diagnosis of Lyme borreliosis

The multisystem disease Lyme borreliosis is the most frequent tick-transmitted disease in the northern hemisphere. In Europe Lyme borreliosis is most frequent in Central Europe and Scandinavia (up to 155 cases per 100,000 individuals) and is caused by the species, B. burgdorferi sensu stricto, B. afzelii and B. garinii. The recently detected genospecies A14S may also play a role in skin manifestations. Microbiological diagnosis in European patients must consider the heterogeneity of borreliae for development of diagnostic tools. According to guidelines of the USA and Germany, serological diagnosis should follow the principle of a two-step procedure (enzyme-linked immunosorbent assay (ELISA) as first step, if reactive; followed by immunoblot). The sensitivity and standardization of immunoblots has been considerably enhanced by use of recombinant antigens (p100, p58, p41i, VlsE, OspC, DbpA) including those expressed primarily in vivo (VlsE and DbpA) instead of whole cell lysates. VlsE is the most sensitive antigen for IgG antibody detection, OspC for IgM antibody detection. At present, detection rates for serum antibodies are 20%-50% in stage I, 70%-90% in stage II, and nearly 100% in stage III Lyme disease. Detection of the etiological agent by culture or polymerase chain reaction (PCR) should be confined to specific indications and specialized laboratories. Recommended specimens are skin biopsy specimens, cerebrospinal fluid (CSF) and synovial fluid. The best results are obtained from skin biopsies with culture or PCR (50%-70%) and synovial tissue or fluid (50%-70% with PCR). CSF yields positive results in only 10%-30% of patients except when the duration of symptoms is shorter than 2 weeks (50% sensitivity). Methods which are not recommended or adequately documented for diagnosis are antigen tests on body fluids, PCR of urine, and lymphocyte transformation tests.

Diagnosis of lyme borreliosis in europe

In Europe, Lyme borreliosis is caused by at least three species, B. burgdorferi sensu stricto, B. afzelii and B. garinii. Thus microbiological diagnosis in European patients must consider the heterogeneity of Lyme disease borreliae for development of diagnostic tools such as PCR primers and diagnostic antigens. According to guidelines of the German Society of Hygiene and Microbiology, the serological diagnosis should follow the principle of a two-step procedure. A sensitive ELISA differentiating IgM and IgG is recommended as the first step. In case the ELISA is reactive, it is followed by immunoblots (IgM and IgG) as the second step. The reactive diagnostic bands should be clearly identified, which is easy if recombinant antigens are used. The sensitivity and standardization of immunoblots has been considerably enhanced by use of recombinant antigens instead of whole cell lysates. Improved sensitivity resulted from use of recombinant proteins that are expressed primarily in vivo (e.g., VlsE) and combination of homologous proteins from different strains of borrelia (e.g., DbpA). It also appears promising to use recombinant proteins (DbpA, VlsE, others) or synthetic peptides (the conserved C6 peptide derived from VlsE) as ELISA antigens. At present, detection rates for serum antibodies are 20-50% in stage I, 70-90% in stage II, and nearly 100% in stage III Lyme disease. The main goals for the future are to improve specificity in general and sensitivity for diagnosis of early manifestations (stage I and II). Detection of the etiological agent by culture or PCR should be confined to specific indications and specialised laboratories. Recommended specimens are skin biopsy specimens, CSF and synovial fluid. The best results are obtained from skin biopsies with culture or PCR (50-70%) and synovial tissue or fluid (50-70% with PCR). CSF yields positive results in only 10-30% of patients. Methods that are not recommended for diagnostic purposes are antigen tests in body fluids, PCR of urine, and lymphocyte transformation tests.

Serum and cerebrospinal fluid pathology in patients with sudden sensorineural hearing loss

The serum and cerebrospinal fluid (CSF) pathology of patients with sudden sensorineural hearing loss (SHL), both seropositive and seronegative to Borrelia burgdorferi (Bb), was prospectively studied. Nineteen consecutive patients were included and trends between the degree of hearing recovery and serum/CSF pathology and given therapy were examined. The pilot study showed a high prevalence (68%) of pathology in serum and CSF in patients with SHL. In 54% of the patients, elevated levels of CSF proteins and/or pathological CSF cell counts were present without positive antibodies to Bb. Positive levels of antibodies against Bb or pathological proteins in CSF were associated with better hearing recovery (means of 47.2 and 51.7%, respectively). The audiometric configuration "high frequency sloping" hearing impairment was associated with the lowest degree of hearing recovery. Patients with SHL and positive serology to Bb who received antibiotic treatment (oral tetracycline), with or without steroids, had the best hearing recovery in this study (61.7 and 48.4%, respectively). In conclusion, we found a high prevalence of serum and CSF pathology in a consecutive group of patients with SHL. Early appropriate antibiotic treatment may prevent the development of major late complications of Lyme disease/borreliosis. We also find it justified to perform more general serological analyses, including CSF analysis, in patients with SHL. A more liberal approach to testing and development of test protocols for SHL patients will increase our knowledge in this field.

CSF oligoclonal bands in MS include antibodies against Chlamydophila antigens

BACKGROUND

Considerable evidence suggests the role of an infectious agent in MS. The presence of Chlamydophila pneumoniae in CSF from patients with MS was shown earlier; to further examine this association the reactivity of the oligoclonal antibody response in the CSF of patients with MS to C pneumoniae antigens was determined and compared with other antigens.

METHODS

Seventeen patients with MS and 14 control subjects with other neurologic disease were studied. Affinity-driven immunoblot studies and solid-phase adsorption of CSF oligoclonal bands by elementary body antigens of C pneumoniae, viral antigens (measles and herpes simplex virus-1), bacterial antigen (Escherichia coli and Staphylococcus aureus), and heat shock protein-60 were performed.

RESULTS

Affinity-driven immunoblot studies demonstrated reactivity of oligoclonal bands in CSF samples from 16 patients with MS against elementary body antigens of C pneumoniae. None of the control subjects showed a prominent reactivity to elementary body antigens of C pneumoniae. In 14 of 17 patients with MS examined, oligoclonal bands were adsorbed either partially or completely from the CSF by elementary body antigens of C pneumoniae, but not by myelin basic protein, heat shock protein-60, or bacterial or viral antigens. In three patients with subacute sclerosing panencephalitis, adsorption of oligoclonal bands was seen with measles virus antigens but not with elementary body antigens of C pneumoniae.

CONCLUSIONS

Oligoclonal bands in CSF of patients with MS include antibodies against Chlamydophila antigens.

Specific diagnostic methods for herpesvirus infections of the central nervous system: a consensus review by the European Union Concerted Action on Virus Meningitis and Encephalitis

BACKGROUND

Herpesvirus infections of the central nervous system are often severe but are fortunately rare. The incidence of these infections has however, increased in recent years as a consequence of an increase in the number of immune-compromised individuals. New diagnostic procedures have improved our ability to diagnose these infections and herpesviruses may yet be implicated as the cause of further neurological diseases with no known aetiology. Methodological standards for selection and evaluation of patient materials are essential to the provision of reliable diagnosis, yet few studies have addressed this important issue.

OBJECTIVES

To describe and define methodological standards and reference methodology for diagnosis of herpesvirus infections of the CNS.

STUDY DESIGN

Information gathered by literature review.

RESULTS

Only for herpes simplex encephalitis is there sufficient data to allow the definition of reference methodology. Good methodological standards exist but few studies have adhered to these standards. As methods for the detection of specific intrathecal antibody synthesis are well established yet under-used in diagnostic virology, the principle of these measurements is reviewed in some detail.

CONCLUSIONS

Herpesvirus infections of the CNS are of increasing importance. High quality, multi-centre studies are needed to establish the value of the new diagnostic test procedures if further improvement in the diagnostic sensitivity and specificity of these procedures is to be achieved.

Lyme neuroborreliosis

Neuroborreliosis, an infection of the nervous system caused by spirochetes of the genus Borrelia, has achieved worldwide attention in the last decade as part of the clinical spectrum of Lyme disease. This disorder, caused by Borrelia burgdorferi, has increased in incidence to become the most frequent arthropod-borne infection in North America and Europe. As a result of this rapid rise in incidence and of its protean neurological manifestations, this disease has created an important challenge to modern neurology. The diverse manifestations of neuroborreliosis require that it be included in the differential diagnosis of many neurological disorders. This review takes a chronological approach to clinical neuroborreliosis to summarize its most important aspects. The limitations as well as the benefits of laboratory diagnosis are also considered, with the aim of providing assistance in this area. Recent advances in neuroimmunology regarding the pathogenesis of neuroborreliosis that may elucidate its protean clinical spectrum are summarized.

Intrathecal immune response in patients with neuroborreliosis: specificity of antibodies for neuronal proteins

Cerebrospinal fluid (CSF) and serum samples of 47 patients with serologically proven neuroborreliosis were examined by Western blotting for antibodies to a crude extract of human cortex (CNS) comprising a multitude (> 40) of protein bands. Intrathecal synthesis of total immunoglobulins was determined by the Reiber formula and of autoantibodies to CNS proteins by enzyme-linked immunoassay (ELISA) and by Western blotting. Employing ELISA, intrathecal synthesis of autoantibodies (IgG, IgM and/or IgA) was demonstrated in 40 of 47 patients with neuroborreliosis (85%), in 5 of 40 with multiple sclerosis (12%), and in 22 of 40 with viral meningoencephalitis (55%). Of 40, 35 and 15 patients with neuroborreliosis and an intrathecal synthesis of total IgG, IgM or IgA, 20 revealed an intrathecal production of IgG antibodies (50%), 24 of IgM antibodies (68%) and 6 of IgA autoantiodies (40%) in the CSF. The specificity of autoantibodies differed greatly between most patients. Of 24 different CNS proteins which elicited an immune response in various patients, identities could be determined only for the myelin basic protein (5 of 40) and for the three neurofilament proteins (NF-68, NF-150, NF-200) (13 of 40 patients). In this limited number of patients no significant correlation between individual clinical symptoms and certain autoantiodies could be detected. The higher frequency of intrathecally produced autoantibodies in patients with neuroborreliosis is assumed to result from mitogenic rather than specific activation of autoreactive B-cell clones by Borrelia burgdorferi. The pathogenic relevance of these autoantibodies remains to be determined.

Intrathecal immune response in neuroborreliosis: importance of cross-reactive antibodies

The intrathecal IgG response to Borrelia burgdorferi was evaluated in 35 patients with neuroborreliosis (NB). Samples were tested with and without preabsorption with Treponema phagedenis. Specific antibody concentrations in the CSF and serum were determined by ELISA. The antibody index (AIBb = QBb/QIgG) was calculated from the ratio between the CSF/serum quotients for specific antibodies (QBb) and total IgG (QIgG). Intrathecal synthesis of B. burgdorferi antibodies was demonstrated in 31 samples before and in 24 samples after preabsorption with T. phagedenis. The clonal distribution of intrathecally produced IgG antibodies was determined by isoelectric focusing combined with affinity blotting. B. burgdorferi-specific oligoclonal IgG bands occurring predominantly in the CSF were demonstrated in 32/35 patients. In 29/32 samples, the major proportion of these bands also reacted with T. phagedenis. Preabsorption of samples with T. phagedenis removed a considerable share of bands reacting with B. burgdorferi. In patients with neurosyphilis, intrathecal synthesis of antibodies with specificity for B. burgdorferi was demonstrated in 7/10 samples before, and in no sample, after preabsorption of cross-reactive antibodies. Due to the lower sensitivity in determining the AIBb (-20%), preabsorption of cross-reactive antibodies cannot be generally recommended. In all patients with suspected neuroborreliosis, but uncommon neurological symptoms and missing anamnestic data concerning a tick bite or erythema migrans, neurosyphilis should be excluded by a negative TPHA test.

Comparison of two methods for detecting intrathecal synthesis of Borrelia burgdorferi-specific antibodies and PCR for diagnosis of Lyme neuroborreliosis

An indirect immunofluorescence assay (IFA), a commercial capture enzyme-linked immunosorbent assay (ELISA), and PCR were compared for the diagnosis of Lyme neuroborreliosis in 16 individuals. Borrelia burgdorferi-specific intrathecal immunoglobulin G was found in 10 of 16 patients by IFA and in 8 of 12 patients by capture ELISA. PCRs performed on cerebrospinal fluid samples stored at -70 degrees C were positive for one of eight children and one of four adults with intrathecal antibody production and negative for all four adults without intrathecal antibody production. For two children with facial palsy following erythema chronicum migrans, neither IFA nor capture ELISA detected specific intrathecal antibodies and PCR was also negative. We conclude that both clinical manifestations and laboratory parameters are important for the diagnosis of Lyme neuroborreliosis.

Intrathecal synthesis of specific antibodies in neuroborreliosis. Comparison of different ELISA techniques and calculation methods

The sensitivity of six different ELISA techniques and calculation methods for the determination of intrathecal synthesis of IgG antibodies specific to Borrelia burgdorferi was investigated in paired CSF and serum specimens from 33 patients with neuroborreliosis. The diagnostic value of the Antibody Index (AI) was compared with the meaningfulness of serum antibodies to B. burgdorferi (Bb), established by immunofluorescence assay (IFA). The AI, as a standard for intrathecal antibody synthesis was determined from specific antibody ratios (QBb) in the CSF and serum and the CSF/serum ratio of IgG (QIgG) or albumin (QAlb). Using Western blotting with identical concentrations of IgG in the CSF and serum all patients displayed intrathecal synthesis of specific antibodies to at least two B. burgdorferi proteins. The different ELISA methods and calculation procedures were almost equivalent in demonstrating intrathecal synthesis of specific antibodies (32 and 33/33). Calculation of AI from IFA titers was somewhat less sensitive (30/33). In 5 patients titers of serum IgG- and IgM-antibodies to B. burgdorferi determined by IFA were within the normal range or borderline, while elevated AIBb values indicated an autochthonous immune response to B. burgdorferi in the CSF. In uncertain cases of neuroborreliosis calculation of AI from ELISA titers will be useful in clarifying the diagnosis.

Intrathecal synthesis of anti-Borrelia burgdorferi antibodies in neuroborreliosis: a study with special emphasis on oligoclonal IgM antibody bands

Pre- and post-treatment (up to 3-26 months after antibiotic therapy) humoral immune responses were investigated in five neuroborreliosis patients. Anti-Borrelia (B.) burgdorferi IgG and IgM antibodies in CSF and serum were quantitated by capture ELISA. Agarose gel isoelectric focusing (AIF) and protein blotting were used to detect oligoclonal IgG and IgM bands as well as oligoclonal anti-B. burgdorferi IgG and IgM antibodies. These latter components were visualized by transfer to antigen-coated membranes (immunoblot) and immunoenzymatic staining. By ELISA, intrathecal anti-B. burgdorferi IgG and IgM antibody synthesis was detected in all initial specimens and continued 3-26 months after antibiotic therapy in four and three cases, respectively. AIF with protein blotting showed oligoclonal bands of total IgG as well as total IgM in the initial CSF specimens of all patients and persistence of such components occurred in four and five cases, respectively. By AIF and immunoblot, oligoclonal anti-B. burgdorferi IgG and IgM antibody bands could be detected in the CSF of every patient. IgG antibody bands were present in all initial CSF samples. The first specimen of one patient was negative for IgM antibody bands but such components appeared 3 weeks later. Oligoclonal CSF anti-B. burgdorferi IgG antibody components persisted over the entire follow-up periods in all but one case where they disappeared 6 weeks after treatment. The oligoclonal IgM antibodies in CSF vanished in two cases (after being present up to 4 and 11 months after antibiotic therapy) while they persisted over the entire (3-6 months after antibiotic therapy) follow-up periods in three cases. The specificity of the IgM antibody immunoblot technique was corroborated by control experiments, including antibody absorption studies and use of 41 kDa flagellar antigen.

Epidemiology and clinical manifestations of Lyme borreliosis in childhood. A prospective multicentre study with special regard to neuroborreliosis

Lyme borreliosis is a tick-borne infection caused by the spirochete Borrelia burgdorferi, whose discovery in 1982 solved an aetiological mystery involving a variety of dermatological and neurological disorders and explained their association with Lyme disease. Lyme borreliosis occurs frequently and is readily treatable with antibiotics. Along with its discovery, however, came the realization that it is difficult to diagnose accurately, especially antibody diagnosis. False-positive antibody results in particular led to gradual widening of the clinical spectrum, and differential diagnosis became increasingly difficult. This prospective, multicentre study presents a systematic description of Lyme borreliosis in childhood, emphasizing epidemiological and clinical issues. Because, predominantly, inpatients were examined, Lyme neuroborreliosis was the focus of the study, with the chief concern being to minimize false-positive results. To this end, we chose to narrow the diagnostic criteria, using the presence of specific antibodies in the cerebrospinal fluid as the determining factor. The epidemiological investigation was focused on the incidence of Lyme neuroborreliosis in childhood in southern Lower Saxony as well as on the prevalence of Lyme neuroborreliosis among acute-inflammatory neurological illnesses in children. The clinical part of the study aimed at establishing criteria for differential diagnosis in addition to the detection of specific antibodies. The detection of specific IgM antibodies using an IgM capture ELISA confirmed the presence of acute Lyme borreliosis. The study examined 208 children with Lyme borreliosis, of whom 169 had Lyme neuroborreliosis, from mid-1986 until the end of 1989. The yearly incidence of Lyme neuroborreliosis in Lower Saxony was 5.8 cases/100,000 children aged 1 to 13. The manifestation index was 0.16, or one case of Lyme neuroborreliosis per 620 infected children, compared with the presence of specific antibodies against B. burgdorferi for children in the same age group and region. Both the seasonal distribution of Lyme borreliosis, which peaked in summer and autumn, as well as the information about when the tick bites took place point to an incubation period of a few weeks. The most frequent manifestation of Lyme neuroborreliosis in childhood was acute peripheral facial palsy, found in 55% of all cases (n = 93). Lyme borreliosis proved to be the most frequently verifiable cause of acute peripheral facial palsy in children, causing every second case of this disorder in summer and autumn.(ABSTRACT TRUNCATED AT 400 WORDS)

Serologic response to the Borrelia burgdorferi flagellin demonstrates an epitope common to a neuroblastoma cell line

Antibodies in sera of 7 patients with neurologic manifestations of Lyme borreliosis and a monoclonal antibody (mAb H9724) to the flagellin of Borrelia burgdorferi have been shown to bind neural tissue. To identify the antibody binding site common to the B. burgdorferi flagellin and the neural tissue, we made recombinant fusion proteins expressing epitopes of flagellin. Antibodies in patients' sera and mAb H9724 bound within an 18-amino acid epitope (residues 208-225) in the central region of flagellin, whereas two other mAbs bound to epitopes mapping elsewhere in the protein. Antibodies in patients sera and mAb H9724 also bound to a human neuroblastoma cell line. Absorption of patients sera with a peptide, EGVQQEGAQQPA, corresponding to amino acids 213-224 of flagellin, inhibited binding to the neuroblastoma cell line. The data suggest that the immune response to a specific B-cell epitope within flagellin, shared by a human neuroblastoma cell line, may be involved in the pathogenesis of neuroborreliosis.

Detection of Borrelia burgdorferi DNA in urine samples and cerebrospinal fluid samples from patients with early and late Lyme neuroborreliosis by polymerase chain reaction

A polymerase chain reaction (PCR) was developed for use in the identification of a 248-bp fragment of the Borrelia burgdorferi flagellin gene in urine and cerebrospinal fluid (CSF) from patients with Lyme neuroborreliosis. The specificities of the PCR products were confirmed by DNA-DNA hybridization with an internal probe. The assay had a detection limit of 10 in vitro-cultivated B. burgdorferi. The PCR assay seemed to be species wide as well as species specific, since DNA from all 21 B. burgdorferi isolates from humans tested but not from Borrelia hermsii or Treponema pallidum could be amplified. We tested 10 consecutively diagnosed patients with untreated neuroborreliosis. There was lymphocytic pleocytosis and intrathecal B. burgdorferi-specific antibody synthesis in the CSF of all patients. Urine and CSF samples were investigated by PCR before, during, and up to 8.5 months after therapy. B. burgdorferi DNA was detected in urine samples from nine patients; five patients, including two patients with chronic neuroborreliosis, were PCR positive prior to treatment, whereas urine samples from the remaining four patients obtained 3 to 6 days after the onset of therapy became PCR positive. All urine samples obtained greater than 4 weeks after therapy were negative by PCR. PCR of CSF was less sensitive, and samples from only four patients, including one with chronic neuroborreliosis, were positive. We conclude that urine is a more suitable sample source than CSF for use in B. burgdorferi DNA detection by PCR. Normalization of inflammatory CSF changes and the negative PCR results during follow-up even in patients with chronic neuroborreliosis do not point to a persistent infection. The future role of PCR as a diagnostic tool for Lyme neuroborreliosis is still uncertain.

Immobilized pH gradient isoelectric focusing and immunoblotting for investigations of anti-Borrelia burgdorferi IgG antibodies

Anti-Borrelia burgdorferi immunoglobulin G (IgG) responses in cerebrospinal fluid, serum, and joint fluid from Lyme disease patients were investigated by immobilized pH gradient (IPG) isoelectric focusing (IEF) in pH 4-10 and pH 4-7 gels. After focusing, the anti-B.-burgdorferi antibodies were blotted by affinity-driven transfer to antigen-coated polyvinylidene difluoride membranes (immunoblot) and the IgG antibodies were immunoenzymatically stained. IPG-IEF gels gave an excellent resolution of IgG and the immunoblot proved advantageous for the detection of anti-B. burgdorferi IgG antibodies. These antibodies, as judged from the electromigration characteristics, were found to contain oligoclonal as well as polyclonal subpopulations. This latter group included IgG antibodies that were inadequately resolved when separated by conventional carrier ampholyte IEF.

Light chain distribution of anti-Borrelia burgdorferi IgG antibodies in Lyme arthritis

Joint fluid (JF) and serum IgG from eight Lyme arthritis patients was investigated by isoelectric focusing, blotting to membranes of uncoated nitrocellulose (NC) as well as Borrelia (B.) burgdorferi antigen-coated NC (immunoblot) and immunoezymatic staining for visualization of the IgG isotype and characterization of the kappa/lambda light chain distribution. Oligoclonal bands of total IgG occurred in JF as well as in serum (3 cases) or in JF only (1 case); IgG lambda components were present in all four subjects and IgG kappa in three. IgG (Fc frag) reactive but kappa/lambda light chain negative oligoclonal bands were present in JF of one further patient. Additional investigations supported the interpretation that these components were free gamma chains. Oligoclonal anti-B. burgdorferi IgG antibodies occurred in JF as well as in serum (6 cases) or in JF only (1 case). There were complete identities, as defined by isoelectric points and light chain types, between JF and serum antibodies in an individual patient while identities between oligoclonal bands of total IgG and anti-B. burgdorferi IgG were infrequent. Antibodies of IgG kappa identity were present in all seven patients and six of them also had IgG lambda antibodies. The antibody response was, therefore, by definition oligo- and not monoclonal in 6 out of 7 patients. Furthermore, the anti-B. burgdorferi antibodies of IgG kappa identity only that were present in one case did not exhibit any completely characteristic monoclonal microheterogeneity.

Acute and chronic neuroborreliosis with and without CNS involvement: a clinical, MRI, and HLA study of 27 cases

Of the 96 serologically confirmed neuroborreliosis cases seen in our clinic between 1983 and 1988, 11 patients had mild to moderate and 4 patients had serious cerebral and/or spinal cord symptoms. Nine of these 15 patients with CNS involvement exhibited a primary chronic course of the illness. After high-dose intravenous therapy with penicillin, doxycycline or cefotaxime, given mostly in combination with cortisone, gradual recovery occurred with normalization of CSF findings characteristic of neuroborreliosis, and normalization of significantly elevated Borrelia burgdorferi IgG antibody titres in CSF and serum. Brain MRI and CT showed evidence of or were suggestive of vascular involvement which correlated with clinical symptoms in 11 of the 15 patients with CNS involvement. Brain MRI changes that were similar but much slighter in number and intensity were seen in 5 of 12 neuroborreliosis patients without clinical signs of CNS involvement (lymphocytic meningoradiculitis; Bannwarth's syndrome). The frequencies of the HLA-DR7 (75%), HLA-B44 (50%) and HLA-A29 (33%) antigens in 12 neuroborreliosis patients with clinical symptoms of CNS involvement were significantly different from the frequencies in 12 neuroborreliosis patients without CNS involvement and in 100 control subjects. Diagnostic criteria of active neuroborreliosis are proposed.

Lyme neuroborreliosis: a new sensitive diagnostic assay for intrathecal synthesis of Borrelia burgdorferi--specific immunoglobulin G, A, and M

An antibody capture enzyme-linked immunosorbent assay was developed to measure directly intrathecal immunoglobulin (Ig) G, A, and M synthesis specific for Borrelia burgdorferi. Purified, biotin-avidin-peroxidase-labeled B. burgdorferi flagella was used as test antigen. Paired cerebrospinal fluid and serum specimens from 100 patients with clinically definite neuroborreliosis and 35 control subjects with neurological diseases were examined. Significant B. burgdorferi-specific intrathecal IgG, A, and M production was found in 89%, 65% and 67% of patients with neuroborreliosis. Local synthesis of specific IgA was only seen in patients with significant local IgG synthesis. Antibody production in cerebrospinal fluid began by 2 weeks after onset of neurological symptoms. At the end of the second week specific IgM, IgG, or both, was detected in 88% of the patients. Specific IgG synthesis was present in all patients by 6 weeks after onset. Specific local IgM synthesis usually disappeared by 3 to 6 months after therapy, whereas specific IgG synthesis persisted after recovery. Even in patients with a severely altered blood-brain barrier, the assay discriminated between intrathecal antibody synthesis and antibody leakage from serum. The assay makes diagnostic measurement of B. burgdorferi-specific intrathecal antibody synthesis reliable, rapid, and accessible as a routine serological test.

Anti-Borrelia burgdorferi antibody response over the course of Lyme neuroborreliosis

Characteristic findings on examination of cerebrospinal fluid (CSF) in Lyme neuroborreliosis include mononuclear pleocytosis, oligoclonal immunoglobulin G (IgG) bands, and evidence for local production of specific antibodies. We utilized an immunospot assay to detect cells secreting anti-Borrelia burgdorferi antibodies of different isotypes over the course of disease. Such cells were detected in CSF from 13 consecutive patients with neuroborreliosis examined before treatment. IgG antibody-secreting cells were present in high numbers (mean, 32 cells per 10(4) CSF cells), whereas IgA and IgM antibody-secreting cells were found less frequently and at lower numbers (mean, 5 and 6 cells per 10(4) CSF cells, respectively). Clinical improvement after penicillin treatment was paralleled by a rapid decline of antibody-secreting cells in CSF, but they were still detected, although at lower numbers, in 5 of 10 patients examined more than 6 months after treatment. This specific B-cell response persisted despite clinical improvement. Whether it reflects persistence of antigen is unsettled.

Lyme borreliosis: host responses to Borrelia burgdorferi

The chronic inflammatory condition that develops after infection by B. burgdorferi is a complex process resulting from host responses to a limited number of organisms. Amplification mechanisms driven by potent proinflammatory molecules, i.e., IL-1, may explain the vigorous response to a paucity of organisms. Spirochete dissemination to distant locations involves adherence to and penetration across endothelium and may be facilitated by host responses that increase vessel permeability. The apparent lack of tissue tropism in Lyme disease is reflected in the organism's ability to adhere to different eucaryotic cell types in vitro and the wide distribution of B. burgdorferi in various organs of infected humans and experimentally infected animals. While phagocytosis and complement activation have been observed in vitro, the specific immune response that develops in humans is inefficient in eradicating the organisms, which may possess some mechanism(s) to evade this response. There is significant evidence for host autoreactivity based on antigenic cross-reactivity between the 41-kDa flagellar subunit and stress proteins of the spirochetes and endogenous host cell components. Although the outer surface proteins appear to be suitable candidates as targets for vaccination in animal studies, fundamental differences in the immune response to spirochetal components may preclude their use in humans.