Host-pathogen interactions in Lyme disease and their application in diagnostics

B. burgdorferi has a wide variety of strategies to hide from the host immune system. Complement regulatory binding proteins have been described for almost all complement resistant B. burgdorferi sl, except for the complement resistant B. bavariensis, one of the species that is known to frequently cause Lyme neuroborreliosis. In chapter 2 it is attempted to identify CRASP-1 proteins in B. bavariensis, formerly known as B. garinii OspA serotype 4. Potential CRASP-1 proteins will be cloned and studied for their ability to interact with host derived fluid phase regulators of complement. The specific role of complement resistance in early effective infection and dissemination of B. burgdorferi sl has not been well investigated. Can complement resistance lead to a better and more effective infection and dissemination? In chapter 3 an in vivo experiment in which the infectivity and dissemination patterns of complement sensitive and complement resistant B. burgdorferi sl in a C3 deficient mouse model is described. After effective transmission from the tick to the host the next challenge in B. burgdorferi infection is rapid and accurate detection of the pathogen. Diagnostics of Lyme disease is often compromised due to specific pathogen properties combined with technical shortcomings of bacterial serology. Two indirect detection methods which can aid in diagnosing patients suffering from Lyme neuroborreliosis were studied. In chapter 4 the performance of the C6-peptide ELISA for detecting antibodies in CSF in Lyme neuroborreliosis patients is studied. While in chapter 5 levels of CXCL13 in several patient populations as a potential biomarker for the diagnosis of Lyme neuroborreliosis is studied. For both indirect markers of presence of B. burgdorferi the specificity in clinically resembling and neuroinfectious diseases is of key importance. Several other infectious and inflammatory diseases that have a clinical presentation that can resemble Lyme disease are included in the analysis. Diagnosing Lyme disease can be difficult in some populations, first because Lyme disease is a relatively rare infection, resembling a large spectrum of other autoimmune and inflammatory diseases. Clinicians could often consider testing for Lyme disease. It is also important to do this in specific preselected populations, because the positive predictive value of a test, but specifically indirect tests such as serology, in a random population, is low.In chapter 6 all patients that present with complaints of arthritis at the early arthritis clinic are tested for Lyme arthritis. The prevalence of B. burgdorferi seropositivity in this population is studied. Another aim is to identify clinical factors which should urge the doctor to test, or explicitely not test, for Lyme disease in a patient presenting with arthritis in Europe. In chapter 7 a case of an HIV positive patient presenting with a meningoencephalitis caused by B. burgdorferi is described. The literature on HIV and Lyme neuroborreliosis co-infections is also reviewed

Identification and functional characterisation of Complement Regulator Acquiring Surface Protein-1 of serum resistant Borrelia garinii OspA serotype 4

Background: B. burgdorferi sensu lato (sl) is the etiological agent of Lyme borreliosis in humans. Spirochetes have adapted themselves to the human immune system in many distinct ways. One important immune escape mechanism for evading complement activation is the binding of complement regulators Factor H (CFH) or Factor H-like protein1 (FHL-1) to Complement Regulator-Acquiring Surface Proteins (CRASPs). Results: We demonstrate that B. garinii OspA serotype 4 (ST4) PBi resist complement-mediated killing by binding of FHL-1. To identify the primary ligands of FHL-1 four CspA orthologs from B. garinii ST4 PBi were cloned and tested for binding to human CFH and FHL-1. Orthologs BGA66 and BGA71 were found to be able to bind both complement regulators but with different intensities. In addition, all CspA orthologs were tested for binding to mammalian and avian CFH. Distinct orthologs were able to bind to CFH of different animal origins. Conclusions: B. garinii ST4 PBi is able to evade complement killing and it can bind FHL-1 to membrane expressed proteins. Recombinant proteins BGA66 can bind FHL-1 and human CFH, while BGA71 can bind only FHL-1. All recombinant CspA orthologs from B. garinii ST4 PBi can bind CFH from different animal origins. This partly explains the wide variety of animals that can be infected by B. garinii.Medical Microbiolog

Identification and functional characterisation of Complement Regulator Acquiring Surface Protein-1 of serum resistant Borrelia garinii OspA serotype 4

Background: B. burgdorferi sensu lato (sl) is the etiological agent of Lyme borreliosis in humans. Spirochetes have adapted themselves to the human immune system in many distinct ways. One important immune escape mechanism for evading complement activation is the binding of complement regulators Factor H (CFH) or Factor H-like protein1 (FHL-1) to Complement Regulator-Acquiring Surface Proteins (CRASPs). Results: We demonstrate that B. garinii OspA serotype 4 (ST4) PBi resist complement-mediated killing by binding of FHL-1. To identify the primary ligands of FHL-1 four CspA orthologs from B. garinii ST4 PBi were cloned and tested for binding to human CFH and FHL-1. Orthologs BGA66 and BGA71 were found to be able to bind both complement regulators but with different intensities. In addition, all CspA orthologs were tested for binding to mammalian and avian CFH. Distinct orthologs were able to bind to CFH of different animal origins. Conclusions: B. garinii ST4 PBi is able to evade complement killing and it can bind FHL-1 to membrane expressed proteins. Recombinant proteins BGA66 can bind FHL-1 and human CFH, while BGA71 can bind only FHL-1. All recombinant CspA orthologs from B. garinii ST4 PBi can bind CFH from different animal origins. This partly explains the wide variety of animals that can be infected by B. garinii

The impact of an infectious disease expert team on outpatient parenteral antimicrobial treatment in the Netherlands

Immunogenetics and cellular immunology of bacterial infectious disease

Prevalence and Clinical Presentation Of Lyme Arthritis In a Large Cohort Of Patients With Recent-Onset Arthritis

Pathophysiology and treatment of rheumatic disease

A Dutch nationwide evaluation of serological assays for detection of Borrelia antibodies in clinically well-defined patients

Numerous tests for the detection of antibodies against Borrelia burgdorferi are commercially available. Manufacturer-derived data invariably report a high sensitivity and specificity, but comparative studies demonstrate large differences in clinical practice, especially with regard to specificity. We retrospectively collected data from validation studies for B. burgdorferi antibody assays from 8 laboratories in the Netherlands. The total number of samples was 809. Samples were selected based on clinical and laboratory parameters. We included samples from patients with erythema migrans, acrodermatitis chronicum atrophicans, and neuroborreliosis; cross-reactivity controls; and healthy controls. Data are presented from 10 enzyme-linked immunosorbent assays and 5 immunoblots. For manifestations of B. burgdorferi infection with short disease duration, the positivity rate of the assays varied significantly. In patients with long disease duration, the positivity rate differed only marginally. In cross-reactivity controls, there was significant variation in the reactivity rate. The majority of false-positive reactions are of the IgM isotype. © 2015 Elsevier Inc.

Acute liver failure, multiorgan failure, cerebral oedema, and activation of proangiogenic and antiangiogenic factors in a case of Marburg haemorrhagic fever

Molecular basis of virus replication, viral pathogenesis and antiviral strategie

High sensitivity and specificity of the C6-peptide ELISA on cerebrospinal fluid in Lyme neuroborreliosis patients

Lyme neuroborreliosis (LNB) is a serious but treatable disease. The diagnosis of LNB poses a challenge to clinicians, and improved tests are needed. The C6-peptide ELISA is frequently used on serum but not on cerebrospinal fluid (CSF). Data on the sensitivity of the C6-peptide ELISA in CSF in patients suffering from LNB have been conflicting. Serum-CSF pairs from 59 LNB patients, 36 Lyme non-neuroborreliosis cases, 69 infectious meningitis/encephalitis controls and 74 neurological controls were tested in a C6-peptide ELISA. With the optimal cut-off of 1.1, the sensitivity of the C6-peptide ELISA for LNB patients in CSF was 95%, and the specificity was 83% in the Lyme non-neuroborreliosis patients, 96% in the infectious controls, and 97% in the neurological controls. These results suggest that the C6-peptide ELISA has a high sensitivity and good specificity for the diagnosis of LNB patients in CSF. The C6-peptide ELISA can be used on CSF in a clinical setting to screen for LNB.Medical Microbiolog

The diagnostic accuracy of serological tests for Lyme borreliosis in Europe: a systematic review and meta-analysis.

Interpretation of serological assays in Lyme borreliosis requires an understanding of the clinical indications and the limitations of the currently available tests. We therefore systematically reviewed the accuracy of serological tests for the diagnosis of Lyme borreliosis in Europe. We searched EMBASE en MEDLINE and contacted experts. Studies evaluating the diagnostic accuracy of serological assays for Lyme borreliosis in Europe were eligible. Study selection and data-extraction were done by two authors independently. We assessed study quality using the QUADAS-2 checklist. We used a hierarchical summary ROC meta-regression method for the meta-analyses. Potential sources of heterogeneity were test-type, commercial or in-house, Ig-type, antigen type and study quality. These were added as covariates to the model, to assess their effect on test accuracy. Seventy-eight studies evaluating an Enzyme-Linked ImmunoSorbent assay (ELISA) or an immunoblot assay against a reference standard of clinical criteria were included. None of the studies had low risk of bias for all QUADAS-2 domains. Sensitivity was highly heterogeneous, with summary estimates: erythema migrans 50% (95% CI 40% to 61%); neuroborreliosis 77% (95% CI 67% to 85%); acrodermatitis chronica atrophicans 97% (95% CI 94% to 99%); unspecified Lyme borreliosis 73% (95% CI 53% to 87%). Specificity was around 95% in studies with healthy controls, but around 80% in cross-sectional studies. Two-tiered algorithms or antibody indices did not outperform single test approaches. The observed heterogeneity and risk of bias complicate the extrapolation of our results to clinical practice. The usefulness of the serological tests for Lyme disease depends on the pre-test probability and subsequent predictive values in the setting where the tests are being used. Future diagnostic accuracy studies should be prospectively planned cross-sectional studies, done in settings where the test will be used in practic