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

Antigenicity and immunogenicity of different morphological forms of Borrelia burgdorferi sensu lato spirochetes

Borrelia burgdorferi sensu lato is a species complex of pleomorphic spirochetes, including species that cause Lyme disease (LD) in humans. In addition to classic spiral forms, these bacteria are capable of creating morphological forms referred to as round bodies and aggregates. The subject of discussion is their possible contribution to the persistence of infection or post-infection symptoms in LD. This study investigates the immunological properties of these forms by monitoring reactivity with early (n = 30) and late stage (n = 30) LD patient sera and evaluating the immune response induced by vaccination of mice. In patient sera, we found a quantitative difference in reactivity with individual morphotypes, when aggregates were recognized most intensively, but the difference was statistically significant in only half of the tested strains. In post-vaccination mouse sera, we observed a statistically significant higher reactivity with antigens p83 and p25 (OspC) in mice vaccinated with aggregates compared to mice vaccinated with spiral forms. The importance of the particulate nature of the antigen for the induction of a Th1-directed response has also been demonstrated. In any of morphological forms, the possibility of inducing antibodies cross-reacting with human nuclear and myositis specific/associated autoantigens was not confirmed by vaccination of mice.

Lyme borreliosis diagnosis: state of the art of improvements and innovations

With almost 700 000 estimated cases each year in the United States and Europe, Lyme borreliosis (LB), also called Lyme disease, is the most common tick-borne illness in the world. Transmitted by ticks of the genus Ixodes and caused by bacteria Borrelia burgdorferi sensu lato, LB occurs with various symptoms, such as erythema migrans, which is characteristic, whereas others involve blurred clinical features such as fatigue, headaches, arthralgia, and myalgia. The diagnosis of Lyme borreliosis, based on a standard two-tiered serology, is the subject of many debates and controversies, since it relies on an indirect approach which suffers from a low sensitivity depending on the stage of the disease. Above all, early detection of the disease raises some issues. Inappropriate diagnosis of Lyme borreliosis leads to therapeutic wandering, inducing potential chronic infection with a strong antibody response that fails to clear the infection. Early and proper detection of Lyme disease is essential to propose an adequate treatment to patients and avoid the persistence of the pathogen. This review presents the available tests, with an emphasis on the improvements of the current diagnosis, the innovative methods and ideas which, ultimately, will allow more precise detection of LB.

Retrospective Evaluation of Various Serological Assays and Multiple Parameters for Optimal Diagnosis of Lyme Neuroborreliosis in a Routine Clinical Setting

Laboratory diagnosis of Lyme neuroborreliosis (LNB) is challenging, and validated diagnostic algorithms are lacking. Therefore, this retrospective cross-sectional study aimed to compare the diagnostic performance of seven commercial antibody assays for LNB diagnosis. Random forest (RF) modeling was conducted to investigate whether the diagnostic performance using the antibody assays could be improved by including several routine cerebrospinal fluid (CSF) parameters (i.e., leukocyte count, total protein, blood-CSF barrier functionality, and intrathecal total antibody synthesis), two-tier serology on serum, the CSF level of the B-cell chemokine (C-X-C motif) ligand 13 (CXCL13), and a Borrelia species PCR on CSF. In total, 156 patients were included who were classified as definite LNB (n = 10), possible LNB (n = 7), or non-LNB patient (n = 139) according to the criteria of the European Federation of Neurological Societies using a consensus strategy for intrathecal Borrelia-specific antibody synthesis. The seven antibody assays showed sensitivities ranging from 47.1% to 100% and specificities ranging from 95.7% to 100%. RF modeling demonstrated that the sensitivities of most antibody assays could be improved by including other parameters to the diagnostic repertoire for diagnosing LNB (range: 94.1% to 100%), although with slightly lower specificities (range: 92.8% to 96.4%). The most important parameters for LNB diagnosis are the detection of intrathecally produced Borrelia-specific antibodies, two-tier serology on serum, CSF-CXCL13, Reibergram classification, and pleocytosis. In conclusion, this study shows that LNB diagnosis is best supported using multiparameter analysis. Furthermore, a collaborative prospective study is proposed to investigate if a standardized diagnostic algorithm can be developed for improved LNB diagnosis. IMPORTANCE The diagnosis of LNB is established by clinical symptoms, pleocytosis, and proof of intrathecal synthesis of Borrelia-specific antibodies. Laboratory diagnosis of LNB is challenging, and validated diagnostic algorithms are lacking. Therefore, this retrospective cross-sectional study aimed to compare the diagnostic performance of seven commercial antibody assays for LNB diagnosis. Multiparameter analysis was conducted to investigate whether the diagnostic performance using the antibody assays could be improved by including several routine (CSF) parameters. The results of this study show that LNB diagnosis is best supported using the detection of intrathecally produced Borrelia-specific antibodies, two-tier serology on serum, CSF-CXCL13, Reibergram classification, and pleocytosis. Furthermore, we propose a collaborative prospective study to investigate the potential role of constructing a diagnostic algorithm using multiparameter analysis for improved LNB diagnosis.

Role of Peptides in Diagnostics

The specificity of a diagnostic assay depends upon the purity of the biomolecules used as a probe. To get specific and accurate information of a disease, the use of synthetic peptides in diagnostics have increased in the last few decades, because of their high purity profile and ability to get modified chemically. The discovered peptide probes are used either in imaging diagnostics or in non-imaging diagnostics. In non-imaging diagnostics, techniques such as Enzyme-Linked Immunosorbent Assay (ELISA), lateral flow devices (i.e., point-of-care testing), or microarray or LC-MS/MS are used for direct analysis of biofluids. Among all, peptide-based ELISA is considered to be the most preferred technology platform. Similarly, peptides can also be used as probes for imaging techniques, such as single-photon emission computed tomography (SPECT) and positron emission tomography (PET). The role of radiolabeled peptides, such as somatostatin receptors, interleukin 2 receptor, prostate specific membrane antigen, αβ3 integrin receptor, gastrin-releasing peptide, chemokine receptor 4, and urokinase-type plasminogen receptor, are well established tools for targeted molecular imaging ortumor receptor imaging. Low molecular weight peptides allow a rapid clearance from the blood and result in favorable target-to-non-target ratios. It also displays a good tissue penetration and non-immunogenicity. The only drawback of using peptides is their potential low metabolic stability. In this review article, we have discussed and evaluated the role of peptides in imaging and non-imaging diagnostics. The most popular non-imaging and imaging diagnostic platforms are discussed, categorized, and ranked, as per their scientific contribution on PUBMED. Moreover, the applicability of peptide-based diagnostics in deadly diseases, mainly COVID-19 and cancer, is also discussed in detail.

Acute facial nerve palsy in children in a Lyme disease-endemic area in the Netherlands

We assessed the prevalence of Lyme neuroborreliosis in children with acute facial nerve palsy in a Lyme-endemic region and patient characteristics associated with this. All children visiting one of three participating hospitals between January 2010 and December 2016 were included in the study. Of 104 children referred to the hospital with facial nerve palsy, 43% had Lyme neuroborreliosis and 57% idiopathic facial palsy. Characteristics significantly associated with Lyme neuroborreliosis were headache (55% versus 18%), meningeal irritation (21% versus 5%), presentation in summer months (69% versus 37%), and a previous tick bite (33% versus 7%).

Lyme borreliosis-from tick bite to diagnosis and treatment

Lyme borreliosis is caused by certain genospecies of the Borrelia burgdorferi sensu lato complex, which are transmitted by hard ticks of the genus Ixodes. The most common clinical manifestation is erythema migrans, an expanding skin redness that usually develops at the site of a tick bite and eventually resolves even without antibiotic treatment. The infecting pathogens can spread to other tissues and organs, resulting in manifestations that can involve the nervous system, joints, heart and skin. Fatal outcome is extremely rare and is due to severe heart involvement; fetal involvement is not reliably ascertained. Laboratory support-mainly by serology-is essential for diagnosis, except in the case of typical erythema migrans. Treatment is usually with antibiotics for 2 to 4 weeks; most patients recover uneventfully. There is no convincing evidence for antibiotic treatment longer than 4 weeks and there is no reliable evidence for survival of borreliae in adequately treated patients. European Lyme borreliosis is a frequent disease with increasing incidence. However, numerous scientifically questionable ideas on its clinical presentation, diagnosis and treatment may confuse physicians and lay people. Since diagnosis of Lyme borreliosis should be based on appropriate clinical signs, solid knowledge of clinical manifestations is essential.

Diagnostic Testing of Neurologic Infections

Neuroinfectious diseases continue to cause morbidity and mortality worldwide, with many emerging or reemerging infections resulting in neurologic sequelae. Careful clinical evaluation coupled with appropriate laboratory investigations still forms the bedrock for making the correct etiologic diagnosis and implementing appropriate management. The treating physician needs to understand the individual test characteristics of each of the many conventional candidate-based diagnostics: culture, pathogen-specific polymerase chain reaction, antigen, antibody tests, used to diagnose the whole array of neuroinvasive infections. In addition, there is a growing need for more comprehensive, agnostic testing modalities that can identify a diversity of infections with a single assay.

Case report: persistently seronegative neuroborreliosis in an immunocompromised patient

Background

Infection with Borrelia burgdorferi sensu lato complex (B. b. sl) spirochetes can cause Lyme borreliosis, manifesting as localized infection (e.g. erythema migrans) or disseminated disease (e.g. Lyme neuroborreliosis). Generally, patients with disseminated Lyme borreliosis will produce an antibody response several weeks post-infection. So far, no case of neuroborreliosis has been described with persistently negative serology one month after infection.

Case presentation

We present a patient with a history of Mantle cell lymphoma and treatment with R-CHOP (rituximab, doxorubicine, vincristine, cyclofosfamide, prednisone), with a meningo-encephalitis, who was treated for a suspected lymphoma relapse. However, no malignant cells or other signs of malignancy were found, and microbial tests did not reveal any clues, including Borrelia serology. He did not recall being bitten by ticks, and a Borrelia PCR on CSF was negative. After spontaneous improvement of symptoms, he was discharged without definite diagnosis. Several weeks later, he was readmitted with a relapse of symptoms of meningo-encephalitis. This time however, a Borrelia PCR on CSF was positive, confirmed by two independent laboratories, and the patient received ceftriaxone upon which he partially recovered. Interestingly, during the diagnostic process of this exceptionally difficult case, a variety of different serological assays for Borrelia antibodies remained negative. Only P41 (flagellin) IgG was detected by blot and the Liaison IgG became equivocal 2 months after initial testing.

Conclusions

To the best of our knowledge this is the first case of neuroborreliosis that is seronegative on repeated sera and multiple test modalities. This unique case demonstrates the difficulty to diagnose neuroborreliosis in severely immunocompromised patients. In this case, a delay in diagnosis was caused by broad differential diagnosis, an absent known history of tick bites, negative serology and the low sensitivity of PCR on CSF. Therefore, awareness of the diagnostic limitations to detect Borrelia infection in this specific patient category is warranted.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3273-8) contains supplementary material, which is available to authorized users.

Lyme borreliosis

Lyme borreliosis is a tick-borne disease that predominantly occurs in temperate regions of the northern hemisphere and is primarily caused by the bacterium Borrelia burgdorferi in North America and Borrelia afzelii or Borrelia garinii in Europe and Asia. Infection usually begins with an expanding skin lesion, known as erythema migrans (referred to as stage 1), which, if untreated, can be followed by early disseminated infection, particularly neurological abnormalities (stage 2), and by late infection, especially arthritis in North America or acrodermatitis chronica atrophicans in Europe (stage 3). However, the disease can present with any of these manifestations. During infection, the bacteria migrate through the host tissues, adhere to certain cells and can evade immune clearance. Yet, these organisms are eventually killed by both innate and adaptive immune responses and most inflammatory manifestations of the infection resolve. Except for patients with erythema migrans, Lyme borreliosis is diagnosed based on a characteristic clinical constellation of signs and symptoms with serological confirmation of infection. All manifestations of the infection can usually be treated with appropriate antibiotic regimens, but the disease can be followed by post-infectious sequelae in some patients. Prevention of Lyme borreliosis primarily involves the avoidance of tick bites by personal protective measures.

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

Background

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.

Methods

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.

Results

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.

Conclusions

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 practice.

Laboratory diagnosis of Lyme disease: advances and challenges

The majority of laboratory tests performed for the diagnosis of Lyme disease are based on detection of the antibody responses against B burgdorferi in serum. The sensitivity of antibody-based tests increases with the duration of the infection. Patients early in their illness are more likely to have a negative result. There is a need to simplify the testing algorithm for Lyme disease, improving sensitivity in early disease while still maintaining high specificity and providing information about the stage of infection. The development of a point of care assay and biomarkers for active infection would be major advances for the field.

CXCL13 and neopterin concentrations in cerebrospinal fluid of patients with Lyme neuroborreliosis and other diseases that cause neuroinflammation

BACKGROUND

Laboratory diagnosis of Lyme neuroborreliosis (LNB) is partly based on the detection of intrathecal Borrelia burgdorferi-specific antibody production (increased antibody index (AI)). However, AI can be negative in patients with early LNB and, conversely, can remain elevated for months after antibiotic treatment. Recent studies suggested that the chemokine CXCL13 in the cerebrospinal fluid (CSF) is a biomarker for active LNB. Also, CSF neopterin-level determination has been used to assess the degree of neuroinflammation in a wide variety of diseases.

METHODS

CXCL13 concentrations were analyzed in CSF samples of 366 retrospectively identified individuals. The samples represented pretreatment LNB (38 patients), non-LNB comparison patients, tick-borne encephalitis, central nervous system (CNS) varicella zoster virus infection, CNS herpes simplex virus infection, CNS HHV6 infection, CNS enterovirus infection, and untreated neurosyphilis. The panel included also samples from patients with multiple sclerosis and other neuroinflammatory conditions. Of the LNB patients, 24 posttreatment CSF samples were available for CXCL13 analysis. Neopterin concentrations were determined in a subset of these samples.

RESULTS

The CXCL13 concentrations in CSF samples of untreated LNB patients were significantly higher (median, 6,480 pg/ml) than the concentrations in the non-LNB group (median, <7.8 pg/ml), viral CNS infection samples (median, <7.8 pg/ml), or samples from patients with noninfectious neuroinflammatory conditions (median, <7.8 pg/ml). The use of cut-off 415 pg/ml led to a sensitivity of 100% and specificity of 99.7% for the diagnosis of LNB in these samples. CSF CXCL13 median concentrations declined significantly from 16,770 pg/ml before to 109 pg/ml after the treatment.CSF neopterin concentration was significantly higher among the untreated LNB patients than in the non-LNB group. The use of neopterin concentration 10.6 nM as the cut-off led to a sensitivity of 88.6% and a specificity of 65.0% for the diagnosis of LNB. The CSF neopterin concentrations decreased statistically significantly with the treatment.

CONCLUSIONS

These results clearly indicate that highly elevated CSF CXCL13 levels are strongly associated with untreated LNB. CXCL13 outperformed neopterin and appears to be an excellent biomarker in differentiating LNB from viral CNS infections and from other neuroinflammatory conditions.

Gender disparity between cutaneous and non-cutaneous manifestations of Lyme borreliosis

Cutaneous manifestations of Lyme borreliosis in Europe include erythema migrans (EM) and acrodermatitis chronica atrophicans (ACA); the most common non-cutaneous manifestations are Lyme neuroborreliosis (LNB) and Lyme arthritis. The purpose of this study was to evaluate the gender distribution of patients with these clinical manifestations of Lyme borreliosis. Data on gender were obtained from the clinical records of patients with Lyme borreliosis aged ≥15 years who had been evaluated at the University Medical Center Ljubljana, Ljubljana, Slovenia. Among 10,539 patients diagnosed with EM, 6,245 (59.3%) were female and among 506 ACA patients 347 (68.6%) were female. In contrast, among the 60 patients with Lyme arthritis only 15 (25%) were female (p<0.0001 for the comparison of gender with EM or ACA) and among the 130 patients with LNB only 51 (39.2%) were females (p<0.0001for the comparison of gender with EM or ACA). Although the proportion that was female in the LNB group was greater than that of patients with Lyme arthritis, this difference did not reach statistical significance (p = 0.10). Although older individuals are more likely to be female in the general Slovenian population, the age of patients with cutaneous versus non-cutaneous manifestations was not the explanation for the observed differences in gender. In conclusion, patients with cutaneous manifestations of Lyme borreliosis were predominantly female, whereas those with non-cutaneous manifestations were predominantly male. This provocative finding is unexplained but may have direct relevance to the pathogenesis of Lyme borreliosis.

Serodiagnosis of Lyme borreliosis with bead based immunoassays using multiplex technology

The serological diagnosis of Lyme borreliosis is accomplished by the detection of IgG and IgM antibodies specific for relevant antigens of the spirochetal pathogen Borrelia burgdorferi. Instead of the usual enzyme immune assay for screening and the Western blot technique for confirmation, bead based multiplex assays with multiple simultaneously performed distinct reactions can provide quick, automatically derived and reliable results in a single run by flow cytometer technology. The broad analytical dynamic range of assay signals and the high sensitivity and specificity of the multiplex formats allow even for a reliable use in CSF based analyses for antibody specificity index in supposed neuroborreliosis. Fluorescence intensity of the bead based reactions can be transformed into quantified values as U/ml, either for each single antigen or summed up for a group of relevant key antigens. Additionally or alternatively distinct reactions of single bead populations can be transformed to Western blot band equivalents. Internal and external quality controls with the multiplex systems show characteristic data equivalent to the conventional assay formats, so that the advantages of the multiplex assays are ready for use in the routine diagnostic laboratory.