The recomBead Borrelia antibody index, CXCL13 and total IgM index for laboratory diagnosis of Lyme neuroborreliosis in children

Cerebrospinal fluid CXCL13 in non-borrelial central nervous system infections: contribution of CXCL13 to the differential diagnosis

BACKGROUND

The chemokine CXCL13 in cerebrospinal fluid (CSF) is used as a diagnostic marker of Lyme neuroborreliosis (LNB). However, the elevated levels in other non-borrelial CNS infections and the lack of a clearly defined cut-off value are limitations of the test.

METHODS

In our prospective study, we evaluated CSF CXCL13 levels in patients with LNB (47 patients), tick-borne encephalitis (TBE; 46 patients), enteroviral CNS infections (EV; 45 patients), herpetic CNS infections (HV; 23 patients), neurosyphilis (NS; 11 patients) and controls (46 patients). The correlation of CXCL13 with CSF mononuclears was determined in all groups.

RESULTS

Median CXCL13 was significantly higher in LNB group; however, the cut-off value of 162 pg/mL was also exceeded in 22% of TBE patients, 2% EV patients, 44% HV patients and in 55% patients with NS. Sensitivity and specificity were 0.83 and 0.78, respectively, with a Youden index of 0.62. CXCL13 was significantly correlated with CSF mononuclears (p = .0024), but the type of infectious agent had a greater influence on CXCL13 levels.

CONCLUSIONS

Increased CXCL13 levels are useful for LNB diagnostics, but other non-purulent CNS infections causes should be considered if intrathecal synthesis of borrelia specific antibodies is not confirmed or clinical manifestations are atypical.

CXCL13-CXCR5 axis: Regulation in inflammatory diseases and cancer

Chemokine C-X-C motif ligand 13 (CXCL13), originally identified as a B-cell chemokine, plays an important role in the immune system. The interaction between CXCL13 and its receptor, the G-protein coupled receptor (GPCR) CXCR5, builds a signaling network that regulates not only normal organisms but also the development of many diseases. However, the precise action mechanism remains unclear. In this review, we discussed the functional mechanisms of the CXCL13-CXCR5 axis under normal conditions, with special focus on its association with diseases. For certain refractory diseases, we emphasize the diagnostic and therapeutic role of CXCL13-CXCR5 axis.

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.

Brain damage markers neuron-specific enolase (NSE) and S100B in serum in children with Lyme neuroborreliosis-detection and evaluation as prognostic biomarkers for clinical outcome

Lyme borreliosis (LB) is the most common tick-borne infection in Europe, with Lyme neuroborreliosis (LNB) its second most frequent clinical manifestation. Prognostic factors for clinical outcomes in LNB have not been identified. Elevated serum levels of the brain damage markers neuron-specific enolase (NSE) and S100 calcium-binding protein B (S100B) have been associated with poor clinical outcomes in other disorders of the central nervous system. The aim of this study is to assess NSE and S100B in serum as prognostic biomarkers for clinical outcomes in paediatric LNB patients. Children evaluated for LNB (n = 121) in Sweden were prospectively included during 2010–2014, serum samples were collected on admission, and all children underwent a 2-month follow-up. Patients with pleocytosis and anti-Borrelia antibodies in cerebrospinal fluid (CSF) were classified as having LNB (n = 61). Controls were age- and gender-matched non-LNB patients (n = 60). NSE was elevated in 38/61 (62%) LNB patients and in 31/60 (52%) controls. S100B was elevated in 3/60 (5%) LNB patients and 0/59 (0%) controls. NSE and S100B concentrations did not differ significantly when comparing LNB patients with controls. No differences were found in the concentrations when comparing the clinical recovery of LNB patients at the 2-month follow-up. NSE was detectable in the majority of LNB patients and controls, whereas S100B was detectable in only a few LNB patients and no controls. NSE and S100B in serum cannot be recommended as prognostic biomarkers for clinical outcomes in children with LNB.

Unique Clinical, Immune, and Genetic Signature in Patients with Borrelial Meningoradiculoneuritis1

This form of Lyme neuroborreliosis is a distinct clinical entity with specific signs and symptoms.

Lyme neuroborreliosis (LNB) in Europe may manifest with painful meningoradiculoneuritis (also known as Bannwarth syndrome) or lymphocytic meningitis with or without cranial neuritis (peripheral facial palsy). We assessed host immune responses and the prevalence of TLR1 (toll-like receptor 1)–1805GG polymorphism to gain insights into the pathophysiology of these conditions. Regardless of LNB manifestation, most mediators associated with innate and adaptive immune responses were concentrated in cerebrospinal fluid; serum levels were unremarkable. When stratified by specific clinical manifestation, patients with meningoradiculoneuritis had higher levels of B-cell chemoattractants CXC motif chemokine ligand (CXCL) 12 and CXCL13 and T-cell–associated mediators CXCL9, CXCL10, and interleukin 17, compared with those without radicular pain. Moreover, these patients had a higher frequency of TLR1–1805GG polymorphism and more constitutional symptoms. These findings demonstrate that meningoradiculoneuritis is a distinct clinical entity with unique immune and genetic pathophysiology, providing new considerations for the study of LNB and borrelial meningoradiculitis.

CXCL13 in laboratory diagnosis of Lyme neuroborreliosis-the performance of the recomBead and ReaScan CXCL13 assays in human cerebrospinal fluid samples

The chemokine CXCL13 is used as complement to serology in the diagnostics of Lyme neuroborreliosis (LNB). We evaluated and compared the semi-quantitative, cassette-based ReaScan CXCL13 assay with the quantitative recomBead CXCL13 assay using a collection of 209 cerebrospinal fluid samples. The categorical agreement between results interpreted as negative, grey zone, and positive by the two methods was 87%. The diagnostic sensitivity was higher using the recomBead assay, whereas specificity was higher using ReaScan. Few manual steps, and a short turn-around time with no batching of samples makes the ReaScan CXCL13 assay an attractive complement to serology in the diagnostics of LNB.

Comparison of the Euroimmun Borrelia 'antibody index' with Virotech immunoblot-based detection of intrathecal Borrelia antibody production for the diagnosis of Lyme neuroborreliosis

For diagnosis of neuroborreliosis, calculation of the antibody index, based on Euroimmun Anti-Borrelia plus VlsE ELISA was compared to Virotech Borrelia Europe plus TpN17 immunoblot-based detection of Borrelia-specific intrathecal antibody production. CXCL13 results in cerebrospinal fluid were used to evaluate discordant results. A total of 64 serum/CSF pairs were analysed. Patients were classified according to European Federation of Neurological Societies criteria incorporating Virotech results. For the Euroimmun assay, a sensitivity of 100% and specificity of 94% was found. Agreement between the both tests was almost perfect (κ 0.81). Both methods are appropriate for the detection of Borrelia-specific intrathecal antibody production.

Lyme neuroborreliosis in Swedish children-PCR as a complementary diagnostic method for detection of Borrelia burgdorferi sensu lato in cerebrospinal fluid

The aim of this study was to evaluate polymerase chain reaction (PCR) as a diagnostic method for the detection of Borrelia burgdorferi s.l. in CSF of Swedish children with LNB. This study was performed retrospectively on CSF and serum samples collected from children evaluated for LNB (n = 233) and controls with other specific neurological disorders (n = 59) in a Swedish Lyme endemic area. For anti-Borrelia antibody index, the IDEIA Lyme Neuroborreliosis kit (Oxoid) was used. Two in-house real-time PCR assays targeting the 16S rRNA gene were evaluated (TaqMan® and LUX™). Among patients classified as LNB cases (n = 102), five children (5%) were Borrelia PCR-positive in CSF with the TaqMan® assay. In the Non-LNB group (n = 131), one patient was Borrelia PCR positive with the TaqMan® assay. Among controls (n = 59), all CSF samples were PCR negative. When amplifying and sequencing ospA, we found B. garinii (n = 2), B. afzelii (n = 2), B. bavariensis (n = 1), and one untypable (n = 1). With the LUX™ technology, all CSF samples were PCR negative. The TaqMan® assay could detect only few cases (n = 6) of B. burgdorferi s.l. in CSF among children with LNB and the sensitivity was very low (5%). However, using larger CSF volumes and centrifugation of samples, the PCR technique could still be useful as a complementary diagnostic method when evaluating LNB. Furthermore, detection of spirochete DNA in clinical matrices, including CSF, is the method of choice for studying epidemiological aspects of LNB, a tick-borne emerging disease.

Diagnostic performance of cerebrospinal fluid free light chains in Lyme neuroborreliosis - a pilot study

Background The aim of this study was to evaluate the diagnostic performance of cerebrospinal fluid (CSF) free light chains (FLCs) in the diagnosis of Lyme neuroborreliosis (LNB). Methods Serum and CSF levels of κ- and λ-FLC, albumin and total concentration of immunoglobulin M (IgM) were determined together with CSF chemokine CXCL13 in 23 patients with definite LNB, 35 inflammatory neurological disease control (INDC) and 18 non-inflammatory control (NIC) patients. Indices and intrathecal fractions (IFs) of FLC and IgM were calculated. Results Significant differences in FLC indices and IFs were found between the LNB group and both control groups, p ≤ 0.007. Sensitivity of intrathecal κ- and λ-FLC synthesis reached 78%-87% in LNB patients with a specificity of 94%-100% in NIC patients, whereas specificity in INDC patients was 69%. The corresponding frequencies of positive results for IF and index of IgM and CSF CXCL13 in these three diagnostic groups were 74%-96% in LNB patients, 0% in NIC patients and 3%-6% in INDC patients at the chosen cut-off levels. Conclusions The findings of this study show a moderate to high sensitivity of CSF κ- and λ-FLC in LNB patients with a high specificity in NIC patients. However, overlap in CSF κ- and λ-FLC levels between LNB and INDC patients calls for caution in the interpretation and limits the diagnostic usefulness in the LNB diagnosis. CSF CXCL13 appears to be the most valuable additional biomarker of LNB aside from routine parameters such as CSF pleocytosis and anti-Borrelia antibody index.

Lyme neuroborreliosis

PURPOSE OF REVIEW

To review the recent evidence clarifying the symptomatology and diagnosis of nervous system Lyme disease.

RECENT FINDINGS

Two-tier testing combining pairs of ELISAs, using C6 or VlsE assays to replace second tier Western blots, may eliminate confusion about test interpretation. Cerebrospinal fluid (CSF) can be informative in diagnosing central nervous system (CNS) Lyme disease, not peripheral nervous system (PNS) disorders. CSF CXCL13 may provide useful adjunctive information in CNS infection; its specificity remains to be defined. Lyme encephalopathy is not indicative of CNS infection. Post treatment Lyme disease symptoms do not occur in patients who have had definite CNS Lyme infection. Whether post treatment Lyme disease symptom (PTLDS) is an actual entity, or reflects anchoring bias when commonly occurring symptoms arise in patients previously treated for Lyme disease, remains to be determined. Regardless, these symptoms do not reflect CNS infection and do not respond to additional antimicrobial therapy.

SUMMARY

Serologic testing is robust in individuals with a priori likelihood of infection of greater than 2-6 weeks duration. Western blots provide useful confirmation of screening ELISAs, but may be replaced by second ELISAs. CSF testing, including CXCL13, may be informative in CNS Lyme, not PNS, and is generally normal in Lyme encephalopathy. PTLDS does not occur following CNS infection, and may not be a distinct entity.

The potential for CXCL13 in CSF as a differential diagnostic tool in central nervous system infection

Introduction: Central nervous system (CNS) infections can be life-threatening and are often associated with disabling sequelae. One important factor in most CNS infections is a timely pathogen-specific treatment. The diagnostic methods available, however, do not always reach a satisfying sensitivity and specificity. In these cases, there is need for additional diagnostic biomarkers. Chemokines represent potential candidates as biomarkers, since they are an important pillar of the host immune response. The aim of this review is to discuss the diagnostic potential of cerebrospinal fluid (CSF) CXCL13 in patients with CNS infections. Areas covered: Data were obtained from a literature search in PubMed up to October 2019. This review focusses on articles on the potential of CXCL13 as a diagnostic tool. The majority of identified studies aimed to characterize its role in two diseases, namely Lyme neuroborreliosis and neurosyphilis. Expert opinion: CSF CXCL13 has a significant potential as a diagnostic and monitoring add-on marker in Lyme neuroborreliosis. Differences in study design, control groups and clinical parameters between studies, however, affect sensitivity, specificity and cutoff values, underlining the need of further studies to address these issues and pave the way for a generalized clinical practice.

Chemokine Ligand 13 (CXCL13) in Neuroborreliosis and Neurosyphilis as Selected Spirochetal Neurological Diseases: A Review of Its Diagnostic Significance

Neuroborreliosis (NB) and neurosyphilis (NS) are abnormal conditions caused by spirochetal bacteria which affect the nervous system. Diagnosis of neuroborreliosis and neurosyphilis is determined by clinical examination of visible symptoms, serum and cerebrospinal fluid (CSF) analysis, and serological detection of antibodies against Borrelia burgdorferi sensu lato and Treponema pallidum, respectively. Establishing a diagnosis may sometimes pose a number of diagnostic difficulties. A potential role of chemokine ligand 13 (CXCL13) as an accurate diagnostic biomarker of intrathecal inflammation has been suggested. In this review, we focused on changes in serum and cerebrospinal fluid concentration of chemokine ligand 13 in selected spirochetal neurological diseases neuroborreliosis and neurosyphilis reported in the available literature. We performed an extensive search of the literature relevant to our investigation via the MEDLINE/PubMed database. It has been proven that CXCL13 determination can provide rapid information regarding central nervous system inflammation in patients with selected spirochetosis. We described that neuroborreliosis and neurosyphilis are associated with an elevated CXCL13 concentration, mainly in the cerebrospinal fluid. Moreover, literature data suggest that CXCL13 determination is the most interesting additional marker for diagnosis and monitoring of neuroborreliosis and neurosyphilis thanks to its high sensitivity. Based on these published findings, we suggest that CXCL13 has high diagnostic utility and may be applied in laboratory diagnostics as a potential diagnostic marker in human spirochetal neurologic diseases.

Modified interpretation criteria significantly improve performance of commercially available confirmatory assays for the serodiagnosis of Lyme borreliosis: a case-control study with clinically defined serum samples

Case-control study for the evaluation of innovative test formats for second-tier testing for the serodiagnosis of Lyme borreliosis (LB). A head-to-head comparison was performed with the test systems ViraStripe, SeraSpot, ViraChip, and recomBead. Serum samples from 62 patients (21 erythema migrans, 33 Lyme neuroborreliosis, 8 late LB) and 91 controls (including 29 potentially cross-reacting sera) were tested. For ViraChip and recomBead, optimised interpretation criteria were developed for both IgG and IgM. The most important modification for the proposed interpretation criteria for ViraChip is the interpretation of strong (> 2.5-fold above cutoff) singular IgG reactions against VlsE as positive. This significantly improves sensitivity (32 to 85%, p < 0.0001) without significant changes in specificity (borderline reactions interpreted as negative). By application of our modified rules, specificity of ViraChip IgM is significantly increased (89 to 97%, p < 0.05; borderline results included to negatives), and sensitivities of recomBead IgG and IgM are also significantly improved (69 to 87%, p < 0.01, and 57 to 74%, p < 0.01, respectively; borderline results included to positives). Further improvement of sensitivity by the rating of strong singular IgG reactions against VlsE as positive can also be shown for recomBead. IgG/IgM result combinations must be interpreted as a function of the assumed disease stage, and the best combinations differ for the various assays. Application of our proposed interpretation criteria significantly improve the discriminatory abilities of two assays; however, this must be confirmed with other data sets. Recommendations from Scientific Societies should be updated as may be necessary.

The chemokine CXCL13 in cerebrospinal fluid in children with Lyme neuroborreliosis

Anti-Borrelia antibodies in the cerebrospinal fluid (CSF) are required for definite diagnosis of Lyme neuroborreliosis (LNB). However, children often present with early LNB, and antibody production in the CSF may not be demonstrated. Recent studies have suggested the chemokine CXCL13 to be an early marker for LNB. The aim of the study was to evaluate CXCL13 for laboratory diagnosis in pediatric LNB patients and to evaluate the association with pleocytosis in CSF, clinical features, and recovery. CSF samples were collected from LNB patients, classified as definite LNB (n = 44) or possible LNB (n = 22), and controls classified as non-LNB (n = 102) or other specific diagnoses (n = 23). CSF samples were analyzed with the recomBead CXCL13 assay (Mikrogen Diagnostik, Germany), cut-off 160 pg/mL. CXCL13 was significantly higher in LNB patients compared to controls (p < 0.001). Among LNB patients, 58/66 had elevated CXCL13, and among controls, 111/125 had CXCL13 levels under cut-off (sensitivity 88%, specificity 89%). In LNB patients with pleocytosis but no detectable anti-Borrelia antibodies in CSF (possible LNB), CXCL13 was elevated in 16/22 (73%). A weak correlation between CXCL13 and pleocytosis in CSF was found in LNB patients (Rho = 0.46, p < 0.01), but no differences in CXCL13 levels in relation to specific clinical features. In conclusion, CXCL13 is elevated in CSF in children with LNB, showing acceptable sensitivity and specificity. In patients with possible LNB, CXCL13 was elevated in a majority of cases (73%) and is suggested as a complementary diagnostic tool in pediatric LNB patients. CXCL13 was not associated with specific clinical features or recovery.