Validation of cellular tests for Lyme borreliosis (VICTORY) study

Evaluation and 1-year follow-up of patients presenting at a Lyme borreliosis expertise centre: a prospective cohort study with validated questionnaires

OBJECTIVES

To describe the course of symptoms reported by patients with symptoms attributed to Lyme borreliosis (LB) without being subsequently diagnosed with LB.

METHODS

We performed a prospective cohort study with patients presenting at the outpatient clinic of two clinical LB centres. The primary outcome was the prevalence of persistent symptoms, which were defined as clinically relevant fatigue (CIS, subscale fatigue), pain (SF-36, subscale bodily pain), and cognitive impairment (CFQ) for ≥ 6 months and onset < 6 months over the first year of follow-up. Outcomes were compared with a longitudinal cohort of confirmed LB patients and a general population cohort. Prevalences were standardised to the distribution of pre-defined confounders in the confirmed LB cohort.

RESULTS

Participants (n = 123) reported mostly fatigue, arthralgia, myalgia, and paraesthesia as symptoms. The primary outcome could be determined for 74.8% (92/123) of participants. The standardised prevalence of persistent symptoms in our participants was 58.6%, which was higher than in patients with confirmed LB at baseline (27.2%, p < 0.0001) and the population cohort (21.2%, p < 0.0001). Participants reported overall improvement of fatigue (p < 0.0001) and pain (p < 0.0001) but not for cognitive impairment (p = 0.062) during the follow-up, though symptom severity at the end of follow-up remained greater compared to confirmed LB patients (various comparisons p < 0.05).

CONCLUSION

Patients with symptoms attributed to LB who present at clinical LB centres without physician-confirmed LB more often report persistent symptoms and report more severe symptoms compared to confirmed LB patients and a population cohort.

Genome-wide analyses in Lyme borreliosis: identification of a genetic variant associated with disease susceptibility and its immunological implications

BACKGROUND

Genetic variation underly inter-individual variation in host immune responses to infectious diseases, and may affect susceptibility or the course of signs and symptoms.

METHODS

We performed genome-wide association studies in a prospective cohort of 1138 patients with physician-confirmed Lyme borreliosis (LB), the most common tick-borne disease in the Northern hemisphere caused by the bacterium Borrelia burgdorferi sensu lato. Genome-wide variants in LB patients-divided into a discovery and validation cohort-were compared to two healthy cohorts. Additionally, ex vivo monocyte-derived cytokine responses of peripheral blood mononuclear cells to several stimuli including Borrelia burgdorferi were performed in both LB patient and healthy control samples, as were stimulation experiments using mechanistic/mammalian target of rapamycin (mTOR) inhibitors. In addition, for LB patients, anti-Borrelia antibody responses were measured. Finally, in a subset of LB patients, gene expression was analysed using RNA-sequencing data from the ex vivo stimulation experiments.

RESULTS

We identified a previously unknown genetic variant, rs1061632, that was associated with enhanced LB susceptibility. This polymorphism was an eQTL for KCTD20 and ETV7 genes, and its major risk allele was associated with upregulation of the mTOR pathway and cytokine responses, and lower anti-Borrelia antibody production. In addition, we replicated the recently reported SCGB1D2 locus that was suggested to have a protective effect on B. burgdorferi infection, and associated this locus with higher Borrelia burgdorferi antibody indexes and lower IL-10 responses.

CONCLUSIONS

Susceptibility for LB was associated with higher anti-inflammatory responses and reduced anti-Borrelia antibody production, which in turn may negatively impact bacterial clearance. These findings provide important insights into the immunogenetic susceptibility for LB and may guide future studies on development of preventive or therapeutic measures.

TRIAL REGISTRATION

The LymeProspect study was registered with the International Clinical Trials Registry Platform (NTR4998, registration date 2015-02-13).

Touching Base with Some Mediterranean Diseases of Interest from Paradigmatic Cases at the "Magna Graecia" University Unit of Infectious Diseases: A Didascalic Review

Among infectious diseases, zoonoses are increasing in importance worldwide, especially in the Mediterranean region. We report herein some clinical cases from a third-level hospital in Calabria region (Southern Italy) and provide a narrative review of the most relevant features of these diseases from epidemiological and clinical perspectives. Further, the pathogenic mechanisms involved in zoonotic diseases are reviewed, focusing on the mechanisms used by pathogens to elude the immune system of the host. These topics are of particular concern for individuals with primary or acquired immunodeficiency (e.g., people living with HIV, transplant recipients, patients taking immunosuppressive drugs). From the present review, it appears that diagnostic innovations and the availability of more accurate methods, together with better monitoring of the incidence and prevalence of these infections, are urgently needed to improve interventions for better preparedness and response.

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.

Classical Borrelia Serology Does Not Aid in the Diagnosis of Persistent Symptoms Attributed to Lyme Borreliosis: A Retrospective Cohort Study

OBJECTIVE

The diagnosis of Lyme borreliosis is based on two-tier testing using an ELISA and Western blot. About 5-10% of patients report persistent symptoms of unknown etiology after treatment, resulting in substantial difficulties in further diagnostic workup. This paper presents a study aimed at determining whether serology can differentiate between patients with persistent symptoms attributed to Lyme and other patients with Lyme borreliosis.

METHODS

A retrospective cohort study included 162 samples from four subgroups: patients with persistent symptoms of Lyme (PSL), early Lyme borreliosis with erythema migrans (EM), patients tested in a general practitioner setting (GP), and healthy controls (HC). ELISA, Western blots, and multiplex assays from different manufacturers were used to determine inter-test variations in PSL and to compare reactivity against Borrelia-specific antigens among the groups.

RESULTS

In comparing the IgG and IgM reactivity by Western blot, IgG was more often positive in the PSL group than in the GP group. The individual antigen reactivity was similar between the PSL and EM or GP groups. Inter-test agreement among the manufacturers was variable, and agreement was higher for IgG testing compared to IgM.

CONCLUSIONS

Serological testing is unable to define the subgroup of patients with persistent symptoms attributed to Lyme borreliosis. Additionally, the current two-tier testing protocol shows a large variance among different manufacturers in these patients.

Diagnostic parameters of cellular tests for Lyme borreliosis in Europe (VICTORY study): a case-control study

BACKGROUND

Cellular tests for Lyme borreliosis might be able to overcome major shortcomings of serological testing, such as its low sensitivity in early stages of infection. Therefore, we aimed to assess the sensitivity and specificity of three cellular tests.

METHODS

This was a nationwide, prospective, multiple-gate case-control study done in the Netherlands. Patients with physician-confirmed Lyme borreliosis, either early localised or disseminated, were consecutively included as cases at the start of antibiotic treatment. Controls were those without Lyme borreliosis from the general population (healthy controls) and those with potentially cross-reactive conditions (eg, autoimmune disease). We used three cellular tests for Lyme borreliosis (Spirofind Revised, iSpot Lyme, and LTT-MELISA) as index tests, and standard two-tier serological testing (STTT) as a comparator. Clinical data from Lyme borreliosis patients were collected at baseline and at 12 weeks after inclusion, and blood samples were obtained at baseline, 6 weeks, and 12 weeks. Control participants underwent clinical and laboratory assessments at baseline only.

FINDINGS

Cases comprised 271 patients with Lyme borreliosis (of whom 245 had early-localised Lyme borreliosis and 26 had disseminated disease) and controls comprised 228 participants without Lyme borreliosis from the general population and 41 participants with potentially cross-reactive conditions. Recruitment occurred between May 14, 2018, and March 16, 2020. The specificity of STTT in healthy controls (216 of 228 samples [94·7%, 95% CI 91·5-97·7]) was higher than that of the cellular tests: Spirofind (140 of 171 [81·9%, 76·1-87·2]), iSpot Lyme (32 of 103 [31·1%, 21·5-40·3]) and LTT-MELISA (100 of 190 [52·6%, 44·9-60·3]). Cellular tests had varying sensitivities: Spirofind (88 of 204 [43·1%, 36·4-50·4]), iSpot Lyme (51 of 94 [54·3%, 44·5-63·7]), and LTT-MELISA (66 of 218 [30·3%, 23·8-36·7]). The Spirofind and iSpot Lyme outperformed STTT for sensitivity, but were similar to the C6-ELISA (C6-ELISA: 135 of 270 [50·0%, 44·5-55·5]; STTT: 76 of 270 [28·1%, 23·0-33·6]).

INTERPRETATION

The cellular tests for Lyme borreliosis used in this study have a low specificity compared with serological tests, which leads to a high number of false-positive test results. We conclude that these cellular tests are unfit for clinical use at this stage.

FUNDING

Netherlands Organization for Health Research and Development, AMC Foundation (Amsterdam UMC), and Ministry of Health of the Netherlands.

Identifying platelet-derived factors as amplifiers of B. burgdorferi-induced cytokine production

Previous studies have shown that monocytes can be 'trained' or tolerized by certain stimuli to respond stronger or weaker to a secondary stimulation. Rewiring of glucose metabolism was found to be important in inducing this phenotype. As we previously found that Borrelia burgdorferi (B. burgdorferi), the causative agent of Lyme borreliosis (LB), alters glucose metabolism in monocytes, we hypothesized that this may also induce long-term changes in innate immune responses. We found that exposure to B. burgdorferi decreased cytokine production in response to the TLR4-ligand lipopolysaccharide (LPS). In addition, B. burgdorferi exposure decreased baseline levels of glycolysis, as assessed by lactate production. Using GWAS analysis, we identified a gene, microfibril-associated protein 3-like (MFAP3L) as a factor influencing lactate production after B. burgdorferi exposure. Validation experiments proved that MFAP3L affects lactate- and cytokine production following B. burgdorferi stimulation. This is mediated by functions of MFAP3L, which includes activating ERK2 and through activation of platelet degranulation. Moreover, we showed that platelets and platelet-derived factors play important roles in B. burgdorferi-induced cytokine production. Certain platelet-derived factors, such chemokine C-X-C motif ligand 7 (CXCL7) and (C-C motif) ligand 5 (CCL5), were elevated in the circulation of LB patients in comparison to healthy individuals.

Borrelia burgdorferi is a poor inducer of interferon-gamma: amplification induced by interleukin-12

Background Laboratory diagnosis of Lyme borreliosis (LB) is mainly based on serology, which has limitations, particularly in the early stages of the disease. In recent years there have been conflicting reports concerning a new diagnostic tool using the cytokine interferon-gamma (IFN-γ). Previous studies have generally found low concentrations of IFN-γ in early LB infection. The goal of this study is to investigate IFN-γ regulation during early LB and provide insights into the host response to B. burgdorferi. Methods We performed in vitro experiments with whole blood assays and peripheral blood mononuclear cells (PBMCs) of LB patients and healthy volunteers exposed to B. burgdorferi and evaluated the IFN-γ response using ELISA and related interindividual variation in IFN-γ production to the presence of single nucleotide polymorphisms. Results IFN-γ production of B. burgdorferi-exposed PBMCs and whole blood was amplified by the addition of IL-12 to the stimulation system. This effect was observed after 24 hours of B. burgdorferi stimulation in both healthy individuals and LB patients. The effect was highly variable between individuals, but was significantly higher in LB patients six weeks since the start of antibiotic treatment compared to healthy individuals. IL-12 p40 and IL-18 mRNA was upregulated upon exposure to B. burgdorferi, whereas IL-12 p35 and IFN-γ mRNA expression remained relatively unchanged. SNP Rs280520 in the downstream IL-12 pathway, Tyrosine Kinase 2, was associated with increased IFN-γ production. Conclusions This study shows that IL-12 evokes an IFN-γ response in B. burgdorferi exposed cells, and LB patients and healthy controls respond differently to this stimulation.

Ticking on Pandora's box: a prospective case-control study into 'other' tick-borne diseases

BACKGROUND

Tick-borne pathogens other than Borrelia burgdorferi sensu lato - the causative agent of Lyme borreliosis - are common in Ixodes ricinus ticks. How often these pathogens cause human disease is unknown. In addition, diagnostic tools to identify such diseases are lacking or reserved to research laboratories. To elucidate their prevalence and disease burden, the study 'Ticking on Pandora's Box' has been initiated, a collaborative effort between Amsterdam University Medical Center and the National Institute for Public Health and the Environment.

METHODS

The study investigates how often the tick-borne pathogens Anaplasma phagocytophilum, Babesia species, Borrelia miyamotoi, Neoehrlichia mikurensis, spotted fever group Rickettsia species and/or tick-borne encephalitis virus cause an acute febrile illness after tick-bite. We aim to determine the impact and severity of these tick-borne diseases in the Netherlands by measuring their prevalence and describing their clinical picture and course of disease. The study is designed as a prospective case-control study. We aim to include 150 cases - individuals clinically suspected of a tick-borne disease - and 3 matched healthy control groups of 200 persons each. The controls consist respectively of a group of individuals with either a tick-bite without complaints, the general population and of healthy blood donors. During a one-year follow-up we will acquire blood, urine and skin biopsy samples and ticks at baseline, 4 and 12 weeks. Additionally, participants answer modified versions of validated questionnaires to assess self-reported symptoms, among which the SF-36, on a 3 monthly basis.

DISCUSSION

This article describes the background and design of the study protocol of 'Ticking on Pandora's Box'. With our study we hope to provide insight into the prevalence, clinical presentation and disease burden of the tick-borne diseases anaplasmosis, babesiosis, B. miyamotoi disease, neoehrlichiosis, rickettsiosis and tick-borne encephalitis and to assist in test development as well as provide recommendations for national guidelines.

TRIAL REGISTRATION

NL9258 (retrospectively registered at Netherlands Trial Register, trialregister.nl in in February 2021).

Comparative Cost and Effectiveness of a New Algorithm for Early Lyme Disease Diagnosis: Evaluation in US, Germany, and Italy

Purpose

This Lyme disease early detection economic model, for patients with suspected Lyme disease without erythema migrans (EM), compares outcomes of standard two-tier testing (sTTT), modified two-tier testing (mTTT) and the DiaSorin Lyme Detection Algorithm (LDA), a combination of both serology tests and Interferon-ɤ Release Assay.

Patients and Methods

A patient-level simulation model was built to incorporate effectiveness estimation from a structured focused literature review, and health-care cost inputs for the United States, Germany, and Italy. Simulated clinical outcomes were 1) percent of patients with timely and correct diagnosis, 2) patients appropriately treated and exposed to antibiotics therapy, and 3) patients with late Lyme disease manifestations. Expected health outcomes were expressed in terms of differences in quality-adjusted life years (QALYs) due to disseminated Lyme disease and persisting symptoms, and economic outcomes were analyzed from a third-party payer perspective.

Results

The DiaSorin LDA resulted in a better sensitivity compared to sTTT and mTTT, 84% vs 49% and 45%, respectively, in the base case (13% of infected patients in the tested population). Due to the improved diagnostic performance, the LDA-based strategy is expected to be more effective, providing mean incremental 0.024 QALYs per tested patient, or 0.19 per infected patient. Furthermore, from a third-party payer perspective, the adoption of the LDA-based strategy would reduce the expected health-care cost for suspected and confirmed Lyme disease by roughly 40%, ie about $410, €130, and €170 per tested patient in the United States, Germany, and Italy, respectively, compared to sTTT. The results are most sensitive to the infection rate in the tested population, with LDA maintaining a cost advantage for Lyme disease active infection rates ≥0.8-2.5%.

Conclusion

LDA early diagnostic testing and subsequent treatment of subjects with early Lyme disease without EM are expected to outperform traditional management strategies both clinically and economically in the US, Germany, and Italy.

Lyme borreliosis: diagnosis and management

Lyme borreliosis is the most common vectorborne disease in the northern hemisphere. It usually begins with erythema migrans; early disseminated infection particularly causes multiple erythema migrans or neurologic disease, and late manifestations predominantly include arthritis in North America, and acrodermatitis chronica atrophicans (ACA) in Europe. Diagnosis of Lyme borreliosis is based on characteristic clinical signs and symptoms, complemented by serological confirmation of infection once an antibody response has been mounted. Manifestations usually respond to appropriate antibiotic regimens, but the disease can be followed by sequelae, such as immune arthritis or residual damage to affected tissues. A subset of individuals reports persistent symptoms, including fatigue, pain, arthralgia, and neurocognitive symptoms, which in some people are severe enough to fulfil the criteria for post-treatment Lyme disease syndrome. The reported prevalence of such persistent symptoms following antimicrobial treatment varies considerably, and its pathophysiology is unclear. Persistent active infection in humans has not been identified as a cause of this syndrome, and randomized treatment trials have invariably failed to show any benefit of prolonged antibiotic treatment. For prevention of Lyme borreliosis, post-exposure prophylaxis may be indicated in specific cases, and novel vaccine strategies are under development.