Increased IFNα activity and differential antibody response in patients with a history of Lyme disease and persistent cognitive deficits

Repeated doxycycline treatment among patients with neuroborreliosis: a nationwide, population-based, registry-based, matched cohort study

OBJECTIVES

To investigate receipt of antibiotics among patients with neuroborreliosis after initial antibiotic treatment, likely attributable to posttreatment symptoms.

METHODS

We performed a nationwide, matched, population-based cohort study in Denmark (2009-2021). We included all Danish patients with neuroborreliosis, i.e. a positive Borrelia burgdorferi intrathecal antibody index test and a cerebrospinal fluid leukocyte count ≥10 × 106/l, and initially treated with doxycycline. To form a comparison cohort, we randomly extracted individuals from the general population matched 1:10 to patients with neuroborreliosis on date of birth and sex. The main outcome was receipt of doxycycline, and the secondary outcome was receipt of phenoxymethylpenicillin. We calculated short-term (<1 year) and long-term (≥1 year) hazard ratios (HR) with 95% confidence intervals (95%CI).

RESULTS

We included 463 patients with neuroborreliosis and 2,315 comparison cohort members. Compared with the comparison cohort members, patients with neuroborreliosis initially treated with doxycycline had increased receipt of additional doxycycline within 1 year (HR: 38.6, 95%CI: 17.5-85.0) and ≥1 years (HR: 3.5, 95%CI: 1.9-6.3). Compared with comparison cohort members, patients with neuroborreliosis had no increased receipt of phenoxymethylpenicillin (<1 year HR 1.0, 95%CI: 0.7-1.3; ≥1 years HR 1.2, 95%CI: 0.9-1.5).

CONCLUSIONS

After initial antibiotic treatment, patients with neuroborreliosis have increased receipt of doxycycline particularly within one year after initial antibiotic therapy but also subsequently. The lack of increased receipt of phenoxymethylpenicillin suggests that the receipt of doxycycline was not merely due to differences in healthcare-seeking behaviour, increased risk of early Lyme borreliosis due to exposure, or differences in antibacterial usage in general.

Current and emerging approaches for eliminating Borrelia burgdorferi and alleviating persistent Lyme disease symptoms

Lyme disease is the most prevalent tick-borne infection caused by Borrelia burgdorferi bacteria in North America. Other Borrelia species are predominately the cause of this disease in Eurasia with some distinct and various overlapping manifestations. Consequently, caution must be exercised when comparing the disease and its manifestations and treatment regimens in North America and Europe. Diagnosis of the early Lyme disease remains difficult using the currently FDA approved serological tests in the absence of a reported tick bite or of erythema migrans in many individuals, non-specific initial symptoms, and the absence of detectable anti-Borrelia antibodies in the prepatent period of infection. Furthermore, it is difficult to distinguish persistence of infection and disease versus reinfection in the endemic regions of Lyme disease by serological assays. If early infection remains untreated, spirochetes can disseminate and could affect various organs in the body with a variety of disease manifestations including arthralgias and musculoskeletal pain, neurologic symptoms and anomalies, and acrodermatitis chronicum atrophicans (ACA) in Europe. Although most patients recover after antibiotic treatment, an estimated ∼10-20% patients in the United States show persistence of symptoms known as post-treatment Lyme disease syndrome (PTLDS). The causes and biomarkers of PTLDS are not well-defined; however, several contributing factors with inconsistent degree of supporting evidence have been suggested. These include antigenic debris, dysregulation of immunological response, bacterial persisters, or combination of these features. This review highlights currently employed treatment approaches describing different antimicrobials used, and vaccine candidates tried to prevent B. burgdorferi infection.

Borrelia burgdorferi Secretes c-di-AMP as an Extracellular Pathogen-Associated Molecular Pattern to Elicit Type I Interferon Responses in Mammalian Hosts

Borrelia burgdorferi (B. burgdorferi), an extracellular spirochetal pathogen, elicits a type-I interferon (IFN-I) response that contributes to the pathology of Lyme disease, including the development and severity of Lyme arthritis. However, the specific Pathogen-Associated Molecular Patterns (PAMPs) of B. burgdorferi responsible for triggering the IFN-I response are not well understood. Previous studies have identified an unknown, nuclease-resistant component in B. burgdorferi culture supernatants that significantly stimulates the IFN-I response, but its identity remains unknown. In this study, we reveal that B. burgdorferi secretes cyclic-di-adenosine monophosphate (c-di-AMP) as a key extracellular PAMP, inducing the host IFN-I response in macrophages. Using genetically manipulated B. burgdorferi strains, we demonstrate a requirement of c-di-AMP for stimulating IFN-I response by macrophages ex vivo. Additionally, infecting mice with B. burgdorferi alongside exogenous c-di-AMP resulted in a markedly increased IFN-I response in mouse tissues. Furthermore, inactivation or inhibition of the host STING signaling pathway significantly reduced the IFN-I response, indicating that c-di-AMP-induced IFN-I production is STING-dependent. Our findings identify c-di-AMP as a crucial PAMP secreted by B. burgdorferi to elicit the host IFN-I response via activation of STING signaling pathway, suggesting that targeting c-di-AMP production could represent a novel therapeutic strategy against Lyme arthritis.

Dysautonomia following Lyme disease: a key component of post-treatment Lyme disease syndrome?

Dysautonomia, or dysfunction of the autonomic nervous system (ANS), may occur following an infectious insult and can result in a variety of debilitating, widespread, and often poorly recognized symptoms. Dysautonomia is now widely accepted as a complication of COVID-19 and is an important component of Post-Acute Sequelae of COVID-19 (PASC or long COVID). PASC shares many overlapping clinical features with other infection-associated chronic illnesses including Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Post-Treatment Lyme Disease Syndrome (PTLDS), suggesting that they may share common underlying mechanisms including autonomic dysfunction. Despite the recognition of this complication of Lyme disease in the care of patients with PTLD, there has been a scarcity of research in this field and dysautonomia has not yet been established as a complication of Lyme disease in the medical literature. In this review, we discuss the evidence implicating Borrelia burgdorferi as a cause of dysautonomia and the related symptoms, propose potential pathogenic mechanisms given our knowledge of Lyme disease and mechanisms of PASC and ME/CFS, and discuss the diagnostic evaluation and treatments of dysautonomia. We also outline gaps in the literature and priorities for future research.

Neuropsychiatric Lyme Disease and Vagus Nerve Stimulation

Lyme disease, the most common tick-borne disease in the United States, is caused by infection with the spirochete Borrelia burgdorferi. While most patients with acute Lyme disease recover completely if treated with antibiotics shortly after the onset of infection, approximately 10-30% experience post-treatment symptoms and 5-10% have residual symptoms with functional impairment (post-treatment Lyme disease syndrome or PTLDS). These patients typically experience pain, cognitive problems, and/or fatigue. This narrative review provides a broad overview of Lyme disease, focusing on neuropsychiatric manifestations and persistent symptoms. While the etiology of persistent symptoms remains incompletely understood, potential explanations include persistent infection, altered neural activation, and immune dysregulation. Widely recognized is that new treatment options are needed for people who have symptoms that persist despite prior antibiotic therapy. After a brief discussion of treatment approaches, the article focuses on vagus nerve stimulation (VNS), a neuromodulation approach that is FDA-approved for depression, epilepsy, and headache syndromes and has been reported to be helpful for other diseases characterized by inflammation and neural dysregulation. Transcutaneous VNS stimulates the external branch of the vagus nerve, is minimally invasive, and is well-tolerated in other conditions with few side effects. If well-controlled double-blinded studies demonstrate that transcutaneous auricular VNS helps patients with chronic syndromes such as persistent symptoms after Lyme disease, taVNS will be a welcome addition to the treatment options for these patients.

Cost of illness in patients with post-treatment Lyme disease syndrome in Belgium

BACKGROUND

A proportion of patients with Lyme borreliosis (LB) report long-term persisting signs and symptoms, even after recommended antibiotic treatment, which is termed post-treatment Lyme disease syndrome (PTLDS). Consensus on guidance regarding diagnosis and treatment is currently lacking. Consequently, patients suffer and are left searching for answers, negatively impacting their quality of life and healthcare expenditure. Yet, health economic data on PTLDS remain scarce. The aim of this article is therefore to assess the cost-of-illness related to PTLDS, including the patient perspective.

METHODS

PTLDS patients (N = 187) with confirmed diagnosis of LB were recruited by a patient organization. Patients completed a self-reported questionnaire on LB-related healthcare utilization, absence from work and unemployment. Unit costs (reference year 2018) were obtained from national databases and published literature. Mean costs and uncertainty intervals were calculated via bootstrapping. Data were extrapolated to the Belgian population. Generalized linear models were used to determine associated covariates with total direct costs and out-of-pocket expenditures.

RESULTS

Mean annual direct costs amounted to €4618 (95% CI €4070-5152), of which 49.5% were out-of-pocket expenditures. Mean annual indirect costs amounted to €36 081 (€31 312-40 923). Direct and indirect costs at the population level were estimated at €19.4 and 151.5 million, respectively. A sickness or disability benefit as source of income was associated with higher direct and out-of-pocket costs.

CONCLUSIONS

The economic burden associated with PTLDS on patients and society is substantial, with patients consuming large amounts of non-reimbursed healthcare resources. Guidance on adequate diagnosis and treatment of PTLDS is needed.

Association of Persistent Symptoms after Lyme Neuroborreliosis and Increased Levels of Interferon-α in Blood

Patients who have Lyme neuroborreliosis (LNB) might experience lingering symptoms that persist despite antibiotic drug therapy. We tested whether those symptoms are caused by maladaptive immune responses by measuring 20 immune mediators in serum and cerebrospinal fluid (CSF) in 79 LNB patients followed for 1 year. At study entry, most mediators were highly concentrated in CSF, the site of the infection. Those responses resolved with antibiotic therapy, and associations between CSF cytokines and signs and symptoms of LNB were no longer observed. In contrast, subjective symptoms that persisted after use of antibiotics were associated with increased levels of serum interferon-α (IFN-α), which were already observed at study entry, and remained increased at each subsequent timepoint. Highest IFN-α levels corresponded with severe disease. Although the infection serves as the initial trigger, sequelae after antibiotic therapy are associated with unremitting systemic IFN-α levels, consistent with the pathogenic role of this cytokine in interferonopathies in other conditions.

Borrelia burgdorferi Engages Mammalian Type I IFN Responses via the cGAS-STING Pathway

Borrelia burgdorferi, the etiologic agent of Lyme disease, is a spirochete that modulates numerous host pathways to cause a chronic, multisystem inflammatory disease in humans. B. burgdorferi infection can lead to Lyme carditis, neurologic complications, and arthritis because of the ability of specific borrelial strains to disseminate, invade, and drive inflammation. B. burgdorferi elicits type I IFN (IFN-I) responses in mammalian cells and tissues that are associated with the development of severe arthritis or other Lyme-related complications. However, the innate immune sensors and signaling pathways controlling IFN-I induction remain unclear. In this study, we examined whether intracellular nucleic acid sensing is required for the induction of IFN-I to B. burgdorferi. Using fluorescence microscopy, we show that B. burgdorferi associates with mouse and human cells in culture, and we document that internalized spirochetes colocalize with the pattern recognition receptor cyclic GMP-AMP synthase (cGAS). Moreover, we report that IFN-I responses in mouse macrophages and murine embryonic fibroblasts are significantly attenuated in the absence of cGAS or its adaptor stimulator of IFN genes (STING), which function to sense and respond to intracellular DNA. Longitudinal in vivo tracking of bioluminescent B. burgdorferi revealed similar dissemination kinetics and borrelial load in C57BL/6J wild-type, cGAS-deficient, or STING-deficient mice. However, infection-associated tibiotarsal joint pathology and inflammation were modestly reduced in cGAS-deficient compared with wild-type mice. Collectively, these results indicate that the cGAS-STING pathway is a critical mediator of mammalian IFN-I signaling and innate immune responses to B. burgdorferi.

Lyme disease and the pursuit of a clinical cure

Lyme disease, caused by the spirochete Borrelia burgdorferi, is the most common vector-borne illness in the United States. Many aspects of the disease are still topics of controversy within the scientific and medical communities. One particular point of debate is the etiology behind antibiotic treatment failure of a significant portion (10-30%) of Lyme disease patients. The condition in which patients with Lyme disease continue to experience a variety of symptoms months to years after the recommended antibiotic treatment is most recently referred to in the literature as post treatment Lyme disease syndrome (PTLDS) or just simply post treatment Lyme disease (PTLD). The most commonly proposed mechanisms behind treatment failure include host autoimmune responses, long-term sequelae from the initial Borrelia infection, and persistence of the spirochete. The aims of this review will focus on the in vitro, in vivo, and clinical evidence that either validates or challenges these mechanisms, particularly with regard to the role of the immune response in disease and resolution of the infection. Next generation treatments and research into identifying biomarkers to predict treatment responses and outcomes for Lyme disease patients are also discussed. It is essential that definitions and guidelines for Lyme disease evolve with the research to translate diagnostic and therapeutic advances to patient care.

Persistent Symptoms After Treatment of Lyme Disease

Most patients with Lyme disease will fully recover with recommended antibiotic therapy. However, some patients report persisting nonspecific symptoms after treatment, referred to as posttreatment Lyme disease symptoms (PTLDs) or syndrome (PTLDS), depending on the degree to which the individual's symptoms impact their quality of life. PTLDs occur in a portion of patients diagnosed with chronic Lyme disease (CLD), a controversial term describing different patient populations, diagnosed based on unvalidated tests and criteria. Practitioners should review the evidence for the Lyme disease diagnosis and not overlook unrelated conditions. Current evidence shows that prolonged antibiotic therapy provides little benefit and carries significant risk. Further research to elucidate the mechanisms underlying persistent symptoms after Lyme disease and to understand CLD is needed.

The Cdkn2a gene product p19 alternative reading frame (p19ARF) is a critical regulator of IFNβ-mediated Lyme arthritis

Type I interferon (IFN) has been identified in patients with Lyme disease, and its abundant expression in joint tissues of C3H mice precedes development of Lyme arthritis. Forward genetics using C3H mice with severe Lyme arthritis and C57BL/6 (B6) mice with mild Lyme arthritis identified the Borrelia burgdorferi arthritis-associated locus 1 (Bbaa1) on chromosome 4 (Chr4) as a regulator of B. burgdorferi-induced IFNβ expression and Lyme arthritis severity. B6 mice introgressed with the C3H allele for Bbaa1 (B6.C3-Bbaa1 mice) displayed increased severity of arthritis, which is initiated by myeloid lineage cells in joints. Using advanced congenic lines, the physical size of the Bbaa1 interval has been reduced to 2 Mbp, allowing for identification of potential genetic regulators. Small interfering RNA (siRNA)-mediated silencing identified Cdkn2a as the gene responsible for Bbaa1 allele-regulated induction of IFNβ and IFN-stimulated genes (ISGs) in bone marrow-derived macrophages (BMDMs). The Cdkn2a-encoded p19 alternative reading frame (p19ARF) protein regulates IFNβ induction in BMDMs as shown by siRNA silencing and overexpression of ARF. In vivo studies demonstrated that p19ARF contributes to joint-specific induction of IFNβ and arthritis severity in B. burgdorferi-infected mice. p19ARF regulates B. burgdorferi-induced IFNβ in BMDMs by stabilizing the tumor suppressor p53 and sequestering the transcriptional repressor BCL6. Our findings link p19ARF regulation of p53 and BCL6 to the severity of IFNβ-induced Lyme arthritis in vivo and indicate potential novel roles for p19ARF, p53, and BCL6 in Lyme disease and other IFN hyperproduction syndromes.

Lyme disease is caused by infection with the tick-transmitted bacterium Borrelia burgdorferi. Although different isolates of B. burgdorferi have distinct potential for dissemination and tissue invasion, factors intrinsic to the infected host also play an important role in directing the severity of Lyme disease. In the animal model, infected C3H mice develop severe Lyme arthritis following elevation of type I IFN in joint tissue, while in C57BL/6 (B6) mice arthritis is mild and not associated with type I IFN. We demonstrated that the Borrelia burgdorferi arthritis-associated locus 1 (Bbaa1) on chromosome 4 (Chr4) intrinsically controls the magnitude of IFNβ production and the severity of Lyme arthritis in C3H vs B6 mice. The Cdkn2a gene was positionally identified as the regulator of IFNβ within Bbaa1, and determined to function through its protein product p19 alternative reading frame (p19ARF). ARF regulates IFNβ expression and Lyme arthritis severity by modulating the activities of the tumor suppressor p53 and transcriptional repressor BCL6. Our study provides new insight and potential therapeutic targets for the investigation of type I IFN-dependent Lyme arthritis and other IFN-driven diseases.

Seroprevalence of Antibodies against Tick-Borne Pathogens in Czech Patients with Suspected Post-Treatment Lyme Disease Syndrome

The hypothesized importance of coinfections in the pathogenesis of post-treatment Lyme disease syndrome (PTLDS) leads to the use of combined, ongoing antimicrobial treatment in many cases despite the absence of symptoms typical of the presence of infection with specific pathogens. Serum samples from 103 patients with suspected post-treatment Lyme disease syndrome were tested for the presence of antibodies to the major tick-borne pathogens Anaplasma phagocytophilum, Bartonella henselae/Bartonella quinatana, and Babesia microti. Although the presence of anti-Anaplasma antibodies was detected in 12.6% of the samples and anti-Bartonella antibodies in 9.7% of the samples, the presence of antibodies against both pathogens in the same samples or anti-Babesia antibodies in the selected group of patients could not be confirmed. However, we were able to detect autoantibodies, mostly antinuclear, in 11.6% of the patients studied. Our results are in good agreement with previously published studies showing the presence of a wide spectrum of autoantibodies in some patients with complicated forms of Lyme disease and post-treatment Lyme disease syndrome, but they do not reveal a significant influence of co-infections on the development of PTLDS in the studied group of patients.

A Review of Post-treatment Lyme Disease Syndrome and Chronic Lyme Disease for the Practicing Immunologist

Lyme disease is an infection caused by Borrelia burgdorferi sensu lato, which is transmitted to humans through the bite of an infected Ixodes tick. The majority of patients recover without complications with antibiotic therapy. However, for a minority of patients, accompanying non-specific symptoms can persist for months following completion of therapy. The constellation of symptoms such as fatigue, cognitive dysfunction, and musculoskeletal pain that persist beyond 6 months and are associated with disability have been termed post-treatment Lyme disease syndrome (PTLDS), a subset of a broader term "chronic Lyme disease." Chronic Lyme disease is a broad, vaguely defined term that is used to describe patients with non-specific symptoms that are attributed to a presumed persistent Borrelia burgdorferi infection in patients who may or may not have evidence of either previous or current Lyme disease. The diagnoses of chronic Lyme disease and of PTLDS have become increasingly relevant to the practice of immunologists due to referrals for consultation or for intravenous immunoglobulin (IVIG) treatment. This review aims to explore the relationship between chronic Lyme disease, post-treatment Lyme disease syndrome, and the immune system. Here, we review the current literature on (1) issues in conventional and alternative diagnostic testing for Lyme disease, (2) the hypothesis that B. burgdorferi infection can persist despite appropriate use of recommended antibiotics, (3) current theories regarding B. burgdorferi's role in causing both immune dysregulation and protracted symptoms, and (4) the use of IVIG for the treatment of Lyme disease.

[Mechanisms underlying chronic fatigue, a symptom too often overlooked]

Acute fatigue after exertion, like acute inflammation after injury, is useful for our body. On the contrary, both chronic fatigue and chronic inflammation are deleterious, and they are associated in many diseases. In this first part, we will analyze different immune phenomena (bystander activation, memory of the innate immune system, link with the intestinal microbiota) involved in triggering chronic inflammation. This review aims at looking for links between different signs and symptoms associated with chronic fatigue, as well as between different diseases in which severe chronic fatigue can manifest. Possible underlying mechanisms for these phenomena are discussed. This is a proposal made by a researcher, with no clinical experience, to doctors confronted with an entity that is still largely mysterious. The link between chronic inflammation, neuroinflammation and fatigue will be examined in a second part.

Lyme Neuroborreliosis: Mechanisms of B. burgdorferi Infection of the Nervous System

Lyme borreliosis is the most prevalent tick-borne disease in the United States, infecting ~476,000 people annually. Borrelia spp. spirochetal bacteria are the causative agents of Lyme disease in humans and are transmitted by Ixodes spp ticks. Clinical manifestations vary depending on which Borrelia genospecies infects the patient and may be a consequence of distinct organotropism between species. In the US, B. burgdorferi sensu stricto is the most commonly reported genospecies and infection can manifest as mild to severe symptoms. Different genotypes of B. burgdorferi sensu stricto may be responsible for causing varying degrees of clinical manifestations. While the majority of Lyme borreliae-infected patients fully recover with antibiotic treatment, approximately 15% of infected individuals experience long-term neurological and psychological symptoms that are unresponsive to antibiotics. Currently, long-term antibiotic treatment remains the only FDA-approved option for those suffering from these chronic effects. Here, we discuss the current knowledge pertaining to B. burgdorferi sensu stricto infection in the central nervous system (CNS), termed Lyme neuroborreliosis (LNB), within North America and specifically the United States. We explore the molecular mechanisms of spirochete entry into the brain and the role B. burgdorferi sensu stricto genotypes play in CNS infectivity. Understanding infectivity can provide therapeutic targets for LNB treatment and offer public health understanding of the B. burgdorferi sensu stricto genotypes that cause long-lasting symptoms.

Detecting Borrelia Spirochetes: A Case Study With Validation Among Autopsy Specimens

The complex etiology of neurodegenerative disease has prompted studies on multiple mechanisms including genetic predisposition, brain biochemistry, immunological responses, and microbial insult. In particular, Lyme disease is often associated with neurocognitive impairment with variable manifestations between patients. We sought to develop methods to reliably detect Borrelia burgdorferi, the spirochete bacteria responsible for Lyme disease, in autopsy specimens of patients with a history of neurocognitive disease. In this report, we describe the use of multiple molecular detection techniques for this pathogen and its application to a case study of a Lyme disease patient. The patient had a history of Lyme disease, was treated with antibiotics, and years later developed chronic symptoms including dementia. The patient's pathology and clinical case description was consistent with Lewy body dementia. B. burgdorferi was identified by PCR in several CNS tissues and by immunofluorescent staining in the spinal cord. These studies offer proof of the principle that persistent infection with the Lyme disease spirochete may have lingering consequences on the CNS.

Innate and Th1/Th17 adaptive immunity in acute and convalescent Brazilian borreliosis disease

Introduction

Brazilian borreliosis (BB) disease is an infectious disease transmitted by ticks that mimics Lyme disease (LD) from the Northern Hemisphere. The BB clinical picture is characterized by a pathognomonic skin lesion (migratory erythema) and joint, neurological, cardiac and psychiatric symptoms. Innate and Th1/Th17 adaptive immunity seem to play an important role in the pathogenesis of Lyme disease.

Objective

The aim of this study was to characterize the role of innate and Th1/Th17 adaptive immunity in BB patients with acute (<3 months) and convalescent (>3 months) disease.

Methods

Fifty BB patients (28 with acute and 22 with convalescent disease) without treatment and 30 healthy subjects were evaluated. Levels of 20 cytokines or chemokines associated with innate and Th1/Th17 adaptive immunity were analyzed using Luminex (Millipore Corp., Billerica, MA).

Results

Overall, BB patients had increased levels of IL-8 (6.29 vs 2.12 p = 0.002) and MIP-1α/CCL3 (5.20 vs 2.06, p = 0.030), associated with innate immunity, and MIP3B/CCL19 (Th1; 297.86 vs 212.41, p = 0.031) and IL-17A (Th17; 3.11 vs 2.20, p = 0.037), associated with adaptive immunity, compared with the levels of healthy controls. When comparing acute BB vs. convalescent BB subjects vs. healthy controls, IL-1β, IL-8 and MIP-1α/CCL3 (innate mediators) levels were highest in patients in the acute phase of disease (p < 0.05). TNF-α was associated with disseminated symptoms and with humoral reactivity against Borrelia burgdorferi. IL-10 was significantly correlated with IL-6 (r = 0.59, p = 0.003), IL-8 (r = 0.51, p < 0.001), MIP-1α/CCL3 (r = 0.42, p < 0.001) and MIP-3β/CCL19 (r = 0.40, p = 0.002) in all BB patients.

Conclusions

This is the first study describing that innate and Th1/Th17 adaptive immunity play a crucial role in BB disease. Furthermore, innate mediators are particularly important in acute BB disease, and TNF-α is associated with evolution of BB symptoms.

Evaluation of selected variables to determine if any had predictive value for, or correlated with, residual symptoms at approximately 12 months after diagnosis and treatment of early Lyme disease

Subjective symptoms may persist after antibiotic treatment of patients with erythema migrans. Selected baseline variables were evaluated to determine if any correlated with symptom persistence to 12 months (PTLDS). Tingling or an abnormal skin sensation were reported by 5 (71.4%) of the 7 PTLDS cases at the baseline visit versus 4 (13.3%) of the 30 initially symptomatic subjects without PTLDS (P= 0.005). The frequency of having a total score of ≥17, when the Beck Depression Inventory score was added to the number of pain sites that the subject reported at the baseline visit, also showed a significant difference: 71.4% versus 10%, P= 0.002. All but 1 of the 7 subjects with possible PTLDS had either a total score of at least 17 on these 2 measures combined or had a score of ≥2 on the stress event questionnaire used. Clinical investigations should be conducted to validate these findings with other patient cohorts.

A Distinct Microbiome Signature in Posttreatment Lyme Disease Patients

Most patients with acute Lyme disease are cured with antibiotic intervention, but 10 to 20% endure debilitating symptoms such as fatigue, neurological complications, and myalgias after treatment, a condition known as posttreatment Lyme disease syndrome (PTLDS). The etiology of PTLDS is not understood, and objective diagnostic tools are lacking. PTLDS symptoms overlap several diseases in which patients exhibit alterations in their microbiome. We found that patients with PTLDS have a distinct microbiome signature, allowing for an accurate classification of over 80% of analyzed cases. The signature is characterized by an increase in Blautia, a decrease in Bacteroides, and other changes. Importantly, this signature supports the validity of PTLDS and is the first potential biological diagnostic tool for the disease.

Lyme disease is the most common vector-borne disease in the United States, with an estimated incidence of 300,000 infections annually. Antibiotic intervention cures Lyme disease in the majority of cases; however, 10 to 20% of patients develop posttreatment Lyme disease syndrome (PTLDS), a debilitating condition characterized by chronic fatigue, pain, and cognitive difficulties. The underlying mechanism responsible for PTLDS symptoms, as well as a reliable diagnostic tool, has remained elusive. We reasoned that the gut microbiome may play an important role in PTLDS given that the symptoms overlap considerably with conditions in which a dysbiotic microbiome has been observed, including mood, cognition, and autoimmune disorders. Analysis of sequencing data from a rigorously curated cohort of patients with PTLDS revealed a gut microbiome signature distinct from that of healthy control subjects, as well as from that of intensive care unit (ICU) patients. Notably, microbiome sequencing data alone were indicative of PTLDS, which presents a potential, novel diagnostic tool for PTLDS.

Immunoserological Diagnosis of Human Borrelioses: Current Knowledge and Perspectives

Spirochetes of the genus Borrelia are divided into relapsing fever borreliae and Lyme disease borreliae. Immunoserological assays have been poorly developed for relapsing fever borreliae, where direct detection methods are more adapted to the pathophysiology of these infections presenting with massive bacteraemia. However, emergence of the novel agent of relapsing fever B. miyamotoi has renewed interest in serology in this context. In Lyme disease, because direct detection methods show low sensitivity, serology plays a central role in the diagnostic strategy. This diagnostic strategy is based on a two-tier methodology involving a first test (ELISA) with high sensitivity and acceptable specificity and a second, more specific test (western blot) for diagnostic confirmation. The most frequent limitations and pitfalls of serology are cross reactions, false IgM positivity, a seronegative window period at the early time of the infection, and serologic scars with a suspicion of reinfection. International guidelines have thus been proposed to avoid these difficulties with interpretation. Finally, unconventional diagnostic tests have been developed recently in the context of a highly publicized disease, with widely varying results, some of which have no available evidence-based data. New two-tier testing strategies using two ELISA tests (C6 and WCS for example) to replace immunoblot are currently proposed by some authors and guidelines, and promising new tests such as CXCL-13 in CSF are promising tools for the improvement of the diagnosis of Lyme borreliosis.

Anti-lysoganglioside and other anti-neuronal autoantibodies in post-treatment Lyme Disease and Erythema Migrans after repeat infection

Background

Molecular mimicry targeting neural tissue has been reported after Borrelia burgdorferi(Bb) infection. Herein, we investigate whether antineuronal autoantibodies are increased and whether antibody-mediated signaling of neuronal cells is elevated in a cohort of symptomatic adults with a history of Lyme Disease (LD).

Methods

Participants (n ​= ​179) included 24 with recent Erythema Migrans (EM) without prior LD, 8 with recent EM and prior LD (EM ​+ ​prior LD), 119 with persistent post-treatment LD symptoms (PTLS), and 28 seronegative endemic controls with no prior LD history. Antineuronal immunoglobulin G (IgG) titers were measured by standard ELISA and compared with mean titers of normal age-matched sera against lysoganglioside, tubulin, and dopamine receptors (D1R and D2R). Antibody-mediated signaling of calcium calmodulin dependent protein kinase II (CaMKII) activity in a human neuronal cell line (SK-N-SH) was identified in serum.

Results

EM ​+ ​prior LD cases had higher antibody titers than controls for anti-lysoganglioside GM1 (p ​= ​0.002), anti-tubulin (p ​= ​0.03), and anti-D1R (p ​= ​0.02), as well as higher expression in the functional antibody-mediated CaMKII Assay (p ​= ​0.03). The EM cases with no prior history showed no significant differences on any measures. The PTLS cases demonstrated significantly higher titers (p ​= ​0.01) than controls on anti-lysoganglioside GM1, but not for the other measures.

Conclusion

The finding of elevated anti-neuronal autoantibodies in our small sample of those with a prior history of Lyme disease but not in those without prior Lyme disease, if replicated in a larger sample, suggests an immune priming effect of repeated infection; the CaMKII activation suggests that antineuronal antibodies have functional significance. The elevation of anti-lysoganglioside antibodies among those with PTLS is of particular interest given the established role of anti-ganglioside antibodies in peripheral and central neurologic diseases. Future prospective studies can determine whether these autoantibodies emerge after Bb infection and whether their emergence coincides with persistent neurologic or neuropsychiatric symptoms.

Unconventional diagnostic tests for Lyme borreliosis: a systematic review

BACKGROUND

Lyme borreliosis (LB) diagnosis currently relies mainly on serological tests and sometimes PCR or culture. However, other biological assays are being developed to try to improve Borrelia-infection diagnosis and/or monitoring.

OBJECTIVES

To analyse available data on these unconventional LB diagnostic assays through a systematic literature review.

METHODS

We searched PubMed and Cochrane Library databases according to the PRISMA-DTA method and the Cochrane Handbook for Systematic Reviews of Interventions. We analysed controlled and uncontrolled studies (published 1983-2018) on biological tests for adults to diagnose LB according to the European Study Group for Lyme Borreliosis or the Infectious Diseases Society of America definitions, or identify strongly suspected LB. Two independent readers evaluated study eligibility and extracted data from relevant study reports; a third reader analysed full texts of papers to resolve disagreements. The quality of each included study was assessed with the QUADAS-2 evaluation scale.

RESULTS

Forty studies were included: two meta-analyses, 25 prospective controlled studies, five prospective uncontrolled studies, six retrospective controlled studies and two case reports. These biological tests assessed can be classified as: (i) proven to be effective at diagnosing LB and already in use (CXCL-13 for neuroborreliosis), but not enough to be standardized; (ii) not yet used routinely, requiring further clinical evaluation (CCL-19, OspA and interferon-α); (iii) uncertain LB diagnostic efficacy because of controversial results and/or poor methodological quality of studies evaluating them (lymphocyte transformation test, interferon-γ, ELISPOT); (iv) unacceptably low sensitivity and/or specificity (CD57⁺ natural killer cells and rapid diagnostic tests); and (v) possible only for research purposes (microscopy and xenodiagnoses).

DISCUSSION

QUADAS-2 quality assessment demonstrated high risk of bias in 25/40 studies and uncertainty regarding applicability for 32/40, showing that in addition to PCR and serology, several other LB diagnostic assays have been developed but their sensitivities and specificities are heterogeneous and/or under-evaluated or unassessed. More studies are warranted to evaluate their performance parameters. The development of active infection biomarkers would greatly advance LB diagnosis and monitoring.

Estimation of cumulative number of post-treatment Lyme disease cases in the US, 2016 and 2020

BACKGROUND

Lyme disease (LD) is an infectious multi-system illness caused by the bacterial genus Borrelia and spread by bites of infected ticks. Although most patients are successfully treated by timely antibiotic therapy, it is broadly accepted that a sizeable number of patients experience treatment failure and continue to suffer long-term, debilitating symptoms, including pain, fatigue, cognitive dysfunction and other symptoms. This is known as post-treatment LD (PTLD), for which diagnosis is not standardized and treatment remains controversial. The prevalence and societal burden of PTLD is unknown.

METHODS

In an effort to help characterize the LD landscape, we estimated the number of PTLD cases in the US in 2016 and 2020 using Monte-Carlo simulation techniques, publically-available demographic datasets, uncertainty in the inputs and realistic assumptions about incidence and treatment failure rates.

RESULTS

Depending on the input assumptions, PTLD prevalence estimates for 2016 ranged from 69,011 persons (95% CI 51,796 to 89,312) to 1,523,869 (CI 1,268,634 to 1,809,416). Prevalence in 2020 is predicted to be higher than 2016, and may be as high as 1,944,189 (CI 1,619,988 to 2,304,147) cases.

CONCLUSIONS

The cumulative prevalence of PLTD in the United States is estimated to be high and continues to increase. These findings will be of interest to epidemiologists and health economists studying disease burden in the US and elsewhere, and justify funding to study PTLD diagnosis and treatment.

Autoimmunity against a glycolytic enzyme as a possible cause for persistent symptoms in Lyme disease

Some patients with a history of Borrelia burgdorferi infection develop a chronic symptomatology characterized by cognitive deficits, fatigue, and pain, despite antibiotic treatment. The pathogenic mechanism that underlines this condition, referred to as post-treatment Lyme disease syndrome (PTLDS), is currently unknown. A debate exists about whether PTLDS is due to persistent infection or to post-infectious damages in the immune system and the nervous system. We present the case of a patient with evidence of exposure to Borrelia burgdorferi sl and a long history of debilitating fatigue, cognitive abnormalities and autonomic nervous system issues. The patient had a positive Western blot for anti-basal ganglia antibodies, and the autoantigen has been identified as γ enolase, the neuron-specific isoenzyme of the glycolytic enzyme enolase. Assuming Borrelia own surface exposed enolase as the source of this autoantibody, through a mechanism of molecular mimicry, and given the absence of sera reactivity to α enolase, a bioinformatical analysis was carried out to identify a possible cross-reactive conformational B cell epitope, shared by Borrelia enolase and γ enolase, but not by α enolase. Taken that evidence, we hypothesize that this autoantibody interferes with glycolysis in neuronal cells, as the physiological basis for chronic symptoms in at least some cases of PTLDS. Studies investigating on the anti-γ enolase and anti-Borrelia enolase antibodies in PTLDS are needed to confirm our hypotheses.

Genetic Control of Lyme Arthritis by Borrelia burgdorferi Arthritis-Associated Locus 1 Is Dependent on Localized Differential Production of IFN-β and Requires Upregulation of Myostatin

Previously, using a forward genetic approach, we identified differential expression of type I IFN as a positional candidate for an expression quantitative trait locus underlying Borrelia burgdorferi arthritis-associated locus 1 (Bbaa1). In this study, we show that mAb blockade revealed a unique role for IFN-β in Lyme arthritis development in B6.C3-Bbaa1 mice. Genetic control of IFN-β expression was also identified in bone marrow-derived macrophages stimulated with B. burgdorferi, and it was responsible for feed-forward amplification of IFN-stimulated genes. Reciprocal radiation chimeras between B6.C3-Bbaa1 and C57BL/6 mice revealed that arthritis is initiated by radiation-sensitive cells, but orchestrated by radiation-resistant components of joint tissue. Advanced congenic lines were developed to reduce the physical size of the Bbaa1 interval, and confirmed the contribution of type I IFN genes to Lyme arthritis. RNA sequencing of resident CD45^- joint cells from advanced interval-specific recombinant congenic lines identified myostatin as uniquely upregulated in association with Bbaa1 arthritis development, and myostatin expression was linked to IFN-β production. Inhibition of myostatin in vivo suppressed Lyme arthritis in the reduced interval Bbaa1 congenic mice, formally implicating myostatin as a novel downstream mediator of the joint-specific inflammatory response to B. burgdorferi.

MicroRNA and mRNA Transcriptome Profiling in Primary Human Astrocytes Infected with Borrelia burgdorferi

Lyme disease is caused by infection with the bacterium Borrelia burgdorferi (Bb), which is transmitted to humans by deer ticks. The infection manifests usually as a rash and minor systemic symptoms; however, the bacteria can spread to other tissues, causing joint pain, carditis, and neurological symptoms. Lyme neuroborreliosis presents itself in several ways, such as Bell's palsy, meningitis, and encephalitis. The molecular basis for neuroborreliosis is poorly understood. Analysis of the changes in the expression levels of messenger RNAs and non-coding RNAs, including microRNAs, following Bb infection could therefore provide vital information on the pathogenesis and clinical symptoms of neuroborreliosis. To this end, we used cultured primary human astrocytes, key responders to CNS infection and important components of the blood-brain barrier, as a model system to study RNA and microRNA changes in the CNS caused by Bb. Using whole transcriptome RNA-seq, we found significant changes in 38 microRNAs and 275 mRNAs at 24 and 48 hours following Bb infection. Several of the RNA changes affect pathways involved in immune response, development, chromatin assembly (including histones) and cell adhesion. Further, several of the microRNA predicted target mRNAs were also differentially regulated. Overall, our results indicate that exposure to Bb causes significant changes to the transcriptome and microRNA profile of astrocytes, which has implications in the pathogenesis, and hence potential treatment strategies to combat this disease.

Posttreatment Lyme disease syndrome

The prognosis following appropriate antibiotic treatment of early or late Lyme disease is favorable but can be complicated by persistent symptoms of unknown cause termed posttreatment Lyme disease syndrome (PTLDS), characterized by fatigue, musculoskeletal pain, and cognitive complaints that persist for 6 months or longer after completion of antibiotic therapy. Risk factors include delayed diagnosis, increased severity of symptoms, and presence of neurologic symptoms at time of initial treatment. Two-tier serologic testing is neither sensitive nor specific for diagnosis of PTLDS because of variability in convalescent serologic responses after treatment of early Lyme disease. Optimal treatment of PTLDS awaits more precise understanding of the pathophysiologic mechanisms involved in this illness and future treatment trials.

Epitope-Specific Evolution of Human B Cell Responses to Borrelia burgdorferi VlsE Protein from Early to Late Stages of Lyme Disease

Most immunogenic proteins of Borrelia burgdorferi, the causative agent of Lyme disease, are known or expected to contain multiple B cell epitopes. However, the kinetics of the development of human B cell responses toward the various epitopes of individual proteins during the course of Lyme disease has not been examined. Using the highly immunogenic VlsE as a model Ag, we investigated the evolution of humoral immune responses toward its immunodominant sequences in 90 patients with a range of early to late manifestations of Lyme disease. The results demonstrate the existence of asynchronous, independently developing, Ab responses against the two major immunogenic regions of the VlsE molecule in the human host. Despite their strong immunogenicity, the target epitopes were inaccessible to Abs on intact spirochetes, suggesting a lack of direct immunoprotective effect. These observations document the association of immune reactivity toward specific VlsE sequences with different phases of Lyme disease, demonstrating the potential use of detailed epitope mapping of Ags for staging of the infection, and offer insights regarding the pathogen's possible immune evasion mechanisms.

Chronic Lyme disease: misconceptions and challenges for patient management

Lyme disease, infection with the tick-borne spirochete Borrelia burgdorferi, causes both specific and nonspecific symptoms. In untreated chronic infection, specific manifestations such as a relapsing large-joint oligoarthritis can persist for years, yet subside with appropriate antimicrobial therapy. Nervous system involvement occurs in 10%-15% of untreated patients and typically involves lymphocytic meningitis, cranial neuritis, and/or mononeuritis multiplex; in some rare cases, patients have parenchymal inflammation in the brain or spinal cord. Nervous system infection is similarly highly responsive to antimicrobial therapy, including oral doxycycline. Nonspecific symptoms such as fatigue, perceived cognitive slowing, headache, and others occur in patients with Lyme disease and are indistinguishable from comparable symptoms occurring in innumerable other inflammatory states. There is no evidence that these nonspecific symptoms reflect nervous system infection or damage, or that they are in any way specific to or diagnostic of this or other tick-borne infections. When these symptoms occur in patients with Lyme disease, they typically also subside after antimicrobial treatment, although this may take time. Chronic fatigue states have been reported to occur following any number of infections, including Lyme disease. The mechanism underlying this association is unclear, although there is no evidence in any of these infections that these chronic posttreatment symptoms are attributable to ongoing infection with B. burgdorferi or any other identified organism. Available appropriately controlled studies indicate that additional or prolonged courses of antimicrobial therapy do not benefit patients with a chronic fatigue-like state after appropriately treated Lyme disease.

New-onset panic, depression with suicidal thoughts, and somatic symptoms in a patient with a history of lyme disease

Lyme Disease, or Lyme Borreliosis, caused by Borrelia burgdorferi and spread by ticks, is mainly known to cause arthritis and neurological disorders but can also cause psychiatric symptoms such as depression and anxiety. We present a case of a 37-year-old man with no known psychiatric history who developed panic attacks, severe depressive symptoms and suicidal ideation, and neuromuscular complaints including back spasms, joint pain, myalgias, and neuropathic pain. These symptoms began 2 years after being successfully treated for a positive Lyme test after receiving a tick bite. During inpatient psychiatric hospitalization his psychiatric and physical symptoms did not improve with antidepressant and anxiolytic treatments. The patient's panic attacks resolved after he was discharged and then, months later, treated with long-term antibiotics for suspected “chronic Lyme Disease” (CLD) despite having negative Lyme titers. He however continued to have subsyndromal depressive symptoms and chronic physical symptoms such as fatigue, myalgias, and neuropathy. We discuss the controversy surrounding the diagnosis of CLD and concerns and considerations in the treatment of suspected CLD patients with comorbid psychiatric diagnoses.

Relevance of chronic lyme disease to family medicine as a complex multidimensional chronic disease construct: a systematic review

Lyme disease has become a global public health problem and a prototype of an emerging infection. Both treatment-refractory infection and symptoms that are related to Borrelia burgdorferi infection remain subject to controversy. Because of the absence of solid evidence on prevalence, causes, diagnostic criteria, tools and treatment options, the role of autoimmunity to residual or persisting antigens, and the role of a toxin or other bacterial-associated products that are responsible for the symptoms and signs, chronic Lyme disease (CLD) remains a relatively poorly understood chronic disease construct. The role and performance of family medicine in the detection, integrative treatment, and follow-up of CLD are not well studied either. The purpose of this paper is to describe insights into the complexity of CLD as a multidimensional chronic disease construct and its relevance to family medicine by means of a systematic literature review.

Borrelia burgdorferi arthritis-associated locus Bbaa1 regulates Lyme arthritis and K/B×N serum transfer arthritis through intrinsic control of type I IFN production

Localized upregulation of type I IFN was previously implicated in development of Borrelia burgdorferi-induced arthritis in C3H mice, and was remarkable due to its absence in the mildly arthritic C57BL/6 (B6) mice. Independently, forward genetics analysis identified a quantitative trait locus on Chr4, termed B. burgdorferi-associated locus 1 (Bbaa1), that regulates Lyme arthritis severity and includes the 15 type I IFN genes. Involvement of Bbaa1 in arthritis development was confirmed in B6 mice congenic for the C3H allele of Bbaa1 (B6.C3-Bbaa1), which developed more severe Lyme arthritis and K/B×N model of rheumatoid arthritis (RA) than did parental B6 mice. Administration of a type I IFN receptor blocking mAb reduced the severity of both Lyme arthritis and RA in B6.C3-Bbaa1 mice, formally linking genetic elements within Bbaa1 to pathological production of type I IFN. Bone marrow-derived macrophages from Bbaa1 congenic mice implicated this locus as a regulator of type I IFN induction and downstream target gene expression. Bbaa1-mediated regulation of IFN-inducible genes was upstream of IFN receptor-dependent amplification; however, the overall magnitude of the response was dependent on autocrine/paracrine responses to IFN-β. In addition, the Bbaa1 locus modulated the functional phenotype ascribed to bone marrow-derived macrophages: the B6 allele promoted expression of M2 markers, whereas the C3H allele promoted induction of M1 responses. This report identifies a genetic locus physically and functionally linked to type I IFN that contributes to the pathogenesis of both Lyme and RA.

Correlates of perceived health-related quality of life in post-treatment Lyme encephalopathy

BACKGROUND

Marked functional impairment has been reported by patients with post-treatment Lyme disease syndrome (PTLDS).

OBJECTIVE

We sought to identify the clinical features that contribute most strongly to the impaired health status associated with PTLDS.

METHODS

Enrolled patients had a well-documented history of Lyme disease, prior treatment with at least 3 weeks with intravenous ceftriaxone, a positive IgG Western blot, and objective problems with memory. An index score to capture aggregate cognitive functioning, Short-Form 36 physical and mental component summary scores, and scores on other clinical and demographic measures were examined. Multiple linear regressions were performed to determine significant predictors of perceptions of impaired life functioning as delineated by the Short-Form 36.

RESULTS

Fatigue was the most important contributor to perceived impairments in overall physical functioning, and fatigue and depression significantly predicted perceived impairments in overall mental functioning.

CONCLUSIONS

Because fatigue and depression contribute prominently to reports of impaired physical functioning and mental functioning among patients with PTLDS, clinicians should assess patients for these symptoms and consider targeting these symptoms in the selection of treatment interventions. Future controlled studies should examine the effectiveness of such agents for patients with PTLDS.