Therapy for Lyme arthritis: strategies for the treatment of antibiotic-refractory arthritis

Wider recognition and greater understanding of postinfectious, antibiotic-refractory Lyme arthritis

Lyme disease, caused by Borrelia burgdorferi (Bb), can progress to Lyme arthritis (LA). While most patients with LA respond successfully to antibiotic therapy, a small percentage fail to improve, a condition known as antibiotic-refractory Lyme arthritis (ARLA). While T cell responses are known to drive ARLA, molecular mechanisms for ARLA remain unknown. In this issue of the JCI, Dirks et al. isolated disease-specific Th cells from patients with ARLA residing in Germany. A distinct TCR-β motif distinguished ARLA from other rheumatic diseases. Notably, the TCR-β motif was linked predominantly to HLA-DRB1*11 or 13 alleles, which differed from alleles in patients from North America. It also mapped primarily to T peripheral helper (Tph) cells, as opposed to classical Th1 cells. These findings provide a roadmap explaining how T cell responses necessary for control of an infection can, despite antibiotic therapy, drive a disadvantageous T cell response, resulting in a postinfectious, inflammatory arthritis.

Variants in the Late Cornified Envelope Gene Locus Are Associated With Elevated T-helper 17 Responses in Patients With Postinfectious Lyme Arthritis

BACKGROUND

Postinfectious Lyme arthritis (LA) is associated with dysregulated immunity and autoreactive T- and B-cell responses in joints. Here we explored the role of host genetic variation in this outcome.

METHODS

The frequency of 253 702 single-nucleotide polymorphisms (SNPs) was determined in 147 patients with LA (87 with postinfectious LA and 60 with antibiotic-responsive LA), and for comparison in 90 patients with erythema migrans or the general population (n = 2504). Functional outcome of candidate SNPs was assessed by evaluating their impact on clinical outcome and on immune responses in blood and synovial fluid in patients with LA.

RESULTS

Six SNPs associated with late cornified envelope (LCE3) genes were present at greater frequency in patients with postinfectious LA compared to those with antibiotic-responsive LA (70% vs 30%; odds ratio, 2; P < .01). These SNPs were associated with heightened levels of inflammatory Th17 cytokines in serum but lower levels of interleukin 27, a regulatory cytokine, implying that they may contribute to dysregulated Th17 immunity in blood. Moreover, in patients with postinfectious LA, the levels of these Th17 mediators correlated directly with autoantibody responses in synovial fluid, providing a possible link between LCE3 SNPs, maladaptive systemic Th17 immunity, and autoreactive responses in joints.

CONCLUSIONS

Variation in the LCE3 locus, a known genetic risk factor in psoriasis and psoriatic arthritis, is associated with dysregulated systemic Th17 immunity and heightened autoantibody responses in joints. These findings underscore the importance of host genetic predisposition and systemic Th17 immunity in the pathogenesis of postinfectious (antibiotic-refractory) Lyme arthritis.

What Makes It Tick: Exploring the Mechanisms of Post-treatment Lyme Disease Syndrome

Post-treatment Lyme disease syndrome (PTLDS), which may also be referred to incorrectly as "chronic Lyme disease," is defined by the Infectious Diseases Society of America (IDSA) as the presence of fatigue, pain, and/or cognitive complaints with the functional impact that persists for more than six months after completing treatment for Lyme disease (LD). These symptoms occur in 10%-20% of patients previously diagnosed with LD caused by the bacteria Borrelia burgdorferi and appropriately treated with a course of antibiotics. The symptoms of PTLDS can be easily overlooked or misdiagnosed as a psychiatric manifestation in geographic locations that rarely see LD. In contrast, geographic locations with a higher prevalence of LD may be more aware of PTLDS symptoms and have higher clinical suspicion leading to this diagnosis. The pathophysiology behind the persistent symptoms some people experience from a primary infection is still largely unknown. Some mechanisms that have been proposed include permanent tissue damage and inflammation, immune system dysfunction, autoimmune response, co-infection, and even persistent infection refractory to treatment. We propose that ongoing PTLDS symptoms seem to be related to an autoimmune response to the tissue damage and inflammation caused by the viable or nonviable spirochete pathogen. At this point, PTLDS is diagnosed clinically as no quantifiable methods are available from laboratory or tissue diagnostics as of 2024. Similar pathophysiological features of PTLDS are seen in diseases such as COVID-19 or chronic fatigue syndrome (CFS). More effective diagnostic approaches might include further studies looking at a possible connection in the genomes of individuals developing PTLDS, quantifiable biomarkers, common inflammatory markers/pathways, and careful histopathological studies of human tissues.

Management of postinfectious inflammatory arthritis

PURPOSE OF REVIEW

Postinfectious inflammatory arthritis can result from various pathogens, including bacteria, viruses, fungi, and parasites. Prompt identification and treatment of acute infection is vital, but some cases progress to chronic arthritis despite successful treatment of infection. Postinfectious inflammatory arthritis varies from mild, self-limited arthralgia to severe, refractory arthritis, necessitating ongoing disease-modifying treatment. This review explores the spectrum of postinfectious inflammatory arthritis to provide insights into effective management.

RECENT FINDINGS

Research continues regarding the benefit of antimicrobial therapy, beyond treatment of the acute infection, to diminish the severity of postinfectious inflammatory arthritis. Following treatment of acute infection, most cases are self-limited so treatment is symptomatic. However, a difficult-to-predict fraction of cases develop chronic postinfectious inflammatory arthritis that can be challenging to manage. Recently, as more biologic, and targeted synthetic DMARDs have become available, treatment options have expanded.

SUMMARY

In this article, we use the term 'postinfectious inflammatory arthritis' rather than 'reactive arthritis' because it describes a broader spectrum of diseases and emphasizes the common pathogenesis of a postinfectious inflammatory process. We summarize the conventional therapies and recent management developments for the most frequently encountered postinfectious inflammatory arthritides.

Borrelia-specific antibody profiles and complement deposition in joint fluid distinguish antibiotic-refractory from -responsive Lyme arthritis

Lyme arthritis, caused by the spirochete Borrelia burgdorferi, is the most common feature of late disseminated Lyme disease in the United States. While most Lyme arthritis resolves with antibiotics, termed "antibiotic-responsive", some individuals develop progressive synovitis despite antibiotic therapy, called "antibiotic-refractory" Lyme arthritis (LA). The primary drivers behind antibiotic-refractory arthritis remain incompletely understood. We performed a matched, cross-compartmental comparison of antibody profiles from blood and joint fluid of individuals with antibiotic-responsive (n = 11) or antibiotic-refractory LA (n = 31). While serum antibody profiles poorly discriminated responsive from refractory patients, a discrete profile of B.burgdorferi-specific antibodies in joint fluid discriminated antibiotic-responsive from refractory LA. Cross-compartmental comparison of antibody glycosylation, IgA1, and antibody-dependent complement deposition (ADCD) revealed more poorly coordinated humoral responses and increased ADCD in refractory disease. These data reveal B.burgdorferi-specific serological markers that may support early stratification and clinical management, and point to antibody-dependent complement activation as a key mechanism underlying persistent disease.

Intestinal flora, intestinal metabolism, and intestinal immunity changes in complete Freud's adjuvant-rheumatoid arthritis C57BL/6 mice

Rheumatoid arthritis (RA) is an inflammatory-mediated autoimmune disease characterized by persistent joint enlargement, synovial cartilage damage, and inflammatory infiltrates. Although the pathogenesis and treatment of RA are still currently insufficient, the importance of the intestine flora, metabolism and immunity for RA has been gradually recognized, and many intestine regulatory strategies have been used to treat RA. However, the relationship between RA and intestine flora, metabolism and immunity has not been fully expounded. In this study, Complete Freund's Adjuvant (CFA) was used to establish RA model, CyTOF technology was used to study the changes of intestinal immune cell types, 16S rRNA technology was used to analyze the differences of intestinal flora, and LC-MS technology was used to explain the effects of metabolites produced by the changed intestinal flora on RA. Moreover, we systematically explored how the imbalance of intestinal flora changed the intestinal immune status through its metabolites in RA mice. Our results showed that the intestinal flora of RA mice changed significantly, and the bacteria producing short-chain fatty acids (SCFAs), indole classes and secondary bile acids were significantly reduced. The abundance of SCFAs, indole classes and secondary bile acids in the intestine were significantly decreased. The balance of immune cells in the intestine of RA mice was significantly disrupted, with an overall decrease in immune cells. This work reveals the possible relationship between intestinal flora, metabolism and immunity and RA in mice, which will provide new therapeutic strategies for RA.

Autoimmunity to synovial extracellular matrix proteins in patients with postinfectious Lyme arthritis

BACKGROUNDAutoimmune diseases often have strong genetic associations with specific HLA-DR alleles. The synovial lesion in chronic inflammatory forms of arthritis shows marked upregulation of HLA-DR molecules, including in postinfectious Lyme arthritis (LA). However, the identity of HLA-DR-presented peptides, and therefore the reasons for these associations, has frequently remained elusive.METHODSUsing immunopeptidomics to detect HLA-DR-presented peptides from synovial tissue, we identified T cell epitopes from 3 extracellular matrix (ECM) proteins in patients with postinfectious LA, identified potential Borreliella burgdorferi-mimic (Bb-mimic) epitopes, and characterized T and B cell responses to these peptides or proteins.RESULTSOf 24 postinfectious LA patients, 58% had CD4+ T cell responses to at least 1 epitope of 3 ECM proteins, fibronectin-1, laminin B2, and/or collagen Vα1, and 17% of 52 such patients had antibody responses to at least 1 of these proteins. Patients with autoreactive T cell responses had significantly increased frequencies of HLA-DRB1*04 or -DRB1*1501 alleles and more prolonged arthritis. When tetramer reagents were loaded with ECM or corresponding Bb-mimic peptides, binding was only with the autoreactive T cells. A high percentage of ECM-autoreactive CD4+ T cells in synovial fluid were T-bet-expressing Th1 cells, a small percentage were RoRγt-expressing Th17 cells, and a minimal percentage were FoxP3-expressing Tregs.CONCLUSIONAutoreactive, proinflammatory CD4+ T cells and autoantibodies develop to ECM proteins in a subgroup of postinfectious LA patients who have specific HLA-DR alleles. Rather than the traditional molecular mimicry model, we propose that epitope spreading provides the best explanation for this example of infection-induced autoimmunity.FUNDINGSupported by National Institute of Allergy and Infectious Diseases R01-AI101175, R01-AI144365, and F32-AI125764; National Institute of Arthritis and Musculoskeletal and Skin Diseases K01-AR062098 and T32-AR007258; NIH grants P41-GM104603, R24-GM134210, S10-RR020946, S10-OD010724, S10-OD021651, and S10-OD021728; and the G. Harold and Leila Y. Mathers Foundation, the Eshe Fund, and the Lyme Disease and Arthritis Research Fund at Massachusetts General Hospital.

Heightened Proinflammatory Glycosylation of Borrelia burgdorferi IgG Antibodies in Synovial Fluid in Patients With Antibiotic-Refractory Lyme Arthritis

OBJECTIVE

Terminal glycans on the Fc portion of IgG antibodies are critical for antibody-triggered, proinflammatory or antiinflammatory responses. We undertook this study to compare glycan profiles of total IgG1 and Borrelia burgdorferi (Bb)-specific IgG1 antibodies in patients with oral antibiotic-responsive or antibiotic-refractory Lyme arthritis (LA).

METHODS

Following affinity-column processing, glycan profiles of IgG antibodies were determined in serum and synovial fluid (SF) samples of 21 LA patients using glycoblotting with hydrazide glycan enrichment and determination of glycan structure by matrix-assisted laser desorption ionization-time-of-flight mass spectrometry. Correlations between glycan profiles and treatment outcomes were analyzed.

RESULTS

Compared with patients with antibiotic-refractory LA, those with antibiotic-responsive LA had total and Bb-specific IgG1 antibody glycans with less intense inflammatory profiles, containing lower percentages of N-acetylglucosamine (GlcNAc) and bisecting GlcNAc and higher percentages of galactose and fucose. In contrast, patients with antibiotic-refractory LA prior to receiving IV antibiotic therapy had total IgG1 and Bb IgG1 antibodies with maximal, minimally opposed, proinflammatory glycan profiles, containing high percentages of GlcNAc and bisecting GlcNAc, intermediate percentages with galactose and fucose, and low percentages with N-acetylneuraminic acid (sialic acid). Patients with refractory LA who were first seen with synovitis after receiving IV antibiotic therapy still had Bb IgG1 antibodies with strongly inflammatory glycan profiles, but their inflammatory potential appeared to be waning.

CONCLUSION

Patients with oral antibiotic-responsive LA had Bb IgG1 antibodies with more balanced proinflammatory/antiinflammatory glycan profiles, whereas patients with antibiotic-refractory LA had Bb IgG1 antibodies with maximal, minimally opposed, proinflammatory glycan profiles. Among patients with antibiotic-refractory LA, antibodies with this unbalanced inflammatory glycan profile may have a role in sustaining maladaptive joint inflammation.

Cell-Mediated Cytotoxicity in Lyme Arthritis

OBJECTIVE

Obliterative microvascular lesions are found in the synovial tissue of ~50% of patients with post-antibiotic Lyme arthritis (LA) and correlate with autoantibodies to certain vascular antigens. In this study, we identified lymphocytes with cytotoxic potential that may also mediate this feature of synovial pathology.

METHODS

The cytotoxic potential of lymphocytes and their T cell receptor (TCR) Vβ gene usage were determined using samples of peripheral blood mononuclear cells (PBMCs) and synovial fluid mononuclear cells (SFMCs) from patients with antibiotic-responsive or post-antibiotic LA. Cell phenotypes were analyzed using flow cytometry and intracellular cytokine staining. Immunohistochemistry was performed on post-antibiotic synovial tissue samples.

RESULTS

In SFMC and PBMC samples, the percentages of CD8+ T cells and double-negative T cells (primarily γδ T cells) were greater among 22 patients with post-antibiotic LA than in 14 patients with antibiotic-responsive LA. Moreover, CD8+ T cells and γδ T cells often expressed cytotoxic mediators, granzyme A/granzyme B, and perforin. The same 3 TCR Vβ segments were over-represented in both CD4+ T cells and CD8+ T cells in SFMC samples from post-antibiotic LA patients. In synovial tissue samples from 3 patients with post-antibiotic LA, CD8+ T cells intermixed with CD4+ T cells were seen around blood vessels, and 2 patients with microvascular damage had autoantibodies to vascular-associated antigens. One of these 2 patients, the one in whom cytotoxicity appeared to be active, had complement (C5b-9) deposition on obliterated vessels. Very few natural killer cells or γδ T cells were seen.

CONCLUSION

We propose that CD8+ T cell-mediated cytotoxicity, CD4+ T cell help, autoantibodies to vascular antigens, and complement deposition may each have a role in microvasculature damage in post-antibiotic LA.

Commonly Used Therapeutics Associated with Changes in Arousal Inhibit GABAAR Activation

GABA_A receptor-positive modulators are well-known to induce sedation, sleep, and general anesthesia. Conversely, GABA_A receptor negative allosteric modulators (GABA_ARNAMs) can increase arousal and induce seizures. Motivated by our studies with patients with hypersomnia, and our discovery that two GABA_ARNAMs can restore the Excitation/Inhibition (E/I) balance in vitro and arousal in vivo, we chose to screen 11 compounds that have been reported to modulate arousal, to see if they shared a GABA-related mechanism. We determined modulation with both conventional and microfluidic patch clamp methods. We found that receptor activation was variably modulated by all 11 compounds: Rifampicin (RIF), Metronidazole (MET), Minocycline (MIN), Erythromycin (ERY), Ofloxacin (OFX), Chloroquine (CQ), Hydroxychloroquine sulfate (HCQ), Flumazenil (FLZ), Pentylenetetrazol (PTZ), (-)-Epigallocatechin Gallate (EGCG), and clarithromycin (CLR). The computational modeling of modulator-receptor interactions predicted drug action at canonical binding sites and novel orphan sites on the receptor. Our findings suggest that multiple avenues of investigation are now open to investigate large and brain-penetrant molecules for the treatment of patients with diminished CNS E/I balance.

Neuropsychiatric Symptoms and Tick-Borne Diseases

In North America, Lyme disease (LD) is primarily caused by the spirochetal bacterium Borrelia burgdorferi, transmitted to humans by Ixodes species tick bites, at an estimated rate of 476,000 patients diagnosed per year. Acute LD often manifests with flu-like symptoms and an expanding rash known as erythema migrans (EM) and less often with neurologic, neuropsychiatric, arthritic, or cardiac features. Most acute cases of Lyme disease are effectively treated with antibiotics, but 10-20% of individuals may experience recurrent or persistent symptoms. This chapter focuses on the neuropsychiatric aspects of Lyme disease, as these are less widely recognized by physicians and often overlooked. Broader education about the potential complexity, severity, and diverse manifestations of tick-borne diseases is needed.

Lyme Disease in Children

Lyme disease is now the most frequently reported vector-borne disease in the United States. The highest incidence is in children aged 5 to 9 years with a male predominance. The most common manifestation, erythema migrans, is sometimes not recognized, leading to risk of complications. Testing for Lyme disease should only be done if there is a consistent clinical syndrome with exposure in a Lyme-endemic area. Most forms of Lyme disease are successfully treated with short courses of oral therapy. Prevention and management of tick bites is important.

Lyme Arthritis

Arthritis is the most common late manifestation of Borrelia burgdorferi infection in the United States, usually beginning months after the tick bite. In most patients with Lyme arthritis (LA) today, arthritis is the presenting manifestation of the disease. Patients have swelling and pain in one or a few large joints, especially the knee. Serologic testing is the mainstay of diagnosis. Responses to antibiotic treatment are generally excellent, although a small percentage of patients have persistent, postinfectious synovitis after 2 to 3 months of oral and IV antibiotics, which respond to anti-inflammatory therapies. Herein we review the clinical presentation, diagnosis, and management of LA.

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.

The Value of Musculoskeletal Ultrasound for Evaluation of Postinfectious Lyme Arthritis

BACKGROUND

Inflammatory arthritis is the most common late manifestation of untreated Lyme disease in the United States. While antimicrobial therapy is effective in resolving swelling and pain for 90% of patients, many patients have persistent inflammation, termed postinfectious Lyme arthritis (PILA). Current outcome measures for Lyme arthritis have several limitations, as improvement is considered a dichotomous outcome based solely on physical examination. There is growing interest in the use of ultrasonography to better define outcomes in inflammatory arthritis, and this is particularly relevant for conditions such as late Lyme arthritis and PILA, which are monoarticular or oligoarticular. We describe results from a series of 5 patients who underwent ultrasound evaluations leading to a diagnosis of PILA.

METHODS

This is a case series describing 5 patients with PILA who were referred for evaluation and treatment of symptomatic joints.

RESULTS

Musculoskeletal ultrasound showed significant joint pathology, even in cases with minimal clinical findings. Synovitis, effusions, enthesitis/tendinopathy, and bone erosions were seen and helped confirm the presence of ongoing inflammatory arthritis.

CONCLUSIONS

Marked inflammatory change-with synovitis, enthesitis and erosions-can be seen in selected patients with PILA. Systematic sonographic evaluation of patients with PILA is needed to further evaluate pathology and treatment response.

The year that shaped the outcome of the OspA vaccine for human Lyme disease

The expansion of Lyme borreliosis endemic areas and the corresponding increase of disease incidence have opened the possibility for greater acceptance of a vaccine. In this perspective article, we discuss the discovery of outer surface protein A (OspA) of B. burgdorferi, and the subsequent pre-clinical testing and clinical trials of a recombinant OspA vaccine for human Lyme disease. We also discuss in detail the open public hearings of the FDA Lyme disease vaccine advisory panel held in 1998 where concerns of molecular mimicry induced autoimmunity to native OspA were raised, the limitations of those studies, and the current modifications of recombinant OspA to develop a multivalent subunit vaccine for Lyme disease.

Stages of Lyme Arthritis

BACKGROUND/HISTORICAL PERSPECTIVE

Lyme arthritis was described in 1977, after an apparent outbreak of juvenile idiopathic arthritis in Lyme, Connecticut. The evolution of the disease has been meticulously described with presentation dependent on disease duration and previous therapy.

SUMMARY INTEGRATING PUBLISHED LITERATURE

Erythema migrans is typically the first manifestation. Untreated patients often develop early disseminated disease, characterized by migratory polyarthralgia, potentially with cardiac and/or neurologic sequelae. If untreated, most patients develop late Lyme arthritis, characterized as a monoarthritis or oligoarthritis, typically involving the knees. Serologies are strongly positive at this stage; if positive, Lyme PCR from synovial fluid confirms the diagnosis. Doxycycline is recommended for late Lyme arthritis, although amoxicillin or ceftriaxone may be considered.Initial antibiotic therapy for late Lyme arthritis is insufficient for a subset of patients. However, serologies and synovial fluid PCR are not useful at determining whether infection persists after oral therapy. As such, ceftriaxone is recommended in patients with inadequate response to doxycycline or amoxicillin.Approximately 10% of patients have persistent arthritis despite antimicrobial therapy, termed postinfectious Lyme arthritis, which is thought to be related to prolonged inflammation and unique microbial and host interaction. Therapy at this stage relies on immunosuppression and/or synovectomy.

MAJOR CONCLUSIONS AND FUTURE RESEARCH

Lyme arthritis provides unique insights into the complex interplay between microbes and host immunity. The progression from localized erythema migrans to early disseminated disease and late Lyme arthritis allows insight into arthritis initiation, and the study of postinfectious Lyme arthritis allows further insight into mechanisms of arthritis persistence.

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.

Lyme arthritis in Western Europe: a multicentre retrospective study

To characterize Lyme arthritis, with a focus on management, and outcome. Observational retrospective multicentre study in Western France, of all consecutive cases of Lyme arthritis, documented by Borrelia burgdorferi IgG on ELISA serological testing, confirmed by Western blot, with or without positive Borrelia PCR in synovial fluid, with no alternative diagnosis. We enrolled 52 patients (29 males), with a mean age of 43 ± 19.4 years. Most patients had monoarthritis (n = 43, 82.7%), involving the knee (n = 51, 98.1%), with a median delay between symptoms onset and Lyme arthritis diagnosis of 5 months (interquartile range, 1.5-8). Synovial fluid analysis yielded median white cell count of 16,000/mm³ (9230-40,500), and positive PCR in 16 cases (39%), for B. burgdorferi sensu stricto (n = 5), B. garinii (n = 5), B. afzelii (n = 3), and undetermined (n = 3). All patients received antibiotics, for a median duration of 28 days (21-30), with doxycycline (n = 44, 84.6%), ceftriaxone (n = 6, 11.5%), or amoxicillin (n = 2). Twelve patients (23.1%) also received intra-articular injection of glucocorticoids as first-line treatment. Of 47 patients with follow-up, 35 (74.5%) had complete resolution of Lyme arthritis. Lyme arthritis in Western Europe may be due to B. burgdorferi ss, B. afzelii, or B. garinii. Clinical presentation is similar to Lyme arthritis in North America (i.e. chronic knee monoarthritis), with low sensitivity of synovial fluid PCR (39%).

Recent Progress in Lyme Disease and Remaining Challenges

Lyme disease (also known as Lyme borreliosis) is the most common vector-borne disease in the United States with an estimated 476,000 cases per year. While historically, the long-term impact of Lyme disease on patients has been controversial, mounting evidence supports the idea that a substantial number of patients experience persistent symptoms following treatment. The research community has largely lacked the necessary funding to properly advance the scientific and clinical understanding of the disease, or to develop and evaluate innovative approaches for prevention, diagnosis, and treatment. Given the many outstanding questions raised into the diagnosis, clinical presentation and treatment of Lyme disease, and the underlying molecular mechanisms that trigger persistent disease, there is an urgent need for more support. This review article summarizes progress over the past 5 years in our understanding of Lyme and tick-borne diseases in the United States and highlights remaining challenges.

Lyme arthritis: linking infection, inflammation and autoimmunity

Infectious agents can trigger autoimmune responses in a number of chronic inflammatory diseases. Lyme arthritis, which is caused by the tick-transmitted spirochaete Borrelia burgdorferi, is effectively treated in most patients with antibiotic therapy; however, in a subset of patients, arthritis can persist and worsen after the spirochaete has been killed (known as post-infectious Lyme arthritis). This Review details the current understanding of the pathogenetic events in Lyme arthritis, from initial infection in the skin, through infection of the joints, to post-infectious chronic inflammatory arthritis. The central feature of post-infectious Lyme arthritis is an excessive, dysregulated pro-inflammatory immune response during the infection phase that persists into the post-infectious period. This response is characterized by high amounts of IFNγ and inadequate amounts of the anti-inflammatory cytokine IL-10. The consequences of this dysregulated pro-inflammatory response in the synovium include impaired tissue repair, vascular damage, autoimmune and cytotoxic processes, and fibroblast proliferation and fibrosis. These synovial characteristics are similar to those in other chronic inflammatory arthritides, including rheumatoid arthritis. Thus, post-infectious Lyme arthritis provides a model for other chronic autoimmune or autoinflammatory arthritides in which complex immune responses can be triggered and shaped by an infectious agent in concert with host genetic factors.

Clinical Practice Guidelines by the Infectious Diseases Society of America (IDSA), American Academy of Neurology (AAN), and American College of Rheumatology (ACR): 2020 Guidelines for the Prevention, Diagnosis and Treatment of Lyme Disease

This evidence-based clinical practice guideline for the prevention, diagnosis, and treatment of Lyme disease was developed by a multidisciplinary panel representing the Infectious Diseases Society of America (IDSA), the American Academy of Neurology (AAN), and the American College of Rheumatology (ACR). The scope of this guideline includes prevention of Lyme disease, and the diagnosis and treatment of Lyme disease presenting as erythema migrans, Lyme disease complicated by neurologic, cardiac, and rheumatologic manifestations, Eurasian manifestations of Lyme disease, and Lyme disease complicated by coinfection with other tick-borne pathogens. This guideline does not include comprehensive recommendations for babesiosis and tick-borne rickettsial infections, which are published in separate guidelines. The target audience for this guideline includes primary care physicians and specialists caring for this condition such as infectious diseases specialists, emergency physicians, internists, pediatricians, family physicians, neurologists, rheumatologists, cardiologists and dermatologists in North America.

Lyme Disease among Patients at an Ambulatory Unit in a Highly Endemic Country: Lithuania

Background and objectives: Lyme disease is the most common tick-borne infectious disease in Europe, caused by the spirocheta bacteria of Borrelia burgdorferi. Several genospecies of B. burgdorferi are pathogenic to humans. B. burgdorferi sensu stricto, which is prevalent in North America, causes reactive arthritis, whereas B. garinii and B. afzelii, common in Europe, can affect the skin, heart, or nervous system; it has been shown that the clinical symptoms of the disease may be very different. The objective of this study was to identify the baseline characteristics of Lyme disease and to elucidate the frequency of different Lyme disease syndromes in Lithuania. Materials and Methods: Patients who were diagnosed with Lyme disease during an ambulatory visit to the Center of Infectious Diseases, Vilnius University Santaros clinics, from 2014 to 2016, were enrolled in this study. A retrospective material analysis was conducted. Results: In total, 1005 patients were enrolled with the following prevalence of clinical syndromes: erythema migrans (EM), 945 (94.02%); Lyme arthritis, 32 (3.18%); neuroborreliosis, 23 (2.28%); Lyme carditis, 4 (0.39%); and acrodermatitis, 1 (0.09%). Erythema migrans was dominant among middle-aged women, with a rash appearing mainly on the lower extremities. Lyme arthritis mainly manifested among middle-aged women as an oligoarthritis, mostly affecting the knee joint. Neuroborreliosis was seen more often in middle-aged women than men and the main symptom was nervus facialis neuropathy. Lyme carditis, manifested as an atrioventricular block, with a male/female ratio of 3:1, and the median age was 51. Acrodermatitis was diagnosed in a 61-year-old woman, as a painful, red rash on the hand. Conclusions: According to the prevalence of B. garinii and B. afzelii in Europe, previously it was thought that Lyme disease presented as erythema migrans, and less frequently as neuroborreliosis; however, this study revealed that other syndromes may also be seen. In addition, we revealed that the longer it takes for erythema migrans to appear, the greater the likelihood of Lyme arthritis developing.

Arthritis and Diagnostics in Lyme Disease

The diagnosis of Lyme disease, caused by Borrelia burgdorferi, is clinical but frequently supported by laboratory tests. Lyme arthritis is now less frequently seen than at the time of its discovery. However, it still occurs, and it is important to recognize this, the differential diagnoses, and how laboratory tests can be useful and their limitations. The most frequently used diagnostic tests are antibody based. However, antibody testing still suffers from many drawbacks and is only an indirect measure of exposure. In contrast, evolving direct diagnostic methods can indicate active infection.

Lyme disease: diagnosis and treatment

PURPOSE OF REVIEW

Lyme disease is an important, vector-borne infection found throughout the temperate Northern hemisphere. The disease causes rash, acute systemic illness, and in some untreated patients, inflammatory arthritis. This review examines the emergence, clinical features and management of early Lyme disease and Lyme arthritis.

RECENT FINDINGS

There has been continuing progress in characterizing the clinical manifestations, diagnostic testing and treatment of Lyme disease. Almost all patients with early Lyme disease can be cured with antibiotic treatment. In most cases, Lyme arthritis also responds to antibiotics, but some patients require additional treatment approaches.

SUMMARY

The diagnosis of Lyme disease is based on clinical manifestations and adjunctive laboratory testing. For the rheumatologist, Lyme arthritis should be recognized by a pattern of attacks of asymmetric, oligo-arthritis, recognizable by clinical manifestations in the same way that other rheumatic diseases, such as gout or rheumatoid arthritis, are diagnosed.

Host transcriptome response to Borrelia burgdorferi sensu lato

The host immune response to infection is a well-coordinated system of innate and adaptive immune cells working in concert to prevent the colonization and dissemination of a pathogen. While this typically leads to a beneficial outcome and the suppression of disease pathogenesis, the Lyme borreliosis bacterium, Borrelia burgdorferi sensu lato, can elicit an immune profile that leads to a deleterious state. As B. burgdorferi s.l. produces no known toxins, it is suggested that the immune and inflammatory response of the host are responsible for the manifestation of symptoms, including flu-like symptoms, musculoskeletal pain, and cognitive disorders. The past several years has seen a substantial increase in the use of microarray and sequencing technologies to investigate the transcriptome response induced by B. burgdorferi s.l., thus enabling researchers to identify key factors and pathways underlying the pathophysiology of Lyme borreliosis. In this review we present the major host transcriptional outcomes induced by the bacterium across several studies and discuss the overarching theme of the host inflammatory and immune response, and how it influences the pathology of Lyme borreliosis.

The Jarisch-Herxheimer reaction associated with doxycycline in a patient with Lyme arthritis

Objectives

The objective of this article was to present the clinical peculiarity of the Jarisch-Herxheimer reaction (JHR) during antibiotic treatment of Lyme arthritis.

Material and methods

Case study presentation as a basis for discussion, literature search of PubMed database particularly in the subject of combination of the JHR and Lyme borreliosis using the combination of words “Jarisch-Herxheimer reaction” and “Lyme borreliosis”, “Lyme arthritis”, “antibiotic treatment”, “generalized inflammation”, “cytokine production”, “children”, “increasing awareness”; discussion of the problem based on a clinical case and cited articles.

Results

The authors present a case of Lyme arthritis in a 13-year-old boy, as well as a discussion of clinical features of this complication of Lyme disease treatment as the Jarisch-Herxheimer reaction. On the 7^th day of doxycycline treatment the patient’s condition deteriorated: a low-grade fever occurred, and severe arthralgias with intense hip, ankle and cervical spine pain and myalgias developed. Erythrocyte sedimentation rate and C-reactive protein were elevated. The Jarisch-Herxheimer reaction was diagnosed. This complication was characterized by severity, long duration and marked signs of inflammation.

Conclusions

In the reviewed literature the Jarisch-Herxheimer reaction in patients with Lyme borreliosis is described more often in adults, with mild course and short duration of the disease. Based on the presented clinical picture this severe complication may also be associated with long duration and marked signs of inflammation. The authors suggest that informing health professionals about occurrence of the Jarisch-Herxheimer reaction should help physicians to distinguish it from allergic reactions or other conditions and improve treatment outcomes.

Genetic Background Amplifies the Effect of Immunodeficiency in Antibiotic Efficacy Against Borrelia burgdorferi

Unrecognized immunodeficiency has been proposed as a possible cause of failure of antibiotics to resolve symptoms of Lyme disease. Here, we examined the efficacy of doxycycline in different immunodeficient mice to identify defects that impair antibiotic treatment outcomes. We found that doxycycline had significantly lower efficacy in the absence of adaptive immunity, specifically B cells. This effect was most pronounced in immunodeficient C3H mice compared with C57BL/6 mice, suggesting a role for genetic background beyond immunodeficiency. Addition of a single dose of ceftriaxone to doxycycline treatment effectively cleared infection in C3H mice with severe combined immunodeficiency.

Effect of dapsone alone and in combination with intracellular antibiotics against the biofilm form of B. burgdorferi

Objective

Lyme disease is a tick-borne, multisystemic disease caused by Borrelia burgdorferi. Standard treatments for early Lyme disease include short courses of oral antibiotics but relapses often occur after discontinuation of treatment. Several studies have suggested that ongoing symptoms may be due to a highly antibiotic resistant form of B. burgdorferi called biofilms. Our recent clinical study reported the successful use of an intracellular mycobacterium persister drug used in treating leprosy, diaminodiphenyl sulfone (dapsone), in combination therapy for the treatment of Lyme disease. In this in vitro study, we evaluated the effectiveness of dapsone individually and in combination with cefuroxime and/or other antibiotics with intracellular activity including doxycycline, rifampin, and azithromycin against Borrelia biofilm forms utilizing crystal violet biofilm mass, and dimethyl methylene blue glycosaminoglycan assays combined with Live/Dead fluorescent microscopy analyses.

Results

Dapsone, alone or in various combinations with doxycycline, rifampin and azithromycin produced a significant reduction in the mass and protective glycosaminoglycan layer and overall viability of B. burgdorferi biofilm forms. This in vitro study strongly suggests that dapsone combination therapy could represent a novel and effective treatment option against the biofilm form of B. burgdorferi.

Protection against Borreliella burgdorferi infection mediated by a synthetically engineered DNA vaccine

Lyme disease is the most common vector-borne disease in North America. The etiological agent is the spirochete Borreliella burgdorferi, transmitted to mammalian hosts by the Ixodes tick. In recent years there has been an increase in the number of cases of Lyme disease. Currently, there is no vaccine on the market for human use. We describe the development of a novel synthetically engineered DNA vaccine, pLD1 targeting the outer-surface protein A (OspA) of Borreliella burgdorferi. Immunization of C3 H/HeN mice with pLD1 elicits robust humoral and cellular immune responses that confer complete protection against a live Borreliella burgdorferi bacterial challenge. We also assessed intradermal (ID) delivery of pLD1 in Hartley guinea pigs, demonstrating the induction of robust and durable humoral immunity that lasts at least 1 year. We provide evidence of the potency of pLD1 by showing that antibodies targeting the OspA epitopes which have been associated with protection are prominently raised in the immunized guinea pigs. The described study provides the basis for the advancement of pDL1 as a potential vaccine for Lyme disease control.

Ex Vivo Murine Skin Model for B. burgdorferi Biofilm

Borrelia burgdorferi, the causative agent of Lyme disease, has been recently shown to form biofilm structures in vitro and in vivo. Biofilms are tightly clustered microbes characterized as resistant aggregations that allow bacteria to withstand harsh environmental conditions, including the administration of antibiotics. Novel antibiotic combinations have recently been identified for B. burgdorferi in vitro, however, due to prohibiting costs, those agents have not been tested in an environment that can mimic the host tissue. Therefore, researchers cannot evaluate their true effectiveness against B. burgdorferi, especially its biofilm form. A skin ex vivo model system could be ideal for these types of experiments due to its cost effectiveness, reproducibility, and ability to investigate host-microbial interactions. Therefore, the main goal of this study was the establishment of a novel ex vivo murine skin biopsy model for B. burgdorferi biofilm research. Murine skin biopsies were inoculated with B. burgdorferi at various concentrations and cultured in different culture media. Two weeks post-infection, murine skin biopsies were analyzed utilizing immunohistochemical (IHC), reverse transcription PCR (RT-PCR), and various microscopy methods to determine B. burgdorferi presence and forms adopted as well as whether it remained live in the skin tissue explants. Our results showed that murine skin biopsies inoculated with 1 × 107 cells of B. burgdorferi and cultured in BSK-H + 6% rabbit serum media for two weeks yielded not just significant amounts of live B. burgdorferi spirochetes but biofilm forms as well. IHC combined with confocal and atomic force microscopy techniques identified specific biofilm markers and spatial distribution of B. burgdorferi aggregates in the infected skin tissues, confirming that they are indeed biofilms. In the future, this ex vivo skin model can be used to study development and antibiotic susceptibility of B. burgdorferi biofilms in efforts to treat Lyme disease effectively.

Successful reintroduction of tumour necrosis factor-alpha inhibition after treatment of disseminated Lyme borreliosis

The importance of tumour necrosis factor-alpha (TNF-α) in the human immune response to Borrelia burgdorferi is uncertain. Murine models suggest a critical role, including spirochaete reactivation following TNF-α inhibition. Our case, combined with a review of the clinical and scientific literature, provides reassurance that TNF-α inhibition can be safely reinstituted after treatment of disseminated borreliosis with standard duration antimicrobial chemotherapy.

If case reports be the food of knowledge, write on: our Cases of the Quarter

The value of publishing case reports has long been debated and the arguments are summarised. Last year, to encourage trainees, the Royal College of Physicians of Edinburgh's Senior Fellows Club inaugurated an annual prize for the best case report or case series published in the Journal of the Royal College of Physicians of Edinburgh by a doctor in training. Some of the highlights of last year's entries are reviewed, commented on and developed. They include cases of myelofibrosis and cherubism due to secondary hyperparathyroidism from renal failure; reversible blindness in diabetic ketoacidosis; the long QT syndrome; ictal asystole; giant cell arteritis; tumour necrosis factor-α inhibition in Lyme borreliosis; and cannabis hyperemesis syndrome.

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.

A joint effort: The interplay between the innate and the adaptive immune system in Lyme arthritis

Articular joints are a major target of Borrelia burgdorferi, the causative agent of Lyme arthritis. Despite antibiotic treatment, recurrent or persistent Lyme arthritis is observed in a significant number of patients. The host immune response plays a crucial role in this chronic arthritic joint complication of Borrelia infections. During the early stages of B. burgdorferi infection, a major hinder in generating a proper host immune response is the lack of induction of a strong adaptive immune response. This may lead to a delayed hyperinflammatory reaction later in the disease. Several mechanisms have been suggested that might be pivotal for the development of Lyme arthritis and will be highlighted in this review, from molecular mimicry of matrix metallopeptidases and glycosaminoglycans, to autoimmune responses to live bacteria, or remnants of Borrelia spirochetes in joints. Murine studies have suggested that the inflammatory responses are initiated by innate immune cells, but this does not exclude the involvement of the adaptive immune system in this dysregulated immune profile. Genetic predisposition, via human leukocyte antigen-DR isotype and microRNA expression, has been associated with the development of antibiotic-refractory Lyme arthritis. Yet the ultimate cause for (antibiotic-refractory) Lyme arthritis remains unknown. Complex processes of different immune cells and signaling cascades are involved in the development of Lyme arthritis. When these various mechanisms are fully been unraveled, new treatment strategies can be developed to target (antibiotic-refractory) Lyme arthritis more effectively.

Skin inflammation associated with arthritis, synovitis and enthesitis. Part 2: rheumatoid arthritis, reactive arthritis, Reiter's syndrome, Lyme borreliosis, dermatomyositis and lupus erythematosus

Syndromes associated with concurrent skin and joint inflammation frequently pose a therapeutic challenge for both dermatologists and rheumatologists. In part 1 of this review, we discussed psoriatic arthritis as well as the autoinflammatory disorders SAPHO syndrome, Still's disease and Behçet's disease. Part 2 will address rheumatoid arthritis, reactive arthritis, Reiter's syndrome and Lyme borreliosis. In addition, we will discuss dermatomyositis and lupus erythematosus, two common autoimmune disorders that frequently present with both cutaneous and joint involvement. For each of the aforementioned disorders, we will highlight aspects of epidemiology, pathogenesis, clinical presentation, diagnosis and treatment.

Post-treatment Lyme Disease as a Model for Persistent Symptoms in Lyme Disease

It has long been observed in clinical practice that a subset of patients with Lyme disease report a constellation of symptoms such as fatigue, cognitive difficulties, and musculoskeletal pain, which may last for a significant period of time. These symptoms, which can range from mild to severe, have been reported throughout the literature in both prospective and population-based studies in Lyme disease endemic regions. The etiology of these symptoms is unknown, however several illness-causing mechanisms have been hypothesized, including microbial persistence, host immune dysregulation through inflammatory or secondary autoimmune pathways, or altered neural networks, as in central sensitization. Evaluation and characterization of persistent symptoms in Lyme disease is complicated by potential independent, repeat exposures to B. burgdorferi, as well as the potential for co-morbid diseases with overlapping symptom profiles. Antibody testing for B. burgdorferi is an insensitive measure after treatment, and no other FDA-approved tests currently exist. As such, diagnosis presents a complex challenge for physicians, while the lived experience for patients is one marked by uncertainty and often illness invalidation. Currently, there are no FDA-approved pharmaceutical therapies, and the safety and efficacy of off-label and/or complementary therapies have not been well studied and are not agreed-upon within the medical community. Post-treatment Lyme disease represents a narrow, defined, mechanistically-neutral subset of this larger, more heterogeneous group of patients, and is a useful definition in research settings as an initial subgroup of study. The aim of this paper is to review the current literature on the diagnosis, etiology, risk factors, and treatment of patients with persistent symptoms in the context of Lyme disease. The meaning and relevance of existing patient subgroups will be discussed, as will future research priorities, including the need to develop illness biomarkers, elucidate the biologic mechanisms of disease, and drive improvements in therapeutic options.

Challenges in the Diagnosis and Treatment of Lyme Disease

PURPOSE OF REVIEW

Since recognition in 1975, Lyme disease has become the most common vector-borne illness in North America and Europe. The clinical features are well-characterized and treatment is usually curative, but misperceptions about morbidity persist. The purpose of this review is to examine advances in the diagnosis and treatment of Lyme disease, as well as ongoing management challenges.

RECENT FINDINGS

It is useful to recognize that Lyme disease occurs in stages, with early- and late-stage disease. Clinical expression is in part determined by Borrelial variability. For example, some strains of Borrelia burgdorferi, the causative organism in North America, are particularly arthritogenic. Most patients with early Lyme disease can be cured with a single course of oral antibiotic therapy, in contrast to some patients with Lyme arthritis, a late-stage manifestation, who are more antibiotic refractory and require other treatment strategies. Successful treatment of Lyme disease begins with successful diagnosis and with an understanding of the emergence, clinical features, and impact of Lyme disease over the past half century.

The Long-Term Persistence of Borrelia burgdorferi Antigens and DNA in the Tissues of a Patient with Lyme Disease

Whether Borrelia burgdorferi, the causative agent of Lyme disease, can persist for long periods in the human body has been a controversial question. The objective of this study was to see if we could find B. burgdorferi in a Lyme disease patient after a long clinical course and after long-term antibiotic treatment. Therefore, we investigated the potential presence of B. burgdorferi antigens and DNA in human autopsy tissues from a well-documented serum-, PCR-, and culture-positive Lyme disease patient, a 53-year-old female from northern Westchester County in the lower Hudson Valley Region of New York State, who had received extensive antibiotic treatments during extensive antibiotic treatments over the course of her 16-year-long illness. We also asked what form the organism might take, with special interest in the recently found antibiotic-resistant aggregate form, biofilm. We also examined the host tissues for the presence of inflammatory markers such as CD3+ T lymphocytes. Autopsy tissue sections of the brain, heart, kidney, and liver were analyzed by histological and immunohistochemical methods (IHC), confocal microscopy, fluorescent in situ hybridization (FISH), polymerase chain reaction (PCR), and whole-genome sequencing (WGS)/metagenomics. We found significant pathological changes, including borrelial spirochetal clusters, in all of the organs using IHC combined with confocal microscopy. The aggregates contained a well-established biofilm marker, alginate, on their surfaces, suggesting they are true biofilm. We found B. burgdorferi DNA by FISH, polymerase chain reaction (PCR), and an independent verification by WGS/metagenomics, which resulted in the detection of B. burgdorferi sensu stricto specific DNA sequences. IHC analyses showed significant numbers of infiltrating CD3+ T lymphocytes present next to B. burgdorferi biofilms. In summary, we provide several lines of evidence that suggest that B. burgdorferi can persist in the human body, not only in the spirochetal but also in the antibiotic-resistant biofilm form, even after long-term antibiotic treatment. The presence of infiltrating lymphocytes in the vicinity of B. burgdorferi biofilms suggests that the organism in biofilm form might trigger chronic inflammation.

Intraarticular Glucocorticoid Injection as Second-line Treatment for Lyme Arthritis in Children

OBJECTIVE

To determine whether second-line intraarticular glucocorticoid (IAGC) injection improves outcomes in children with persistently active Lyme arthritis after initial antibiotics.

METHODS

We conducted an observational comparative effectiveness study through chart review within 3 pediatric rheumatology centers with distinct clinical approaches to second-line treatment of Lyme arthritis. We primarily compared children receiving second-line IAGC to children receiving a second course of antibiotics alone. We evaluated the risk of developing antibiotic-refractory Lyme arthritis (ARLA) using logistic regression and the time to clinical resolution of Lyme arthritis using Cox regression.

RESULTS

Of 112 children with persistently active Lyme arthritis after first-line antibiotics, 18 children received second-line IAGC (13 with concomitant oral antibiotics). Compared to children receiving second-line oral antibiotics alone, children treated with IAGC had similar baseline characteristics but lower rates of ARLA (17% vs 44%; OR 0.3, 95% CI 0.1-0.95; p = 0.04) and faster rates of clinical resolution (HR 2.2, 95% CI 1.2-3.9; p = 0.01). Children in IAGC and oral antibiotic cohorts did not differ in treatment-associated adverse events. Among children receiving second-line IAGC, outcomes appeared similar irrespective of use of concomitant antibiotics. Outcomes were also similar between intravenous (IV) and oral antibiotic-treated cohorts, but older children seemed to respond more favorably to IV therapy. IV antibiotics were also associated with higher rates of toxicity.

CONCLUSION

IAGC injection appears to be an effective and safe second-line strategy for persistent Lyme arthritis in children, associated with rapid clinical resolution and reduced need for additional treatment.

Pediatric Antibiotic-refractory Lyme Arthritis: A Multicenter Case-control Study

OBJECTIVE

Few factors have consistently been linked to antibiotic-refractory Lyme arthritis (ARLA). We sought to identify clinical and treatment factors associated with pediatric ARLA.

METHODS

We performed a case-control study in 3 pediatric rheumatology clinics in a Lyme-endemic region (2000-2013). Eligible children were aged ≤ 18 years with arthritis and had positive testing for Lyme disease by Western blot. Cases were 49 children with persistently active arthritis despite ≥ 8 weeks of oral antibiotics or ≥ 2 weeks of parenteral antibiotics; controls were 188 children whose arthritis resolved within 3 months of starting antibiotics. We compared preselected demographic, clinical, and treatment factors between groups using logistic regression.

RESULTS

Characteristics positively associated with ARLA were age ≥ 10 years, prolonged arthritis at diagnosis, knee-only arthritis, and worsening after starting antibiotics. In contrast, children with fever, severe pain, or other signs of systemic inflammation were more likely to respond quickly to treatment. Secondarily, low-dose amoxicillin and treatment nonadherence were also linked to higher risk of ARLA. Greater antibiotic use for children with ARLA was accompanied by higher rates of treatment-associated adverse events (37% vs 15%) and resultant hospitalization (6% vs 1%).

CONCLUSION

Older children and those with prolonged arthritis, arthritis limited to the knees, or poor initial response to antibiotics are more likely to have antibiotic-refractory disease and treatment-associated toxicity. Children with severe symptoms of systemic inflammation have more favorable outcomes. For children with persistently active Lyme arthritis after 2 antibiotic courses, pediatricians should consider starting antiinflammatory treatment and referring to a pediatric rheumatologist.

Interferon-gamma production in Lyme arthritis synovial tissue promotes differentiation of fibroblast-like synoviocytes into immune effector cells

Lyme arthritis (LA), a late disease manifestation of Borrelia burgdorferi infection, usually resolves with antibiotic therapy. However, some patients develop proliferative synovitis lasting months to several years after spirochetal killing, called postinfectious LA. In this study, we phenotyped haematopoietic and stromal cell populations in the synovial lesion ex vivo and used these findings to generate an in vitro model of LA using patient-derived fibroblast-like synoviocytes (FLS). Ex vivo analysis of synovial tissue revealed high abundance of IFNγ-producing T cells and NK cells. Similar to marked IFNγ responses in tissue, postinfectious LA synovial fluid also had high levels of IFNγ. HLA-DR-positive FLS were present throughout the synovial lesion, particularly in areas of inflammation. FLS stimulated in vitro with B. burgdorferi, which were similar to conditions during infection, expressed 68 genes associated primarily with innate immune activation and neutrophil recruitment. In contrast, FLS stimulated with IFNγ, which were similar to conditions in the postinfectious phase, expressed >2,000 genes associated with pathogen sensing, inflammation, and MHC Class II antigen presentation, similar to the expression profile in postinfectious synovial tissue. Furthermore, costimulation of FLS with B. burgdorferi and IFNγ induced greater expression of IL-6 and other innate immune response proteins and genes than with IFNγ stimulation alone. These results suggest that B. burgdorferi infection, in combination with IFNγ, initiates the differentiation of FLS into a highly inflammatory phenotype. We hypothesise that overexpression of IFNγ by lymphocytes within synovia perpetuates these responses in the postinfectious period, causing proliferative synovitis and stalling appropriate repair of damaged tissue.

The Emerging Role of Microbial Biofilm in Lyme Neuroborreliosis

Lyme borreliosis (LB) is the most common tick-borne disease caused by the spirochete Borrelia burgdorferi in North America and Borrelia afzelii or Borrelia garinii in Europe and Asia, respectively. The infection affects multiple organ systems, including the skin, joints, and the nervous system. Lyme neuroborreliosis (LNB) is the most dangerous manifestation of Lyme disease, occurring in 10-15% of infected individuals. During the course of the infection, bacteria migrate through the host tissues altering the coagulation and fibrinolysis pathways and the immune response, reaching the central nervous system (CNS) within 2 weeks after the bite of an infected tick. The early treatment with oral antimicrobials is effective in the majority of patients with LNB. Nevertheless, persistent forms of LNB are relatively common, despite targeted antibiotic therapy. It has been observed that the antibiotic resistance and the reoccurrence of Lyme disease are associated with biofilm-like aggregates in B. burgdorferi, B. afzelii, and B. garinii, both in vitro and in vivo, allowing Borrelia spp. to resist to adverse environmental conditions. Indeed, the increased tolerance to antibiotics described in the persisting forms of Borrelia spp., is strongly reminiscent of biofilm growing bacteria, suggesting a possible role of biofilm aggregates in the development of the different manifestations of Lyme disease including LNB.

Identifying Vancomycin as an Effective Antibiotic for Killing Borrelia burgdorferi

Borrelia burgdorferi is the causative agent of Lyme borreliosis. Antibiotic therapy of early acute infection is effective for most patients, but 10 to 20% go on to develop posttreatment Lyme disease syndrome (PTLDS). The nature of PTLDS remains unknown, but currently approved antibiotics for the treatment of Lyme disease do not appear to impact these symptoms after they have developed. We reason that minimizing the time the pathogen interacts with the host will diminish the probability of developing PTLDS, irrespective of its nature. This calls for an efficient eradication of the pathogen during acute infection. In search of a superior killing antibiotic, we examined approved antibiotics for their ability to kill B. burgdorferi Vancomycin proved more effective in killing the pathogen in vitro than ceftriaxone, the standard of care for disseminated B. burgdorferi infection. Both compounds were also the most effective in killing stationary-phase cells. This is surprising, given that inhibitors of cell wall biosynthesis are known to only kill growing bacteria. We found that peptidoglycan synthesis continues in stationary-phase cells of B. burgdorferi, explaining this paradox. A combination of vancomycin and gemifloxacin sterilized a stationary-phase culture of B. burgdorferi Examination of the action of antibiotics in severe combined immunodeficient (SCID) mice showed that doxycycline, a standard of care for uncomplicated acute infection, did not clear the pathogen. In contrast, both ceftriaxone and vancomycin cleared the infection. A trial examining the early use of more potent antibiotics on the development of PTLDS may be warranted.

Robust interferon signature and suppressed tissue repair gene expression in synovial tissue from patients with postinfectious, Borrelia burgdorferi-induced Lyme arthritis

In most patients with Lyme arthritis (LA), antibiotic therapy results in Borrelia burgdorferi pathogen elimination, tissue repair, and return to homeostasis. However, despite spirochetal killing, some patients develop proliferative synovitis, characterised by synovial hyperplasia, inflammation, vascular damage, and fibrosis that persists for months to several years after antibiotic treatment, called postinfectious LA. In this study, we characterised the transcriptomes of postinfectious LA patients' synovial tissue, the target tissue of the immune response. High-throughput RNA sequencing to a depth of ~30 million reads per sample was used to profile gene expression in synovial tissue from 14 patients with postinfectious LA, compared with eight patients with other types of chronic inflammatory arthritis and five with minimally inflammatory osteoarthritis (OA). Synovium from postinfectious LA and other inflammatory arthritides shared gene signatures associated with antigen presentation, innate immune responses, and cell-mediated immune activation, whereas these responses were diminished in OA synovium. Unique to postinfectious LA was a particularly robust interferon-gamma (IFNγ) signature. Moreover, this heightened IFNγ signature inversely correlated with expression of genes involved in repair of damaged tissue, including genes associated with stromal cell proliferation and differentiation, neovascularisation, and extracellular matrix synthesis, which were markedly suppressed in postinfectious LA. Transcriptional observations were confirmed by cytokine profiling, histologic analyses, and clinical correlations. We propose that in patients with postinfectious LA, overexpression of IFNγ in synovium prevents appropriate repair of tissue damaged by B. burgdorferi infection, blocking return to tissue homeostasis long after completion of antibiotic therapy and resolution of active infection.