A comprehensive genetic map of cytokine responses in Lyme borreliosis.

The incidence of Lyme borreliosis has risen, accompanied by persistent symptoms. The innate immune system and related cytokines are crucial in the host response and symptom development. We characterized cytokine production capacity before and after antibiotic treatment in 1,060 Lyme borreliosis patients. We observed a negative correlation between antibody production and IL-10 responses, as well as increased IL-1Ra responses in patients with disseminated disease. Genome-wide mapping the cytokine production allowed us to identify 34 cytokine quantitative trait loci (cQTLs), with 31 novel ones. We pinpointed the causal variant at the TLR1-6-10 locus and validated the regulation of IL-1Ra responses at transcritpome level using an independent cohort. We found that cQTLs contribute to Lyme borreliosis susceptibility and are relevant to other immune-mediated diseases. Our findings improve the understanding of cytokine responses in Lyme borreliosis and provide a genetic map of immune function as an expanded resource.

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

OBJECTIVE: The diagnosis of Lyme borreliosis is based on two-tier testing using an ELISA and Western blot. About 5-10% of patients report persistent symptoms of unknown etiology after treatment, resulting in substantial difficulties in further diagnostic workup. This paper presents a study aimed at determining whether serology can differentiate between patients with persistent symptoms attributed to Lyme and other patients with Lyme borreliosis. METHODS: A retrospective cohort study included 162 samples from four subgroups: patients with persistent symptoms of Lyme (PSL), early Lyme borreliosis with erythema migrans (EM), patients tested in a general practitioner setting (GP), and healthy controls (HC). ELISA, Western blots, and multiplex assays from different manufacturers were used to determine inter-test variations in PSL and to compare reactivity against Borrelia-specific antigens among the groups. RESULTS: In comparing the IgG and IgM reactivity by Western blot, IgG was more often positive in the PSL group than in the GP group. The individual antigen reactivity was similar between the PSL and EM or GP groups. Inter-test agreement among the manufacturers was variable, and agreement was higher for IgG testing compared to IgM. CONCLUSIONS: Serological testing is unable to define the subgroup of patients with persistent symptoms attributed to Lyme borreliosis. Additionally, the current two-tier testing protocol shows a large variance among different manufacturers in these patients.

Lyme Borreliosis Serology: A Prospective Cohort Study of Forestry Service Workers in the Netherlands over 8 Years (2008 to 2016) of Follow-Up.

There is little known about the dynamics within responses to Borrelia spp. upon repeated exposure to tick bites and the development of serological markers over time. Most studies have investigated antibody development in risk populations over a short period of time. Therefore, we aimed to study the dynamics of anti-Borrelia antibodies in forestry service workers over 8 years in association with tick bite exposure. METHODS: Blood samples from 106 forestry service workers originally included in the 200 Functional Genomics Project (Radboudumc, Nijmegen, the Netherlands) were followed for 8 years and tested annually for anti-Borrelia antibodies (ELISA and Western blot). IgG seroconversion was related to the number of tick bites in the previous year, which was obtained through annual questionnaires. The hazard ratio for Borrelia IgG seroconversion was calculated using Cox regression survival analysis and a logistic regression model, both adjusting for age, gender and smoking. RESULTS: Borrelia IgG seropositivity in the study population did not vary significantly between years and the average prevalence was 13.4%. Of the 27 subjects that underwent seroconversion during the study period, 22 reconverted from positive to negative. Eleven subjects seroconverted a second time. The total seroconversion rate per year (negative to positive) was 4.5%. Active smoking was associated with IgG seroconversion in the >5 tick bites group (p < 0.05). According to the two models used, the risks of IgG seroconversion in the >5 tick bites group were HR = 2.93 (p = 0.10) and OR = 3.36 (p < 0.0005). CONCLUSIONS: Borrelia IgG seroconversion in forestry service workers was significantly related to increasing tick bite exposure in a survival and logistic regression model adjusting for age, gender and smoking.

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

BACKGROUND: Cellular tests for Lyme borreliosis might be able to overcome major shortcomings of serological testing, such as its low sensitivity in early stages of infection. Therefore, we aimed to assess the sensitivity and specificity of three cellular tests. METHODS: This was a nationwide, prospective, multiple-gate case-control study done in the Netherlands. Patients with physician-confirmed Lyme borreliosis, either early localised or disseminated, were consecutively included as cases at the start of antibiotic treatment. Controls were those without Lyme borreliosis from the general population (healthy controls) and those with potentially cross-reactive conditions (eg, autoimmune disease). We used three cellular tests for Lyme borreliosis (Spirofind Revised, iSpot Lyme, and LTT-MELISA) as index tests, and standard two-tier serological testing (STTT) as a comparator. Clinical data from Lyme borreliosis patients were collected at baseline and at 12 weeks after inclusion, and blood samples were obtained at baseline, 6 weeks, and 12 weeks. Control participants underwent clinical and laboratory assessments at baseline only. FINDINGS: Cases comprised 271 patients with Lyme borreliosis (of whom 245 had early-localised Lyme borreliosis and 26 had disseminated disease) and controls comprised 228 participants without Lyme borreliosis from the general population and 41 participants with potentially cross-reactive conditions. Recruitment occurred between May 14, 2018, and March 16, 2020. The specificity of STTT in healthy controls (216 of 228 samples [94·7%, 95% CI 91·5-97·7]) was higher than that of the cellular tests: Spirofind (140 of 171 [81·9%, 76·1-87·2]), iSpot Lyme (32 of 103 [31·1%, 21·5-40·3]) and LTT-MELISA (100 of 190 [52·6%, 44·9-60·3]). Cellular tests had varying sensitivities: Spirofind (88 of 204 [43·1%, 36·4-50·4]), iSpot Lyme (51 of 94 [54·3%, 44·5-63·7]), and LTT-MELISA (66 of 218 [30·3%, 23·8-36·7]). The Spirofind and iSpot Lyme outperformed STTT for sensitivity, but were similar to the C6-ELISA (C6-ELISA: 135 of 270 [50·0%, 44·5-55·5]; STTT: 76 of 270 [28·1%, 23·0-33·6]). INTERPRETATION: The cellular tests for Lyme borreliosis used in this study have a low specificity compared with serological tests, which leads to a high number of false-positive test results. We conclude that these cellular tests are unfit for clinical use at this stage. FUNDING: Netherlands Organization for Health Research and Development, AMC Foundation (Amsterdam UMC), and Ministry of Health of the Netherlands.

Borrelia burgdorferi is strong inducer of IFN-γ production by human primary NK cells.

Natural Killer (NK) cells belong to the innate lymphoid lineage and are highly present in the human skin. NK cells can produce a range of pro-inflammatory mediators, including cytokines and chemokines. The role of NK(-T) cells in the immune response towards Borrelia burgdorferi infection was studied. The production of interleukin (IL)-6, IL-1ß and interferon-gamma (IFN-γ) by human primary peripheral blood mononuclear cells (PBMCs) exposed to B. burgdorferi was assessed. Interestingly, CD56+ (NK + NK-T) cells were the only cells within the PBMC-fraction that produced IFN-γ during the first 24 h of stimulation. Within the NK(-T) cell fraction, NK cells seemed to be responsible for the IFN-γ production. Since it was previously demonstrated that both TLR2 and NOD2 receptors are involved in the recognition of B. burgdorferi, the expression of both TLR2 and NOD2 mRNA on NK cells was determined. In contrast to TLR2, NOD2 mRNA was upregulated on CD56+ (NK + NK-T) cells after Borrelia exposure. Finally, to unravel the mechanisms underlying erythema migrans (EM) development, crosstalk between CD56+ (NK + NK-T) cells and keratinocytes was investigated. CD56+ (NK + NK-T) cells activated by B. burgdorferi produced soluble mediators strongly inducing the expression of antimicrobial peptides, such as ß-defensin-2 and psoriasin in human keratinocytes. In conclusion, CD56+ (NK + NK-T) cells produced IFN-γ shortly after exposure to B. burgdorferi and released soluble mediators that were able to activate keratinocytes. These observations underscore the important role of CD56+ (NK + NK-T) cells during early host defence when Borrelia burgdorferi enters the human skin during a tick bite.

Borrelia burgdorferi Is a Poor Inducer of Gamma Interferon: Amplification Induced by Interleukin-12.

Laboratory diagnosis of Lyme borreliosis (LB) is mainly based on serology, which has limitations, particularly in the early stages of the disease. In recent years there have been conflicting reports concerning a new diagnostic tool using the cytokine interferon-gamma (IFN-γ). Previous studies have generally found low concentrations of IFN-γ in early LB infection. The goal of this study is to investigate IFN-γ regulation during early LB and provide insights into the host response to B. burgdorferi. We performed in vitro experiments with whole blood assays and peripheral blood mononuclear cells (PBMCs) of LB patients and healthy volunteers exposed to B. burgdorferi and evaluated the IFN-γ response using ELISA and related interindividual variation in IFN-γ production to the presence of single nucleotide polymorphisms. IFN-γ production of B. burgdorferi-exposed PBMCs and whole blood was amplified by the addition of interleukin-12 (IL-12) to the stimulation system. This effect was observed after 24 h of B. burgdorferi stimulation in both healthy individuals and LB patients. The effect was highly variable between individuals, but was significantly higher in LB patients 6 weeks since the start of antibiotic treatment compared to healthy individuals. IL-12 p40 and IL-18 mRNA were upregulated upon exposure to B. burgdorferi, whereas IL-12 p35 and IFN-γ mRNA expression remained relatively unchanged. SNP Rs280520 in the downstream IL-12 pathway, Tyrosine Kinase 2, was associated with increased IFN-γ production. This study shows that IL-12 evokes an IFN-γ response in B. burgdorferi exposed cells, and that LB patients and healthy controls respond differently to this stimulation.

Expectancies as predictors of symptom improvement after antimicrobial therapy for persistent symptoms attributed to Lyme disease.

INTRODUCTION/OBJECTIVE: Expectancies about symptom improvement or deterioration are reliable predictors of symptom progression and treatment outcomes (symptom resolution or symptomatic improvement) in many (non-)pharmacological studies and treatments. This study examined predictors of symptom improvement after antimicrobial therapy for persistent symptoms attributed to Lyme disease, hypothesizing particularly pre-treatment expectancies regarding symptom improvement to be predictive. METHODS: A predictive study was performed on pre-treatment and post-treatment individual characteristics, including expectancies, and physical and mental health-related quality of life (HRQoL) from the PLEASE-trial comparing randomized 12-weeks of doxycycline, clarithromycin-hydroxychloroquine, or placebo following 2 weeks of intravenous ceftriaxone. At end-of-treatment (14 weeks after trial start) and follow-up (52 weeks), complete data of 231 and 170 (of initial 280) patients with persistent symptoms temporally related to a history of erythema migrans or otherwise confirmed symptomatic Lyme disease, or accompanied by B. burgdorferi IgG or IgM antibodies, were examined through hierarchical regression analyses. RESULTS: In addition to pre-treatment HRQoL, pre-treatment expectancies regarding symptom improvement were consistently associated with stronger physical and mental HRQoL improvements at both end-of-treatment and follow-up (95% CI range: .09;.54, p < .01 to .27;.92, p < .001). Post-treatment expectancies regarding having received antibiotics vs. placebo was associated with more HRQoL improvement at end-of-treatment, but not at follow-up (95% CI-range 1.00;4.75, p = .003 to -7.34; -2.22, p < .001). CONCLUSIONS: The present study shows that, next to pre-treatment functioning, patients' pre-treatment and post-treatment expectancies regarding improvement of persistent symptoms attributed to Lyme disease relate to a more beneficial symptom course. Expectancies of patients may be relevant to explain and potentially improve patient outcomes (e.g., by optimized communication about treatment success). TRIAL REGISTRATION: ClinicalTrials.gov, NCT01207739 (Registration date: 23-09-2010) Key Points • As there is currently no sufficient symptom resolution or symptomatic improvement for many patients with persistent symptoms attributed to Lyme disease, it is relevant to know which factors determine symptom progression and predict heterogeneity in treatment response. • Next to pre-treatment functioning, expectancies regarding symptom improvement and having received antimicrobial study medication are associated with a more beneficial symptom course after both shorter-term and longer-term antimicrobial treatment. • Expectancies are relevant to consider in treatment studies and may be useful in clinical settings to improve symptom course and treatment outcome (e.g., by optimized communication about treatment success).

Cognitive impairments in patients with persistent symptoms attributed to Lyme disease.

BACKGROUND: Persistent symptoms attributed to Lyme borreliosis often include self-reported cognitive impairment. However, it remains unclear whether these symptoms can be substantiated by objective cognitive testing. METHODS: For this observational study, cognitive performance was assessed in 280 adults with persistent symptoms attributed to Lyme borreliosis (as part of baseline data collected for the Dutch PLEASE study). Cognitive testing covered the five major domains: episodic memory, working memory / attention, verbal fluency, information-processing speed and executive function. Patients' profiles of test scores were compared to a large age-, education- and sex-adjusted normative sample using multivariate normative comparison. Performance validity was assessed to detect suboptimal effort, and questionnaires were administered to measure self-reported cognitive complaints, fatigue, anxiety, depressive symptoms and several other psychological factors. RESULTS: Of 280 patients, one was excluded as the test battery could not be completed. Of the remaining 279 patients, 239 (85.4%) displayed sufficient performance validity. Patients with insufficient performance validity felt significantly more helpless and physically fatigued, and less orientated. Furthermore, they had a lower education level and less often paid work. Of the total study cohort 5.7% (n = 16) performed in the impaired range. Among the 239 patients who displayed sufficient performance validity, 2.9% (n = 7) were classified as cognitively impaired. No association between subjective cognitive symptoms and objective impairment was found. CONCLUSIONS: Only a small percentage of patients with borreliosis-attributed persistent symptoms have objective cognitive impairment. Performance validity should be taken into account in neuropsychological examinations of these patients. Self-report questionnaires are insufficiently valid to diagnose cognitive impairment. TRIAL REGISTRATION: ClinicalTrials.gov NCT01207739 . Registered 23 September 2010.

Effect of prolonged antibiotic treatment on cognition in patients with Lyme borreliosis.

OBJECTIVE: To investigate whether longer-term antibiotic treatment improves cognitive performance in patients with persistent symptoms attributed to Lyme borreliosis. METHODS: Data were collected during the Persistent Lyme Empiric Antibiotic Study Europe (PLEASE) trial, a randomized, placebo-controlled study. Study participants passed performance-validity testing (measure for detecting suboptimal effort) and had persistent symptoms attributed to Lyme borreliosis. All patients received a 2-week open-label regimen of intravenous ceftriaxone before the 12-week blinded oral regimen (doxycycline, clarithromycin/hydroxychloroquine, or placebo). Cognitive performance was assessed at baseline and after 14, 26, and 40 weeks with neuropsychological tests covering the cognitive domains of episodic memory, attention/working memory, verbal fluency, speed of information processing, and executive function. RESULTS: Baseline characteristics of patients enrolled (n = 239) were comparable in all treatment groups. After 14 weeks, performance on none of the cognitive domains differed significantly between the treatment arms (p = 0.49-0.82). At follow-up, no additional treatment effect (p = 0.35-0.98) or difference between groups (p = 0.37-0.93) was found at any time point. Patients performed significantly better in several cognitive domains at weeks 14, 26, and 40 compared to baseline, but this was not specific to a treatment group. CONCLUSIONS: A 2-week treatment with ceftriaxone followed by a 12-week regimen of doxycycline or clarithromycin/hydroxychloroquine did not lead to better cognitive performance compared to a 2-week regimen of ceftriaxone in patients with Lyme disease-attributed persistent symptoms. CLINICALTRIALSGOV IDENTIFIER: NCT01207739. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that longer-term antibiotics in patients with borreliosis-attributed persistent symptoms does not increase cognitive performance compared to shorter-term antibiotics.

Cost-effectiveness of longer-term versus shorter-term provision of antibiotics in patients with persistent symptoms attributed to Lyme disease.

BACKGROUND: The treatment of persistent symptoms attributed to Lyme disease remains controversial. Recently, the PLEASE study did not demonstrate any additional clinical benefit of longer-term versus shorter-term antibiotic treatment. However, the economic impact of the antibiotic strategies has not been investigated. METHODS: This prospective economic evaluation, adhering a societal perspective, was performed alongside the PLEASE study, a multicenter, placebo-controlled, double-blind 1:1:1 randomized clinical trial in which all patients received open-label intravenous ceftriaxone for two weeks before the 12-week randomized blinded oral antibiotic regimen (doxycycline, clarithromycin plus hydroxychloroquine, or placebo). Between 2010 and 2013, patients (n = 271) with borreliosis-attributed persistent symptoms were enrolled and followed for one year. Main outcomes were costs, quality-adjusted life years, and incremental net monetary benefit of longer-term versus shorter-term antibiotic therapy. RESULTS: Mean quality-adjusted life years (95% CI) were not significantly different (p = 0.96): 0.82 (0.77-0.88) for ceftriaxone/doxycycline (n = 82), 0.81 (0.76-0.88) for ceftriaxone/clarithromycin-hydroxychloroquine (n = 93), and 0.81 (0.76-0.86) for ceftriaxone/placebo (n = 96). Total societal costs per patient (95% CI) were not significantly different either (p = 0.35): €11,995 (€8,823-€15,670) for ceftriaxone/doxycycline, €12,202 (€9,572-€15,253) for ceftriaxone/clarithromycin-hydroxychloroquine, and €15,249 (€11,294-€19,781) for ceftriaxone/placebo. Incremental net monetary benefit (95% CI) for ceftriaxone/doxycycline compared to ceftriaxone/placebo varied from €3,317 (-€2,199-€8,998) to €4,285 (-€6,085-€14,524) over the willingness-to-pay range, and that of ceftriaxone/clarithromycin-hydroxychloroquine compared to ceftriaxone/placebo from €3,098 (-€888-€7,172) to €3,710 (-€4,254-€11,651). For every willingness-to-pay threshold, the incremental net monetary benefits did not significantly differ from zero. CONCLUSION: The longer-term treatments were similar with regard to costs, effectiveness and cost-effectiveness compared to shorter-term treatment in patients with borreliosis-attributed persistent symptoms after one year of follow-up. Given the results of this study, and taking into account the external costs associated with antibiotic resistance, the shorter-term treatment is the antibiotic regimen of first choice.

Randomized Trial of Longer-Term Therapy for Symptoms Attributed to Lyme Disease.

BACKGROUND: The treatment of persistent symptoms attributed to Lyme disease remains controversial. We assessed whether longer-term antibiotic treatment of persistent symptoms attributed to Lyme disease leads to better outcomes than does shorter-term treatment. METHODS: In a randomized, double-blind, placebo-controlled trial conducted in Europe, we assigned patients with persistent symptoms attributed to Lyme disease--either related temporally to proven Lyme disease or accompanied by a positive IgG or IgM immunoblot assay for Borrelia burgdorferi--to receive a 12-week oral course of doxycycline, clarithromycin plus hydroxychloroquine, or placebo. All study groups received open-label intravenous ceftriaxone for 2 weeks before initiating the randomized regimen. The primary outcome measure was health-related quality of life, as assessed by the physical-component summary score of the RAND-36 Health Status Inventory (RAND SF-36) (range, 15 to 61, with higher scores indicating better quality of life), at the end of the treatment period at week 14, after the 2-week course of ceftriaxone and the 12-week course of the randomized study drug or placebo had been completed. RESULTS: Of the 281 patients who underwent randomization, 280 were included in the modified intention-to-treat analysis (86 patients in the doxycycline group, 96 in the clarithromycin-hydroxychloroquine group, and 98 in the placebo group). The SF-36 physical-component summary score did not differ significantly among the three study groups at the end of the treatment period, with mean scores of 35.0 (95% confidence interval [CI], 33.5 to 36.5) in the doxycycline group, 35.6 (95% CI, 34.2 to 37.1) in the clarithromycin-hydroxychloroquine group, and 34.8 (95% CI, 33.4 to 36.2) in the placebo group (P=0.69; a difference of 0.2 [95% CI, -2.4 to 2.8] in the doxycycline group vs. the placebo group and a difference of 0.9 [95% CI, -1.6 to 3.3] in the clarithromycin-hydroxychloroquine group vs. the placebo group); the score also did not differ significantly among the groups at subsequent study visits (P=0.35). In all study groups, the SF-36 physical-component summary score increased significantly from baseline to the end of the treatment period (P<0.001). The rates of adverse events were similar among the study groups. Four serious adverse events thought to be related to drug use occurred during the 2-week open-label ceftriaxone phase, and no serious drug-related adverse event occurred during the 12-week randomized phase. CONCLUSIONS: In patients with persistent symptoms attributed to Lyme disease, longer-term antibiotic treatment did not have additional beneficial effects on health-related quality of life beyond those with shorter-term treatment. (Funded by the Netherlands Organization for Health Research and Development ZonMw; PLEASE ClinicalTrials.gov number, NCT01207739.).

Persistent Lyme Empiric Antibiotic Study Europe (PLEASE)--design of a randomized controlled trial of prolonged antibiotic treatment in patients with persistent symptoms attributed to Lyme borreliosis.

BACKGROUND: Lyme borreliosis, a potentially severe tick-borne infection caused by Borrelia burgdorferi, can cause multi-system inflammatory disease. The incidence has been increasing, as has the number of patients with persistent symptoms attributed to Borrelia. These symptoms, also referred to as post-Lyme disease syndrome, may follow an erythema migrans or other Lyme manifestations, and include pain, fatigue, and cognitive disturbances. The optimal duration of treatment for these symptoms is a subject of controversy. The PLEASE study is designed to determine whether prolonged antibiotic treatment leads to better patient outcome than standard treatment. METHODS/DESIGN: The PLEASE study is a double-blind, randomized, placebo-controlled trial. Based on power analysis and compensating for possible loss to follow-up, a minimum of 255 patients with borreliosis-attributed persistent symptoms are included. These symptoms are either (a) temporally related to an erythema migrans or otherwise proven symptomatic borreliosis, or (b) accompanied by a positive B. burgdorferi IgG or IgM immunoblot. All patients receive open-label ceftriaxone for two weeks. Patients are then randomized (ratio 1:1:1) to blinded oral follow-up treatment for 12 weeks with (I) doxycycline, (II) clarithromycin combined with hydroxychloroquine, or (III) placebo. The primary outcome is the physical component summary score (PCS) of the RAND-36 Health Status Inventory (RAND SF-36) at week 14. Secondary outcomes include physical and mental aspects of health-related quality of life (assessed by the subscales of the RAND SF-36), fatigue, neuropsychological evaluation, physical activity, and cost-effectiveness. DISCUSSION: This article describes the background and design issues of the PLEASE study protocol. The results of this study may provide evidence for prescribing or withholding prolonged antibiotic treatment. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01207739 , Netherlands Trial Register: NTR2469.

The European Medicines Agency review of Tegafur/Gimeracil/Oteracil (Teysuno™) for the treatment of advanced gastric cancer when given in combination with cisplatin: summary of the Scientific Assessment of the Committee for medicinal products for human use (CHMP).

The product Teysuno™ (S-1) contains tegafur, a prodrug of 5-fluorouracil (5-FU), and two modulators of 5-FU metabolism, gimeracil and oteracil. The main clinical study in this application was a randomized controlled study comparing S-1 plus cisplatin with 5-FU plus cisplatin. In this study, median overall survival times of 8.6 months and 7.9 months for S-1 plus cisplatin and 5-FU plus cisplatin, respectively, were observed (hazard ratio, 0.92; 95% confidence interval, 0.80-1.05). The Committee for Medicinal Products for Human Use of the European Medicines Agency concluded that S-1 in combination with cisplatin (75 mg/m²) was noninferior to 5-FU plus cisplatin (100 mg/m²) in patients with advanced gastric cancer and adopted a positive opinion recommending the marketing authorization for this product for the treatment of advanced gastric cancer when given in combination with cisplatin. The recommended dose of S-1 is 25 mg/m² (expressed as tegafur content) twice a day, for 21 consecutive days followed by 7 days rest (one treatment cycle), in combination with 75 mg/m² cisplatin i.v. administered on day 1. This treatment cycle is repeated every 4 weeks. The most common side effects reported in the pivotal study were anemia, neutropenia, vomiting, diarrhea, abdominal pain, weight decrease, anorexia, and fatigue. The objective of this paper is to summarize the scientific review of the application leading to approval in the EU. The full scientific assessment report and the summary of product characteristics are available on the European Medicines Agency website (http://www.ema.europa.eu).

TLR1/TLR2 heterodimers play an important role in the recognition of Borrelia spirochetes.

After infection with Borrelia species, the risk for developing Lyme disease varies significantly between individuals. Recognition of Borrelia by the immune system is mediated by pattern recognition receptors (PRRs), such as TLRs. While TLR2 is the main recognition receptor for Borrelia spp., little is known about the role of TLR1 and TLR6, which both can form functionally active heterodimers with TLR2. Here we investigated the recognition of Borrelia by both murine and human TLR1 and TLR6. Peritoneal macrophages from TLR1- and TLR6- gene deficient mice were isolated and exposed to Borrelia. Human PBMCs were stimulated with Borrelia with or without specific TLR1 and TLR6 blocking using specific antibodies. Finally, the functional consequences of TLR polymorphisms on Borrelia-induced cytokine production were assessed. Splenocytes isolated from both TLR1-/- and TLR6-/- mice displayed a distorted Th1/Th2 cytokine balance after stimulation with B.burgdorferi, while no differences in pro-inflammatory cytokine production were observed. In contrast, blockade of TLR1 with specific neutralizing antibodies led to decreased cytokine production by human PBMCs after exposure to B.burgdorferi. Blockade of human TLR6 did not lead to suppression of cytokine production. When PBMCs from healthy individuals bearing polymorphisms in TLR1 were exposed to B.burgdorferi, a remarkably decreased in vitro cytokine production was observed in comparison to wild-type controls. TLR6 polymorphisms lead to a minor modified cytokine production. This study indicates a dominant role for TLR1/TLR2 heterodimers in the induction of the early inflammatory response by Borrelia spirochetes in humans.

Role of interleukin-23 (IL-23) receptor signaling for IL-17 responses in human Lyme disease.

Interleukin-23 (IL-23) is known to play a crucial role in the development and maintenance of T helper 17 cells. It has been previously demonstrated that IL-17 is involved in experimental Lyme arthritis, caused by Borrelia burgdorferi bacteria. However, the precise role of the IL-23 receptor (IL-23R) for the B. burgdorferi-induced IL-17 responses or human Lyme disease has not yet been elucidated. IL-23R single nucleotide polymorphism (SNP) rs11209026 was genotyped using the TaqMan assay. Functional studies were performed using peripheral blood mononuclear cells, and cytokines were measured using enzyme-linked immunosorbent assay (ELISA). Dose-dependent production of IL-23 and IL-17 by B. burgdorferi could be observed. Interestingly, when IL-23 bioactivity was inhibited by a specific antibody against IL-23p19, IL-17 production was significantly downregulated. In contrast, production of gamma interferon (IFN-γ) was not affected after the blockade of IL-23 activity. Moreover, individuals bearing a single nucleotide polymorphism in the IL-23R gene (Arg381Gln) produced significantly less IL-17 after B. burgdorferi stimulation compared with that of the individuals bearing the wild type. Despite lower IL-17 production, the IL-23R gene polymorphism did not influence the development of chronic Lyme disease in a cohort of patients with Lyme disease. This study demonstrates that IL-23R signaling is needed for B. burgdorferi-induced IL-17 production in vitro and that an IL-23R gene SNP leads to impaired IL-17 production. However, the IL-23R gene polymorphism is not crucial for the pathogenesis of chronic Lyme.

Recognition of Borrelia burgdorferi by NOD2 is central for the induction of an inflammatory reaction.

Toll-like receptor 2 (TLR2) plays an important role in the recognition of Borrelia bacteria, the causative agent of Lyme disease, but the existence and importance of additional receptors in this process has been hypothesized. In the present study, we confirmed the role played by TLR2 in the recognition of Borrelia bacteria but also demonstrated a crucial role for the intracellular peptidoglycan receptor NOD2 for sensing the spirochete. Cells from individuals who were homozygous for the loss-of-function mutation 3020insC in the NOD2 gene were defective with respect to cytokine release after stimulation with Borrelia species, and this was confirmed in peritoneal macrophages from mice lacking RICK, the adaptor molecule used by NOD2. In contrast, NOD1 played no major role in the recognition of Borrelia spirochetes. This raises the intriguing possibility that recognition of Borrelia spirochetes is exerted by TLR2 in combination with NOD2 and that both receptors are necessary for an effective induction of cytokines by Borrelia species. The interplay between TLR2 and NOD2 might not only be necessary for the induction of a proper immune response but may also contribute to inflammatory-induced pathology.

Stavudine plasma concentrations and lipoatrophy.

OBJECTIVES: The objective of this study was to determine the correlation between plasma stavudine concentrations and lipoatrophy (LA), one of the major adverse events in patients on stavudine and one of the major reasons to discontinue stavudine. METHODS: Plasma drug concentrations were retrospectively analysed in patients who were on a stavudine-containing regimen for at least 12 months. We defined two groups of patients: 21 patients with LA and 15 patients without LA or other stavudine-related side effects (i.e. neuropathy). RESULTS: We analysed stavudine concentrations in 212 plasma samples: 87 in the control group and 125 in the LA group, with a mean of four plasma samples per person (at least two a year). Demographics were comparable in LA patients and controls, except the duration of stavudine use, which was longer in the LA group: 55 versus 42 months in the control group. Overall, LA patients had higher drug exposure to stavudine when compared with the controls, and this was seen in the geometric concentration ratios (CRs), which were 0.978 and 0.741, respectively (P = 0.04), and also a higher percentage of CR values >1.0, representing a drug concentration above the normal population curve (46% versus 23%, P = 0.02). In addition, the duration of stavudine therapy was independently associated with LA (P = 0.05). In the multivariate analysis, both duration of stavudine (P = 0.05) and CR > 1.0 (P = 0.02) were independently correlated with LA. CONCLUSIONS: Monitoring of plasma stavudine concentrations can be useful to prevent stavudine-related LA.

Oral glucose loading for detection of mitochondrial toxicity during HAART in HIV-infected patients.

Nucleoside reverse transcriptase inhibitors used in antiretroviral therapy may cause mitochondrial toxicity. Mitochondrial dysfunction leads to disturbance of the glucose metabolism, resulting in an accumulation of L-lactate. We tested the hypothesis that an oral glucose tolerance test (OGTT) can be used to detect mitochondrial toxicity in patients on antiretroviral nucleoside analogues. An OGTT was performed in 30 subjects: 16 HIV-infected treated patients without adverse events (group 1) and 14 HIV-infected patients with adverse events related to nucleoside reverse transcriptase inhibitor-induced mitochondrial toxicity (group 2). Lactate was measured at baseline and 60 and 120 min after glucose loading. At all time points the lactate levels were higher in the adverse events group compared to the other group, with the highest levels of lactate at t = 60 min (mean 1912 micromol/L, SD +/- 609); mean lactates in the group without adverse events was 1429 micromol/L (SD +/- 464). When levels above the upper limit of normal of 1800 micromol/L were used as an indication for mitochondrial toxicity, the sensitivity and specificity were 57% and 81%, respectively. The area under the ROC curve was 0.75. For L-lactate levels > 2000 micromol/L the specificity was 90%. An OGTT with measurement of lactate at baseline and one hour after glucose loading can detect (occult) hyperlactataemia in patients with mitochondrial impairment. From our study we suggest to perform an OGTT as an additional test in patients with symptoms suspect for adverse events to discern mitochondrial toxicity.

Lopinavir/ritonavir reduces lamotrigine plasma concentrations in healthy subjects.

BACKGROUND: Limited data are available about the effect of lopinavir and low-dose ritonavir on glucuronidation. Lamotrigine undergoes glucuronidation. We studied the effect of lopinavir/ritonavir on the pharmacokinetics of lamotrigine and vice versa. METHODS: Twenty-four healthy subjects received 50 mg lamotrigine once daily on days 1 and 2 and 100 mg twice daily on day 3 through day 23. Lopinavir (400 mg twice daily)/ritonavir (100 mg twice daily) was added on day 11. Depending on the decrease in lamotrigine trough level between days 10 and 20, either the study was stopped (<20% decrease) or a dose increase was applied from day 23 to day 31, as follows: increase to 150 mg lamotrigine twice daily if there was a 20% to 33% decrease, increase to 200 mg twice daily if there was a 34% to 66% decrease, and increase to 300 mg twice daily if there was a greater than 66% decrease. On days 10, 20, and 31, 12-hour pharmacokinetic curves were drawn. RESULTS: The mean decrease in lamotrigine trough level between days 10 and 20 was 55.4% (n = 18). A dose increment to 200 mg lamotrigine twice daily was used in all subjects. The area under the plasma concentration-time curve (AUC) values of lamotrigine on day 20 (with lopinavir/ritonavir) and day 10 (without lopinavir/ritonavir) were bioinequivalent, with a point estimate of 0.50 (90% confidence interval, 0.47-0.54). After dose adjustment of lamotrigine to 200 mg twice daily, the AUC on day 31 (n = 15) was bioequivalent to that on day 10, with a point estimate of 0.91 (90% confidence interval, 0.82-1.02). The median AUC ratios of lamotrigine 2N-glucuronide to lamotrigine on day 10 and day 20 were 0.57 (interquartile range, 0.39-0.75) and 1.12 (interquartile range, 0.87-1.31). Pharmacokinetic parameters for lopinavir/ritonavir were similar to historical controls. CONCLUSION: Lopinavir/ritonavir decreases the AUC of lamotrigine, probably by induction of glucuronidation. A dose increment to 200% of the initial lamotrigine dose is needed to achieve concentrations similar to those with lamotrigine alone. Lamotrigine does not appear to affect the pharmacokinetics of lopinavir/ritonavir.

Serum L-lactate and pyruvate in HIV-infected patients with and without presumed NRTI-related adverse events compared to healthy volunteers.

BACKGROUND: Nucleoside reverse transcriptase inhibitors (NRTIs) used in antiretroviral therapy may cause mitochondrial toxicity. Mitochondrial dysfunction leads to disturbance of the glucose metabolism, resulting in an accumulation of L-lactate (L) and pyruvate (P), with an enhanced L/P ratio. OBJECTIVES: We analysed lactate and pyruvate blood samples of patients of our outpatient department. Aim of the analysis was to detect preliminary mitochondrial toxicity in patients on antiretroviral nucleoside analogues, which might result in disturbances of L, P, L/P ratio, bicarbonate (Bic) or beta-hydroxybutyrate/aceto-acetate (beta-HB/AA) ratios. STUDY DESIGN: Blood samples of L, P, Bic, beta-HB and AA were analysed in four groups of subjects. The first group (A) consisted of patients with presumed NRTI-related adverse events (n=21), the second group (B) consisted of patients without adverse events (n=28), the third group (C) were HIV-infected patients without antiretroviral therapy (n=6) and the last group (D) were healthy controls (n=12). The mean duration of NRTI-treatment was 18 months (range 0-78 months). RESULTS: The mean lactate level in group A was 2319 micromol/l (S.D. +/-1231, median 1741 micromol/l), in group B 1257 micromol/l (S.D. +/-607, median 1087), Group C 1285 (S.D. +/-451, median 1245 micromol/l) and 951 micromol/l (S.D. +/-270, median 979) in the healthy controls. No significant differences in pyruvate, L/P, Bic and beta-HB/AA were seen in the four groups. The mean lactate level in patients on stavudine was 1980 micromol/l (S.D. +/-1197) versus 1051 micromol/l (S.D. +/-395, P=0.01) in patients on zidovudine. All patients with lactate values above 2700 micromol/l (eight) experienced adverse events. CONCLUSION: Lactate levels were higher in patients with presumed NRTI-related adverse events. Furthermore, HIV patients receiving a stavudine containing antiretroviral therapy had higher lactate values than patients without stavudine. Although routine lactate measurement in all patients on antiretroviral therapy is not recommended, lactate measurement might be useful for follow up of patients with presumed NRTI-related adverse events and in patients with lactate levels above 2500 micromol/l. These patients require extra surveillance to evaluate if discontinuation of the current antiretroviral therapy is needed.