Pekka Lahdenne

The complement regulator factor H binds to the surface protein OspE of Borrelia burgdorferi.

Spirochete bacteria of the Borrelia burgdorferi sensu lato complex cause Lyme borreliosis. The three pathogenic subspecies Borrelia garinii, Borrelia afzelii, and Borrelia burgdorferi sensu stricto differ in their disease profiles and susceptibility to complement lysis. We investigated whether complement resistance ofBorreliae could be due to acquisition of the main soluble inhibitors of the alternative complement pathway, factor H and the factor H-like protein 1. When exposed to nonimmune EDTA-plasma, the serum-resistant B. afzelii and B. burgdorferisensu stricto strains bound factor H/factor H-like protein 1 to their surfaces. Assays with radiolabeled proteins showed that factor H bound strongly to the B. burgdorferi sensu stricto strain. To identify factor H ligands on the borrelial surface, we analyzed a panel of outer surface proteins of B. burgdorferi sensu stricto with the surface plasmon resonance technique. The outer surface lipoprotein OspE was identified as a specific ligand for factor H. Using recombinant constructs of factor H, the binding site for OspE was localized to the C-terminal short consensus repeat domains 15–20. Specific binding of factor H to B. burgdorferi sensu stricto OspE may help the pathogen to evade complement attack and phagocytosis.

Infliximab or etanercept in the treatment of children with refractory juvenile idiopathic arthritis: an open label study

Objective: To study infliximab and etanercept in the treatment of refractory juvenile idiopathic arthritis (JIA). Methods: In a non-randomised, prospective, open label study, 24 patients (mean age 10.2 years, range 3.3–16.3) with polyarticular JIA were treated with either infliximab (n=14) or etanercept (n=10). The patients had had active polyarthritis for at least one year and standard treatment had failed. Anti-tumour necrosis factor (TNF) treatment was added to the current drug treatment. Infliximab (3–4 mg/kg) was given intravenously at weeks 0, 2, and 6, and thereafter at 4 to 8 week intervals. Etanercept (0.4 mg/kg) was given subcutaneously twice a week. Improvement of the patients was assessed at 3, 6, and 12 months according to established JIA response criteria. Results: In intention to treat analyses, patients in both treatment groups improved significantly. ACR Paediatric 50 was achieved at 3, 6, and 12 months by 9/10 (90%), 8/9 (89%), and 8/9 (89%) patients with etanercept and by 8/12 (67%), 10/12 (83%), and 7/9 (78%) with infliximab, respectively. At 12 months, ACR Paediatric 75 was achieved by 67% of patients in both treatment groups. Five withdrawals due to adverse effects or lack of efficacy occurred in the infliximab group and one due to lack of compliance in the etanercept group. Conclusion: In this open label clinical study of active JIA, both infliximab and etanercept provided a significant rapid and sustained reduction in disease activity. Adequately powered randomised controlled trials are needed to elucidate the long term safety and efficacy of TNF modulators in the treatment of JIA.

Infliximab and etanercept in the treatment of chronic uveitis associated with refractory juvenile idiopathic arthritis

Objective: To evaluate the efficacy of anti-tumour necrosis factor (anti-TNF) treatment in juvenile idiopathic arthritis (JIA)-associated uveitis. Methods: 24 patients with uveitis taking etanercept and 21 taking infliximab were studied. The endpoint ophthalmological evaluation was at 24 months or at the termination of the first biological agent. The ocular inflammatory activity was graded on the basis of the number of anterior chamber cells. Results: Of the 45 patients, uveitis improved in 14 (31%), no change was observed in 14 (31%) and the activity of uveitis increased in 17 (38%). Inflammatory activity improved more frequently (p = 0.047) in the patients taking infliximab than in those taking etanercept. The number of uveitis flares/year was higher (p = 0.015) in the patients taking etanercept (mean 1.4, range 0–3.2) than in those taking infliximab (mean 0.7, range 0–2). Uveitis developed for the first time while taking anti-TNF treatment in five patients—4 taking etanercept (2.2/100 patient-years) and 1 taking infliximab (1.1/100 patient-years). Conclusions: During anti-TNF treatment, the ophthalmological condition improved in one-third of the patients with uveitis. In chronic anterior uveitis, associated with refractory JIA, infliximab may be more effective than etanercept.

Complement Inhibitor Factor H Binding to Lyme Disease Spirochetes Is Mediated by Inducible Expression of Multiple Plasmid-Encoded Outer Surface Protein E Paralogs

Borrelia burgdorferi spirochetes can circumvent the vertebrate host’s immune system for long periods of time. B. burgdorferi sensu stricto and B. afzelii, but not B. garinii, bind the complement inhibitor factor H to protect themselves against complement-mediated opsonophagocytosis and killing. We found that factor H binding and complement resistance are due to inducible expression of a wide repertoire of outer surface protein E (OspE) lipoproteins variably called OspE, p21, ErpA, and ErpP. Individual Borrelia strains carry multiple plasmid-encoded OspE paralogs. Together the OspE homologs were found to constitute an array of proteins that bind factor H via multiple C-terminal domains that are exposed outwards from the Borrelial surface. Charged residue substitutions in the key binding regions account for variations between OspE family members in the optimal binding pH, temperature, and ionic strength. This may help the spirochetes to adapt into various host environments. Our finding that multiple plasmid-encoded OspE proteins act as virulence factors of Borrelia can provide new tools for the prevention and treatment of borreliosis.

Adalimumab in juvenile idiopathic arthritis-associated chronic anterior uveitis

OBJECTIVE To evaluate the efficacy of adalimumab in juvenile idiopathic arthritis (JIA)-associated uveitis. METHODS Retrospective observational study of 20 patients with JIA and chronic uveitis on adalimumab treatment. The ocular inflammation and improvement was assessed according to the Standardization of Uveitis Nomenclature criteria. RESULTS At the initiation of adalimumab, the mean age of patients was 13.4 yrs and the mean duration of uveitis 8.7 yrs. Seventeen (85%) patients had polyarticular JIA and 19 (95%) had previously been on anti-TNF treatment. The mean duration of adalimumab therapy was 18.7 months. Of the 20 patients, 7 (35%) showed improved activity, 1 (5%) worsening activity and in 12 (60%) no change was observed in the activity of uveitis. Those with improved activity were younger and had shorter disease duration. The mean number of flares/yr decreased from 1.9 to 1.4 during adalimumab treatment. Serious adverse events or side-effects were not observed. Seven patients discontinued adalimumab during the follow-up: six because of inefficacy and one because of inactive uveitis. CONCLUSION Adalimumab is a potential treatment option in JIA-associated uveitis, even in patients non-responsive to previous other anti-TNF therapy.

Aggressive Combination Drug Therapy in Very Early Polyarticular Juvenile Idiopathic Arthritis (ACUTE–JIA): a multicentre randomised open-label clinical trial

Objectives In juvenile idiopathic arthritis (JIA), the efficacy of very early disease-modifying drug therapy, synthetic or biological, is not well known. Three alternative strategies were compared for treating recent‑onset polyarticular JIA. Methods In a 54-week multicentre open-label clinical trial, 60 disease-modifying antirheumatic drug (DMARD)-naive patients aged 4–15 years were randomly assigned into three treatment arms. The efficacy of infliximab plus methotrexate (TNF) was compared to that of two synthetic therapies: methotrexate alone (MTX) and DMARD methotrexate, sulphasalazine and hydroxychloroquine in combination (COMBO). Primary endpoint was American College of Rheumatology paediatric 75% improvement (ACR Pedi 75). Secondary endpoints were inactive disease and safety. Results In 59 patients, mean (±SE) age at baseline was 9.6±0.4 years, duration of JIA 1.9±0.2 months and number of active joints 18±1. ACR Pedi 75 was achieved in 100% (19/19) of patients receiving TNF, 65% (13/20) on COMBO (95% CI 44% to 86%) and 50% (10/20) on methotrexate (95% CI 28% to 72%) p<0.0001. Thirteen patients receiving TNF (68%; 95% CI 47% to 89%) achieved inactive disease, whereas eight (40%; 95% CI 22% to 63%) on COMBO and five (25%; 95% CI 6% to 44%) on methotrexate did (p=0.002). Patients on TNF spent a mean 26 weeks (95% CI 18 to 34) with inactive disease, longer than did those receiving COMBO (13 weeks; 95% CI 6 to 20), or methotrexate (6 weeks; 95% CI 2 to 10). Serious adverse events were rare. Conclusion In early polyarticular JIA, targeting to achieve minimally active or inactive disease, infliximab plus methotrexate was superior to synthetic DMARD in combination and strikingly superior to methotrexate alone.

Ongoing disease activity and changing categories in a long‐term nordic cohort study of juvenile idiopathic arthritis

OBJECTIVE To describe the disease characteristics, long-term course, and outcome of patients with juvenile idiopathic arthritis (JIA) in a population-based setting. METHODS Consecutive cases of JIA from defined geographic areas of Denmark, Finland, Sweden, and Norway in whom disease onset occurred in 1997-2000 were included in a prospective, multicenter cohort study. The study was designed to be as close to a population-based study as possible, with centers participating only if they were able to include in their catchment area all children in whom JIA was diagnosed. RESULTS Of 500 children included, 440 (88.0%) had repeated visits, with the last visit occurring at least 7 years after disease onset (median 98 months, range 84-147 months). Changes in the International League of Associations for Rheumatology category were observed in 10.8% of the children, and, in addition, extended oligoarthritis developed in 34.7% of the group with oligoarticular JIA. During the observation period, 58.0% of the children were treated with disease-modifying antirheumatic drugs, including biologic medications. Ongoing disease activity was mostly mild, but some JIA-related damage developed in 22.9% of the children. At the last followup visit, remission off medication was observed in 42.4% of the children, 8.9% were in remission on medication, and 48.7% were not in remission. The highest rates of remission were observed in patients with persistent oligoarticular JIA and in those with systemic JIA. CONCLUSION In this long-term prospective study of JIA in a population-based Nordic setting, ongoing disease was evident in a majority of the children. The present results underline the need to identify early predictors of outcome, to further improve therapy, and to continue long-term followup of patients with JIA.

Impact of anti-TNF treatment on growth in severe juvenile idiopathic arthritis.

Objectives: To evaluate the impact of anti-tumour necrosis factor (TNF) treatment on growth and to identify the predictors for the change in growth in severe juvenile idiopathic arthritis (JIA). Methods: Data from 71 JIA patients (43 on etanercept, 28 on infliximab) were reviewed two years before and two years on the anti-TNF treatment. The patients had polyarticular disease course (48 polyarthritis, 19 extended oligoarthritis, two systemic arthritis, and two enthesitis related arthritis). At the initiation of the anti-TNF treatment, their mean age was 9.6 years and the mean duration of JIA, 5.7 years. Results: In the patients with delayed growth before anti-TNF treatment (n = 53), the growth velocity, measured as the change in height standard deviation score, accelerated +0.45 (95% confidence interval, 0.33 to 0.56) (p<0.001) during the anti-TNF treatment. In the patients with normal or accelerated growth before anti-TNF treatment (n = 18), the change in growth velocity was +0.05 (0.07 to 0.16) (p = 0.39). At two years on anti-TNF treatment, the growth velocity between these two groups was similar. No difference was found between the patients treated with etanercept or infliximab. A decelerating growth rate before the anti-TNF treatment was the strongest predictor for the observed increase in the growth velocity. The change in the inflammatory activity remained a significant predictor of the growth velocity even after the decrease in glucocorticoid dose was taken into account. Conclusions: In the treatment of polyarticular JIA, the anti-TNF treatment not only suppresses inflammation but also restores growth velocity.

Lysine-Dependent Multipoint Binding of the Borrelia burgdorferi Virulence Factor Outer Surface Protein E to the C Terminus of Factor H

Serum resistance, an important virulence determinant of Borrelia burgdorferi sensu lato strains belonging to the Borrelia afzelii and B. burgdorferi sensu stricto genotypes, is related to binding of the complement inhibitor factor H to the spirochete surface protein outer surface protein E (OspE) and its homologues. In this study, we show that the C-terminal short consensus repeats 18–20 of both human and mouse factor H bind to OspE. Analogously, factor H-related protein 1, a distinct plasma protein with three short consensus repeat domains homologous to those in factor H, bound to OspE. Deleting 15-aa residues (region V) from the C terminus of the OspE paralog P21 (a 20.7-kDa OspE-paralogous surface lipoprotein in the B. burgdorferi sensu stricto 297 strain) abolished factor H binding. However, C-terminal peptides from OspE, P21, or OspEF-related protein P alone and the C-terminal deletion mutants of P21 inhibited factor H binding to OspE only partially when compared with full-length P21 or its N-terminal mutant. Alanine substitution of amino acids in peptides from the key binding regions of the OspE family indicated that several lysine residues are required for factor H binding. Thus, the borrelial OspE family proteins bind the C inhibitor factor H via multiple sites in a lysine-dependent manner. The C-terminal site V (Ala151-Lys166) is necessary, but not sufficient, for factor H binding in both rodents and humans. Identification of the necessary binding sites forms a basis for the development of vaccines that block the factor H-OspE interaction and thereby promote the killing of Borreliae.

Drug survival of the first and second course of anti-tumour necrosis factor agents in juvenile idiopathic arthritis

Objectives: To evaluate drug survival (continuation rates on drug) of anti-tumour necrosis factor (TNF) agents in juvenile idiopathic arthritis (JIA) and predictors for treatment discontinuation. Methods: A retrospective observational study on JIA patients taking etanercept (n  =  105) or infliximab (n  =  104) with at least one year follow-up. Kaplan–Meier curves and log-rank statistics were used to compare treatments and a proportional hazards model to assess risk factors for discontinuation. Results: Etanercept versus infliximab treatment survival at 12 months was 83% versus 80%, at 24 months 68% versus 68%, at 36 months 64% versus 53%, at 48 months 61% versus 48% (p = 0.194), respectively. Reasons for discontinuing the first biological treatment were inefficacy (etanercept 28% vs infliximab 20%, p = 0.445), adverse events (7% vs 22%, p = 0.002) or inactive disease (10% vs 16%, p = 0.068). Women (hazard ratio (HR) 2.8, 95% CI 1.3 to 5.8), patients with systemic JIA (HR 7.8, 95% CI 1.7 to 34.9) or those taking infliximab (HR 2.0, 95% CI 1.2 to 3.3) were at higher risk of treatment discontinuation. One-third of the patients were switched to the second anti-TNF therapy, which was discontinued less frequently than the first. At 12 months treatment survival of etanercept was 60%, infliximab 58% and adalimumab 66% as the second-line anti-TNF therapy. Conclusions: Although infliximab was discontinued more often than etanercept because of adverse events, during a 48-month follow-up the overall treatment survival of etanercept and infliximab as the first biological agent in JIA was comparable. A switch from one anti-TNF agent to another appears a reasonable therapeutic option.