The value of synovial cytokine expression in predicting the clinical response to TNF antagonist therapy (infliximab).

OBJECTIVES: Clinical response to TNF-alpha blockade in the treatment of RA is heterogeneous. The study aims were to determine whether pre-treatment synovial cytokine expression predicted infliximab response and whether synovial changes after therapy correlated with response. METHODS: Fifty-one patients had arthroscopic biopsies of the knee joint prior to infliximab (3 mg/kg) treatment. Synovial tissue cell numbers (CD68 and CD3 positive) and cytokine expression (TNF-alpha, lymphotoxin-alpha, IL-1alpha, -beta and receptor antagonist, and IL-6) pre-treatment was assessed using semi-quantitative immunohistochemistry. Changes in these parameters were assessed 16 weeks after infliximab in 32 patients who underwent repeat arthroscopic biopsy. RESULTS: Of the total patients, 47% (n = 24) achieved an ACR20 response; 53% (n = 27) did not. Baseline synovial TNF-alpha, IL-1alpha and -beta expression did not differ between the two groups. No differences in baseline TNF-alpha levels were observed with ACR levels of response (ACR20 and ACR50/70 groups). Post-treatment biopsies (17 ACR responders, 15 ACR non-responders) revealed significant reductions in sub-lining layer TNF-alpha expression in both response and non-response groups with significant reduction in vascularity and membrane proliferation scores. The worst ACR non-responders (<20% CRP suppression) demonstrated no reduction in any of the parameters. CONCLUSION: Pre-treatment synovial TNF-alpha or IL-1 expression does not predict TNF blockade response. Both ACR response and non-response was associated with reduction in synovial TNF-alpha-level expression. Suppression in TNF-alpha levels was not observed in the worst non-responders. The improvements (including in vascularity), independent of ACR clinical response, are compatible with the reduced structural damage documented in all groups of patients independent of response.

Spectroscopic studies of Rhodobacter capsulatus cytochrome c' in the isolated state and in intact cells.

Ferricytochrome c' from Rhodobacter capsulatus was investigated by 1H-NMR, EPR and optical spectroscopies. A haem-linked ionisation, occurring with a pKa of 8.4 at 25 degrees C, was observed and assigned to the ionisation of the axial histidine ligand by comparison with data for related proteins. At pH values below this pKa the spin-state of the haem Fe3+ is shown to be a quantum mechanically admixed S = 3/2, 5/2 state. Above the pKa the Fe3+ is high-spin. EPR studies of intact cells grown photoheterotrophically reveal that in situ cytochrome c' exists largely in the ferrous state. Upon the addition of [Fe(CN)6]3- the protein becomes oxidised and EPR spectra reveal that the Fe3+ spin-state is a quantum mechanically admixed S = 3/2, 5/2 state. These data indicate that the unusual spin-state of ferricytochrome c' is not a consequence of changes to the protein on its isolation, as had been suggested previously. They also indicate that in situ cytochrome c' is located in an environment with a pH less than 7.

Stem cell transplantation for autoimmune disorders. Rheumatoid arthritis.

Haematopoietic stem cell transplantation (HSCT) is now being investigated as a potential therapy for patients with severe refractory rheumatoid arthritis unresponsive to conventional therapies, including tumour necrosis factor-alpha blockade. Pilot studies and an analysis of worldwide cases included in the European Group for Blood and Marrow Transplantation/Autologous Blood and Marrow Transplant Registry registry have enabled the progression of the technique. HSCT is well tolerated in patients with rheumatoid arthritis, and there has been no transplant-related mortality. Although HSCT is not a cure, an improved response to previously ineffective therapies is often seen. Further research is, however, required, and this procedure is still considered appropriate only for those patients for whom there is no reasonable therapeutic alternative. This paper reviews all the previous data relating to HSCT in rheumatoid arthritis, outlines the current stand and discusses future protocol options and research.

Requirement for presenilin 1 in facilitating lagged 2-mediated endoproteolysis and signaling of notch 1.

Presenilin 1 (PS1), a polytopic membrane protein, is required for endoproteolytic processing at gamma-secretase site within the transmembrane domain of amyloid precursor proteins (APP). In addition, PS1 and its orthologues facilitate signaling of Notch family members, cell-surface receptors that specify cell fates during development. To clarify the mechanism(s) by which PS facilitates Notch signaling, we examined human Jagged-2-dependent metabolism and activity of a chimeric full-length Notchl-GFP molecule expressed in fibroblasts with heterozygous, or homozygous deletions of PS1. We demonstrate that PS1 is required for facilitating Jagged 2-mediated proteolysis and that translocation and accumulation of NICD in the nucleus correlates with signaling activity. Moreover, in a ligand-independent, Ca2+-depletion paradigm, we demonstrate that PS1 facilitates endoproteolysis of a plasma-membrane-associated, Notch1-GFP derivative. Finally, we report that NICD production is inhibited by L-685,458, a potent and selective inhibitor that blocks solubilized gamma-secretase activity and Abeta production in cultured cells. These findings strongly suggest that intramembranous processing of APP and Notch 1 are mediated by similar, if not identical, proteases that require PS1 for their activation.

Autologous stem cell transplantation for rheumatoid arthritis--interim report of 6 patients.

We assessed the safety and efficacy of autologous stem cell transplantation (ASCT) using T cell depleted grafts in the treatment of severe rheumatoid arthritis. Methods included mobilization 2 g/m2 cyclophosphamide (Cy) and granulocyte-colony stimulating factor; graft manipulation of positive CD34+ and negative T cell selection; and conditioning by 200 mg/kg Cy. All 6 patients improved according to American College of Rheumatology response criteria (one patient ACR70, 2 ACR50, 3 ACR20), but relapsed at 1.5-9 months when they began cyclosporine A (CSA). Five improved (one patient ACR remission, 2 ACR70, one ACR50, one improved but did not satisfy ACR response criteria). No serious complications occurred during ASCT or up to 30 months' followup. There was prolonged reduction in CD4+ T cells. ASCT is safe and has short term efficacy. T cell purging does not prevent relapse. Five patients responded to CSA when their disease had previously been refractory, suggesting an immunomodulatory effect. No serious infectious complications occurred despite prolonged reduction in CD3+CD4+ lymphocytes.

The effect of vitamin D levels on the assessment of disease activity in rheumatoid arthritis.

Disease activity in rheumatoid arthritis (RA) is assessed by a combination of objective and subjective tests, combined to produce a disease activity score in 28 joints (DAS28). There is some evidence that RA disease activity, as assessed by DAS28, can be influenced by vitamin D levels. It is difficult to know whether this is due to a true immunomodulatory effect of vitamin D or a more subjective effect of low vitamin D on pain perception. We addressed this issue by comparing vitamin D levels with disease activity, analysing each component of the DAS28 score separately. We measured 25-hydroxy vitamin D levels in 176 outpatients with RA at two different centres and recorded a DAS28 score using an ESR checked at the same time. We calculated DAS28 both with and without the patient's rating of their symptoms on the visual analogue score (VAS) to assess the effect of VAS on DAS28. The vitamin D results were expressed as nanomole per litre with 50 nmol/l taken as the lower limit of normal. We calculated mean levels of vitamin D and undertook a multivariate regression analysis to assess correlations between vitamin D levels and DAS28 (and its individual components), corrected for centre, age and gender. The overall mean DAS28 score was 3.66 (SE ± 0.11) using all four criteria and 3.43 (SE ± 0.10) using just three criteria (omitting VAS). The mean vitamin D level was 39.42 nmol/l (SE ± 1.55). There was no significant correlation between vitamin D and DAS28 scores with or without the inclusion of VAS. However, there was a significant inverse relationship between vitamin D and VAS itself (coefficient = 0.249, p = 0.013). The mean DAS28 score was greater in vitamin D-deficient patients and this was explained by their higher VAS scores. Our data confirms that vitamin D deficiency is common in RA. This paper provides evidence that the VAS component, assessing patient perception of symptoms, is inversely related to vitamin D, with lower levels producing higher VAS values. Although there was no overall correlation between vitamin D levels and DAS28, patients may perceive themselves or be perceived by assessors as having responded less well to disease modification in the presence of vitamin D deficiency. This could have major implications for subsequent management, and clinicians need to be aware of the potential confounding effect of vitamin D deficiency in assessing RA disease activity using the full DAS28 tool.

Long-term infliximab treatment in rheumatoid arthritis: subsequent outcome of initial responders.

OBJECTIVE: Patients may cease therapy with anti-tumour necrosis factor (TNF) agents due to inefficacy at 12 weeks (termed primary non-response) or later. Until now, the extent of this later secondary non-response has not been clearly defined. We followed-up a substantial single-centre cohort to determine kinetics of this secondary loss of response. The licensed dose of 3 mg/kg was used throughout. METHODS: Prospective data collection since anti-TNF therapy introduction in 1999 formed the basis of the analysis. Patients with rheumatoid arthritis who received infliximab as their first biologic agent, with at least 2 yrs follow-up were included. All relevant clinical data to calculate DAS-28 score and EULAR response were collected at 3, 6, 9, 12, 18 and 24 months. Reasons for cessation in those patients achieving a EULAR response at 3 months (secondary failures) were determined. RESULTS: Of a total of 309 patients commenced on infliximab, 290 received this as their first biologic agent.; 195 commenced > or = 2 yrs ago. Efficacy data to identify EULAR responders at 3 months was available in 174 patients. Sixty-seven per cent achieved a 'moderate' or 'good' EULAR response; 25% failed to achieve a response, 8% developed toxicity within the first 12 weeks. Of the primary responders, over 55% subsequently ceased therapy in the first year, the predominant reason was a secondary loss of response; other reasons included high disease activity despite achieving a definable response, toxicity, and intercurrent illness. Subsequent loss of response in the second year was less pronounced. CONCLUSIONS: This study of patients treated in clinical practice with infliximab demonstrated that secondary non-response occurred in around half the patients in the first year. The data highlight the need to continue development of other therapies as well as investigation of the underlying causes of this loss of response.

Autologous blood stem cell transplantation as therapy for autoimmune diseases.

Autologous stem cell transplantation (ASCT) is starting to be investigated as a potential therapy for severe refractory autoimmune disease including rheumatological, neurological and haematological diagnoses. Increasing numbers of cases are now reported in the literature. Data from all transplanted patients are being collated in a centralized register by the European Group for Blood and Marrow Transplantation (EBMT) and the European League against Rheumatism (EULAR) to enable effective evaluation of the safety and efficacy of this promising technique. Thus far, results have been encouraging; however, more treatment-related deaths were reported in multiorgan diseases such as scleroderma and less in diseases such as rheumatoid arthritis, which confirms the importance of careful patient selection. Optimization of mobilization, conditioning regimen and graft manipulation is required to maximize efficacy without increasing mortality and morbidity. The use of maintenance therapy after ASCT in order to prevent relapse needs to be explored. Following individual case reports and small cohort studies, the next step is likely to involve multicentre randomized controlled trials.

The impact of escalating conventional therapy in rheumatoid arthritis patients referred for anti-tumour necrosis factor-alpha therapy.

OBJECTIVE: To assess the impact of escalating conventional therapy in patients with RA who satisfy BSR/NICE criteria for biologics. METHODS: A total of 308 consecutive patients referred to a tertiary centre for biological therapy between January 1999 and February 2001 were studied prospectively. They were considered by their own consultant to have failed standard therapy. Prior to biologics, conventional therapy was escalated to include combination and parenteral methotrexate treatment. Patients were assessed at 12-weekly intervals for 1 yr and therapy was changed if response was not satisfactory. The subsequently released BSR/NICE biologic eligibility criteria were applied retrospectively. Response (disease activity, disability and quality of life) to escalated therapy in those patients who did or did not satisfy current eligibility criteria were compared. RESULTS: In total, 159 satisfied BSR/NICE criteria and would have been eligible for immediate treatment with biologics [DAS28 > 5.1, failed methotrexate (20 mg/week or lower dose owing to toxicity) and one other DMARD]; however, 93 of these responded to escalated conventional therapy and did not require biologics [significant improvement (P < 0.01) in disease activity, disability and quality of life]. However, mild disease activity (DAS28 < 3.2) was only achieved in 7% of these patients at 12 months. CONCLUSIONS: Although over half the patients who satisfied standard criteria for biologics responded satisfactorily to escalated therapy, only a minority achieved mild disease activity. The savings achieved by treating with conventional therapies need to be weighed against the risk of persistent disease activity.

Probing the electronic structure of transition metal ion centres in proteins by coherent Raman-detected electron paramagnetic resonance spectroscopy.

The simultaneous excitation of a paramagnetic sample with optical (laser) and microwave radiation can cause an amplitude or phase modulation of the transmitted light at the microwave frequency. The detection of this modulation indicates the presence of coupled optical and electron paramagnetic resonance (EPR) transitions in the sample. Here we report the first application of this technique to a biomolecule: the blue copper centre of Pseudomonas aeruginosa azurin. Using optical excitation at 686 nm, in the thiol to copper(II) charge transfer band, we measure a coherent Raman-detected EPR spectrum of a frozen aqueous solution. Its lineshape is characteristic of the magnetic circular dichroism along each principal g-value axis. This information allows electronic and structural models of transition metal ion centres in proteins to be tested.

Deconvolution and assignment of different optical transitions of the blue copper protein azurin from optically detected electron paramagnetic resonance spectroscopy.

Magnetic circular dichroism is a powerful spectroscopic tool for the assignment of optical resonance lines. An extension of this technique, microwave-modulated circular dichroism, provides additional details, in particular information about the orientation of optical transition moments. It arises from magnetization precessing around the static magnetic field, excited by a microwave field, in close analogy to electron paramagnetic resonance (EPR). In this paper we investigate the visible and near-infrared spectrum of the blue copper protein Pseudomonas aeruginosa azurin. Using a nonoriented sample (frozen solution), we apply this technique to measure the variation of the optical anisotropy with the wavelength. A comparison with the optical anisotropies of the possible ligand-field and charge-transfer transitions allows us to identify individual resonance lines in the strongly overlapping spectrum and assign them to specific electronic transitions. The technique is readily applicable to other proteins with transition metal centers.

True infliximab resistance in rheumatoid arthritis: a role for lymphotoxin alpha?

BACKGROUND: The combination of methotrexate and the anti-tumour necrosis factor alpha (TNFalpha) antibody infliximab is a very effective treatment for rheumatoid arthritis (RA). However, a proportion of patients are not responsive to this treatment. Inefficacy may represent a TNFalpha independent disease or insufficient drug at the site of action. CASE REPORT: A patient with RA resistant to repeated high dose infliximab infusions and intra-articular infliximab into an inflamed knee is described. No beneficial clinical effect was observed. Pre-injection arthroscopic biopsy of the study knee demonstrated TNFalpha staining but also confirmed the presence of lymphotoxin alpha (LTalpha or TNFbeta) on immunohistochemistry. Subsequent treatment with etanercept (which blocks LTalpha as well as TNFalpha) resulted in clinical remission of disease. CONCLUSION: This case suggests that resistance to TNF blockade may occur when TNFalpha is not the dominant inflammatory cytokine and suggests that LTalpha may have a pathogenic role in RA.

Micro-SAXS and force/strain measurements during the tensile deformation of single struts of an elastomeric polyurethane foam.

A microdeformation stage based on a piezoelectric crystal actuator capable of measuring the force applied to micrometre-sized polymeric samples is described. Laboratory force/strain measurements on a single strut of an elastomeric polyurethane foam have been conducted for the first time. The device has also been used on the microfocus beamline at the European Synchrotron Radiation Facility to collect microbeam small-angle X-ray scattering data simultaneously with strain and force measurements during the time-resolved tensile deformation of a single strut of elastomeric polyurethane foam.

FcgammaRIIIA-158V and rheumatoid arthritis: a confirmation study.

OBJECTIVES: To develop a robust assay for genotyping the FcgammaRIIIA-158V/F polymorphism and to confirm the putative association between the FcgammaRIIIA-158V allele and rheumatoid arthritis (RA). METHODS: This allelic association study examined the FcgammaRIIIA-158V/F polymorphism for association with RA. A novel single-stranded conformational polymorphism assay was used to genotype 828 RA patients and 581 controls from the UK. RESULTS: The FcgammaRIIIA-158V allele was associated with both RA (P=0.02) and nodules (P=0.04). Individuals homozygous for this higher affinity allele had a significantly increased risk of RA (OR 1.53, 95% CI 1.08-2.18) and the development of nodules (OR 2.20, 95% CI 1.20-4.01). There was no evidence of an interaction with the shared epitope. CONCLUSIONS: We have developed a novel assay to genotype the FcgammaRIIIA-158F/V polymorphism and confirmed that homozygosity for the FcgammaRIIIA-158V allele is associated with UK Caucasian RA, particularly in those individuals with nodules, suggesting FcgammaRIIIA may play a role in determining disease severity or in the development of nodules per se.