In ankylosing spondylitis (AS), joint remodeling leading to joint ankylosis involves cartilage fusion. Here, we analyzed whether chondrocyte hypertrophy is involved in cartilage fusion and subsequent joint remodeling in AS.
We assessed the expression of chondrocyte hypertrophy markers runt-related transcription factor 2 (Runx2), type X collagen (COL10), matrix metalloproteinase 13 (MMP13), osteocalcin and beta-catenin and the expression of positive bone morphogenic proteins (BMPs) and negative regulators (dickkopf-1 (DKK-1)), sclerostin, (wingless inhibitory factor 1 (wif-1)) of chondrocyte hypertrophy in the cartilage of facet joints from patients with AS or osteoarthritis (OA) and from autopsy controls (CO) by immunohistochemistry. Sex determining region Y (SRY)-box 9 (Sox9) and type II collagen (COL2) expression was assessed as indicators of chondrocyte integrity and function.
The percentage of hypertrophic chondrocytes expressing Runx2, COL10, MMP13, osteocalcin or beta-catenin was significantly increased in OA but not in AS joints compared to CO joints. Frequencies of sclerostin-positive and DKK-1-positive chondrocytes were similar in AS and CO. In contrast, wif-1- but also BMP-2- and BMP-7-expressing and Sox9-expressing chondrocytes were drastically reduced in AS joints compared to CO as well as OA joints whereas the percentage of COL2-expressing chondrocytes was significantly higher in AS joints compared to CO joints.
We found no evidence for chondrocyte hypertrophy within hyaline cartilage of AS joints even in the presence of reduced expression of the wnt inhibitor wif-1 suggesting that chondrocyte hypertrophy is not a predominant pathway involved in joint fusion and remodeling in AS. In contrast, the reduced expression of Sox9, BMP-2 and BMP-7 concomitantly with induced COL2 expression rather point to disturbed cartilage homeostasis promoting cartilage degeneration in AS.
Innate immune responses, including monocyte functions, seem to play an important role in the pathogenesis of axial spondyloarthritis (axSpA). Therefore, we characterized the phenotype and functional state of monocytes of patients with axSpA.
Fifty-seven patients with axSpA, 11 patients with rheumatoid arthritis (RA), and 29 healthy controls were included in the study. We determined the percentage of classic, intermediate, and non-classic monocytes according to CD14 and CD16 expression and the expression of Toll-like receptor (TLR) 1, 2, and 4 in whole blood by flow cytometry. The percentage of monocytes producing interleukin (IL)-1beta, IL-6, tumor necrosis factor alpha (TNFα), IL-12/23p40, and IL-1 receptor antagonist (IL-1ra) was detected by flow cytometry after stimulation of whole blood without and with different TLR and nucleotide-binding oligomerization domain ligands—i.e., lipopolysaccharide (LPS), fibroblast-stimulating lipopeptid-1, PAM3CSK4, and muramyl dipeptide (MDP)—for 5 h. IL-10 production was measured after 18 h of stimulation in supernatants by enzyme-linked immunosorbent assay.
In patients with axSpA but not patients with RA, we found higher frequencies of classic monocytes than in controls (median of 90.4 % versus 80.4 %, P < 0.05), higher frequencies of monocytes spontaneously producing IL-1beta and IL-1ra (P < 0.05), and a higher percentage of monocytes producing IL-1beta after MDP stimulation (P < 0.05). Elevated cytokine production was confined to axSpA patients under conventional therapy (non-steroidal anti-inflammatory drugs) and not found in patients under TNFα inhibitor treatment. The LPS-induced production of IL-6 and IL-10 was lower in axSpA patients compared with controls (P < 0.05). Monocytic TLR expression was unaffected in patients with axSpA.
Enhanced spontaneous and MDP-induced cytokine secretion by monocytes suggests in vivo pre-activation of monocytes in axSpA patients under conventional therapy which is reverted under TNF inhibitor treatment.
The ALIGN study (NCT01061723) evaluated the efficacy and safety of sarilumab, the first fully human monoclonal antibody against interleukin-6 receptor-α (IL-6Rα), in patients with ankylosing spondylitis (AS).
Patients with active AS despite conventional treatment were randomised to placebo, or one of five subcutaneous dose regimens of sarilumab (100, 150 or 200 mg every other week, or 100 or 150 mg every week), for 12 weeks. The primary efficacy end point was the percentage of patients achieving the Axial SpondyloArthritis international Society (ASAS) 20 response criteria at week 12. Secondary endpoints included ASAS40 response, ASAS partial remission, AS Disease Activity Score, high-sensitivity C-reactive protein (hs-CRP) value, and safety.
Baseline demographic and disease characteristics of the 301 patients enrolled were similar across treatment groups. At week 12, there was no statistically significant difference in ASAS20 response rate between placebo (ASAS20 = 24.0%) and any sarilumab dose group. A significantly greater reduction in hs-CRP value was achieved with the higher sarilumab doses versus placebo. No other statistically significant differences were evident for secondary efficacy endpoints.
The most common treatment-emergent adverse events reported for sarilumab included infections (non-serious), neutropenia, and increase in alanine aminotransferase. No cases of tuberculosis, opportunistic, or fungal infections, or bowel perforations were reported. Seven patients experienced a treatment-emergent serious adverse event (all in sarilumab treatment groups). No deaths occurred.
The ALIGN study shows that IL-6Rα blockade with sarilumab was not an effective treatment for AS. Sarilumab was generally well tolerated with a manageable safety profile.
Ankylosing Spondylitis; Cytokines; DMARDs (biologic); Autoimmune Diseases; Inflammation
To evaluate the efficacy and safety of adalimumab in patients with active nonpsoriatic peripheral spondyloarthritis (SpA).
ABILITY-2 is an ongoing phase III, multicenter study of adalimumab treatment. Eligible patients age ≥18 years fulfilled the Assessment of SpondyloArthritis international Society (ASAS) classification criteria for peripheral SpA, did not have a prior diagnosis of psoriasis, psoriatic arthritis (PsA), or ankylosing spondylitis (AS), and had an inadequate response or intolerance to nonsteroidal antiinflammatory drugs (NSAIDs). Patients were randomized 1:1 to receive adalimumab 40 mg every other week or matching placebo for 12 weeks, followed by a 144-week open-label period. The primary end point was the proportion of patients achieving 40% improvement in disease activity according to the Peripheral SpA Response Criteria (PSpARC40) at week 12. This was defined as ≥40% improvement from baseline (≥20-mm absolute improvement on a visual analog scale) in patient's global assessments of disease activity and pain, and ≥40% improvement in at least one of the following features: swollen joint and tender joint counts, total enthesitis count, or dactylitis count. Adverse events were recorded throughout the study.
In total, 165 patients were randomized to a treatment group, of whom 81 were randomized to receive placebo and 84 to receive adalimumab. Baseline demographics and disease characteristics were generally similar between the 2 groups. At week 12, a greater proportion of patients receiving adalimumab achieved a PSpARC40 response compared to patients receiving placebo (39% versus 20%; P = 0.006). Overall, improvement in other outcomes was greater in the adalimumab group compared to the placebo group. The rates of adverse events were similar in both treatment groups.
Treatment with adalimumab ameliorated the signs and symptoms of disease and improved physical function in patients with active nonpsoriatic peripheral SpA who exhibited an inadequate response or intolerance to NSAIDs, with a safety profile consistent with that observed in patients with AS, PsA, or other immune-mediated diseases.
Repeatedly activated T helper 1 (Th1) cells present during chronic inflammation can efficiently adapt to the inflammatory milieu, for example, by expressing the transcription factor Twist1, which limits the immunopathology caused by Th1 cells. Here, we show that in repeatedly activated murine Th1 cells, Twist1 and T-bet induce expression of microRNA-148a (miR-148a). miR-148a regulates expression of the proapoptotic gene Bim, resulting in a decreased Bim/Bcl2 ratio. Inhibition of miR-148a by antagomirs in repeatedly activated Th1 cells increases the expression of Bim, leading to enhanced apoptosis. Knockdown of Bim expression by siRNA in miR-148a antagomir-treated cells restores viability of the Th1 cells, demonstrating that miR-148a controls survival by regulating Bim expression. Thus, Twist1 and T-bet not only control the differentiation and function of Th1 cells, but also their persistence in chronic inflammation.
Bim; miR-148a; T-bet; Th1; Twist1
Objective. Chronic pain and progressive loss of physical function with AS may adversely affect health-related quality of life (HRQoL). The objective of this study was to assess the 5-year data regarding spinal mobility, physical function and HRQoL in patients with AS who participated in the Adalimumab Trial Evaluating Long-term Efficacy and Safety for AS (ATLAS) study.
Methods. Patients received blinded adalimumab 40 mg or placebo every other week for 24 weeks, then open-label adalimumab for up to 5 years. Spinal mobility was evaluated using linear BASMI (BASMIlin). BASDAI, total back pain, CRP, BASFI, Short Form-36 and AS quality of life (ASQoL) were also assessed. Correlations between BASMIlin and clinical, functional and ASQoL outcomes after 12 weeks and after 5years of adalimumab exposure were evaluated using Spearman’s rank correlation. Associations were further analysed using multivariate regression.
Results. Three hundred and eleven patients received ≥1 dose of adalimumab; 125 of the 208 patients originally randomized to adalimumab received treatment for 5 years. Improvements in BASMIlin were sustained through 5 years, with a mean change of –0.6 from baseline in the population who completed 5 years of treatment with adalimumab. Improvements in disease activity, physical function and ASQoL were also sustained through 5 years. BASMIlin was significantly correlated with all evaluated clinical outcomes (P < 0.001). The highest correlation was with BASFI at 12 weeks (r = 0.52) and at 5 years (r = 0.65). Multivariate regression analysis confirmed this association (P < 0.001).
Conclusion. Treatment with adalimumab for up to 5 years demonstrated sustained benefits in spinal mobility, disease activity, physical function and HRQoL in patients with active AS. Spinal mobility was significantly associated with short- and long-term physical function in these patients.
Trial registration: Clinicaltrials.gov; https://clinicaltrials.gov/ NCT00085644.
anti-TNF drugs; ankylosing spondylitis; spinal mobility; health-related quality of life; physical function
The aim of this study was to investigate the influence of symptom duration on treatment response and on the correlation between improvements in patient reported outcomes (PRO) and objective inflammation in patients with axial spondylarthritis (SpA) treated with etanercept (ETA) or adalimumab (ADA).
Data from 112 patients with axial SpA originally enrolled in two randomized controlled clinical trials were pooled and analyzed after one year of treatment with ETA (n = 66) or ADA (n = 46). Patients with <4 years and ≥4 years of disease were compared for improvement in Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), Ankylosing Spondylitis Disease Activity Score (ASDAS), C-reactive protein (CRP) and magnetic resonance imaging (MRI) score for sacroiliac joints (SIJ).
Patients with <4 years of disease showed a significantly better improvement than longer diseased patients in BASDAI (3.2 (95% confidence interval (CI): 2.7 to 3.7) vs. 1.7 (1.1 to 2.2)), BASFI, BASMI and ASDAS (1.6 (1.4 to 1.8) vs. 0.9 (0.7 to 1.1)). The change in BASDAI showed a significant correlation with the change in SIJ score (Spearman’s rank correlation coefficient (rho) = 0.37, P = 0.01) and the change in CRP (rho = 0.45, P = 0.001) in patients with <4 years of disease. For long diseased patients this correlation was poor and did not achieve statistical significance (rho = 0.13, P = 0.46; rho = 0.22, P = 0.13 respectively).
The low correlation between change of PROs and change of objective signs of inflammation seen in axial SpA patients with longer symptom duration treated with tumor necrosis factor-blocker seems to indicate that inflammation is not the only cause of the patients’ symptoms, while inflammation seems to be the major cause in short diseased patients.
Clinical Trials.gov NCT00844142 (Trial 1); NCT00235105 (Trial 2)
Data from clinical studies on the long-term efficacy and safety of anti-tumor necrosis factor (TNF)-α therapy in patients with ankylosing spondylitis (AS) are scarce. This is the first report on continuous treatment with the TNFα fusion protein etanercept over seven years (y).
Overall, 26 patients with active AS were initially treated with etanercept 2 × 25 mg s.c./week with no concomitant disease modifying anti-rheumatic drugs (DMARDs) or steroids. The clinical response was assessed by standardized parameters. The primary outcome was the proportion of patients in the Spondyloarthritis International Society (ASAS) partial remission at seven years. AS disease activity scores (ASDAS) for status and improvement were compared to conventional outcome measures.
Overall, 21/26 patients (81%) completed two years of treatment and 16/26 patients (62%) completed seven years. In the completer analysis, 31% patients were in ASAS partial remission at seven years, while 44% patients showed an ASDAS inactive disease status. Mean Bath AS activity index (BASDAI) scores, which were elevated at baseline (6.3 ± 0.9), showed constant improvement and remained low: 3.1 ± 2.5 at two years and 2.5 ± 2.2 at seven years, while ASDAS also improved (3.9 ± 0.7 at baseline, 1.8 ± 0.9 at two years, 1.6 ± 0.8 at seven years), all P <0.001. From the 10 dropouts, only 5 patients discontinued treatment due to adverse events. Patients who completed the study had lower baseline Bath AS function index (BASFI) scores vs. patients who discontinued. No other clinical parameter at baseline could predict any long-term outcome.
This study confirms the clinical efficacy and safety of etanercept in patients with active AS over seven years of continuous treatment. After seven years, more than half of the initially treated patients remained on anti-TNF therapy, and one-third were in partial remission.
ankylosing spondylitis; TNFa; etanercept; ASDAS, BASDAI
To evaluate the efficacy and safety of adalimumab in patients with non-radiographic axial spondyloarthritis (nr-axSpA).
Patients fulfilled Assessment of Spondyloarthritis international Society (ASAS) criteria for axial spondyloarthritis, had a Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score of ≥ 4, total back pain score of ≥ 4 (10 cm visual analogue scale) and inadequate response, intolerance or contraindication to non-steroidal anti-inflammatory drugs (NSAIDs); patients fulfilling modified New York criteria for ankylosing spondylitis were excluded. Patients were randomised to adalimumab (N=91) or placebo (N=94). The primary endpoint was the percentage of patients achieving ASAS40 at week 12. Efficacy assessments included BASDAI and Ankylosing Spondylitis Disease Activity Score (ASDAS). MRI was performed at baseline and week 12 and scored using the Spondyloarthritis Research Consortium of Canada (SPARCC) index.
Significantly more patients in the adalimumab group achieved ASAS40 at week 12 compared with patients in the placebo group (36% vs 15%, p<0.001). Significant clinical improvements based on other ASAS responses, ASDAS and BASDAI were also detected at week 12 with adalimumab treatment, as were improvements in quality of life measures. Inflammation in the spine and sacroiliac joints on MRI significantly decreased after 12 weeks of adalimumab treatment. Shorter disease duration, younger age, elevated baseline C-reactive protein or higher SPARCC MRI sacroiliac joint scores were associated with better week 12 responses to adalimumab. The safety profile was consistent with what is known for adalimumab in ankylosing spondylitis and other diseases.
In patients with nr-axSpA, adalimumab treatment resulted in effective control of disease activity, decreased inflammation and improved quality of life compared with placebo. Results from ABILITY-1 suggest that adalimumab has a positive benefit–risk profile in active nr-axSpA patients with inadequate response to NSAIDs.
TNF, an inflammatory cytokine that is enriched in the tumor microenvironment, promotes tumor growth and subverts innate immune responses to cancer cells. We previously reported that tumors implanted in TNF receptor–deficient (Tnfr–/–) mice are spontaneously rejected; however, the molecular mechanisms underlying this rejection are unclear. Here we report that TNF signaling drives the peripheral accumulation of myeloid-derived suppressor cells (MDSCs). MDSCs expand extensively during inflammation and tumor progression in mice and humans and can enhance tumor growth by repressing T cell–mediated antitumor responses. Peripheral accumulation of MDSCs was drastically impaired in Tnfr–/– mice. Signaling of TNFR-2, but not TNFR-1, promoted MDSC survival through upregulation of cellular FLICE-inhibitory protein (c-FLIP) and inhibition of caspase-8 activity. Loss of TNFRs impaired the induction of MDSCs from bone marrow cells, but this could be reversed by treatment with caspase inhibitors. These results demonstrate that TNFR-2 signaling promotes MDSC survival and accumulation and helps tumor cells evade the immune system.
This study examines the expression of IL-17A-secreting cells within the inflamed synovium and the relationship to in vivo joint hypoxia measurements.
IL-17A expression was quantified in synovial tissue (ST), serum and synovial fluid (SF) by immunohistochemistry and MSD-plex assays. IL-6 SF and serum levels were measured by MSD-plex assays. Dual immunofluorescence for IL-17A was quantified in ST CD15+ cells (neutrophils), Tryptase+ (mast cells) and CD4+ (T cells). Synovial tissue oxygen (tpO2) levels were measured under direct visualisation at arthroscopy. Synovial infiltration was assessed using immunohistochemistry for cell specific markers. Peripheral blood mononuclear and polymorphonuclear cells were isolated and exposed to normoxic or 3% hypoxic conditions. IL-17A and IL-6 were quantified as above in culture supernatants.
IL-17A expression was localised to mononuclear and polymorphonuclear (PMN) cells in inflamed ST. Dual immunoflourescent staining co-localised IL-17A expression with CD15+ neutrophils Tryptase+ mast cells and CD4+T cells. % IL-17A positivity was highest on CD15+ neutrophils, followed by mast cells and then CD4+T-cells. The number of IL-17A-secreting PMN cells significantly correlated with sublining CD68 expression (r = 0.618, p<0.01). IL-17A SF levels correlated with IL-6 SF levels (r = 0.675, p<0.01). Patients categorized according to tp02< or >20mmHg, showed those with low tp02<20mmHg had significantly higher IL-17A+ mononuclear cells with no difference observed for PMNs. Exposure of mononuclear and polymorphonuclear cells to 3% hypoxia, significantly induced IL-6 in mononuclear cells, but had no effect on IL-17A expression in mononuclear and polymorphonuclear cells.
This study demonstrates IL-17A expression is localised to several immune cell subtypes within the inflamed synovial tissue, further supporting the concept that IL-17A is a key mediator in inflammatory arthritis. The association of hypoxia with Il-17A expression appears to be indirect, probably through hypoxia-induced pro-inflammatory pathways and leukocyte influx within the joint microenvironment.
In this study, we analysed the number of IL-17+ cells in facet joints, in the peripheral blood (PB) and synovial fluid (SF) of spondyloarthritis (SpA) patients and compared these results with those of patients with other rheumatic diseases and controls.
Immunohistochemical analysis of IL-17+ cells was performed in facet joints of 33 ankylosing spondylitis (AS) patients and compared with data from 20 osteoarthritis (OA) patients. The frequency of IL-17+CD4+ T cells in PB and SF of SpA patients (PB n = 30, SF n = 11), rheumatoid arthritis (RA) patients (PB n = 14, SF n = 7), OA patients (PB n = 10) and healthy controls (PB n = 12) was analysed after stimulation with Staphylococcus aureus Enterotoxin B and phorbol 12-myristate 13-acetate/ionomycin and quantified by flow cytometry.
In AS facet joints, the frequency of IL-17-secreting cells was significantly higher than in samples obtained from OA patients (P < 0.001), with a slight predominance of IL-17+ cells among the mononuclear cells (61.5% ± 14.9%) compared to cells with polysegmental nuclei. Immunofluorescence microscopy revealed that the majority of IL-17+ cells were myeloperoxidase-positive (35.84 ± 13.06/high-power field (HPF) and CD15+ neutrophils (24.25 ± 10.36/HPF), while CD3+ T cells (0.51 ± 0.49/HPF) and AA-1+ mast cells (2.28 ± 1.96/HPF) were less often IL-17-positive. The frequency of IL-17+CD4+ T cells in the PB and SF of SpA patients did not differ significantly compared to RA patients, OA patients or healthy controls.
Our data suggest an important role for IL-17 in the inflammatory processes in AS. However, the innate immune pathway might be of greater relevance than the Th17-mediated adaptive immune response.
To create a model that provides a potential basis for candidate selection for anti-tumour necrosis factor (TNF) treatment by predicting future outcomes relative to the current disease profile of individual patients with ankylosing spondylitis (AS).
ASSERT and GO–RAISE trial data (n=635) were analysed to identify baseline predictors for various disease-state and disease-activity outcome instruments in AS. Univariate, multivariate, receiver operator characteristic and correlation analyses were performed to select final predictors. Their associations with outcomes were explored. Matrix and algorithm-based prediction models were created using logistic and linear regression, and their accuracies were compared. Numbers needed to treat were calculated to compare the effect size of anti-TNF therapy between the AS matrix subpopulations. Data from registry populations were applied to study how a daily practice AS population is distributed over the prediction model.
Age, Bath ankylosing spondylitis functional index (BASFI) score, enthesitis, therapy, C-reactive protein (CRP) and HLA-B27 genotype were identified as predictors. Their associations with each outcome instrument varied. However, the combination of these factors enabled adequate prediction of each outcome studied. The matrix model predicted outcomes as well as algorithm-based models and enabled direct comparison of the effect size of anti-TNF treatment outcome in various subpopulations. The trial populations reflected the daily practice AS population.
Age, BASFI, enthesitis, therapy, CRP and HLA-B27 were associated with outcomes in AS. Their combined use enables adequate prediction of outcome resulting from anti-TNF and conventional therapy in various AS subpopulations. This may help guide clinicians in making treatment decisions in daily practice.
Ankylosing spondylitis (AS) and its early form account for up to 5% of all patients with chronic back pain. Interest has recently focused on shortening the delay of 5–10 years between the appearance of first symptoms and the diagnosis of AS, particularly because effective treatments have now become available. Referral parameters that are easy for doctors in primary care to apply to patients presenting with possible AS could contribute to earlier diagnosis.
Orthopaedists and primary‐care doctors were requested to refer patients with (1) chronic low back pain (duration >3 months) and (2) onset of back pain before <45 years of age to a specialist rheumatology outpatient clinic for further diagnostic investigation if at least one of the following screening parameters was present: (1) inflammatory back pain, (2) positive human leucocyte antigen B27, and (3) sacroiliitis detected by imaging. The final diagnosis was made according to expert opinion.
In total, 350 referred cases were analysed. A diagnosis of definite axial spondyloarthritis (axial SpA), comprising established AS and pre‐radiographic axial SpA, could be made in 45.4% of all referred patients (of which 50.3% were classified as AS and 49.7% as preradiographic axial SpA), whereas 45.4% were classified as non‐SpA and 9.1% as possible SpA. A diagnosis of definite axial SpA could be made in 34.2% if only one referral parameter was positive, and in 62.6% if there was >1 positive referral parameter.
The proposed referral parameters have proven useful when applied in primary care in identifying patients with AS/pre‐radiographic axial SpA among young to middle‐aged patients with chronic low back pain.
ankylosing spondylitis; spondyloarthritis; pre‐radiographic; screening; early diagnosis
We evaluated the three-year impact of adalimumab on patient-reported physical function and health-related quality-of-life (HRQOL) outcomes in patients with active ankylosing spondylitis (AS).
The Adalimumab Trial Evaluating Long-Term Efficacy and Safety in AS (ATLAS) is an ongoing five-year study that included an initial 24-week, randomized, placebo-controlled, double-blind period, followed by open-label extension treatment with adalimumab. Clinical and HRQOL data collected for up to three years from ATLAS were used for these analyses. Patients were randomized to receive adalimumab 40 mg or placebo by subcutaneous injection every other week. Physical function was assessed by the Bath AS Functional Index (BASFI), as well as by the Short Form 36 (SF-36) Health Survey Physical Component Summary (PCS) and Physical Function subscale scores. HRQOL was assessed using the AS Quality of Life (ASQOL) questionnaire. Disease activity was assessed by the Bath AS Disease Activity Index (BASDAI).
Of 315 patients enrolled in ATLAS, 288 (91%) participated in an open-label adalimumab treatment extension and 82% provided three-year outcome data. During the 24-week double-blind phase, adalimumab-treated patients experienced significant improvement compared with placebo-treated patients in the BASDAI (P < 0.001), BASFI (P < 0.001), ASQOL (P < 0.001), and both the SF-36 PCS (P < 0.001) and Physical Function subscale (P < 0.001) scores, but not the SF-36 Mental Component Summary score (P = 0.181) and Mental Health subscale scores (P = 0.551). Mean changes from baseline through three years of adalimumab treatment were statistically significant for the BASDAI (change score: -3.9, P < 0.001), BASFI (change score: -29.6, P < 0.001), SF-36 PCS (change score: 11.6, P < 0.001), and Physical Function (change score: 23.3, P < 0.001). Comparable results were observed for the other SF-36 scores and for the ASQOL (all P < 0.001).
Adalimumab significantly improved disease activity, patient-reported physical function, and HRQOL. These benefits were maintained over three years of treatment in patients with AS.
Major advances have been achieved over the last 10 years both in the clinical and scientific understanding of the spondyloarthritides (SpA), which can be separated in predominantly axial and predominantly peripheral SpA. The clinical progress includes the development of classification criteria, strategies for early diagnosis, definition of outcome criteria for clinical studies, and the conduction of a series of clinical studies with a focus on tumor necrosis factor (TNF) blockers. The proven high efficacy of TNF blocker treatment has meant a breakthrough for SpA patients, who until recently had only quite limited treatment options. More and more data have accumulated over recent years in regard to long-term efficacy and safety, prediction of response, and the relevance of extrarheumatic manifestations such as uveitis, psoriasis, and inflammatory bowel disease for treatment decisions with TNF blockers. A better understanding of the interaction of the immune system and inflammation with bone degradation/new bone formation is crucial for the development of optimal treatment strategies to prevent structural damage. Recent results from genetic studies could show that, besides HLA-B27, the interleukin-23 receptor and the ARTS1 enzyme are associated with ankylosing spondylitis. Only when the exact pathogenesis is clarified will a curative treatment be possible.
Recent data about radiographic progression during treatment with tumor necrosis factor-alpha (TNF-α) blocker agents in patients with ankylosing spondylitis (AS) have prompted an intensive discussion about the link between inflammation/bone destruction and new bone formation and the order of events. Therefore, we analysed parameters of cartilage degradation, neoangiogenesis, and new bone formation in different cohorts of patients with axial spondyloarthritis with and without treatment with TNF-α blocker agents.
TNF-α blocker-naïve AS patients were investigated for serum levels of metalloproteinase-3 (MMP-3) (n = 71), vasoendothelial growth factor (VEGF) (n = 50), and bone-specific alkaline phosphatase (BALP) (n = 71) at baseline and after 1 and 2 years. This was compared with 34 adalimumab-treated patients with axial spondyloarthritis (22 AS and 12 non-radiographic axial spondyloarthritis patients) before and after 36 to 52 weeks of treatment.
There were no significant changes in serum levels of MMP-3 (P > 0.05), VEGF (P > 0.05), and BALP (P > 0.05) in a large cohort of TNF-α blocker-naïve AS patients followed for 2 years. In contrast, adalimumab-treated spondyloarthritis (AS and non-radiographic axial spondyloarthritis) patients had a significant decrease of VEGF (P < 0.001) and MMP-3 (P = 0.022) after 36 to 52 weeks of therapy. Most interestingly, the level of BALP increased significantly after 36 to 52 weeks of therapy (P < 0.001). A decrease in MMP-3 serum levels correlated significantly to an increase of BALP (r = -0.398, P = 0.02). In the case of VEGF, there was a negative correlation without significance (r = -0.214, P > 0.05).
Rising levels of BALP and the negative correlation between MMP-3 and BALP in spondyloarthritis patients with TNF-α blocker treatment indicate that new bone formation in AS occurs if inflammation is successfully treated and might be part of a healing process.
Spinal inflammation as detected by magnetic resonance imaging and new bone formation as identified by conventional radiographs are characteristic of ankylosing spondylitis. Whether and how spondylitis and syndesmophyte formation are linked are unclear. Our objective was to investigate whether and how spinal inflammation are associated with new bone formation in ankylosing spondylitis.
Spinal magnetic resonance images and conventional radiographs from 39 ankylosing spondylitis patients treated with anti-tumour necrosis factor (anti-TNF) agents at baseline and after 2 years were analysed for syndesmophyte formation at vertebral edges with or without inflammatory lesions at baseline.
Overall, 922 vertebral edges at the cervical and lumbar spine were analysed. At baseline, the proportion of vertebral edges with and without inflammation (magnetic resonance imaging) that showed structural changes (conventional radiographs) was similar (in total, 16.6% of all vertebral edges in 71.4% of patients). From the perspective of syndesmophyte formation (n = 26, 2.9%) after 2 years, there were more vertebral edges without (62%) than with (38%) inflammation at baseline (P = 0.03). From the perspective of spinal inflammation at baseline (n = 153 vertebral edges), more syndesmophytes developed at vertebral edges with (6.5%) than without (2.1%) inflammation (P = 0.002, odds ratio 3.3, 95% confidence interval 1.5 to 7.4). Inflammation persisted in 31% of the initially inflamed vertebral edges (n = 132), and new lesions developed in 8% of the vertebral edges without inflammation at baseline (n = 410). From the perspective of spinal inflammation after 2 years (n = 72 vertebral edges), 5.6% of the vertebral edges showed syndesmophyte development in contrast to 1.9% of the vertebral edges with new syndesmophytes without inflammation (P = 0.06).
These findings obtained in patients treated with anti-TNF agents suggest linkage and some dissociation of inflammation and new bone formation in ankylosing spondylitis. Although syndesmophytes were also found to develop at sites where no inflammation had been seen by magnetic resonance imaging at baseline, it was more likely that syndesmophytes developed in inflamed vertebral edges. More effective suppression of spinal inflammation may be required to inhibit structural damage in ankylosing spondylitis.
IL-1β is a proinflammatory cytokine driving joint inflammation as well as systemic signs of inflammation, such as fever and acute phase protein production.
ACZ885, a fully human monoclonal antibody that neutralizes the bioactivity of human IL-1β, was generated to study the potent and long-lasting neutralization of IL-1β in mechanistic animal models as well as in a proof-of-concept study in patients with rheumatoid arthritis (RA).
The mouse IL-1 receptor cross-reacts with human IL-1β, and it was demonstrated that ACZ885 can completely suppress IL-1β-mediated joint inflammation and cartilage destruction in mice. This observation prompted us to study the safety, tolerability and pharmacodynamic activity of ACZ885 in RA patients in a small proof-of-concept study – the first to be conducted in humans. Patients with active RA despite treatment with stable doses of methotrexate were enrolled in this dose escalation study. The first 32 patients were split into four cohorts of eight patients each (six were randomly assigned to active treatment and two to placebo). ACZ885 doses were 0.3, 1, 3 and 10 mg/kg, administered intravenously on days 1 and 15. To explore efficacy within 6 weeks of treatment, an additional 21 patients were randomly assigned to the 10 mg/kg cohort, resulting in a total of 20 patients dosed with 10 mg/kg and 15 patients treated with placebo. There was clinical improvement (American College of Rheumatology 20% improvement criteria) at week 6 in the 10 mg/kg treatment group; however, this did not reach statistical significance (P = 0.085). A statistically significant reduction in disease activity score was observed after 4 weeks in the 10 mg/kg group. Onset of action was rapid, because most responders exhibited improvement in their symptoms within the first 3 weeks. C-reactive protein levels decreased in patients treated with ACZ885 within 1 week. ACZ885 was well tolerated. Three patients receiving ACZ885 developed infectious episodes that required treatment. No anti-ACZ885 antibodies were detected during the study.
ACZ885 administration to methotrexate-refractory patients resulted in clinical improvement in a subset of patients. Additional studies to characterize efficacy in RA and to determine the optimal dose regimen appear warranted.
ClinicalTrials.gov identifier NCT00619905.
Genetic factors and a dysregulated immune response towards commensal bacteria contribute to the pathogenesis of Inflammatory Bowel Disease (IBD). Animal models demonstrated that the normal intestinal flora is crucial for the development of intestinal inflammation. However, due to the complexity of the intestinal flora, it has been difficult to design experiments for detection of proinflammatory bacterial antigen(s) involved in the pathogenesis of the disease. Several studies indicated a potential association of E. coli with IBD. In addition, T cell clones of IBD patients were shown to cross react towards antigens from different enteric bacterial species and thus likely responded to conserved bacterial antigens. We therefore chose highly conserved E. coli proteins as candidate antigens for abnormal T cell responses in IBD and used high-throughput techniques for cloning, expression and purification under native conditions of a set of 271 conserved E. coli proteins for downstream immunologic studies.
As a standardized procedure, genes were PCR amplified and cloned into the expression vector pQTEV2 in order to express proteins N-terminally fused to a seven-histidine-tag. Initial small-scale expression and purification under native conditions by metal chelate affinity chromatography indicated that the vast majority of target proteins were purified in high yields. Targets that revealed low yields after purification probably due to weak solubility were shuttled into Gateway (Invitrogen) destination vectors in order to enhance solubility by N-terminal fusion of maltose binding protein (MBP), N-utilizing substance A (NusA), or glutathione S-transferase (GST) to the target protein. In addition, recombinant proteins were treated with polymyxin B coated magnetic beads in order to remove lipopolysaccharide (LPS). Thus, 73% of the targeted proteins could be expressed and purified in large-scale to give soluble proteins in the range of 500 μg.
Here, we report a cost-efficient procedure to produce around 200 soluble recombinant E. coli proteins in large-scale, including removal of LPS by polymyxin B coated beads for subsequent use of the proteins in downstream immunological studies.
Ankylosing spondylitis (AS) is a chronic inflammatory disease which affects primarily the sacroiliac joints and the spine. In patients with active disease, magnetic resonance imaging (MRI) of the spine shows areas of bone marrow edema, the histopathological equivalent of which is unknown. In this study we correlate inflammation in the spine of patients with AS as revealed by histological examination with bone marrow edema as detected by MRI. We have compared the histopathological findings of zygapophyseal joints from 8 patients with AS (age: 30 to 64, disease duration 7 to 33 years) undergoing spinal surgery with findings in MRI. For histopathological analysis, we quantified infiltrates of CD3+, CD4+ and CD8+ T cells as well as CD20+ B cells immunohistochemically. Bone marrow edema was evaluated in hematoxylin and eosin stained sections and quantified as the percentage of the bone marrow area involved. All patients with AS showed interstitial mononuclear cell infiltrates and various degrees of bone marrow edema (range from 10% to 60%) in histopathological analysis. However, in only three of eight patients histopathological inflammation and edema in the zygapophyseal joints correlated with bone marrow edema in zygapophyseal joints of the lumbar spine as detected by MRI. Interestingly, two of these patients showed the highest histological score for bone marrow edema (60%). This first study correlating histopathological changes in the spine of patients with AS with findings in MRI scans suggests that a substantial degree of bone marrow inflammation and edema is necessary to be detected by MRI.
We analyzed the clinical response and the time to relapse after discontinuation of continuous long-term infliximab therapy in patients with ankylosing spondylitis (AS). After 3 years of infliximab therapy, all AS patients (n = 42) discontinued treatment (time point (TP)1) and were visited regularly for 1 year in order to assess the time to relapse (TP2). Relapse was defined as an increase to a value ≥ 4 on the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and a physician's global assessment ≥ 4 according to the recommendations of the Assessments in Ankylosing Spondylitis (ASAS) working group. After 52 weeks, 41 of the 42 patients (97.6%) had to be reinfused because of relapse. The mean change in the BASDAI between TP1 and TP2 was 3.6 ± 1.7 and that in the physician's global assessment was 4.4 ± 1.8 (both P < 0.001). The mean time to relapse was 17.5 weeks (± 7.9 weeks, range 7 to 45). Ten patients (24%) showed a relapse within 12 weeks and 38 patients (90.5%), within 36 weeks. After 52 weeks, only one patient had remained in ongoing remission without further treatment with anti-tumor-necrosis factor. Patients who were in partial remission according to the ASAS criteria and those with normal C-reactive protein levels at the time point of withdrawal had longer times to relapse after discontinuation of the treatment. Retreatment with infliximab was safe and resulted in clinical improvement in all patients to a state similar to that before the treatment was stopped. Discontinuation of long-term therapy with infliximab eventually led to relapse of disease activity in all patients but one.
Reports of the use of HLA-B27/peptide tetrameric complexes to study peptide-specific CD8+ T cells in HLA-B27+-related diseases are rare. To establish HLA-B27 tetramers we first compared the function of HLA-B27 tetramers with HLA-A2 tetramers by using viral epitopes. HLA-B27 and HLA-A2 tetramers loaded with immunodominant peptides from Epstein–Barr virus were generated with comparable yields and both molecules detected antigen-specific CD8+ T cells. The application of HLA-B27 tetramers in HLA-B27-related diseases was performed with nine recently described Chlamydia-derived peptides in synovial fluid and peripheral blood, to examine the CD8+ T cell response against Chlamydia trachomatis antigens in nine patients with Chlamydia-triggered reactive arthritis (Ct-ReA). Four of six HLA-B27+ Ct-ReA patients had specific synovial T cell binding to at least one HLA-B27/Chlamydia peptide tetramer. The HLA-B27/Chlamydia peptide 195 tetramer bound to synovial T cells from three of six patients and HLA-B27/Chlamydia peptide 133 tetramer to synovial T cells from two patients. However, the frequency of these cells was low (0.02–0.09%). Moreover, we demonstrate two methods to generate HLA-B27-restricted T cell lines. First, HLA-B27 tetramers and magnetic beads were used to sort antigen-specific CD8+ T cells. Second, Chlamydia-infected dendritic cells were used to stimulate CD8+ T cells ex vivo. Highly pure CD8 T cell lines could be generated ex vivo by magnetic sorting by using HLA-B27 tetramers loaded with an EBV peptide. The frequency of Chlamydia-specific, HLA-B27 tetramer-binding CD8+ T cells could be increased by stimulating CD8+ T cells ex vivo with Chlamydia-infected dendritic cells. We conclude that HLA-B27 tetramers are a useful tool for the detection and expansion of HLA-B27-restricted CD8+ T cells. T cells specific for one or more of three Chlamydia-derived peptides were found at low frequency in synovial fluid from HLA-B27+ patients with Ct-ReA. These cells can be expanded ex vivo, suggesting that they are immunologically functional.
HLA-B27; T cells; tetramers; reactive arthritis
Kaposi's sarcoma-associated herpesvirus (KSHV) is the infectious cause of Kaposi's sarcoma (KS) and certain lymphoproliferations particularly in the context of human immunodeficiency virus (HIV) type 1-induced immunosuppression. The introduction of effective therapies to treat HIV has led to a decline in the incidence of KS, suggesting that immune responses may play a role in controlling KSHV infection and pathogenesis. Cytotoxic-T-lymphocyte (CTL) activity against KSHV proteins has been demonstrated; however, the identification of KSHV CTL epitopes remains elusive and problematic. Although the herpesvirus genomic layout is generally conserved, KSHV encodes a unique hypervariable protein, K1, with intense biological selection pressure at specific amino acid sites. To investigate whether this variability is partly driven by cellular immunity, we designed K1 peptides that match only the unique viral sequence for every individual studied here (autologous peptides). We identified functional CTL epitopes within K1's most variable areas, and we show that a given individual responds only to autologous peptides and not to peptides from other individuals. Furthermore, these epitopes are highly conserved sequences within KSHV isolates from a specific strain but are not conserved between different strains. We conclude that CTL recognition contributes to K1, and therefore to KSHV, evolution.