Cécile Poulain

Dendritic cells from spondylarthritis‐prone HLA–B27–transgenic rats display altered cytoskeletal dynamics, class II major histocompatibility complex expression, and viability

OBJECTIVE Spondylarthritis (SpA) is characterized by spinal and peripheral joint inflammation, frequently combined with extraarticular manifestations. Despite the well-established association of SpA with the class I major histocompatibility complex (MHC) allele HLA-B27, there are still different, parallel hypotheses on the relationship between HLA-B27 and disease mechanisms. The present study was undertaken to investigate several characteristics of mature dendritic cells (DCs), which are believed to be essential for triggering disease in a model of SpA in HLA-B27-transgenic rats. METHODS We combined different whole-proteome approaches (2-dimensional polyacrylamide gel electrophoresis and iTRAQ) to define the most aberrant molecular processes occurring in spleen DCs. Videomicroscopy and flow cytometry were used to confirm both cytoskeletal and class II MHC expression deficiencies. RESULTS Our proteome studies provided evidence of up-regulation of proteins involved in class I MHC loading, and unfolded protein response, along with a striking down-regulation of several cytoskeleton-reorganizing proteins. The latter result was corroborated by findings of deficient motility, altered morphology, and decreased immunologic synapse formation. Furthermore, class II MHC surface expression was reduced in DCs from B27-transgenic rats, and this could be linked to differences in class II MHC-induced apoptotic sensitivity. Finally, we found reduced viability of the CD103+CD4- DC subpopulation, which likely exerts tolerogenic function. CONCLUSION Taken together, our findings have different important implications regarding the physiology of B27-transgenic rat DCs, which have a putative role in spontaneous disease in these rats. In particular, the reduced motility and viability of putatively tolerogenic CD4+ DCs could play an important role in initiating the inflammatory process, resulting in SpA.

Correlation between dendritic cell functional defect and spondylarthritis phenotypes in HLA–B27/HUMAN β2‐microglobulin–transgenic rat lines

OBJECTIVE To examine the functional capacity of dendritic cells (DCs) from a panel of HLA-B27/human beta2-microglobulin (Hubeta2m)-transgenic rat lines and crosses with varying susceptibilities to spondylarthritis (SpA)-like disease. METHODS Mature splenic DCs were isolated from HLA-B27-transgenic, HLA-B7-transgenic, and/or Hubeta2m-transgenic rats and tested for support of allogeneic proliferation, compared with nontransgenic controls (all male rats on Lewis background). Graded numbers of DCs were cultured with allogeneic lymph node CD4+ T cells (dark agouti background). Proliferation was assayed by incorporation of tritiated deoxythymidine after 2-4 days of culture. RESULTS Allogeneic proliferation stimulated by DCs from the healthy HLA-B27/Hubeta2m-transgenic line 21-3 and from the healthy Hubeta2m-transgenic line 283-2 was weakly decreased (21-3) or close to normal (283-2) as compared with that observed with control nontransgenic Lewis rat DCs. In contrast, the ability of DCs from (21-3 x 283-2)F1 rats, which develop a dramatic SpA phenotype, to stimulate allogeneic proliferation was markedly defective. When DC-induced allogeneic proliferation was compared among different transgenic lines and crosses with distinct levels of susceptibility to SpA-like disease, stimulatory capacity was inversely correlated with disease susceptibility. CONCLUSION In HLA-B27/Hubeta2m-transgenic rats, a defective functional capacity of DCs correlates with susceptibility to SpA. Since it was previously demonstrated that defective DC function is not a consequence of disease, it could well be a principal factor in the spontaneous development of SpA in these lines.

Is IL-6 an appropriate target to treat spondyloarthritis patients refractory to anti-TNF therapy? A multicentre retrospective observational study.

IntroductionThe aim of this study was to evaluate, under real-life conditions, the safety and efficacy of tocilizumab in patients having failed anti-TNFα therapy for spondyloarthritis.MethodsFrench rheumatologists and internal-medicine practitioners registered on the Club Rhumatismes et Inflammations website were asked to report on patients given tocilizumab (4 or 8 mg/kg) to treat active disease meeting Assessment of SpondyloArthritis International Society (ASAS) criteria for axial or peripheral spondyloarthritis, after anti-TNFα treatment failure. Safety and efficacy after 3 and 6 months were assessed retrospectively using standardised questionnaires.ResultsData were obtained for 21 patients, 13 with axial spondyloarthritis (46% men; median age, 42 years; disease duration, 11 years; HLA-B27-positive, 92.3%) and eight with peripheral spondyloarthritis (25% men; median age, 40 years; disease duration, 10 years; HLA-B27-positive, 62.5%). No patients with axial disease had at least a 20 mm decrease in the BASDAI, nor a BASDAI50 response or major ASAS-endorsed disease activity score improvements after 3 or 6 months; an ASAS-endorsed disease activity score clinically important improvement was noted at month 3 in five of 13 patients and at month 6 in one of four patients. A good DAS28 response was achieved in four patients with peripheral disease, including one in EULAR remission at month 3. Four patients were still taking tocilizumab at month 6, including one in EULAR remission and one with a good DAS28 response. Tocilizumab was well tolerated, with no serious adverse events. Initially elevated acute-phase reactants declined during tocilizumab therapy.ConclusionIn patients having failed anti-TNFα therapy, tocilizumab decreased acute-phase reactants but failed to substantially improve axial spondyloarthritis and was inconsistently effective in peripheral spondyloarthritis.

Does the site of magnetic resonance imaging abnormalities match the site of recent-onset inflammatory back pain? The DESIR cohort

Objectives To assess whether the site of axial pain (thoracic spine, lumbar spine or buttock(s)) was associated with the site of MRI lesions in patients with recent inflammatory back pain (IBP) suggesting spondyloarthritis. Methods We conducted a cross-sectional study of baseline data in 708 patients with recent IBP from the DESIR cohort. Radiographs of the sacroiliac joints (SIJs) and MRI scans of the SIJs and thoracic and lumbar spine were obtained routinely. Associations between pain sites and sites of inflammatory and structural MRI changes were evaluated using separate multivariate logistic regressions. Results Of the 648 patients with complete data, 61% had thoracic pain, 91.6% lumbar pain and 79.2% buttock pain. MRI inflammation was seen in 19%, 21% and 46% of patients at the thoracic, lumbar and SIJ sites, respectively. By multivariate analysis, pain was significantly associated with MRI inflammation only at the same site (adjusted OR (aOR)thoracic pain 1.71; 95% CI 1.09 to 2.67; p=0.02; aORlumbar pain 2.53; 95% CI 1.03 to 6.20; p=0.04; aORbuttock pain 2.86; 95% CI 1.84 to 4.46; p<0.0001). Pain site was not significantly associated with the site of structural MRI changes, except for buttock pain and SIJ structural MRI changes (aORbuttock pain 1.89; 95% CI 1.22 to 2.90; p=0.004). The association between pain site and site of MRI inflammation persisted in the subgroups with normal or doubtful SIJ radiographs or with Assessment of SpondyloArthritis international Society criteria for axial spondyloarthritis. Conclusions The site of pain (thoracic spine, lumbar spine or buttock(s)) is associated with MRI inflammation at the same site in patients with recent IBP.

Early tumor necrosis factor α antagonist therapy in everyday practice for inflammatory back pain suggesting axial spondyloarthritis: results from a prospective multicenter french cohort.

To determine the frequency of and factors associated with early tumor necrosis factor α (TNFα) antagonist therapy in everyday clinical practice in patients with suspected axial spondyloarthropathy (SpA).

Early TNFα-antagonist therapy in everyday practice for inflammatory back pain suggesting axial spondyloarthritis: The DESIR cohort.

To determine the frequency of and factors associated with early tumor necrosis factor α (TNFα) antagonist therapy in everyday clinical practice in patients with suspected axial spondyloarthropathy (SpA).

Can power Doppler ultrasound of the entheses help in classifying recent axial spondyloarthritis? Data from the DESIR cohort

Early diagnosis of axial spondyloarthritis (axSpA) remains a challenge due to the lack of specificity of clinical symptoms and variable prevalence of axial imaging findings permitting a definite diagnosis. Power Doppler ultrasonography (PDUS) of the entheses has demonstrated to be a potential useful tool for the classification and diagnostic management of early SpA independently of the phenotype. Objectives To assess the classification value (sensitivity and specificity) of PDUS-defined enthesitis for identifying patients fulfilling Assessment of SpondyloArthritis international Society (ASAS) classification criteria for axSpA (ASAS+) in patients with recent inflammatory back pain (IBP) (the DESIR (DEvenir des Spondylarthropathies Indifférenciées Récentes) cohort). Methods Baseline PDUS was performed at eight entheseal sites, and PDUS enthesitis was defined by the presence of vascularisation at entheseal insertion. Results 402 patients from the DESIR cohort underwent a PDUS evaluation. PDUS enthesitis was detected in 58 (14.4%) patients of whom 40 (14.2%) belonged to the ASAS+ patients and 18 (17%) to the ASAS- patients. The sensitivity of PDUS enthesitis was 13.9% and the specificity was 83.5%, with a positive predictive value of 69% and 26.8% of negative predictive value for meeting ASAS criteria for axSpA. Of the 18 ASAS- patients with positive PDUS, 59% fulfilled Amor’s criteria, 88% European Spondyloarthropathy Study Group criteria and 59% both. Conclusions In a cohort of patients with recent IBP, the prevalence of PDUS enthesitis was low (14.4%); however, its specificity for classifying patients as axSpA according to ASAS criteria was high (83.5%). PDUS enthesitis might be of additional value for classifying as patients with axSpA IBP who do not fulfil ASAS criteria.

SAT0239 Entheses Evaluation by Power Doppler Ultrasonography in Patients with Recent Inflammatory Back Pain, Results From the Desir Cohort

Background Early diagnosis of axial spondyloarthritis (axSpA) remains a challenge and the potential role of power Doppler (PD) ultrasonography (PDUS) of entheses is still under evaluation. Objectives To assess: i) the accuracy of PDUS enthesitis at 3 entheseal sites for the diagnosis of axSpA (ASAS criteria) in patients with recent inflammatory back pain (IBP); ii) the prevalence of PDUS enthesitis in each arm of the ASAS criteria; and iii) the prevalence of PDUS enthesitis according to the presence of pain at the same site. Methods We used patients from the DESIR cohort, with IBP (>3 months and <3 years) suggestive of axSpA according to rheumatologists opinion1. At baseline, 14/25 centers performed a PDUS examination according to a standardized protocol1, 3 sites were tested bilaterally: Achilles tendon (site A), patellar ligament (site B), common extensor tendon of the elbow (site C). PDUS enthesitis was defined as any vascularised enthesitis by PD within 2 mm from bony cortex. Sample size for the best cut-off for sensitivity (Se) and (Spe) of PDUS for diagnosis of axSpA (ASAS+) was calculated as follow: i) Se>0.8 with a relative error (RE) of 5% and an absolute error (AE) of 5%, requiring 246 patients ASAS+ (274 with 10% of non-interpretable data); ii) Spe>0.7 with an AE of 10% and RE of 5%, requiring 81 patients ASAS- (90 with 10% of non-interpretable data). Thus 364 patients were necessary with a ratio ASAS+/ASAS- of 3/1, for covering both hypotheses. Results 402 out of 708 included patients were examined by PDUS. After Bonferroni correction for multiple tests, there was no significant difference between patients having received or not the PDUS examination.58 (14%) patients had at least 1 PDUS enthesitis (PDUS+), of which 15 (26%) at site A, 36 (62%) at site B and 20 (34%) at site C. Se of PDUS for the diagnosis of axSpA was 14%, Sp 83%, positive predictive value 69%, and negative predictive value 27%. After Bonferroni correction the lone significant difference between PDUS+ and PDUS- patients was a more frequent history of clinical enthesitis (74.1% vs 47.7%, p<0.001). Table 1 shows the prevalence of PDUS+ patients according to ASAS criteria. Among the 18 patients PDUS+ASAS-, 11/17 (65%) fulfilled Amors criteria, 16 (89%) ESSG criteria, and 11/17 (65%) both sets of criteria. No statistical relationship was observed between current pain at one site and presence of PDUS enthesitis at the same site.Table 1. PDUS enthesitis according to ASAS criteria PDUS+ 58/402 (14%) ASAS+ (40, 69%) ASAS− (18, 31%) 14% (40/288) of all ASAS+ patients 16% (18/109) of all ASAS− patients Imaging+ (29, 50%) Clinical+ Imaging− (10, 17%) 15% (29/189) of all Imaging+ 10% (10/96) of all Clinical+ Imaging− (m=1) Rx+ MRI+ Rx+ MRI− Rx− MRI+ CRP+ CRP− CRP+ CRP− 13 8 8 1 9 3 14 22% 14% 14% 2% 15% 5% 24% (m=1) 15%* 22%* 13%* 8%* 11%* 16%* 15%** PDUS+ in each corresponding arm of all 402 patients. Conclusions These results raise the potential value of PDUS enthesitis in patients with IBP suggestive of axSpA, but who do not fulfill the ASAS classification criteria for AxSpA. References Dougados M., JBS 2011:78:598-603 Disclosure of Interest None declared