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Dive into the research topics where Xavier Le Loët is active.

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Featured researches published by Xavier Le Loët.


Arthritis & Rheumatism | 2011

B cell activation biomarkers as predictive factors for the response to rituximab in rheumatoid arthritis: A six-month, national, multicenter, open-label study†

Jérémie Sellam; Houria Hendel-Chavez; Stéphanie Rouanet; Karim Abbed; Bernard Combe; Xavier Le Loët; Jacques Tebib; Jean Sibilia; Yassine Taoufik; Maxime Dougados; Xavier Mariette

OBJECTIVEnTo examine whether serum B cell markers can predict response to rituximab, a B cell-depleting monoclonal antibody, in patients with refractory rheumatoid arthritis (RA).nnnMETHODSnThis rituximab re-treatment dose study (SMART [eSsai MAbthera sur la dose de Re-Traitement]) involved 208 patients with refractory RA. Serum markers of B cell activation (anti-cyclic citrullinated peptide [anti-CCP] antibodies, rheumatoid factor [RF], serum IgG, IgA, and IgM levels, serum κ and λ free light chains, and serum BAFF) were assessed before the first rituximab cycle (1,000 mg on days 1 and 15). Univariate and multivariate analyses were performed to identify factors associated with a European League Against Rheumatism (EULAR) response at 24 weeks.nnnRESULTSnThere were 149 responders (72%). Two baseline factors were associated with a EULAR response at 24 weeks in multivariate analysis: the presence of anti-CCP antibodies or RF (odds ratio 3.5 [95% confidence interval 1.6-7.6]) and a serum IgG concentration above normal (odds ratio 2.11 [95% confidence interval 1.02-4.33]), with synergy between them (odds ratio 6.0 [95% confidence interval 2.2-16.2]).nnnCONCLUSIONnThe presence of RF or anti-CCP antibodies and elevated IgG are 2 simple biomarkers that can be used routinely before therapy to predict response to rituximab in patients with refractory RA.


Arthritis & Rheumatism | 2000

Evolution of chronic recurrent multifocal osteitis toward spondylarthropathy over the long term

Olivier Vittecoq; Lamia Ait Said; Chantal Michot; O. Mejjad; Jean-Michel Thomine; Paul Mitrofanoff; Joël Lechevallier; Patrick Ledosseur; A. Gayet; Philippe Lauret; Xavier Le Loët

OBJECTIVEnTo retrospectively assess, with a sufficiently long followup (mean 11.6 years; median 9 years), the long-term outcome of chronic recurrent multifocal osteitis (CRMO), a multifocal, inflammatory bone disease.nnnMETHODSnPatients included were 8 children/adolescents and 7 adults with no family history of rheumatic disease who had been diagnosed as having CRMO between 1979 and 1995. Ten patients had undergone at least 1 bone biopsy of the lesions, with histologic examination and multiple cultures. In 1996, in addition to an in-depth interview, 12 patients underwent an extensive physical examination, laboratory evaluation, HLA-A, B, C, and DR typing, bone radiography and scintigraphy, and computed tomography scan of the sternoclavicular and sacroiliac joints.nnnRESULTSnRemission was observed in 3 patients. The other 12 patients developed various associations of vertebral (n = 10), sacroiliac (n = 6), anterior thoracic (n = 7), peripheral articular (n = 2), enthesopathic (n = 4), or dermatologic (palmoplantar pustulosis in 3 cases and psoriasis in 2) involvements. Spine involvement was the most common and occurred the earliest (median time to appearance after the onset of osteitis 5.63 years). Clinical sacroiliitis was always unilateral. No patients carried the HLA-B27 haplotype. CRMO responded well to nonsteroidal antiinflammatory drugs. Twelve patients met the European Spondylarthropathy Study Group criteria for spondylarthopathy.nnnCONCLUSIONnAfter 10 years, CRMO had usually evolved to spondylarthropathy, but with certain features not usually seen in the latter: predominantly, unilateral sacroiliitis, no familial form, and no link with HLA-B27.


Arthritis & Rheumatism | 2011

Blood Memory B Cells Are Disturbed and Predict the Response to Rituximab in Patients With Rheumatoid Arthritis

Jérémie Sellam; Stéphanie Rouanet; Houria Hendel-Chavez; Karim Abbed; Jean Sibilia; Jacques Tebib; Xavier Le Loët; Bernard Combe; Maxime Dougados; Xavier Mariette; Yassine Taoufik

OBJECTIVEnTo examine blood B cell subsets in patients with rheumatoid arthritis (RA) prior to B cell depletion therapy and to assess their potential as predictors of clinical response to rituximab (RTX).nnnMETHODSnBlood B cell subsets were assessed by flow cytometry in 208 RA patients included in an RTX retreatment study (assessed prior to RTX treatment) and in 47 age-matched controls. Expression of BAFF receptor (BAFF-R) on B cells and serum B cell biomarkers was also measured. B cell subsets and BAFF-R expression were compared between RA patient and control populations. Univariate and multivariate analyses were performed to identify baseline factors associated with a European League Against Rheumatism response 24 weeks after 1 cycle of RTX.nnnRESULTSnMean ± SD counts of both CD27- naive and CD27+ memory B cells were decreased in RA patients (188.6 ± 121.4/mm(3)) compared with controls (257.3 ± 154.1/mm(3)) (P = 0.001) and were partially restored in patients treated with methotrexate (MTX) plus anti-tumor necrosis factor compared with patients treated with MTX alone. Within the CD27+ memory B cells, the CD27+IgD- switched memory subtype was selectively decreased, irrespective of treatment. The frequency of CD27+ memory B cells correlated inversely with levels of several B cell activation biomarkers in RA. Serum BAFF level and BAFF-R expression was comparable in RA patients and controls. A low baseline CD27+ memory B cell frequency was associated with a greater clinical response to RTX (odds ratio 0.97 [95% confidence interval 0.95-0.99], P = 0.0015).nnnCONCLUSIONnIn B cell depletion therapy-naive RA patients, a low frequency of CD27+ memory B cells correlated with levels of serum B cell activation biomarkers and may predict response to RTX. These results suggest that low memory B cell frequency may be indicative of a B cell-driven RA subtype that is more sensitive to B cell depletion therapy.


Arthritis & Rheumatism | 2012

Soluble VE-cadherin in rheumatoid arthritis patients correlates with disease activity: Evidence for tumor necrosis factor α–induced VE-cadherin cleavage

Adama Sidibé; Tiphaine Mannic; Mélanie Arboleas; Mariela Subileau; Danielle Gulino-Debrac; Laurence Bouillet; Mary Jan; Thibault Vandhuick; Xavier Le Loët; Olivier Vittecoq; Isabelle Vilgrain

OBJECTIVEnRheumatoid arthritis (RA) is a chronic, systemic inflammatory disorder that principally attacks synovial joints. However, accelerated atherosclerosis and increased cardiovascular morbidity and mortality are major clinical consequences of endothelial dysfunction in RA patients. Tumor necrosis factor α (TNFα) is the major mediator of inflammation in RA, related to vascular injury by targeting VE-cadherin, an endothelium-specific adhesion molecule of vital importance for endothelium integrity and angiogenesis. We undertook this study to examine the mechanisms regulating VE-cadherin processing by TNFα and their occurrence in RA.nnnMETHODSnHuman umbilical vein endothelial cells were used in primary culture and treated with recombinant TNFα to study VE-cadherin cleavage. Cell lysates and conditioned media were analyzed by Western blotting for VE-cadherin cytoplasmic domain and extracellular domain (VE-90) generation, respectively. VE-90 was analyzed at baseline and at the 1-year followup in sera from 63 RA patients (from the Very Early Rheumatoid Arthritis cohort) with disease duration of <6 months.nnnRESULTSnTNFα induced a time-dependent shedding of VE-90 in cell media. This effect was prevented by tyrosine kinase inhibitors (genistein and PP2) or by knocking down Src kinase. In contrast, tyrosine phosphatase blockade enhanced VE-cadherin cleavage, confirming the requirement of tyrosine phosphorylation processes. In addition, using the matrix metalloproteinase (MMP) activator APMA and the MMP inhibitor GM6001, we demonstrated that MMPs are involved in TNFα-induced VE-cadherin cleavage. Of major importance, VE-90 was detected in sera from the 63 RA patients and was positively correlated with the Disease Activity Score at baseline and after 1-year followup.nnnCONCLUSIONnThese findings provide the first evidence of VE-cadherin proteolysis upon TNFα stimulation and suggest potential clinical relevance of soluble VE-cadherin in management of RA.


Arthritis Research & Therapy | 2012

Matrix to predict rapid radiographic progression of early rheumatoid arthritis patients from the community treated with methotrexate or leflunomide: results from the ESPOIR cohort

Bruno Fautrel; Benjamin Granger; Bernard Combe; Alain Saraux; Francis Guillemin; Xavier Le Loët

IntroductionEarly rheumatoid arthritis (RA) patients may show rapid radiographic progression (RRP) despite rapid initiation of synthetic disease-modifying anti-rheumatic drugs (DMARDs). The present study aimed to develop a matrix to predict risk of RRP despite early DMARD initiation in real life settings.MethodsThe ESPOIR cohort included 813 patients from the community with early arthritis for < 6 months; 370 patients had early RA and had received methotrexate or leflunomide during the first year of follow-up. RRP was defined as an increase in the van der Heijde-modified Sharp score (vSHS) ≥ 5 points at 1 year. Determinants of RRP were examined first by bivariate analysis, then multivariate stepwise logistic regression analysis. A visual matrix model was then developed to predict RRP in terms of patient baseline characteristics.ResultsWe analyzed data for 370 patients. The mean Disease Activity Score in 28 joints was 5.4 ± 1.2, 18.1% of patients had typical RA erosion on radiographs and 86.4% satisfied the 2010 criteria of the American College of Rheumatology/European League Against Rheumatism. During the first year, mean change in vSHS was 1.6 ± 5.5, and 41 patients (11.1%) showed RRP. A multivariate logistic regression model enabled the development of a matrix predicting RRP in terms of baseline swollen joint count, C-reactive protein level, anti-citrullinated peptide antibodies status, and erosions seen on radiography for patients with early RA who received DMARDs.ConclusionsThe ESPOIR matrix may be a useful clinical practice tool to identify patients with early RA at high risk of RRP despite early DMARD initiation.


Arthritis & Rheumatism | 2013

CCL19, a B Cell Chemokine, Is Related to the Decrease of Blood Memory B Cells and Predicts the Clinical Response to Rituximab in Patients With Rheumatoid Arthritis

J. Sellam; Stéphanie Rouanet; Houria Hendel-Chavez; Corinne Miceli-Richard; Bernard Combe; Jean Sibilia; Xavier Le Loët; Jacques Tebib; R. Jourdan; Maxime Dougados; Yassine Taoufik; Xavier Mariette

OBJECTIVEnMigration of B cells from peripheral blood to the synovium in patients with rheumatoid arthritis (RA) may predict clinical response to rituximab (RTX). We undertook this study to investigate whether serum levels of chemokines involved in B cell trafficking are correlated with blood levels of memory B cells or serum levels of B cell activation biomarkers before B cell depletion and whether chemokine levels predict RTX responsiveness.nnnMETHODSnBlood B cell subsets were analyzed by flow cytometry (CD27, IgD), and serum B cell activation biomarkers (rheumatoid factor, anti-cyclic citrullinated peptide, free light chains, IgG, IgA, IgM, and BAFF) were measured in 208 RA patients and 70 control subjects. Serum CCL19, CXCL12, and CXCL13 chemokine levels in patients and controls were determined by enzyme-linked immunosorbent assay. The first course of RTX was administered to RA patients, and the response was evaluated at week 24 according to European League Against Rheumatism (EULAR) criteria. Results were expressed as the odds ratio (OR) and 95% confidence interval (95% CI).nnnRESULTSnLevels of all chemokines were increased in RA patients compared with controls, and levels were inversely correlated with CD27+ memory B cell frequency. CCL19 and CXCL13 levels correlated with levels of 6 serum B cell biomarkers and 4 serum B cell biomarkers, respectively. By univariate analysis, the CCL19 level was positively associated with EULAR response (OR 1.43 [95% CI 1.08-1.90], P = 0.01). By multivariate analysis, the CCL19 level was predictive of a response to RTX (OR 1.48 [95% CI 1.06-2.06], P = 0.02), but this did not persist after adjustment for autoantibody status.nnnCONCLUSIONnCXCL13 and CCL19 reflect blood B cell disturbances and their levels correlate with those of other serum B cell biomarkers. CXCL13 and CCL19 are, therefore, surrogate measures for serum B cell biomarkers in RA. Serum CCL19 measurement is a new hallmark of the B cell-mediated RA subtype and may predict clinical response to RTX.


Arthritis Research & Therapy | 2005

Association between the TNFRII 196R allele and diagnosis of rheumatoid arthritis.

V. Goëb; Philippe Dieudé; Olivier Vittecoq; Othmane Mejjad; Jean-François Ménard; Marlène Thomas; Danièle Gilbert; Patrick Boumier; Sophie Pouplin; A. Daragon; Patrice Fardellone; François Tron; François Cornélis; Xavier Le Loët

Tumour necrosis factor (TNF)-α plays a key role in the pathogenesis of rheumatoid arthritis (RA). It binds to two receptors, namely TNF receptor (TNFR)I and TNFRII. Several studies have suggested an association between TNFRII 196R/R genotype and RA. The objective of the present study was to evaluate the predictive value of the TNFRII 196R allele for RA diagnosis and prognosis in a cohort of patients with very early arthritis. We followed up a total of 278 patients recruited from the community, who had swelling of at least two joints that had persisted for longer than 4 weeks but had been evolving for less than 6 months, and who had not received disease-modifying antirheumatic drugs or steroid therapy. At 2 years, patients were classified according to the American College of Rheumatology criteria. All patients were genotyped with respect to TNFRII 196M/R polymorphism. Radiographs of hands and feet (read according to the modified Sharp method) and the Health Assessment Questionnaire were used to quantify structural and functional severity. The cohort of 278 patients was found to include 156 and 122 RA and non-RA patients, respectively. The TNFRII 196R allele was found to be associated with RA (P = 0.002). However, progression of radiographic severity and Health Assessment Questionnaire scores over 1 year did not differ between carriers of the 196R allele and noncarriers. Our findings suggest that the TNFRII 196R allele may be associated with RA diagnosis but that it does not predict early radiographic progression or functional severity in patients with very early, unclassified arthritis.


Arthritis & Rheumatism | 2014

Use of Whole‐Blood Transcriptomic Profiling to Highlight Several Pathophysiologic Pathways Associated With Response to Rituximab in Patients With Rheumatoid Arthritis: Data From a Randomized, Controlled, Open‐Label Trial

J. Sellam; Sandrine Marion-Thore; Florent Dumont; Sébastien Jacques; Henri-Jean Garchon; Stéphanie Rouanet; Yassine Taoufik; Houria Hendel-Chavez; Jean Sibilia; Jacques Tebib; Xavier Le Loët; Bernard Combe; Maxime Dougados; Xavier Mariette; Gilles Chiocchia

To identify a molecular signature that could be predictive of the clinical response to rituximab (RTX) and elucidate the transcriptomic changes after RTX therapy in patients with rheumatoid arthritis (RA), with the use of whole‐blood transcriptomic profiling.


Rheumatology | 2009

Benefits of ultrasonography in the management of early arthritis: a cross-sectional study of baseline data from the ESPOIR cohort

T. Funck-Brentano; Fabien Etchepare; Sandrine Jousse Joulin; Frédérique Gandjbakch; Valérie Devauchelle Pensec; Catherine Cyteval; Anne Miquel; Mathilde Benhamou; Frédéric Banal; Xavier Le Loët; Alain Cantagrel; Pierre Bourgeois; Bruno Fautrel

OBJECTIVEnTo assess ultrasonographys (US) performance to detect the structural damage in the initial evaluation of early arthritis (EA) using the Etude et Suivides Polyarthrites Indifférenciées Récentes (ESPOIR) cohort.nnnMETHODSnESPOIR is a French, multi-centric EA cohort. Four centres assessed the structural damage by both X-ray and US examination at baseline. X-rays of hands and feet were read first by the centres local investigator (usual reading), then in the X-ray coordinating centre (central reading). Four trained examiners performed US blindly from clinical data to detect erosions on the second and fifth MCP (MCP2 and 5) and the fifth MTP (MTP5) joints bilaterally.nnnRESULTSnPatients characteristics (n = 126) were: female 78%; mean age 50.3 years; disease duration 103 days; disease activity score on 28 joints 5; CRP level 22.7 mg/l; and 79.4% of the patients fulfilling RA ACR criteria. Twelve patients had missing data for X-rays. US revealed 42 (36.8%) patients with erosive disease, whereas radiography revealed only 30 (26%) with central reading and only 11% with usual reading. US missed erosive disease present in X-rays in 10 (8.8%) patients. Combined technique of both revealed 52 (45.6%) patients with erosive diseases. On the targeted joints, US detected erosion on 75 (11%) joints vs X-rays on only 11 (1.5%). Only three joints with erosion(s) detected on X-rays were missed on US. At baseline, the presence of PD activity was not associated with joint erosions.nnnCONCLUSIONSnUS on six joints detected 1.4-fold more patients with erosions (3.3-fold more with the usual reading). In clinical practice, US combined with X-rays is of helpful diagnostic value in EA.


Joint Bone Spine | 2001

Rheumatoid factors, anti-filaggrin antibodies and low in vitro interleukin-2 and interferon-γ production are useful immunological markers for early diagnosis of community cases of rheumatoid arthritis. A preliminary study

Olivier Vittecoq; Fabienne Jouen-Beades; Kataryna Krzanowska; Isabelle Bichon-Tauvel; Jean-François Ménard; A. Daragon; François Tron; Xavier Le Loët

OBJECTIVEnTo determine whether measurements of different autoantibodies (Ab) and cytokines are useful to distinguish very early rheumatoid arthritis (RA) from other inflammatory rheumatisms.nnnMETHODSnFrom a population-based recruitment, 32 patients with very early polyarthritis (median duration: 4 months) were studied. Evaluations at entry (M0), and at 6 (M6) and 12 months (M12). Ab tested: rheumatoid factors (RF) by agglutination methods and ELISA, antiperinuclear factor (APF), antikeratin Ab (AKA), anti-Sa and antinuclear Ab. Cytokine production (TNFalpha, IL2, IFNgamma, IL1beta, IL10) in whole blood cell culture (WBCC) was determined at M0. At M12, patients were classified as having RA (N = 15) or other rheumatic diseases.nnnRESULTSnAt M0, AKA/APF and anti-Sa Ab frequencies were low, 13% and 7%, respectively. While most Ab detected at M0 persisted, others appeared during follow-up, particularly APF, which rose from 13 to 40% at M12. At M6, IgM-RF was detected in two RA patients exclusively by ELISA. AKA/APF were found to be highly specific markers for RA (100% specificity). At some time during follow-up, two RF-negative RA patients were AKA-positive. In two patients, AKA and APF were present at M0 before they satisfied ACR criteria. IL2 and IFNgamma production was significantly lower (P < 0.05) for RA patients.nnnCONCLUSIONnAKA/APF and anti-Sa Ab were detected in community cases of very early RA. AKA/APF and RF detected by ELISA might contribute to an earlier diagnosis of RA. Low production of IFNgamma and IL2 in WBCC constituted a distinct immunopathological feature in very early RA patients.

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Bernard Combe

University of Montpellier

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Jean Sibilia

University of Strasbourg

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Maxime Dougados

Paris Descartes University

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