Delphine Nigon

A Phosphorus-Based Dendrimer Targets Inflammation and Osteoclastogenesis in Experimental Arthritis

A phosphorus-based dendrimer suppresses inflammation and reduces bone erosion in mouse models of rheumatoid arthritis. Dendrimer Doubles Up Rheumatoid arthritis (RA) is an autoimmune inflammatory disease that is characterized by inflamed synovial tissue, cartilage degeneration, and bone erosion, leading to joint deformation and physical handicap. Biologic therapeutic approaches, such as monoclonal antibodies and soluble receptors, have been developed to relieve the symptoms of RA. Unfortunately, these drugs typically act on a single target: proinflammatory cytokines. There is an unmet clinical need for anti-RA drugs that target not only proinflammatory molecules and pathways, but also the osteoclastic differentiation of monocytes—a process that leads to bone resorption. In response, Hayder et al. synthesized a new dendrimer-based therapeutic that boasts a two-pronged attack on RA, with both anti-inflammatory and anti-osteoclastogenic activity. Dendrimers are highly branched polymers whose multivalency allows for interaction with several cellular and molecular targets. The authors created an azabisphosphonate (ABP)–capped dendrimer that has been shown to target human monocytes and direct them toward an anti-inflammatory response. Two animal models of autoimmune arthritis were used: the IL-1ra−/− mouse and the K/BxN serum transfer mouse. Dendrimer ABP was administered to IL-1ra−/− mice via weekly intravenous injections. At high doses, the dendrimer completely inhibited inflammation, as evidenced by a decrease in paw swelling, and prevented arthritis histopathology, with ankle joints showing near-normal synovial membranes and intact cartilage after 12 weeks. Dendrimer ABP also decreased the amount of proinflammatory cytokines and increased levels of anti-inflammatory cytokines interleukin-4 (IL-4) and IL-10, thereby suggesting a skewing toward a T helper 2 (TH2) response. The K/BxN mouse demonstrated similar results upon treatment with dendrimer ABP. Treatment with dendrimer ABP also prevented osteoclastogenesis, as shown in human synovial tissue ex vivo and human peripheral blood monocytes in vitro. The authors further outlined a potential dendrimer-mediated mechanism that involves inhibition of c-FMS—a signaling molecule that promotes monocyte differentiation into osteoclasts. This study by Hayder and colleagues has shown that dendrimer ABP, by doubling up against inflammation and bone erosion, might be more effective at treating RA than existing antibody- and small-molecule–based biologic drugs. Dendrimers are highly branched “tree-like” polymers that have demonstrated therapeutic potential in drug delivery, medical imaging, and tissue engineering in recent years. In addition, we have shown that an azabisphosphonate (ABP)–capped dendrimer selectively targets monocytes and directs them toward anti-inflammatory activation. We explored this property to assess the therapeutic potential of dendrimer ABP in the treatment of an inflammatory disease, rheumatoid arthritis. Intravenous injections of dendrimer ABP inhibited the development of inflammatory arthritis in two animal models: IL-1ra−/− mice and mice undergoing K/BxN serum transfer. Suppression of disease was characterized by normal synovial membranes, reduced levels of inflammatory cytokines, and the absence of cartilage destruction and bone erosion. Dendrimer ABP also exhibited anti-osteoclastic activity on mouse and human cells, mediated by c-FMS (cellular-feline McDonough strain sarcoma virus oncogene homolog) inhibition. These preclinical demonstrations suggest the potential use of dendrimer ABP as a nanotherapeutic for rheumatoid arthritis.

Aiming for SDAI remission versus low disease activity at 1 year after inclusion in ESPOIR cohort is associated with better 3-year structural outcomes.

Objectives Using data for patients with early rheumatoid arthritis (RA) from the ESPOIR cohort, we aimed to evaluate the impact of remission versus low disease activity (LDA) by the Simple Disease Activity Index (SDAI) at 1 year on 3-year structural damage assessed by the modified Sharp–van der Heijde total score (mTSS) and functional impairment assessed by the Health Assessment Questionnaire Disability Index (HAQ-DI). Methods We included 625 patients from the ESPOIR cohort who fulfilled the 2010 American College of Rheumatology/European League Against Rheumatism criteria for RA at baseline and had an SDAI score at 1 year. mTSS and HAQ-DI scores were compared at 3 years for patients with SDAI remission or LDA status at 1 year. A linear mixed model was used to assess the independent effect of SDAI status at 1 year on mTSS and HAQ-DI at 3 years. Results Of the 625 patients included (mean (SD) age 48.5 (12.1) years; 491 (78.6%) were women), 121 (19.4%) were in SDAI remission and 223 (35.7%) in LDA at 1 year. The mean (SD) mTSS and HAQ-DI score at 3 years was 9.6 (9.2) and 0.23 (0.42), respectively, for patients in remission at 1 year and 15.8 (16.1) and 0.43 (0.52), respectively, for patients with LDA (both p<0.05). Multivariate analysis revealed an association of remission rather than LDA status at 1 year and reduced mTSS score (p=0.005) but not HAQ-DI score (p=0.4) at 3 years. Conclusions Aiming for SDAI remission rather than LDA at 1 year leads to better radiographic outcomes at 3 years in early RA patients.

Association of IL-2RA and IL-2RB genes with erosive status in early rheumatoid arthritis patients (ESPOIR and RMP cohorts).

OBJECTIVES To assess the impact of single nucleotide polymorphisms (SNPs) in IL-2RA (rs2104286) and IL-2RB (rs743777 and rs3218253) genes on the risk of erosions in rheumatoid arthritis (RA) patients. METHODS This work is derived from 2 prospective cohorts of early RA: ESPOIR (n = 439) and RMP (n = 180). The proportions of patients with erosions at baseline and 1 year according to the genotypes of IL2RA (rs2104286) or the haplotypes constructed with the 2 SNPs of IL2RB were compared in the whole population and in ACPA positive patients. A meta-analysis assessing the risk of erosion depending on the haplotypes of the 2 SNPs of IL-2RB was performed using the Mantel-Haenszel method. A multivariate model was used to assess the independent effect of the haplotypes of IL-2RB on the risk of erosions. RESULTS The AC haplotype of IL-2RB carriage was significantly associated with the rate of erosions in ACPA positive patients in ESPOIR cohort (rate of erosions: AC/AC: 78% versus GC or GT/GC or GT: 44%, p = 0.001). A meta-analysis of ESPOIR and RMP cohorts confirmed that the carriage of AC haplotype was significantly associated with the rate of erosions at 1 year in the whole sample (OR[95%CI] = 1.92[1.14-3.22], p = 0.01) and in ACPA positive patients (OR[95%CI] = 3.34[1.68-6.67], p = 0.0006). A multivariate model in ESPOIR cohort demonstrated the independent effect of the carriage of the AC haplotype (6.03[1.94-18.69], p = 0.002) on the risk of erosions in ACPA+ patients. CONCLUSION A haplotype constructed with 2 SNPs located on IL-2RB gene was associated with erosive status in early RA.

Modulation of pro-inflammatory activation of monocytes and dendritic cells by aza-bis-phosphonate dendrimer as an experimental therapeutic agent

IntroductionOur objective was to assess the capacity of dendrimer aza-bis-phosphonate (ABP) to modulate phenotype of monocytes (Mo) and monocytes derived dendritic cells (MoDC) activated in response to toll-like receptor 4 (TLR4) and interferon γ (IFN- γ) stimulation.MethodsMo (n = 12) and MoDC (n = 11) from peripheral blood of healthy donors were prepared. Cells were preincubated or not for 1 hour with dendrimer ABP, then incubated with lipopolysaccharide (LPS; as a TLR4 ligand) and (IFN-γ) for 38 hours. Secretion of tumor necrosis factor α (TNFα), interleukin (IL) -1, IL-6, IL-12, IL-10 and IL-23 in the culture medium was measured by enzyme-linked immunosorbent assay (ELISA) and Cytokine Bead Array. Differentiation and subsequent maturation of MoDC from nine donors in the presence of LPS were analyzed by flow cytometry using CD80, CD86, CD83 and CD1a surface expression as markers.ResultsMo and MoDC were orientated to a pro-inflammatory state. In activated Mo, TNFα, IL-1β and IL-23 levels were significantly lower after prior incubation with dendrimer ABP. In activated MoDC, dendrimer ABP promoted IL-10 secretion while decreasing dramatically the level of IL-12. TNFα and IL-6 secretion were significantly lower in the presence of dendrimer ABP. LPS driven maturation of MoDC was impaired by dendrimer ABP treatment, as attested by the significantly lower expression of CD80 and CD86.ConclusionOur data indicate that dendrimer ABP possesses immunomodulatory properties on human Mo and MoDC, in TLR4 + IFN-γ stimulation model, by inducing M2 alternative activation of Mo and promoting tolerogenic MoDC.

Maintenance of cytomegalovirus-specific CD4pos T-cell response in rheumatoid arthritis patients receiving anti-tumor necrosis factor treatments.

IntroductionAnti-tumor necrosis factor (TNF)-α biotherapies have considerably changed the treatment of rheumatoid arthritis (RA). However, serious infections are a major concern in patients with rheumatic diseases treated with anti-TNF-α. Little is known about viral, especially latent, infections in anti-TNF-α treatments. Infections by cytomegalovirus (CMV), a β-herpes virus, are frequent and induce a strong CD4pos T-cell immunity, which participates in the control of infection. We thus have chosen to analyze the CD4pos T-cell response to CMV antigens as a model of antiviral response in RA patients treated with anti-TNF-α. CD28 expression was evaluated.MethodsWe have measured the CD4pos response to CMV antigens in RA patients, before and after initiation of treatment with an anti-TNF-α agent. The intracellular production of interferon (IFN)-γ in total and CD28neg CD4pos T cells in response to CMV antigens (Ags) was evaluated with flow cytometry. The proliferation of total CD4pos T cells in the presence of CMV antigens was measured with 3H-thymidine incorporation.ResultsAnti-TNF-α treatments impaired neither the anti-CD4pos anti-CMV IFN-γ response nor the proliferative response in patients. The percentage of CD28neg CD4pos cells remained constant.ConclusionsOur data suggest that the CD4pos T-cell response against CMV is not altered by anti-TNF-α treatments and that infection remains controlled in treated RA patients latently infected with CMV. Our observation brings new insight into the current knowledge of the risks of infection in patients treated with anti-TNF-α biotherapies.

Predictive value of autoantibodies from anti-CCP2, anti-MCV and anti-human citrullinated fibrinogen tests, in early rheumatoid arthritis patients with rapid radiographic progression at 1 year: results from the ESPOIR cohort.

Objectives We compared the ability of antibodies against cyclic citrullinated peptides (anti-CCP2), against mutated citrullinated vimentin (anti-MCV) and against citrullinated fibrinogen (AhFibA) to predict 1 year rapid radiographic progression (RRP; total Sharp score variation ≥5 points), in early rheumatoid arthritis (RA). Methods We analysed 566 patients from the ESPOIR cohort with early RA fulfilling the 2010 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) criteria at year 1. We assayed the 3 anticitrullinated peptide antibodies (ACPA) tests on baseline sera. We compared the performance of these 3 ACPA tests to predict first-year RRP, by comparing areas under the receiver operating characteristic curves (ROCs). We assessed the 1 year RRP risk by ACPA titres. We used a logistic multivariate regression to analyse RRP risk in terms either of ACPA positivity or titre: high (>3 times the N cut-off) and low (1 to 3N). Results 145 patients displayed RRP. Areas under the ROCs were similar (0.60) for the 3 tests. High ACPA titres were associated with 1 year RRP, whatever the test was, and with similar ORs. Low+ anti-MCV titres were not associated with 1-year RRP, whereas low+ anti-CCP2 titres (p=0.0226) and low+ AhFibA titres (p=0.0332) were significantly associated. In multivariate analysis, 1 year RRP was associated with anti-CCP2 positivity (p<0.0001), AhFibA positivity (p<0.0001) and high anti-MCV titres (p<0.0001). Conclusions Anti-CCP2 antibodies and AhFibA were predictive of 1 year RRP in early RA whatever their titre was, whereas only high anti-MCV antibody titres were predictive, potentially making them more discriminant to predict 1 year RRP risk.

SPP1 rs9138 variant contributes to the severity of radiological damage in anti-citrullinated protein autoantibody-negative rheumatoid arthritis

Objective We recently reported an association of the SPP1 rs9138 and rs11439060 functional variants with the risk of rheumatoid arthritis (RA), the association being greater in anti-citrullinated protein autoantibody (ACPA)-negative patients. We hypothesised that SPP1 may contribute to the severity of joint destruction in RA, specifically in the ACPA-negative population. Methods Patients with RA in the ESPOIR cohort underwent genotyping for SPP1 rs9138 and rs11439060. Radiographs of the hands and feet were obtained at the first visit and at 1- and 2-year follow-up. Association analyses were performed by ACPA status. A replication study of the relevant subset of the Leiden Early Arthritis Clinic (EAC) cohort was performed. Results In the ESPOIR cohort (652 patients), rs9138 was significantly associated with radiological progression of joint destruction at 2 years, the association being restricted to 358 ACPA-negative patients (p=0.034). In the replication study with the Leiden EAC cohort (273 ACPA-negative patients), rs4754, which is in complete linkage disequilibrium with rs9138, was significantly associated with joint damage progression in ACPA-negative patients at 2- and 7-year follow-up (p=0.019 and p=0.005, respectively). Combined analysis of the two cohorts revealed a 0.95-fold rate of joint destruction per year per minor allele (p=0.022). Conclusions The SPP1 rs9138 variant contributes to joint damage progression in ACPA-negative RA.

Relationships between ultrasound enthesitis, disease activity and axial radiographic structural changes in patients with early spondyloarthritis: data from DESIR cohort

Background To search for association between ultrasound (US) enthesis abnormalities and disease activity, spine and sacro-iliac joints (SIJ) MRI inflammatory lesions and spine structural changes in a cohort of patients suspected for axial spondyloarthritis (SpA). Methods Patients: Of 708 patients included in the DESIR(Devenir des Spondyloarthrites Indifférenciées Récentes) cohort, 402 had an US enthesis assessment and were selected for this study. Imaging: Achilles, lateral epicondyles, superior patellar ligament, inferior patellar ligament entheses were systematically US scanned and abnormalities were summed in US structural and power Doppler (PDUS) scores. Spine radiographs, SIJ and spine MRI scans were centrally scored modified Stoke Ankylosing Spondylitis Spine Score (mSASSS), presence of MRI sacro-iliitis, Spondyloarthritis Research Consortium of Canada and Berlin scores. Analysis: The associations between the US structural/PDUS scores and disease activity, C reactive protein (CRP), MRI SIJ and spine inflammatory lesions and mSASSS were tested by Spearmans correlation tests. Results Among the 402 patients included (median age: 33.5 years, males: 48.5%), 55% had US enthesis structural abnormalities while 14% had PDUS abnormalities. There was no association between US scores and Bath Ankylosing Spondylitis Disease Activity Index, CRP or inflammatory lesions on SIJ and spine MRI. There was a correlation between US structural and PDUS scores and the mSASSS (respectively, r=0.151, p=0.005; r=0.143, p=0.007). The proportion of patients with syndesmophytes was higher in the case of US enthesophytes (26% of syndesmophytes vs 6% in the absence of US enthesophytes, p<0.0001). Conclusion While the US abnormalities do not seem to be a helpful tool for monitoring disease activity in axial SpA, US enthesophytes, strongly associated with axial syndesmophytes, might be a marker of interest for disease severity. Trial registration number NCT01648907, date of registration : 20 July 2012.

Prevalence and risk factors for fragility fracture in systemic mastocytosis

OBJECTIVES Systemic mastocytosis (SM) is characterized by the accumulation of mast cells in tissues other than the skin. Bone involvement although frequent has not been thoroughly evaluated. Primary objective was to determine risk factors associated with fragility fractures (FF) in SM. Secondary objectives were to evaluate the ability of bone marrow tryptase (BMT) level to identify patients with FF, and to describe bone involvement in SM. METHODS We analyzed retrospectively all consecutive patients seen in our expert center, with a diagnosis of SM according to the 2001 WHO criteria, and with complete bone assessment. We collected data about lifetime fractures, types of cutaneous manifestations, degranulation symptoms, blood and BMT levels, bone mineral density assessed by densitometry and KIT mutation. We performed a univariate analysis investigating the factors associated with FF and then a logistic multivariable regression analysis. We assessed the ability of bone marrow tryptase to identify patients with FF. RESULTS Eighty-nine patients with SM were included. Thirty-six patients (40.4%) suffered from osteoporosis and twenty-five (28.1%) experienced lifetime FF. Univariate analysis identified age at diagnosis and disease onset, presence of telangiectasia macularis eruptiva perstans, digestive symptoms, mast cells activation symptoms, elevated BMT, low femoral and lumbar BMD, as associated with FF. Multivariate analysis identified elevated BMT, low femoral T score and older age at diagnosis as independently associated with FF. CONCLUSIONS Low femoral T-score, BMT level, and older age at diagnosis are markers associated with FF in SM. BMT may represent an important biomarker to predict FF in SM patients.

Diminished bone resorption in overweight/obese women despite vitamin D insufficiency

Joint Bone Spine - In Press.Proof corrected by the author Available online since lundi 25 avril 2016