Dimitrios Daoussis

Experience with rituximab in scleroderma: results from a 1-year, proof-of-principle study

Objective. To assess the efficacy of rituximab (RTX) in SSc. Methods. Fourteen patients with SSc were evaluated. Eight patients were randomized to receive two cycles of RTX at baseline and 24 weeks [each cycle consisted of four weekly RTX infusions (375 mg/m2)] in addition to standard treatment, whereas six patients (control group) received standard treatment alone. Lung involvement was assessed by pulmonary function tests (PFTs) and chest high-resolution CT (HRCT). Skin involvement was assessed both clinically and histologically. Results. There was a significant increase of forced vital capacity (FVC) in the RTX group compared with baseline (mean ± s.d.: 68.13 ± 19.69 vs 75.63 ± 19.73, at baseline vs 1-year, respectively, P = 0.0018). The median percentage of improvement of FVC in the RTX group was 10.25%, whereas that of deterioration in the controls was 5.04% (P = 0.002). Similarly, diffusing capacity of carbon monoxide (DLCO) increased significantly in the RTX group compared with baseline (mean ± s.d.: 52.25 ± 20.71 vs 62 ± 23.21, at baseline vs 1-year respectively, P = 0.017). The median percentage of improvement of DLCO in the RTX group was 19.46%, whereas that of deterioration in the control group was 7.5% (P = 0.023). Skin thickening, assessed with the Modified Rodnan Skin Score (MRSS), improved significantly in the RTX group compared with the baseline score (mean ± s.d.: 13.5 ± 6.84 vs 8.37 ± 6.45 at baseline vs 1-year, respectively, P < 0.001). Conclusion. Our results indicate that RTX may improve lung function in patients with SSc. To confirm our encouraging results we propose that larger scale, multicentre studies with longer evaluation periods are needed.

Evidence that Dkk‐1 is dysfunctional in ankylosing spondylitis

OBJECTIVE Dkk-1 is an inhibitory molecule that regulates the Wnt pathway, which controls osteoblastogenesis. This study was undertaken to explore the potential role of Dkk-1 in ankylosing spondylitis (AS), a prototypical bone-forming disease. METHODS Serum Dkk-1 levels were measured in 45 patients with AS, 45 patients with rheumatoid arthritis (RA), 15 patients with psoriatic arthritis (PsA), and 50 healthy subjects by sandwich enzyme-linked immunosorbent assay (ELISA). A functional ELISA was used to assess the binding of Dkk-1 to its receptor (low-density lipoprotein receptor-related protein 6). Furthermore, we studied the effect of sera from patients with AS and healthy subjects on the activity of the Wnt pathway in the Jurkat T cell model, with and without a neutralizing anti-Dkk-1 monoclonal antibody, by Western immunoblotting. RESULTS Serum Dkk-1 levels were significantly increased in patients with AS (mean +/- SEM 2,730 +/- 135.1 pg/ml) as compared with normal subjects (P = 0.040), patients with RA (P = 0.020), and patients with PsA (P = 0.049). Patients with AS receiving anti-tumor necrosis factor alpha (anti-TNFalpha) treatment had significantly higher serum Dkk-1 levels than patients with AS not receiving such treatment (P = 0.007). Patients with AS studied serially prior to and following anti-TNFalpha administration exhibited a significant increase in serum Dkk-1 levels (P = 0.020), in contrast to patients with RA, who exhibited a dramatic decrease (P < 0.001). Jurkat cells treated with serum from AS patients exhibited increased Wnt signaling compared with cells treated with control serum. In that system, Dkk-1 blockade significantly enhanced Wnt signaling in control serum-treated, but not AS serum-treated, Jurkat T cells. CONCLUSION Our findings indicate that in patients with AS, circulating bone formation-promoting factors functionally prevail. This can be at least partially attributed to decreased Dkk-1-mediated inhibition.

THE EMERGING ROLE OF DICKKOPF-1 IN BONE BIOLOGY: IS IT THE MAIN SWITCH CONTROLLING BONE AND JOINT REMODELING?

BACKGROUND Dickkopf-1 (DKK-1), an inhibitor of the Wnt pathway, has recently emerged as an important player in several critical aspects of bone biology. METHODS We performed an extensive internet search (MEDLINE) using the key words Dickkopf-1 and the abbreviation DKK-1. RESULTS DKK-1 is a regulator of bone mass with increased expression linked to osteopenia and decreased expression to high bone mass. Moreover, it appears to actively participate in joint remodeling in animal models of arthritis, with increased levels related to bone resorption and decreased levels to new bone formation. Recent studies indicate its possible involvement in the remodeling process of human systemic rheumatic diseases such as rheumatoid arthritis and ankylosing spondylitis. DKK-1 may also play a role in osteoarthritis, metabolic bone disease (osteoporosis and Pagets disease), as well as multiple myeloma-associated bone disease and prostate cancer bone metastases. CONCLUSIONS DKK-1 is a regulator of bone mass and joint remodeling. It may be a promising therapeutic target in osteoporosis; monoclonal antibody-based inhibition of Dkk-1 is already under development for osteoporosis treatment. Its role as a regulator of joint remodeling in animal models requires further exploration in humans.

Treatment of Systemic Sclerosis-Associated Calcinosis: A Case Report of Rituximab-Induced Regression of CREST-Related Calcinosis and Review of the Literature

OBJECTIVES Calcinosis is frequently encountered in patients with systemic sclerosis (SSc) and may be associated with significant morbidity. No treatment has shown so far an unequivocal beneficial effect. METHODS We performed an extensive internet search (MEDLINE) using the keywords calcinosis, calcification, scleroderma, systemic sclerosis, and treatment. RESULTS Our patient had extensive Calcinosis, Raynaud, Esophagitis, Sclerodactyly, telangiectasia (CREST)-related calcinosis, frequently ulcerating and painful. Following 2 rituximab courses (consisting of 4 weekly infusions, 375 mg/m(2) each), calcinosis significantly improved and pain disappeared. Pharmacologic agents used in the treatment of SSc-associated calcinosis include diltiazem, minocycline, warfarin, biphosphonates, and intravenous immunoglobulin. Other therapeutic approaches include surgical excision, laser vaporization, and extracorporeal shock wave lithotripsy. CONCLUSIONS Evidence for all existing therapies is weak and therefore larger scale controlled studies are needed. Rituximab appears as a promising treatment especially in view of recent evidence that this therapy may be also effective in the underlying disease.

Is There a Role for B-cell Depletion as Therapy for Scleroderma? A Case Report and Review of the Literature

OBJECTIVES Rituximab (RTX) has been successfully used in the treatment of several rheumatic diseases with an acceptable safety profile. We present herein a patient with systemic sclerosis (SSc) who exhibited significant improvement of his lung function and skin fibrosis following RTX administration, and review the literature regarding the role of B-cells in SSc and the potential efficacy of RTX in its treatment. METHODS We performed an internet search using the keywords systemic sclerosis, scleroderma, rituximab, B-cells, fibrosis, interstitial lung disease (ILD), and therapy. RESULTS Our patient, a 40-year old man with severe SSc-associated ILD, received 4 courses of RTX. The patients lung function improved; forced vital capacity and diffusing capacity of carbon monoxide reached values of 35% and 33%, respectively, compared with 30% and 14% of pretreatment values. Skin thickening assessed clinically and histologically improved as well. Several lines of evidence suggest that B-cells may have a pathogenic role in SSc. B-cells from tight skin mice--an animal model of SSc--exhibit chronic hyperactivity; likewise, B-cells from patients with SSc overexpress CD19 and are chronically activated. Furthermore, studies have revealed that B-cell genes were specifically transcribed in SSc skin and that B-cell infiltration was a prominent feature of SSc-associated ILD. The potential clinical efficacy of RTX in SSc has been explored in a limited number of patients with encouraging results. Preliminary data suggest that RTX may favorably affect skin as well as lung disease in SSc. CONCLUSIONS Several basic research data underscore the potential pathogenic role of B-cells in SSc and clinical evidence suggests that RTX might be a therapeutic option in SSc. Large-scale multicenter studies are needed to evaluate the potential clinical efficacy of RTX in SSc.

Wnt Pathway and IL-17: Novel Regulators of Joint Remodeling in Rheumatic Diseases. Looking Beyond the RANK-RANKL-OPG Axis

OBJECTIVES During the last decade research has focused on the RANK-RANKL-OPG (Receptor Activator of Nuclear factor KappaB-Receptor Activator of Nuclear factor KappaB Ligand-Osteoprotegerin) pathway that is currently considered the final common route to bone and joint remodeling. The potential role of novel additional mediators has been highlighted by several reports. This review focuses on the recent information about the pathophysiology of the Wingless (Wnt) pathway and interleukin-17 (IL-17) in relation of their role in bone and joint remodeling. METHODS An extensive internet search was performed (PubMed) from 1998 and onward using the following keywords: Wnt, bone remodeling, bone, rheumatic diseases, rheumatoid arthritis, IL-17, Th17, osteoblastogenesis, and osteoclastogenesis. RESULTS Several members of the Wnt pathway play an important role in bone remodeling. Recent experimental data indicate a key role for Dickkopf-1, a soluble inhibitor of the Wnt pathway, in bone remodeling. Increased Dickkopf-1 levels are linked to bone resorption and decreased levels to new bone formation. Low-density lipoprotein receptor-related protein-5, the main receptor that mediates Wnt signaling, plays a critical role in bone mass regulation. Gain-of-function mutations of lipoprotein receptor-related protein-5 cause high bone mass phenotypes, whereas loss-of-function mutations are linked to severe osteoporosis. IL-17 is a proinflammatory cytokine that is produced by a recently described T-cell subset, known as Th17 cells. Evidence suggests that IL-17 is a critical mediator of joint destruction in animal models of arthritis. IL-17 blockade has beneficial effects on murine arthritis, a fact that points to the direction of this cytokine as a potential therapeutic target in human inflammatory arthritides as well. CONCLUSIONS The available data suggest that mediators in these 2 biologic systems are critical in joint remodeling and may be appropriate targets in the treatment of bone and joint abnormalities that characterize a variety of inflammatory arthritides and bone diseases.

Cardiovascular risk factors and not disease activity, severity or therapy associate with renal dysfunction in patients with rheumatoid arthritis

Objectives The present study aimed to evaluate the prevalence and associations of renal dysfunction in patients with rheumatoid arthritis (RA). It specifically addressed the hypotheses that renal dysfunction in these patients may associate with the presence of insulin resistance, dyslipidaemia, uric acid levels and/or current levels of systemic inflammation. Methods Renal function was assessed by estimated glomerular filtration rate (GFR) using the modification of diet in renal disease equation in 400 consecutive RA patients for this cross-sectional, single-centre study. Risk factors for renal dysfunction were recorded/measured in all participants. Correlations between GFR and other variables were analysed by Pearson or Spearman test as appropriate. Linear regression was used to test the independence of the associations between GFR and other variables. Results In this RA patient cohort, 67.75% of patients had a reduced GFR of less than 90 ml/minute per 1.73 m2 and 12.75% had a GFR of less than 60 ml/minute per 1.73 m2. Multivariable analysis revealed significant associations between GFR and age (β = −0.370, p<0.001), female sex (β = −0.181, p=0.002), total cholesterol (β = −0.112, p=0.022), serum uric acid (SUA) (β = −0.425, p<0.001) and the presence of extra-articular disease, apart from sicca and/or nodules (β = −0.084, p=0.040). Conclusions Renal dysfunction in RA is quite common and associates with classic cardiovascular risk factors such as advanced age and dyslipidaemia, levels of SUA and the presence of extra-articular disease. Renal dysfunction was not related to other RA-related factors including disease activity and duration, disability and past or present use of nephrotoxic medications.

A multicenter, open-label, comparative study of B-cell depletion therapy with Rituximab for systemic sclerosis-associated interstitial lung disease

OBJECTIVES Rituximab (RTX) may favorably affect lung function and skin fibrosis in patients with systemic sclerosis (SSc). We aimed to assess long-term efficacy and safety of RTX in SSc compared to standard treatment. METHODS A total of 51 patients with SSc-associated interstitial lung disease were recruited and treated with RTX (n = 33) or conventional treatment (n = 18). Median follow-up was 4 years (range: 1-7). Conventional treatment consisted of azathioprine (n = 2), methotrexate (n = 6), and mycophenolate mofetil (n = 10). RESULTS Patients in the RTX group showed an increase in FVC at 2 years (mean ± SD of FVC: 80.60 ± 21.21 vs 86.90 ± 20.56 at baseline vs 2 years, respectively, p = 0.041 compared to baseline). In sharp contrast, patients in the control group had no change in FVC during the first 2 years of follow-up. At the 7 year time point the remaining patients in the RTX group (n = 5) had higher FVC compared to baseline (mean ± SD of FVC: 91.60 ± 14.81, p = 0.158 compared to baseline) in contrast to patients in the control group (n = 9) where FVC deteriorated (p < 0.01, compared to baseline). Direct comparison between the 2 groups showed a significant benefit for the RTX group in FVC (p = 0.013). Improvement of skin thickening was found in both the RTX and the standard treatment group; however, direct comparison between groups strongly favored RTX at all-time points. Adverse events were comparable between groups. CONCLUSIONS Our data indicate that RTX has a beneficial effect on lung function and skin fibrosis in patients with SSc. Randomized controlled studies are highly needed.

B-cell depletion therapy in systemic sclerosis: experimental rationale and update on clinical evidence.

Systemic sclerosis (SSc) is a systemic rheumatic disease with poor prognosis since therapeutic options are limited. Recent evidence from animal models suggests that B-cells may be actively involved in the fibrotic process. B-cells from tight skin mice, an animal model of scleroderma, display a “hyperresponsive” phenotype; treatment with rituximab (RTX) significantly attenuates skin fibrosis in this animal model. In humans, B-cell infiltration is a prominent finding in most lung biopsies obtained from patients with SSc-associated interstitial lung disease. Several open label studies have assessed the clinical efficacy of RTX in SSc. In most patients skin fibrosis improved; lung function either improved or remained stable. Definite conclusions regarding the clinical efficacy of RTX in SSc cannot be drawn but further exploration with a multicenter, randomized study is warranted.

Uric acid is a strong independent predictor of renal dysfunction in patients with rheumatoid arthritis

IntroductionRecent evidence suggests that uric acid (UA), regardless of crystal deposition, may play a direct pathogenic role in renal disease. We have shown that UA is an independent predictor of hypertension and cardiovascular disease (CVD), and that CVD risk factors associate with renal dysfunction, in patients with rheumatoid arthritis (RA). In this study we investigated whether UA associates with renal dysfunction in patients with RA and whether such an association is independent or mediated through other comorbidities or risk factors for renal impairment.MethodsRenal function was assessed in 350 consecutive RA patients by estimated glomerular filtration rate (GFR) using the six-variable Modification of Diet in Renal Disease equation. Risk factors for renal dysfunction were recorded or measured in all participants. Linear regression was used to test the independence of the association between GFR and UA.ResultsUnivariable analysis revealed significant associations between GFR and age, systolic blood pressure, total cholesterol, triglycerides, RA duration and UA. UA had the most powerful association with renal dysfunction (r = -0.45, P < 0.001). A basic model was created, incorporating all of the above parameters along with body mass index and gender. UA ranked as the first correlate of GFR (P < 0.001) followed by age. Adjustments for the use of medications (diuretics, low-dose aspirin, cyclooxygenase II inhibitors and nonsteroidal anti-inflammatory drugs) and further adjustment for markers of inflammation and insulin resistance did not change the results.ConclusionsUA is a strong correlate of renal dysfunction in RA patients. Further studies are needed to address the exact causes and clinical implications of this new finding. RA patients with elevated UA may require screening for renal dysfunction and appropriate management.