Specific Antinuclear Antibody Level Changes after B Cell Depletion Therapy in Systemic Sclerosis Are Associated with Improvement of Skin Thickening

Anti-topoisomerase 1 Antibody Level Changes after B Cell Depletion Therapy in Systemic Sclerosis

The aim of our study was to assess the relationship between the changes of antinuclear autoantibodies (ANAs) and autoantibodies to topoisomerase 1 (anti-Topo 1) in systemic sclerosis (SSs) patients on rituximab (RTX) therapy. The prospective study included 88 patients (73 women) with a mean age of 47 (17-71) years. The mean disease duration was 5.9 ± 4.8 years. The mean follow-up period was more than 2 years (27 (12-42) months). We documented a statistically significant change in skin score, the disease activity index, improvement of pulmonary function and reduction of mean dose of prednisolone after RTX treatment. There was a significant decrease in the number of patients with high levels of ANA and overall decrease of the ANA and anti-Topo 1 levels. A moderate positive statistically significant correlation was found between ANA and anti-Topo 1 (r = 0.403). In the group of patients positive for anti-Topo 1 there were a more pronounced depletion of B lymphocytes, significantly higher increase in forced vital capacity and diffusion capacity, decrease in the disease activity index, compared with patients negative for anti-Topo 1. We observed the decline in the level of ANA and anti-Topo 1 in SSc patients after RTX therapy, and it was correlated by an improvement of the main outcome parameters of the disease. Therefore, anti-Topo 1 positivity could be considered as a predictor of a better response to RTX treatment, especially in SSc patients with hyperproduction of anti-Topo 1.

Anti-RNA polymerase III antibodies in patients with suspected and definite systemic sclerosis: Why and how to screen

Anti-RNA Polymerase III antibodies are the most frequent anti-nuclear antibodies in systemic sclerosis, after anti-centromere and anti-Topoisomerase I. Considering their specificity for systemic sclerosis, they have been included in 2013 American College of Rheumatology/European League Against Rheumatism classification criteria for systemic sclerosis. They were first identified in 1993 using an immunoprecipitation method; the subsequent diffusion of commercial assays, based on the enzyme-linked immunosorbent assay or multiplex line immunoblot techniques, has allowed an increasing number of systemic sclerosis patients to be tested for this autoantibody; nevertheless, the diffusion of this test in systemic sclerosis patients is probably still sub-optimal. Anti-RNA Polymerase III antibodies have been associated with important clinical manifestations: rapid and diffuse cutaneous involvement, joint contractures, scleroderma renal crisis, gastric antral vascular ectasia and malignancies synchronous to systemic sclerosis onset. Moreover, other possible clinical associations, including pulmonary hypertension, still need confirmation. Since the correct approach for screening for anti- RNA Polymerase III antibodies in patients with suspected or definite systemic sclerosis is still debated, possible strategies are proposed here. Moreover, issues that are still controversial are discussed, including the interpretation of multiple simultaneous positivity for anti-RNA Polymerase III antibodies and other autoantibodies in line immunoassay, and the possible relevance of anti-RNA Polymerase III antibodies titre.

Systemic sclerosis phase III clinical trials: Hope on the horizon?

While significant progress has been made in treating systemic sclerosis, many patients still have an outcome that is far from satisfactory. For the first time in history, several drugs are now in phase III randomized controlled trials. Approaches tested include the anti-B cell antibody rituximab, the anti-interleukin-6 receptor antibody tocilizumab, the antifibrotic drugs nintedanib and pirfenidone, and the cannabinoid receptor mimetic lenabasum. That all these drugs are in advanced clinical trials despite the relatively low incidence of the disease therefore is good news. Not only is there realistic hope that at least some of the approaches will work, this also indicates growing industry interest, for most of the trials are company-sponsored. This review attempts to delineate the ongoing trials and to summarize the underlying evidence of these candidate systemic sclerosis drugs.

Two years follow-up of an open-label pilot study of treatment with rituximab in patients with early diffuse cutaneous systemic sclerosis

OBJECTIVES

Following results in open-label studies of rituximab in patients with systemic sclerosis, a Belgian three-centre initiative was launched to explore safety and efficacy of rituximab in early, diffuse cutaneous systemic sclerosis (dcSSc).

METHODS

Open-label study of 17 patients with early dcSSc, treated with two courses of rituximab, at month 0 and 6. Clinical examination, lung function testing, echocardiography, disease activity score (DAS) and functional status were performed at baseline and over 24 months of follow-up.

RESULTS

Modified Rodnan skin score (MRSS) changed significantly over time, with a mean of 25.5 (standard deviation [SD] 6.0) at baseline to 12.6 (SD 5.1) at month 24 (Mixed Model Analysis [MMA] p < 0.0001), which is a decrease of 51% at month 24 vs. baseline. DAS showed significant decrease over the total study period, with a score of 4.1 (SD 1.7) at baseline to 1.5 (SD 1.8) at month 24 (MMA p < 0.0001). Additionally, this was significant at all time points vs. baseline, both for MRSS and DAS. Internal organ status remained clinically stable throughout the study period. No statistically significant differences compared to baseline were found at the follow-up time points. Seven serious adverse events took place, all except for one, considered unrelated to study medication.

CONCLUSIONS

This is the first multicentre Belgian collaboration investigating potential efficacy of rituximab in early dcSSc. Rituximab appears to be safe and tolerable and it may have beneficial effects on skin involvement, on overall disease activity and on stabilization of internal organ status in early dcSSc.

Systemic sclerosis with anti-RNA polymerase III positivity following silicone breast implant rupture: possible role of B-cell depletion and implant removal in the treatment

Despite some case reports and small series of women with silicone breast implants (SBI) developing Systemic Sclerosis (SSc), no clear evidence of an association of SBI with SSc is available. However, SSc is characterized by clinical and immunological heterogeneity and autoantibodies are currently the best markers to stratify this heterogeneity of patients. Therefore, we have reviewed the literature for details of autoantibody characterization in reports of SSc associated with SBI. Moreover, the case of an anti-RNA polymerase III-positive SSc with rapid onset and progression, in which SBI rupture was found is described. This case may support a previous observation suggesting a possible role of SBI rupture as a trigger for anti-RNA polymerase III-positive SSc. This possible causal role may be reinforced by the observation that in our patient, despite immunosuppressive treatment, the disease progressed until SBI were removed, and reduction of anti-RNA polymerase III titer was obtained after rituximab treatment. This result may support data suggesting that B-cell depleting therapy may decrease specific autoantibody level in SSc patients, and that these changes are associated with disease improvement.