Nationwide epidemiological survey of polyarteritis nodosa in Japan in 2020.

Polyarteritis nodosa (PAN) is a systemic necrotizing vasculitis that predominantly affects medium-sized arteries. With advances in our understanding of the pathogenesis and classification of vasculitis, PAN and microscopic polyangiitis (MPA), a disease of anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV), were separated from the group of diseases previously diagnosed as periarteritis nodosa (PN) at the Chapel Hill Consensus Conference (CHCC) in 1994 (1).

Cross-sectional study using the University of California, Los Angeles, Scleroderma Clinical Trials Consortium Gastrointestinal Tract Instrument 2.0 (UCLA SCTC GIT 2.0) for gastrointestinal disorders of systemic sclerosis.

This study aimed to identify severe gastrointestinal ailments in patients with systemic sclerosis (SSc), investigate the role of antibodies in gastrointestinal disorders, and explore the relationship between limited cutaneous SSc (lcSSc) and diffuse cutaneous SSc (dcSSc) in terms of gastrointestinal involvement and its association with skin stiffness. We used the University of California, Los Angeles, Scleroderma Clinical Trials Consortium Gastrointestinal Tract Instrument 2.0 (UCLA SCTC GIT 2.0) questionnaire to assess gastrointestinal disturbances in 100 patients with SSc. Gastrointestinal impairment was categorized into three levels: absence of or minor symptoms, moderate symptoms, and severe symptoms, as indicated by the total gastrointestinal tract (GIT) score. Comparing 27 patients with dcSSc and 73 patients with lcSSc, severe gastrointestinal disturbances were found in 7.4% of patients with dcSSc and 4.1% of patients with lcSSc. A total of 18.0% of anticentromere antibody (ACA)-positive patients exhibited moderate to severe symptoms, while 9.1% of antitopoisomerase 1 antibody-positive patients displayed similar symptoms. The average disease duration in patients with severe symptoms was 15.0 years, in those with moderate symptoms was 10.3 years, and in those who were symptom-free or mildly affected was 8.5 years. Among 16 patients with moderate to severe gastrointestinal disorders, a positive correlation was observed between the modified Rodnan skin thickness score (mRSS) and total GIT score. In addition, a positive correlation was identified between fecal incontinence and mRSS, with weaker correlations for reflux and bloating symptoms. Patients with gastrointestinal disorders showed a tendency to worsen over time, particularly in ACA-positive patients with dcSSc. Furthermore, a correlation was observed between mRSS and fecal incontinence, reflux, and abdominal bloating in patients with moderate to severe gastrointestinal disturbances.

GWAS for systemic sclerosis identifies six novel susceptibility loci including one in the Fcγ receptor region.

Here we report the largest Asian genome-wide association study (GWAS) for systemic sclerosis performed to date, based on data from Japanese subjects and comprising of 1428 cases and 112,599 controls. The lead SNP is in the FCGR/FCRL region, which shows a penetrating association in the Asian population, while a complete linkage disequilibrium SNP, rs10917688, is found in a cis-regulatory element for IRF8. IRF8 is also a significant locus in European GWAS for systemic sclerosis, but rs10917688 only shows an association in the presence of the risk allele of IRF8 in the Japanese population. Further analysis shows that rs10917688 is marked with H3K4me1 in primary B cells. A meta-analysis with a European GWAS detects 30 additional significant loci. Polygenic risk scores constructed with the effect sizes of the meta-analysis suggest the potential portability of genetic associations beyond populations. Prioritizing the top 5% of SNPs of IRF8 binding sites in B cells improves the fitting of the polygenic risk scores, underscoring the roles of B cells and IRF8 in the development of systemic sclerosis. The results also suggest that systemic sclerosis shares a common genetic architecture across populations.

Safety and efficacy of rituximab in systemic sclerosis (DESIRES): open-label extension of a double-blind, investigators-initiated, randomised, placebo-controlled trial.

BACKGROUND: Results from the double-blind phase 2 DESIRES trial showed that rituximab improves skin thickening in systemic sclerosis. Here, we present the findings of a subsequent 24-week open-label extension phase. METHODS: Patients with systemic sclerosis aged 20-79 years, who fulfilled the 2013 American College of Rheumatology and European League Against Rheumatism classification criteria, with a baseline modified Rodnan Skin Score (mRSS) of 10 or greater were enrolled into the DESIRES trial, which was an investigator-initiated, phase 2, double-blind, randomised controlled trial of rituximab versus placebo conducted at four sites in Japan. After completion of 24 weeks of treatment with either rituximab or placebo, patients in both groups received a further 24 weeks of rituximab (375 mg/m2 intravenously, once per week for 4 consecutive weeks) in an open-label extension. The primary endpoint of the double-blind trial was mRSS at week 24, which was reassessed at week 48 in the open-label extension. All endpoints were exploratory. Safety analyses included all participants who received at least one dose of study drug; efficacy analyses included those who had received at least one dose and undergone efficacy assessment at 24 weeks in the double-blind phase and at 48 weeks in the extension phase. The DESIRES study is registered with ClinicalTrials.gov, NCT04274257, and UMIN-CTR, UMIN000030139. FINDINGS: Between Nov 28, 2017, and Nov 6, 2018, 56 patients were randomly assigned to either rituximab (n=28) or placebo (n=28) in a double-blind study. 26 patients initially assigned to rituximab and 20 assigned to placebo transitioned to the open-label extension and all received at least one dose of rituximab; 24 participants in the rituximab-rituximab group and 19 in the placebo-rituximab group completed the extension phase. In the rituximab-rituximab group, there was an improvement in mRSS from baseline at week 24 (-5·81 [SD 3·16]), with further improvement at week 48 (-8·88 [3·10]). In the placebo-rituximab group, mRSS worsened at week 24 (2·14 [SD 5·51]) but improved at the week 48 assessment (-6·05 [4·43]). One patient each in the rituximab-rituximab and placebo-rituximab groups experienced one serious adverse event during the open-label phase (cholangitis and pneumococcal pneumonia, respectively). There were no deaths during follow-up. INTERPRETATION: Two courses of rituximab is a safe treatment that can provide sustained improvement in systemic sclerosis for at least 48 weeks. FUNDING: Japan Agency for Medical Research and Development. TRANSLATION: For the Japanese translation of the abstract see Supplementary Materials section.

Safety and efficacy of rituximab in systemic sclerosis (DESIRES): a double-blind, investigator-initiated, randomised, placebo-controlled trial.

BACKGROUND: Systemic sclerosis is a connective tissue disease characterised by multiorgan fibrosis with an autoimmune background and poor prognosis. Although a few drugs have shown some efficacy in treating the disease, there remains a great unmet medical need. We aimed to investigate the efficacy and safety of rituximab in patients with systemic sclerosis. METHODS: We did a double-blind, investigator-initiated, randomised, placebo-controlled trial at four hospitals in Japan. Patients aged 20-79 years, who fulfilled the 2013 American College of Rheumatology and European League Against Rheumatism classification criteria for systemic sclerosis, with a modified Rodnan Skin Score (mRSS) of 10 or greater, and an expected survival of at least 6 months were randomly assigned (1:1) to receive intravenous rituximab (375 mg/m2) or placebo once per week for 4 weeks. Patients and investigators were masked to treatment allocation. The primary endpoint was the absolute change in mRSS 24 weeks after initiation of study treatment, measured in all patients who received at least one dose of study treatment and had one endpoint assessment. This study is registered with ClinicalTrials.gov, NCT04274257, and UMIN-CTR, UMIN000030139. FINDINGS: Between Nov 28, 2017, and Nov 6, 2018, 80 individuals were screened and 56 (70%) were enrolled and randomly assigned; 51 (91%) were women and five (9%) were men. 27 (96%) of 28 patients in the rituximab group and 22 (79%) of 28 patients in the placebo group received at least one dose of their allocated treatment and completed 24 weeks of follow-up. The absolute change in mRSS 24 weeks after initiation of study treatment was lower in the rituximab group than in the placebo group (-6·30 in the rituximab group vs 2·14 in the placebo group; difference -8·44 [95% CI -11·00 to -5·88]; p<0·0001). Adverse events were similar in both groups and occurred in 28 (100%) of 28 patients in the rituximab group and 23 (88%) of 26 patients in the placebo group. One serious adverse event leading to treatment discontinuation occurred in one patient in each group (decreased serum albumin in the rituximab group and biliary enzyme increase in the placebo group). The most common adverse event was upper respiratory infection, which occurred in 11 patients (39%) in the rituximab group and ten patients (38%) in the placebo group. There were no deaths during follow-up. INTERPRETATION: Rituximab appears to be an effective and safe treatment for systemic sclerosis. Although this study has some limitations, this is the first clinical trial to show efficacy of rituximab with skin sclerosis as the primary endpoint. FUNDING: Japan Agency for Medical Research and Development (AMED), Zenyaku Kogyo. TRANSLATION: For the Japanese translation of the abstract see Supplementary Materials section.