Dual blockade of interleukin-17A and interleukin-17F as a therapeutic strategy for liver fibrosis: Investigating the potential effect and mechanism of brodalumab

Liver fibrosis is a terminal manifestation of various chronic liver diseases. There are no drugs that can reverse the condition. Recently, the importance of interleukin-17 (IL17) in the pathophysiology has been revealed and has attracted attention as a therapeutic target. We aimed to reveal the roles of IL17A and IL17F in liver fibrosis, and to validate the potential of their dual blockade as therapeutic strategy. First, we retrospectively reviewed the longitudinal change of FIB-4 index, a clinical indicator of liver fibrosis, among psoriasis patients treated by brodalumab, which blocks IL17 receptor A (IL17RA). Next, we examined anti-fibrotic efficacy of anti-IL17RA antibody (Ab) in two murine liver fibrosis models by histopathological investigation and real-time reverse transcription polymerase chain reaction (RT-PCR). Finally, we analyzed the effect of IL17A and IL17F upon human hepatic stellate cells with RNA sequencing, real-time RT-PCR, western blotting, chromatin immunoprecipitation, and flow cytometry. Clinical data showed that FIB-4 index significantly decreased among psoriasis patients treated by brodalumab. In vivo studies additionally demonstrated that anti-IL17RA Ab ameliorates liver fibrosis induced by tetrachloride and methionine-choline deficient diet. Furthermore, in vitro experiments revealed that both IL17A and IL17F enhance cell-surface expression of transforming growth factor-β receptor II and promote pro-fibrotic gene expression via the JUN pathway in human hepatic stellate cells. Our insights suggest that IL17A and IL17F share their pro-fibrotic function in the context of liver fibrosis, and moreover, dual blockade of IL17A and IL17F by anti-IL17RA Ab would be a promising strategy for the management of liver fibrosis.

Deregulated JNK signaling enhances apoptosis during hyperthermia

PURPOSE

c-Jun N-terminal kinases (JNKs) comprise a subfamily of mitogen-activated protein kinases (MAPKs). The JNK group is known to be activated by a variety of stimuli. However, the molecular mechanism underlying heat-induced JNK activation is largely unknown. The aim of this study was to clarify how JNK activity is stimulated by heat.

METHODS AND MATERIALS

The expression levels of various MAPK members in HeLa cells, with or without hyperthermia treatment, were evaluated via western blotting. The kinase activity of MAPK members was assessed through in vitro kinase assays. Cell death was assessed in the absence or presence of siRNAs targeting MAPK-related members.

RESULTS

Hyperthermia decreased the levels of MAP3Ks, such as ASK1 and MLK3 which are JNK kinase kinase members, but not those of the downstream MAP2K/SEK1 and MAPK/JNK. Despite the reduced or transient phosphorylation of ASK1, MLK3, or SEK1, downstream JNK was phosphorylated in a temperature-dependent manner. In vitro kinase assays demonstrated that heat did not directly stimulate SEK1 or JNK. However, the expression levels of DUSP16, a JNK phosphatase, were decreased upon hyperthermia treatment. DUSP16 knockdown enhanced the heat-induced activation of ASK1-SEK1-JNK pathway and apoptosis.

CONCLUSION

JNK was activated in a temperature-dependent manner despite reduced or transient phosphorylation of the upstream MAP3K and MAP2K. Hyperthermia-induced degradation of DUSP16 may induce activation of the ASK1-SEK1-JNK pathway and subsequent apoptosis.

Reliability, validity, and sensitivity of the Japanese version of the University of California Los Angeles scleroderma clinical trial consortium gastrointestinal tract instrument: Application to efficacy assessment of intravenous immunoglobulin administration

This study aimed to develop and assess the reliability, validity, and sensitivity of the Japanese version of the University of California Los Angeles Scleroderma Clinical Trial Consortium gastrointestinal tract (GIT) Instrument 2.0 (the GIT score), as an evaluation tool for GIT symptoms in systemic sclerosis (SSc). The Japanese version of the GIT score was constructed using the forward-backward method. The reliability and validity of this instrument were evaluated in a cohort of 38 SSc patients. Correlation analysis was conducted to assess the relationship between the GIT score and existing patient-reported outcome measures. Additionally, the sensitivity of the GIT score was examined by comparing GIT scores before and after intravenous immunoglobulin (IVIG) administration in 10 SSc-myositis overlap patients, as IVIG has recently demonstrated effectiveness in alleviating GIT symptoms of SSc. As a result, the Japanese version of the GIT score exhibited internal consistency and a significant association with the Frequency Scale for the Symptoms of Gastroesophageal Reflux Disease. Furthermore, the total GIT score, as well as the reflux and distention/bloating subscales, displayed moderate correlations with the EuroQol 5 dimensions (EQ-5D) pain/discomfort subscale and the Short Form-36 body pain subscale. Notably, following IVIG treatment, there was a statistically significant reduction in the total GIT score and multiple subscales. We first validated the Japanese version of the GIT score in Japanese SSc patients in real-world clinical settings. This instrument holds promise for application in future clinical trials involving this patient population.

Cannabinoids for the treatment of autoimmune and inflammatory skin diseases: A systematic review

In recent years, the medical use of cannabinoids has attracted growing attention worldwide. In particular, anti-inflammatory properties of cannabinoids led to their emergence as potential therapeutic options for autoimmune and inflammatory disorders. Recent studies have also shown that cannabinoid receptors are widely expressed and have endogenous ligands in the skin, suggesting that the skin has its own endocannabinoid system. The aim of this review is to discuss the potential therapeutic effects of cannabinoids in autoimmune and inflammatory skin diseases. Following an overview of cannabinoids and the endocannabinoid system, we describe the cellular and molecular mechanisms of cannabinoids in skin health and disease. We then review the clinical studies of cannabinoids in autoimmune and inflammatory skin diseases including systemic sclerosis (SSc), dermatomyositis (DM), psoriasis (Pso) and atopic dermatitis (AD). A primary literature search was conducted in July 2023, using PubMed and Web of Science. A total of 15 articles were included after excluding reviews, non-human studies and in vitro studies from 389 non-duplicated articles. Available evidence suggests that cannabinoids may be beneficial for SSc, DM, Pso and AD. However, further studies, ideally randomized controlled trials, are needed to further evaluate the use of cannabinoids in autoimmune and inflammatory skin diseases.

The role of B cells in systemic sclerosis

Systemic sclerosis (SSc) is a rare and refractory systemic disease characterized by fibrosis and vasculopathy in the presence of autoimmune abnormalities. While the exact cause of SSc is incompletely understood, the specific autoantibodies identified in SSc are closely linked to disease severity and prognosis, indicating a significant role of autoimmune abnormalities in the pathogenesis of SSc. Although the direct pathogenic mechanisms of autoantibodies in SSc are not fully elucidated, numerous prior investigations have demonstrated the involvement of B cells in the pathogenesis of SSc through various mechanisms. Additionally, several clinical trials have explored the efficacy of B-cell depletion therapy for SSc, with many reporting positive outcomes. However, the role of B cells in SSc pathogenesis is multifaceted, as they can both promote inflammation and exert inhibitory functions. This article provides an overview of the involvement of B cells in SSc development, incorporating the latest research findings.

Optimal treatments and outcome measures of palmoplantar pustulosis: A systematic review and network meta-analysis-based comparison of treatment efficacy

Few studies have made direct comparisons between treatments for palmoplantar pustulosis (PPP); therefore, it is difficult to select the best treatment for each patient. To determine the best therapy and to compare reported measures of efficacy in clinical trials of systemic treatments for PPP in this systematic review and network meta-analysis. Six databases were used to perform database search on 10 July 2022. Randomized controlled trials (RCTs) were identified through a systematic literature search. The titles and abstracts of articles were initially screened for inclusion by two authors independently using our predetermined criteria. The full texts of selected articles were then independently assessed for inclusion in a blinded fashion. Disagreement between the authors was resolved by consensus. Data were abstracted in duplicate. Random-effects model was accepted to perform network meta-analysis. Assessed Grading of Recommendations Assessment, Development and Evaluation certainty of evidence were performed according to the PRISMA guidelines. The analysis was completed in July 2022. The primary outcome was the change of PPP Area and Severity Index (PPPASI) from baseline and the secondary outcome was the achievement of PPPASI-50 response. Seven RCTs with 567 patients were included. Guselkumab 100 mg was the one with the highest probability of reaching the proposed outcomes (mean difference [MD], -8.00; 95% confidence interval [CI], 4.88-11.11), while the achievement of PPPASI-50 response did not show a significant difference (odds ratio [OR], 3.79; 95% CI, 0.51-28.37). Guselkumab 200 mg was next to 100 mg of reaching the proposed outcomes (MD, -4.71; 95% CI, 2.12-7.30), while the achievement of PPPASI-50 response did not show a significant difference (OR, 2.34; 95% CI, 0.48-11.43). Network meta-analysis showed guselkumab 100 mg was the treatment with the highest probability of reaching both PPPASI and PPPASI-50 outcomes. Absolute PPPASI may be more appropriate as an outcome than PPPASI-50.

Autoantibodies to nuclear valosin-containing protein-like protein: systemic sclerosis-specific antibodies revealed by in vitro human proteome

OBJECTIVES

To identify and characterize undescribed systemic sclerosis (SSc)-specific autoantibodies targeting nucleolar antigens and to assess their clinical significance.

METHODS

We conducted proteome-wide autoantibody screening (PWAS) against serum samples from SSc patients with nucleolar patterned anti-nuclear antibodies (NUC-ANAs) of specific antibodies (Abs) unknown, utilizing wet protein arrays fabricated from in vitro human proteome. Controls included SSc patients with already-known SSc-specific autoantibodies, patients with other connective tissue diseases, and healthy subjects. The selection of nucleolar antigens was performed by database search in the Human Protein Atlas. The Presence of autoantibodies was certified by immunoblots and immunoprecipitations. Indirect immunofluorescence assays on HEp-2 cells were also conducted. Clinical assessment was conducted by retrospective review of electric medical records.

RESULTS

PWAS identified three candidate autoantibodies, including anti-nuclear valosin-containing protein-like (NVL) Ab. Additional measurements in disease controls revealed that only anti-NVL Abs are exclusively detected in SSc. Detection of anti-NVL Abs was reproduced by conventional assays such as immunoblotting and immunoprecipitation. Indirect immunofluorescence assays demonstrated homogeneous nucleolar patterns. Anti-NVL Ab-positive cases were characterized by significantly low prevalence of diffuse skin sclerosis and interstitial lung disease, compared with SSc cases with NUC-ANAs other than anti-NVL Abs, such as anti-U3-RNP and anti-Th/To Abs.

CONCLUSION

Anti-NVL Ab is an SSc-specific autoantibody associated with a unique combination of clinical features, including limited skin sclerosis and lack of lung involvement.

Utility of nailfold capillary assessment for predicting pustulotic arthro-osteitis in palmoplantar pustulosis based on a prospective cohort study

BACKGROUND

Pustulotic arthro-osteitis (PAO) is 1 of the most serious comorbidities associated with palmoplantar pustulosis (PPP). Risk factors of PAO development are not well-known.

OBJECTIVE

To evaluate the clinical significance of nailfold capillary (NFC) changes in patients with PPP.

METHODS

We conducted a prospective cohort study in a population of 102 PPP patients. Correlations of NFC abnormalities, including nailfold bleeding and enlarged capillaries, with the prevalence of PAO, the incidence of new PAO, and serum levels of cytokines were analyzed.

RESULTS

Detailed examination revealed that of 102 PPP patients, 52 without PAO and 50 with PAO. Both nailfold bleeding and enlarged capillaries were significantly more frequent in patients with PAO (50.0% vs 92.0%, P < .0001; 50.0% vs 94.0%, P < .0001). In addition, PPP patients without PAO were prospectively observed before they developed PAO (mean 28 months [1-52 months]). Multivariate analysis suggested that these NFC abnormalities were predictors of PAO development (hazard ratio 3.37, 95% confidence interval 1.13-10.07; 3.37, 1.13-10.07) and guselkumab prevent PAO development (0.093, 0.012-0.76). The degree of NFC abnormalities correlated with the severity of PAO and serum cytokine levels.

LIMITATIONS

All participants were Japanese.

CONCLUSION

NFC abnormalities could be predictors of PAO in PPP patients, and their degree indicators of disease severity.

The optimal use of tildrakizumab in the elderly via improvement of Treg function and its preventive effect of psoriatic arthritis

Introduction

As a form of precision medicine, this study aimed to investigate the specific patient population that would derive the greatest benefit from tildrakizumab, as well as the mechanism of action and efficacy of tildrakizumab in reducing the occurrence of psoriatic arthritis (PsA).

Methods

To achieve this, a multi-center, prospective cohort study was conducted, involving a population of 246 psoriasis patients who had not received any systemic therapy or topical finger therapy between January 2020 and April 2023. Two independent clinicians, who were blinded to the study, analyzed nailfold capillary (NFC) abnormalities, such as nailfold bleeding (NFB) and enlarged capillaries, as well as the incidence of new PsA. Additionally, the factors that determined the response of psoriasis after seven months of tildrakizumab treatment were examined. The study also examined the quantity and role of regulatory T cells (Tregs) and T helper 17 cells both pre- and post-treatment.

Results

The severity of psoriasis, as measured by the Psoriasis Area and Severity Index (PASI), was found to be more pronounced in the tildrakizumab group (n=20) in comparison to the topical group (n=226). At 7 months after tildrakizumab treatment, multivariate analysis showed that those 65 years and older had a significantly better response to treatment in those achieved PASI clear or PASI 2 or less (Likelihood ratio (LR) 16.15, p<0.0001; LR 6. 16, p=0.01). Tildrakizumab improved the number and function of Tregs, which had been reduced by aging. Tildrakizumab demonstrated significant efficacy in improving various pathological factors associated with PsA. These factors include the reduction of NFB, enlargement of capillaries, and inhibition of PsA progression. The hazard ratio for progression to PsA was found to be 0.06 (95% confidence interval: 0.0007-0.46, p=0.007), indicating a substantial reduction in the risk of developing PsA.

Discussion

Tildrakizumab's effectiveness in improving skin lesions can be attributed to its ability to enhance the number and function of Tregs, which are known to decline with age. Furthermore, the drug's positive impact on NFB activity and capillary enlargement, both of which are recognized as risk factors for PsA, further contribute to its inhibitory effect on PsA progression.

The Autoantibody Array Assay: A Novel Autoantibody Detection Method

Systemic sclerosis (SSc) and dermatomyositis (DM) are autoimmune collagen diseases. Specific autoantibodies are known to be involved in their pathogeneses, each presenting with a different clinical manifestation. Although immunoprecipitation is the gold standard method for detecting autoantibodies, it is difficult to perform in all cases owing to the use of radioisotopes. In this study, we developed a new detection method for SSc and DM autoantibodies (A-cube) using cell-free protein synthesis and examined its validity. Proteins were synthesized using wheat germ cell-free protein synthesis. A total of 100 cases of SSc, 50 cases of DM, and 82 healthy controls were examined. The validity of the method was examined by a comparison with existing test results. Anti-centromere antibody, anti-topoisomerase I antibody, anti-RNA polymerase III antibody, anti-U1RNP anti-body, anti-Jo-1 antibody, anti-TIF1γ antibody, anti-Mi-2 antibody, and anti-ARS antibody were tested for. The results suggested that A-cube is comparable with existing testing methods or has a high sensitivity or specificity. In addition, there was a case in which the diagnosis was reconsidered using the A-cube. The quality of the A-cube was ensured, and its usefulness for a comprehensive analysis was demonstrated. The A-cube can therefore contribute to the clinical assessment and treatment of SSc and DM.

Comprehensive autoantibody profiling in systemic autoimmunity by a highly-sensitive multiplex protein array

Comprehensive autoantibody evaluation is essential for the management of autoimmune disorders. However, conventional methods suffer from poor sensitivity, low throughput, or limited availability. Here, using a proteome-wide human cDNA library, we developed a novel multiplex protein assay (autoantibody array assay; A-Cube) covering 65 antigens of 43 autoantibodies that are associated with systemic sclerosis (SSc) and polymyositis/dermatomyositis (PM/DM). The performance of A-Cube was validated against immunoprecipitation and established enzyme-linked immunosorbent assay. Further, through an evaluation of serum samples from 357 SSc and 172 PM/DM patients, A-Cube meticulously illustrated a diverse autoantibody landscape in these diseases. The wide coverage and high sensitivity of A-Cube also allowed the overlap and correlation analysis between multiple autoantibodies. Lastly, reviewing the cases with distinct autoantibody profiles by A-Cube underscored the importance of thorough autoantibody detection. Together, these data highlighted the utility of A-Cube as well as the clinical relevance of autoantibody profiles in SSc and PM/DM.

Utility of nailfold capillary assessment for predicting psoriatic arthritis based on a prospective observational cohort study

OBJECTIVES

PsA is one of the most serious comorbidities associated with psoriasis. While the early intervention in PsA is demanded, risk factors of PsA development are not well-known. This is the first prospective study to evaluate the clinical significance of nailfold capillary (NFC) changes in patients with psoriasis.

METHODS

We conducted a prospective cohort study in a population of 449 psoriasis patients who had not been treated with systemic therapy or topical finger therapy. NFCs were observed by dermoscopy and capillaroscopy, and the correlation of NFC abnormalities, including nailfold bleeding (NFB) and enlarged capillaries, with the prevalence of PsA, incidence of new PsA, and serum levels of TNF-a, IL-17A and IL-23 were analysed.

RESULTS

Detailed examination at the time of inclusion revealed that of 449 patients, 236 had Psoriasis vulgaris (PsV) and 213 had PsA. Both NFB and enlarged capillaries were significantly more frequent in patients with PsA (34.7% vs 84.5%, P < 0.0001; 25.4% vs 100%, P < 0.0001). In addition, PsV patients were prospectively observed before they developed PsA (mean 21 months, 95% CI 2, 77 months). Multivariate analysis suggested that the appearance of NFB and enlarged capillaries was a predictor of PsA development (HR 2.75, 95% CI 1.38, 5.47 and HR 4.49, 95% CI 2.25, 8.96, respectively). The degree of NFC abnormalities also correlated with the severity of PsA and serum cytokine levels.

CONCLUSIONS

NFC abnormalities were suggested to be a predictor of PsA in psoriasis patients, and at the same time, its degree could be an indicator of disease severity.

Long-term Outcomes After Rituximab Treatment for Patients With Systemic Sclerosis: Follow-up of the DESIRES Trial With a Focus on Serum Immunoglobulin Levels

Importance

Rituximab is emerging as a promising therapeutic option for systemic sclerosis (SSc), but its long-term outcomes and response markers are unknown.

Objective

To evaluate the long-term outcomes after rituximab treatment for SSc and identify potential response markers.

Design, Setting, and Participants

In this single-center cohort study, patients with SSc who continued to receive rituximab after the DESIRES trial were analyzed with a median follow-up of 96 weeks. Among the 43 patients who completed the DESIRES trial, 31 continued to receive rituximab, of which 29 with complete data were included in this study.

Exposures

Rituximab treatment.

Main Outcomes and Measures

A post hoc analysis of the clinical and laboratory data.

Results

In 29 patients with SSc (27 female [93%]; median [IQR] age, 48 [35-45] years), significant improvement in modified Rodnan skin score (MRSS) and percentage of predicted forced vital capacity (FVC%) were observed after 1 (median [IQR] change in MRSS, -7 [-8.5 to -4]; P < .001) and 3 (median [IQR] change in FVC% predicted, 1.85 [0.13-5.68]; P < .001) courses of rituximab, respectively, both of which were sustained during follow-up. High responders (MRSS improvement of ≥9; n = 16) experienced a greater decrease in serum levels of IgG (median [IQR] change in IgG, -125 [-207 to -83] vs 7 [-120 to 43]; P = .008) and IgA (median [IQR] change in IgA, -45 [-96 to -32] vs -11 [-20 to 3]; P < .001) compared with low responders (MRSS improvement of ≤8; n = 13). In particular, decrease in serum IgA levels significantly correlated with the improvement in MRSS (r = 0.64; P < .001). At the last follow-up, low IgM, low IgA, and low IgG was observed in 7, 1, and 1 patient, respectively, of which low IgM was associated with greater improvement in FVC% predicted (median [IQR] change in FVC% predicted, 7.2 [3.8-8.9] vs 3.6 [1.4-6.2]; P = .003).

Conclusions and Relevance

In this cohort study, rituximab treatment was associated with significantly improved skin and lung fibrosis in SSc in a long-term follow-up. Decrease in serum immunoglobulins was associated with greater clinical response.

The Role of Mammalian STK38 in DNA Damage Response and Targeting for Radio-Sensitization

Protein kinases, found in the nucleus and cytoplasm, play essential roles in a multitude of cellular processes, including cell division, proliferation, apoptosis, and signal transduction. STK38 is a member of the protein kinase A (PKA)/PKG/PKC family implicated in regulating cell division and morphogenesis in yeast and C. elegans. However, its function remained largely unknown in mammals. In recent years, advances in research on STK38 and the identification of its substrates has led to a better understanding of its function and role in mammals. This review discusses the structure, expression, and regulation of activity as a kinase, its role in the DNA damage response, cross-talk with other signaling pathways, and its application for radio-sensitization.

Significance of anti-transcobalamin receptor antibodies in cutaneous arteritis revealed by proteome-wide autoantibody screening

Cutaneous arteritis (CA) is a single-organ vasculitis that exclusively affects the small to medium-sized arteries of the skin. Diagnosis depends on a histological investigation with skin biopsy, which could be burdensome for both patients and clinicians. Moreover, the pathogenesis of CA remains unstudied, and treatment has not yet been established. Herein, we applied our proteome-wide autoantibody screening method to explore autoantibodies in the serum of CA patients. As a result, anti-transcobalamin receptor (TCblR) antibodies (Abs) were specifically detected in 24% of CA patients. Patients with positive anti-TCblR Abs were spared from peripheral neuropathy compared to those with negative anti-TCblR Abs, showing characteristics as CA confined to the skin. In addition, we revealed that anti-TCblR Abs trigger the autocrine loop of interleukin-6 mediated by tripartite motif-containing protein 21 in human endothelial cells and induce periarterial inflammation in murine skin. Furthermore, we demonstrated that methylcobalamin, a ligand of TCblR, ameliorates inflammation caused by anti-TCblR Abs both in vitro and in vivo. Collectively, our investigation unveils the pathologic significance of anti-TCblR Abs in CA and their potential as a diagnostic marker and a pathophysiology-oriented therapeutic target.

Involvement of the Thalamus, Hippocampus, and Brainstem in Hypsarrhythmia of West Syndrome: Simultaneous Recordings of Electroencephalography and fMRI Study

BACKGROUND AND PURPOSE

West syndrome is a developmental and epileptic encephalopathy characterized by epileptic spasms, neurodevelopmental regression, and a specific EEG pattern called hypsarrhythmia. Our aim was to investigate the brain activities related to hypsarrhythmia at onset and focal epileptiform discharges in the remote period in children with West syndrome using simultaneous electroencephalography and fMRI recordings.

MATERIALS AND METHODS

Fourteen children with West syndrome underwent simultaneous electroencephalography and fMRI at the onset of West syndrome. Statistically significant blood oxygen level-dependent responses related to hypsarrhythmia were analyzed using an event-related design of 4 hemodynamic response functions with peaks at 3, 5, 7, and 9 seconds after the onset of each event. Six of 14 children had focal epileptiform discharges after treatment and underwent simultaneous electroencephalography and fMRI from 12 to 25 months of age.

RESULTS

At onset, positive blood oxygen level-dependent responses were seen in the brainstem (14/14 patients), thalami (13/14), basal ganglia (13/14), and hippocampi (13/14), in addition to multiple cerebral cortices. Group analysis using hemodynamic response functions with peaks at 3, 5, and 7 seconds showed positive blood oxygen level-dependent responses in the brainstem, thalamus, and hippocampus, while positive blood oxygen level-dependent responses in multiple cerebral cortices were seen using hemodynamic response functions with peaks at 5 and 7 seconds. In the remote period, 3 of 6 children had focal epileptiform discharge-related positive blood oxygen level-dependent responses in the thalamus, hippocampus, and brainstem.

CONCLUSIONS

Positive blood oxygen level-dependent responses with hypsarrhythmia appeared in the brainstem, thalamus, and hippocampus on earlier hemodynamic response functions than the cerebral cortices, suggesting the propagation of epileptogenic activities from the deep brain structures to the neocortices. Activation of the hippocampus, thalamus, and brainstem was still seen in half of the patients with focal epileptiform discharges after adrenocorticotropic hormone therapy.

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.

Involvement of B cells in the development of systemic sclerosis

Systemic sclerosis (SSc) is a rare intractable systemic disease that causes fibrosis and vasculopathy against a background of autoimmune abnormalities. Although the etiology is not yet fully understood, the type of autoantibodies detected in SSc is closely associated with disease severity and prognosis, supporting that those autoimmune abnormalities play an important role in the pathogenesis of SSc. Although the direct pathogenicity of autoantibodies found in SSc is unknown, many previous studies have shown that B cells are involved in the development of SSc through a variety of functions. Furthermore, a number of clinical studies have been conducted in which B-cell depletion therapy has been tried for SSc, and many of these studies have found B-cell depletion therapy to be effective for SSc. However, the involvement of B cells in pathogenesis is complex, as they not only promote inflammation but also play an inhibitory role. This article outlines the role of B cells in the development of SSc, including the latest research.

Pharmacotherapy of Itch-Antihistamines and Histamine Receptors as G Protein-Coupled Receptors

Itching can decrease quality of life and exacerbate skin symptoms due to scratching. Itching not only contributes to disease progression but also triggers complications such as skin infections and eye symptoms. Therefore, controlling itching is very important in therapeutic management. In addition to the well-known histamine, IL-31, IL-4 and IL-13 have recently been reported as factors that induce itching. Itching may also be caused by factors other than these histamines. However, we do not know the extent to which these factors are involved in each disease. In addition, the degree of involvement is likely to vary among individuals. To date, antihistamines have been widely used to treat itching and are often effective, suggesting that histamine is more or less involved in itchy diseases. This review discusses the ligand-receptor perspective and describes the dynamics of G protein-coupled receptors, their role as biased agonists, their role as inverse agonists, proactive antihistamine therapy, and drug selection with consideration of impaired performance and anti-PAF effects.

POS0857 PHARMACOKINETICS, SAFETY, AND EFFICACY OF SUBCUTANEOUS BRODALUMAB FOR SYSTEMIC SCLEROSIS WITH MODERATE-TO-SEVERE SKIN THICKENING: A SINGLE-ARM, OPEN-LABEL, MULTI-DOSE, PHASE 1 TRIAL

Background

Systemic sclerosis (SSc) is a rare autoimmune disease that causes fibrosis of the skin and internal organs. The mechanism of SSc pathogenesis and progression is not clear yet and SSc is therefore a disease with high unmet medical need. Though recent evidence reveals that interleukin-17 (IL-17) may play an essential role in the pathogenesis of multiple autoimmune inflammatory diseases, the role of IL-17 in SSc has not been established.

Objectives

This trial assessed the pharmacokinetics (PK), safety, and efficacy of multiple subcutaneous doses of brodalumab, a fully human anti–IL-17RA monoclonal antibody that inhibits the activity of IL-17A, IL-17C, IL-17F, IL-17A/F, and IL-17E (also called IL 25), in Japanese SSc patients with moderate-to-severe skin thickening.

Methods

In this trial, eligible patients (the modified Rodnan skin score (mRSS):10-29, present with the first symptoms of SSc other than Raynaud’s phenomenon within 60 months at enrolment) were enrolled and received subcutaneous brodalumab 210 mg every 2 weeks (Q2W) during the 52-week period. Primary endpoints were PK and safety. Secondary endpoints included change from baseline in mRSS and Composite Response Index in SSc (CRISS) score. Exploratory endpoints included lymphocyte subset testing.

Results

Eligible 8 patients were enrolled. Mean (SD) age was 53.6 (10.6) years. All patients had diffuse cutaneous SSc, total mRSS was 23.1 (5.1) and disease duration was 2.2 (1.9) years. Mean (SD) serum brodalumab trough concentration increased to 21.8 (16.7) μg/mL at week 2 and remained almost constant at week 52. Drug-related treatment-emergent adverse events were observed in three patients: oral candidiasis (n=3), vulvovaginal candidiasis (n=1), and arthralgia (n=1). A rapid decrease in mRSS was observed as early as week 4 (-1.3 vs baseline, p<0.005), which continued until week 52 (-10.125 vs baseline, p<0.0001). Brodalumab reduced dermal thickness of the lesional skin consistent with the decrease in mRSS. All patients achieved a CRISS score ≥0.6 at week 24, which continued until week 52. Brodalumab induced Th17/Treg balance to Treg dominance over 52 weeks (vs baseline, p<0.05). The rapid decrease in the number of immunoglobulin G class-switched memory B cells and plasmablasts (vs baseline, p<0.01) was accompanied by an increase in the number of transitional B cells (vs baseline, p<0.05) by week 52.

Conclusion

Brodalumab demonstrated a rapid and sustained decrease in mRSS over 52 weeks in Japanese SSc patients with moderate-to-severe skin thickening, which could be attributed to its direct effects on fibroblasts and indirect effects via impacts on B and T cell subsets.

References

None.

Mean Change from Baseline in mRSS and Mean mRSS over the 52-week follow up. (Mean +/- SD)

Table 1.

Other efficacy endpoints

BaselineWeek 12Week 24Week 52Number of finger digital ulcersmean1.91.610.3SD2.32.31.60.7P valueNA0.170.040.04Percent predicted FVC, %mean86.787.185.985.3SD13.114.41414.1P valueNA0.70.450.3Percent predicted DLCO, %mean92.689.388.989.1SD22.522.919.422.2P valueNA0.060.090.18PGA, mmmean48.647.943.445.8SD23.925.72624.6P valueNA0.660.040.71CGA, mmmean68.953.539.530.3SD23.91916.713.9P valueNA<.001<.001<.001J-HAQ-DI scoremean0.220.170.130.19SD0.490.440.350.35P valueNA0.40.170.7

Acknowledgements

We gratefully acknowledge the patients and their families for their participation in this trial. We thank all the investigators who had a part in this study for their contribution.

Disclosure of Interests

Takemichi Fukasawa: None declared, Ayumi Yoshizaki: None declared, Hisashi Kagebayashi Employee of: Kyowa Kirin Co., Ltd., Shinichi Sato Consultant of: Kyowa Kirin Co., Ltd.

POS0881 EFFICACY AND SAFETY OF SUBCUTANEOUS BRODALUMAB, A FULLY HUMAN ANTI–IL-17RA MONOCLONAL ANTIBODY, FOR SYSTEMIC SCLEROSIS WITH MODERATE-TO-SEVERE SKIN THICKENING: A MULTICENTER, RANDOMIZED, PLACEBO-CONTROLLED, DOUBLE-BLIND PHASE 3 STUDY

Background

Systemic sclerosis (SSc) is a rare chronic connective tissue disease of unknown cause characterized by autoimmunity, vasculopathy, and fibrosis of the skin and various internal organs. It is considered to constitute an area of high unmet medical needed due to limited treatment options and no sufficiently effective treatments. Our previous study (the single-arm, open-label, phase 1 study) indicated that brodalumab, a fully human anti-IL-17RA monoclonal antibody, had a potential to improve skin sclerosis in SSc patients, which could be attributed to its direct effects on fibroblasts and indirect effects via impacts on both B cell and T cell subsets (NCT04368403).

Objectives

To evaluate the efficacy and safety of brodalumab for SSc patients with moderate-to-severe skin thickening in a phase 3, multicenter, randomized, placebo-controlled, double-blind study.

Methods

Eligible patients (modified Rodnan skin score (mRSS):10-29, present with the first symptoms of SSc other than Raynaud’s phenomenon within 60 months at enrolment) were randomized (1:1) to receive subcutaneous brodalumab 210 mg every 2 weeks (Q2W) or placebo during the 52-week placebo-controlled period. Primary endpoint was change from baseline of mRSS at week 24. Patients with an increase in mRSS of ≥5 points and ≥20% from baseline at or after week 24 were permitted to receive open-label treatment with brodalumab.

Results

A total of 100 patients was randomized to the brodalumab group (n=50) or the placebo group (n=50). Forty-six and 45 patients had diffuse cutaneous SSc in the brodalumab and placebo groups, respectively. In both groups, 47 patients completed the 24-week follow-up. Forty-four and 43 patients in the brodalumab and placebo groups completed the 52-week follow-up, respectively. At or after week 24, 38 patients (placebo, n=37; brodalumab, n=1) were switched to the active drug. Brodalumab achieved the primary endpoint (treatment difference of least square mean: −21.2 [95% CI -23.9, 18.5]; P<0.0001), and demonstrated a rapid, sustained reduction in mRSS over 52 weeks. Brodalumab also elevated the composite response index in SSc (CRISS) score, suppressed new development of digital ulcers, deterioration of respiratory function, and progression of lung lesions. Moreover, treatment of brodalumab improved the frequency scale for the symptoms of gastroesophageal reflux disease (FSSG) score, global assessment by physician (CGA) and patient (PGA), the Japanese version of the health assessment questionnaire-disability index (J-HAQ-DI) score, and the functional assessment of chronic illness therapy-fatigue (FACIT-Fatigue) score. The safety profile did not differ from that previously observed in other diseases such as psoriasis and ankylosing spondylitis and non-radiographic axial spondyloarthritis.

Conclusion

Brodalumab demonstrated a rapid, sustained, and significant decrease in skin sclerosis. Moreover, the outcome of brodalumab treatment suggested its therapeutic effects on lung/respiratory functions, digital ulcers, the symptoms of gastroesophageal reflux disease, and QOL without any noteworthy safety concerns.

References

None.

Figure 1.

mRSS over the 24-week follow up. (Mean +/- SD)

Table 1.

Secondary endpoints at week 24

BrodalumabPlacebomeanSDmeanSDDifference95% CIP valueMedian CRISS score1NA0NANANA<0.0001Cumulative new digital ulcer count0.10.285.06.5-4.9[-6.8, -3.0]<0.0001Percent predicted FVC*, %0.194.43-5.047.395.23[2.73, 7.72]<0.0001Percent predicted DLCO*, %-0.596.808-5.966.7735.38[2.60, 8.16]0.00022FSSG score*-2.35.9910.111.16-12.4[-16.1, -8.7]<0.0001PGA*, mm-6.821.9426.124.17-32.9[-42.3, -23.4]<0.0001CGA*, mm-34.014.6913.823.05-63.4[-71.9, -54.9]<0.0001J-HAQ-DI*-0.0450.2340.6980.7065-0.743[-0.958, -0.527]<0.0001FACIT-Fatigue subscale score*2.2346.869-9.40414.765811.638[6.920, 16.356]<0.0001

*Change from baseline

Acknowledgements

We gratefully acknowledge the patients and their families for their participation in this trial. We thank all the investigators who had a part in this study for their contribution.

Disclosure of Interests

Takemichi Fukasawa: None declared, Ayumi Yoshizaki: None declared, Hisashi Kagebayashi Employee of: Kyowa Kirin Co., Ltd., Shinichi Sato Consultant of: Kyowa Kirin Co., Ltd.

Autoantibody Landscape Revealed by Wet Protein Array: Sum of Autoantibody Levels Reflects Disease Status

Autoantibodies are found in various pathological conditions such as autoimmune diseases, infectious diseases, and malignant tumors. However their clinical implications have not yet been fully elucidated. Herein, we conducted proteome-wide autoantibody screening and quantification with wet protein arrays consisting of proteins synthesized from proteome-wide human cDNA library (HuPEX) maintaining their three-dimensional structure. A total of 565 autoantibodies were identified from the sera of three representative inflammatory disorders (systemic sclerosis, psoriasis, and cutaneous arteritis). Each autoantibody level either positively or negatively correlated with serum levels of C-reactive protein, the best-recognized indicator of inflammation. In particular, we discovered total levels of a subset of autoantibodies correlates with the severity of clinical symptoms. From the sera of malignant melanoma, 488 autoantibodies were detected. Notably, patients with metastases had increased overall autoantibody production compared to those with tumors limiting to the primary site. Collectively, proteome-wide screening of autoantibodies using the in vitro proteome can reveal the "autoantibody landscape" of human subjects and may provide novel clinical biomarkers.

Serum C-X-C Chemokine Ligand 1 Levels in Patients with Systemic Sclerosis: Relationship of Clinical and Laboratory Observations to Anti-CD20 Monoclonal Antibody Administration

Objectives: To determine whether C-X-C chemokine ligand 1 (CXCL1), which is a potent neutrophil chemoattractant and activator that plays important role in inflammation, is elevated in patients with systemic sclerosis (SSc) and whether it is associated with the clinical features and disease activity of patients with SSc. In addition, to determine whether the changes in serum CXCL1 levels before and after treatment correlate with changes in disease activity in SSc patients who received an anti-CD20 monoclonal antibody drug. Patients and method: We examined patient serum collected in the DesiReS trial, which was a double-blind, parallel-group, randomized, placebo-controlled, multicenter, phase II clinical trial. In the trial, patients were randomly allocated to the drug or placebo group and received 375 mg/m2 of an anti-CD20 antibody, rituximab, or placebo once a week for four weeks. We obtained serum samples from 47 patients administered at our hospital, including 3 males and 44 females, the median age of 48 years, range 27−71 years, with 42 diffuse cutaneous SSc and 5 with limited cutaneous SSc. Serum CXCL1 levels were measured using multiplex immunoassay in patient serum before and 24 weeks after administration and also in serum from 33 healthy controls. Results: Serum CXCL1 levels were significantly higher in SSc patients (mean 25.70 ng/mL; 95% confidence interval (CI) 18.35−33.05 ng/mL) than in the healthy controls (15.61 ng/mL; 95% CI 9.73−21.51 ng/mL). In addition, SSc patients with elevated CXCL1 levels had a significantly higher percentage of area occupied with interstitial shadows (p < 0.05), increased serum levels of surfactant protein (SP)-A (p < 0.05), SP-D (p < 0.05), Krebs von den Lungen-6 (p < 0.01), and C-reactive protein (p < 0.05) compared to those with normal levels. Furthermore, defining Δ as the value after rituximab administration minus the value before rituximab administration, baseline serum CXCL1 levels correlated with Δ percent predicted diffusing capacity for carbon monoxide (p < 0.01). In addition, ΔCXCL1 correlated with ΔSP-A (p < 0.05). Similarly, serum CXCL1 levels after rituximab administration correlated with percent predicted forced vital capacity (p < 0.05) and serum SP-D levels (p < 0.05) after rituximab. Conclusions: Our results suggest that serum CXCL1 is associated with the disease activity of SSc-ILD, and high serum CXCL1 levels are one of the predictors of improvement in SSc-ILD with rituximab.

Decrease in MAP3Ks expression enhances the cell death caused by hyperthermia

PURPOSE

Hyperthermia is a promising anticancer treatment modality. However, the molecular mechanism underlying the thermal sensitivity of tumor cells is largely unknown. The aim of this study was to clarify how biochemical changes triggered by heat stimulate antitumor activity.

METHODS AND MATERIALS

The expression levels of various MAPK members in HeLa cells with or without hyperthermia were evaluated by western blotting and RT-PCR. The intracellular Ca²⁺ concentration [Ca²⁺]_i was monitored by digital imaging using CaTM-2 AM. An in vitro cleavage assay was used to determine whether calcium-dependent protease calpain cleaves MAPK components. Cell proliferation and clonogenicity were assessed in the absence or presence of siRNAs targeting MAPK members.

RESULTS

Hyperthermia decreased the levels of MAP3K TAK1, RAF1 and MEKK2 but not of the downstream MAP2K and MAPK members. The hyperthermia-induced degradation of TAK1 and MEKK2 was rescued by either the proteasome inhibitor MG132 or the calpain inhibitor ALLN; however, RAF1 was not affected by the inhibitors. Heat induced down regulation of RAF1. Hyperthermia increased [Ca²⁺]_i and calpain I expression. The calcium ionophore A23187 decreased TAK1 and MEKK2 levels. An in vitro cleavage assay demonstrated that TAK1 and MEKK2 are calpain I substrates. Knockdown of TAK1, RAF1 and MEKK2 suppressed cell proliferation and clonogenicity.

CONCLUSIONS

Hyperthermia decreased the levels of MAP3K TAK1, RAF1 and MEKK2, without reduction of the downstream components in the MAP3K-MAP2K-MAPK cascade, by a calpain-dependent degradation pathway or transcriptional regulation. TAK1, RAF1 and/or MEKK2 play crucial roles in cell proliferation and clonogenicity and are potential molecular targets for hyperthermia.

Increased Red Blood Cell Distribution Width in the First Year after Diagnosis Predicts Worsening of Systemic Sclerosis-Associated Interstitial Lung Disease at 5 Years: A Pilot Study

The course of systemic sclerosis-associated interstitial lung disease (SSc-ILD) varies among individuals. Red blood cell distribution width (RDW) has been reported to be a predictor of idiopathic pulmonary fibrosis. However, there are no studies on the relationship between RDW and SSc-ILD. We conducted a retrospective study of 28 patients who were diagnosed with SSc-ILD on their first visit to our hospital and were followed-up for 5 years. The correlation between the changes in RDW, KL-6, and SP-D (ΔRDW, ΔKL-6, ΔSP-D) and the changes in percent-predicted forced lung volume and % carbon monoxide diffusion (Δ%FVC, Δ%DLco) was investigated. ΔRDW at 1 year after diagnosis was significantly inversely correlated with Δ%FVC at 5 years after diagnosis (r = -0.51, p < 0.001) and Δ%DLco at 5 years after diagnosis (r = -0.47, p < 0.001), whereas ΔKL-6 and ΔSP-D at 1 year were not correlated with Δ%FVC or Δ%DLco at 5 years. In the group of SSc-ILD patients with RDW increase in the first year after diagnosis, %FVC and %DLco were significantly lower than baseline at 3-, 4-, and 5-year assessments. In the group of patients without RDW increase in the first year, %FVC and %DLco did not decrease during the follow-up period. In conclusion, the changes in RDW in the first year after diagnosis may be useful surrogate markers to predict the long-term course of SSc-ILD.

Single-cell-level protein analysis revealing the roles of autoantigen-reactive B lymphocytes in autoimmune disease and the murine model

Despite antigen affinity of B cells varying from cell to cell, functional analyses of antigen-reactive B cells on individual B cells are missing due to technical difficulties. Especially in the field of autoimmune diseases, promising pathogenic B cells have not been adequately studied to date because of its rarity. In this study, functions of autoantigen-reactive B cells in autoimmune disease were analyzed at the single-cell level. Since topoisomerase I is a distinct autoantigen, we targeted systemic sclerosis as autoimmune disease. Decreased and increased affinities for topoisomerase I of topoisomerase I-reactive B cells led to anti-inflammatory and pro-inflammatory cytokine production associated with the inhibition and development of fibrosis, which is the major symptom of systemic sclerosis. Furthermore, inhibition of pro-inflammatory cytokine production and increased affinity of topoisomerase I-reactive B cells suppressed fibrosis. These results indicate that autoantigen-reactive B cells contribute to the disease manifestations in autoimmune disease through their antigen affinity.

Percentage of residual B cells after 2 weeks of rituximab treatment predicts the improvement of systemic sclerosis-associated interstitial lung disease

The benefit of rituximab (RTX) for systemic sclerosis-associated interstitial lung disease (SSc-ILD) has been shown in previous clinical trials. However, predictors of RTX efficacy have not been clarified. We investigated whether B-cell responsiveness to RTX is related to therapeutic effect. Ten SSc-ILD patients treated with RTX in an independent clinical trial (Japan Registry of Clinical Trials, jRCTs031180373) were included in this analysis. Peripheral B-cell counts were examined retrospectively before RTX administration (baseline) and at 2, 4, 12, and 24 weeks after the first RTX administration, along with percent-predicted forced vital capacity (%FVC) before and 24 weeks after RTX treatment. Relative to baseline, the percentage of residual peripheral blood B cells at 2 weeks after RTX was negatively correlated with the %FVC improvement at the 24-week assessment (r = -0.41, p = 0.04). In the subgroup with less than 5% B-cell persistence at week 2, %FVC at the 24-week assessment was significantly improved compared to baseline (p = 0.02). In another subgroup with more than 5% residual B cells, %FVC was not significantly different after 24 weeks compared to baseline (p = 0.41). In conclusion, the removal rate of B cells after 2 weeks of RTX treatment may be a useful surrogate marker of subsequent SSc-ILD improvement.

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.

B cell depletion inhibits fibrosis via suppressing pro-fibrotic macrophage differentiation in a mouse model of systemic sclerosis

OBJECTIVE

We investigated the effect of B cell depletion on fibrosis in systemic sclerosis (SSc) and its mechanism of action.

METHODS

Bleomycin-induced SSc (BLM-SSc) model mice were treated with anti-CD20 antibody, and skin and lung fibrosis was evaluated histopathologically. T cells and macrophages were co-cultured with B cells, and the effect of B cells on their differentiation was assessed by flow cytometry. We also co-cultured B cells and monocytes from SSc patients and analyzed the correlation between fibrosis and pro-fibrotic macrophage induction by B cells.

RESULTS

B cell depletion inhibited fibrosis in BLM-SSc mice. B cells from BLM-SSc mice increased pro-inflammatory cytokine producing T cells in co-culture. In BLM-SSc mice, B cell depletion before BLM treatment (pre-depletion) inhibited fibrosis more strongly than B cell depletion after BLM treatment (post-depletion). However, the frequencies of pro-inflammatory T cells were lower in the post-depletion group than in the pre-depletion group. This discrepancy suggests that the effect of B cell depletion on fibrosis cannot be explained by its effect on T cell differentiation. On the other hand, pro-fibrotic macrophages were markedly decreased in the pre-depletion group than in the post-depletion group. Furthermore, B cells from BLM-SSc mice increased pro-fibrotic macrophage differentiation in co-culture. In SSc patients, the extent of pro-fibrotic macrophage induction by B cells correlated with the severity of fibrosis.

CONCLUSION

These findings suggest that B cell depletion inhibits tissue fibrosis via suppressing pro-fibrotic macrophage differentiation in BLM-SSc mice, providing a new rationale for B cell depletion therapy in SSc.

Development of a prediction model of treatment response in patients with cutaneous arteritis: Insights from a cohort of 33 patients

Cutaneous arteritis (CA) is necrotizing vasculitis invading the small- to medium-sized arteries of the skin. The majority of patients can be favorably managed by low- to medium-dose systemic corticosteroids (prednisolone, <0.5 mg/kg/day) or other oral medications such as non-steroidal anti-inflammatory drugs, dapsone, and azathioprine. Meanwhile, some patients require more intensive therapy including high-dose systemic corticosteroids (prednisolone, ≥0.5 mg/kg/day), i.v. immunoglobulin, and i.v. cyclophosphamide therapy. Although predicting such treatment response among CA patients is critical in clinical decision-making, prediction rules have not yet been established. Herein, we retrospectively reviewed 33 patients regularly visiting our clinic to reveal predictive factors of their treatment response. Clinical data were collected from electronic medical records. Association between each factor and treatment response was examined by logistic regression analysis. Progression-free time was calculated by Kaplan-Meier's method and analyzed by log-rank test and Cox progression hazard model. Potential predictive factors were selected, given 1 point for each, and integrated into a classification model. Discrimination of the model was examined by the receiver operating characteristic (ROC) curve analysis. In total, 33 CA patients were enrolled in our study. Of these, 11 patients required intensive therapy, classified as treatment non-responders. Logistic analyses revealed that treatment response was significantly associated with male sex, presence of skin ulcers, and elevated serum levels of C-reactive protein at the initial work-up. Kaplan-Meier analyses also demonstrated that those factors are predictive of progression-free time. The area under the ROC curve of our classification model was 0.92 (95% confidence interval, 0.83-1.00), which classified non-responders from the others with a sensitivity of 90.9% and specificity of 81.8% at the cut-off point of 2 or more. Collectively, treatment response of CA could be predictable by a combination of sex, presence of skin ulcers, and serum levels of C-reactive protein.

Serum Calponin 3 Levels in Patients with Systemic Sclerosis: Possible Association with Skin Sclerosis and Arthralgia

Systemic sclerosis (SSc) is a connective tissue disease characterized by tissue fibrosis and vasculopathy in various organs with a background of inflammation initiated by autoimmune abnormalities. Calponin 3 plays a role in the cell motility and contractibility of fibroblasts during wound healing in the skin. We aimed to evaluate serum calponin 3 levels in SSc patients and their association with clinical manifestations of SSc. Serum samples were collected from 68 patients with SSc and 20 healthy controls. Serum calponin 3 levels were examined using enzyme-linked immunosorbent assay kits, and their association with clinical features of SSc was statistically analyzed. The upper limit of the 95% confidence interval of serum calponin 3 levels in healthy controls was utilized as the cut-off value when dividing SSc patients into the elevated and normal groups. Serum calponin 3 levels were significantly higher in SSc patients than in healthy controls (mean (95% confidence interval), 15.38 (14.66–16.11) vs. 13.56 (12.75–14.38) ng/mL, p < 0.05). The modified Rodnan total skin thickness score was significantly higher in the elevated serum calponin 3 level group than in the normal level group (median (25–75th percentiles), 10.0 (2.0–16.0) vs. 6.5 (3.25–8.75), p < 0.05). Moreover, SSc patients with increased serum calponin 3 levels also had a higher frequency of arthralgia (40% vs. 9%, p < 0.05). Elevated serum calponin 3 levels were associated with skin sclerosis and arthralgia in SSc patients. Serum calponin 3 levels might be a biomarker that reflects the severity of skin sclerosis and joint involvement in SSc.

Interleukin (IL)-17F and IL-17E are related to fibrosis and vasculopathy in systemic sclerosis

Systemic sclerosis (SSc) is an autoimmune disease that causes fibrosis and vasculopathy of the skin and internal organs against a background of autoimmune abnormalities. In recent years, the importance of the interleukin (IL)-17 family for inflammatory diseases has received much attention, but autoimmune diseases have not yet been fully explored. As for SSc, there is also no unified perspective on the involvement of the IL-17 family in its development, and few studies have been conducted linking IL-17F and IL-17E particularly to the disease severity. In the present study, we examined the correlation between serum IL-17F and IL-17E levels and disease severity in SSc patients. Moreover, the expression of the receptors for these cytokines, IL-17RB and IL-17RC, in skin tissues obtained by skin biopsy was examined by immunohistochemistry. Both cytokines were significantly elevated in the sera of patients with diffuse cutaneous SSc patients compared with healthy controls. Serum IL-17F levels correlated with modified Rodnan total skin thickness score, a semiquantitative measure of skin sclerosis, percent predicted forced vital capacity, percent predicted carbon monoxide lung diffusion capacity and serum levels of Krebs von den Lungen-6 and surfactant protein-D, serological markers of interstitial lung disease. Serum IL-17E levels were significantly correlated with percent predicted forced vital capacity and serum Krebs von den Lungen-6 levels. Serum levels of IL-17F and IL-17E also correlated with the prevalence of digital ulcers, and serum IL-17F levels were associated with elevated right ventricle systolic pressure values. In addition, IL-17RC and IL-17RB expression was increased in the skin tissues of diffuse cutaneous SSc patients. These results suggested that IL-17F and IL-17E could be involved in fibrosis and vasculopathy in SSc through their respective receptors in the affected organ tissues.

Rapid decrease of serum surfactant protein-D levels predicts the reactivity of rituximab therapy in systemic sclerosis-associated interstitial lung disease

Systemic sclerosis (SSc) is an autoimmune disorder characterized by vascular damage and excessive fibrosis. SSc-associated interstitial lung disease (ILD) is a leading cause of death in SSc. Several studies have shown the efficacy of rituximab (RTX) in SSc-ILD, but no study has examined the relation between RTX reactivity and change of serum marker levels. In this study we examined the relation between change of serum surfactant protein-D (SP-D) levels and change of percentage forced vital capacity (FVC) in 11 SSc-ILD patients with anti-topoisomerase I antibody treated by RTX. Serum SP-D levels were significantly decreased compared with baseline at 2 weeks after first RTX infusion in good responders (P = 0.04), while not in poor responders (P = 0.77). Moreover, ΔSP-D at 2 weeks negatively correlated with Δ%FVC at 24 weeks (P = 0.001). In conclusion, we suggested that the rapid decrease of SP-D levels may be a predictive marker of RTX effect against SSc-ILD.

Single-cell analysis of autoreactive B cells in patients with systemic sclerosis revealed that responses to therapy are determined by effector and regulatory B cell balance

Objective

Systemic sclerosis (SSc) is a connective tissue disease with poor prognosis. Although the standard treatment for skin and lung fibrosis is cyclophosphamide (CYC), there are not a few non-responders to the treatment. Recent studies showed that autoreactive B cells play a critical role in SSc. We hypothesized that these B cells determine the effectiveness of CYC treatment. We focused on cytokine profiles of single autoreactive B cells in patients with SSc.

Methods

We simulated the interaction of B cells and endothelial cells in microfluidic cell culture systems. We cultured endothelial cells in a microchannel. Then, we loaded B cells of patients with SSc. We collected single B cells which adhere to endothelial cells by trypsin treatment. We stimulated these B cells, with PMA and ionomycin, and measured the levels of produced interleukin (IL)-10 and IL-6 to detect the percentages of regulatory and effector B cells, by our original micro fluidic-ELISA system.

Results

In SSc patients, the number of B cells adhering to endothelial cells significantly increased compared with healthy controls. Most of these B cells produced anti-endothelial cells antibodies. The frequencies of IL-10-producing regulatory B cells after the CYC treatment increased in responders and decresed in non-responders. Those of IL-6-producing effector B cells after the treatment decreased in responders and increased in non-responders.

Conclusions

The effectiveness of CYC treatment to SSc patients is associated with cytokine profiles of B cells, which interact with endothelial cells. Checking the profiles of these B cells, after the first few months on from initiation of CYC therapy, may help to decide whether or not we should continue the treatment.

Cytokine analysis on a countable number of molecules from living single cells on nanofluidic devices

Analysis of proteins released from living single cells is strongly required in the fields of biology and medicine to elucidate the mechanism of gene expression, cell-cell communication and cytopathology. However, as living single-cell analysis involves fL sample volumes with ultra-small amounts of analyte, comprehensive integration of entire chemical processing for single cells and proteins into spaces smaller than single cells (pL) would be indispensable to prevent dispersion-associated analyte loss. In this study, we proposed and developed a living single-cell protein analysis device based on micro/nanofluidics and demonstrated analysis of cytokines released from living single B cells by enzyme-linked immunosorbent assay. Based on our integration method and technologies including top-down nanofabrication, surface modifications and pressure-driven flow control, we designed and prepared the device where pL-microfluidic- and fL-nanofluidic channels are hierarchically allocated for cellular and molecular processing, respectively, and succeeded in micro/nanofluidic control for manipulating single cells and molecules. 13-unit operations for pL-cellular processing including single-cell trapping and stimulation and fL-molecular processing including fL-volumetry, antigen-antibody reactions and detection were entirely integrated into a microchip. The results suggest analytical performances for countable interleukin (IL)-6 molecules at the limit of detection of 5.27 molecules and that stimulated single B cells secrete 3.41 IL-6 molecules per min. The device is a novel tool for single-cell targeted proteomics, and the methodology of device integration is applicable to other single-cell analyses such as single-cell shotgun proteomics. This study thus provides a general approach and technical breakthroughs that will facilitate further advances in micro/nanofluidics, single-cell life science research, and other fields.

Combined immunosuppressive therapy provides favorable prognosis and increased risk of cytomegalovirus reactivation in anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis

Anti-melanoma differentiation-associated gene 5 (MDA5) antibody (Ab) is myositis-specific autoantibody associated with rapidly progressive interstitial lung disease (ILD) and poor prognosis. In this retrospective observational study, we aimed to verify the efficacy and safety of introducing combined immunosuppressive therapy for anti-MDA5 Ab-positive dermatomyositis (DM) from their early stage. We recruited all Japanese patients diagnosed with DM in our clinic between January 2011 and October 2018, who had anti-MDA5 Ab, anti-aminoacyl transfer RNA synthetase Ab or anti-transcriptional intermediary factor 1-γ Ab. Combined immunosuppressive therapy was defined as combination of systemic corticosteroids, i.v. cyclophosphamide and tacrolimus. The difference of clinical features among the three groups was analyzed by multiple comparison analysis. The longitudinal change of the measurements from baseline was examined by Wilcoxon signed-rank test. Association between therapeutic regimens and adverse events was examined by logistic regression analysis. As a result, combined immunosuppressive therapy was most frequently used in the anti-MDA5 Ab-positive group, which significantly improved their forced vital capacity of the lung. Interval time since initial visit until starting treatment was the shortest in the anti-MDA5 Ab-positive group. There was no significant difference in the incidence of death and recurrence among the three groups. Cytomegalovirus reactivation was most common in the anti-MDA5 Ab-positive group, associated with combined immunosuppressive therapy. Collectively, early introduction of combined immunosuppressive therapy was effective for DM patients with anti-MDA5 Ab. At the same time, clinicians should be aware of the risk of cytomegalovirus reactivation during the treatment.

Rituximab therapy is more effective than cyclophosphamide therapy for Japanese patients with anti-topoisomerase I-positive systemic sclerosis-associated interstitial lung disease

Systemic sclerosis-associated interstitial lung disease (SSc-ILD) is the most frequent cause of death for SSc but there is still no sufficient treatment available. Although cyclophosphamide (CYC) therapy is a common treatment which has shown statistical efficacy against SSc-ILD to date, its effects are temporary and not enough. Rituximab (RTX), the anti-CD20 monoclonal antibody, has recently shown efficacy in many autoimmune diseases. In SSc-ILD, RTX is also considered to be one of the novel treatment candidates. However, studies of SSc-ILD in Japanese treated with RTX have only a few case reports. Therefore, in this study, we retrospectively compared nine patients treated with RTX and 30 patients treated with CYC to investigate the efficacy of RTX treatment for Japanese anti-topoisomerase I-positive SSc-ILD patients. At the 24-month evaluation, the improvement rates of percent predicted of forced vital capacity and percent predicted of diffusing capacity of the lung carbon monoxide in the RTX-treated group were significantly higher than those in the CYC-treated group (20.6 ± 8.8% vs 1.1 ± 3.9%; P < 0.05 and 34.0 ± 6.0% vs -1.5 ± 2.8%; P < 0.01, respectively). In addition, skin thickness scores also showed a marked improvement from 13.5 points before the start of treatment to 5.8 points after 24 months by RTX therapy (P < 0.05). These results suggest that RTX treatment is more effective for Japanese SSc-ILD patients than CYC treatment. In the future, it is expected that large-scale clinical trials will show the usefulness of RTX treatment for SSc-ILD.

Skin thickness score as a surrogate marker of organ involvements in systemic sclerosis: a retrospective observational study

Background

Previous studies have shown the relationship between higher skin thickness score and the existence of organ involvements in systemic sclerosis (SSc). Here, we firstly investigated the correlation between skin thickness score and quantitative measurements of each organ involvement in Japanese patients with SSc.

Methods

All Japanese SSc patients hospitalized to our clinic for initial evaluation of SSc were selected. Skin thickness was evaluated by modified Rodnan total skin thickness score (mRSS). Relationship between mRSS and prevalence or incidence of organ involvements was examined by logistic analyses. Correlation between mRSS and quantitative measurements of organ involvements was examined by correlation analyses and regression analyses.

Results

We recruited 198 patients into our study. The mean disease duration was 7.3 years with the mean follow-up duration of 3.2 years. Multivariate logistic regression analyses revealed that higher mRSS is related to higher prevalence of interstitial lung disease (P < 0.05), restrictive impairment (P < 0.01), and diffusion impairment (P < 0.05) of the lung. Correlation analyses revealed mRSS negatively correlates with forced vital capacity (P < 0.001) and diffusing capacity (P < 0.001) of the lung. Correlation between longitudinal change of mRSS and that of forced vital capacity (P < 0.05) or diffusing capacity (P < 0.001) of the lung was also demonstrated.

Conclusions

Skin thickness score significantly correlates with quantitative measurements of lung involvement in Japanese patients with SSc.

Assessment of endothelial function during the loading phase of infliximab in psoriasis: a potential predictor of its drug survival

BACKGROUND

Tumor necrosis factor inhibitors decrease the risk of cardiovascular events in moderate to severe psoriasis, but the association between their effects on endothelial function and those on skin lesions has not been well studied. We investigated the association between infliximab effects on endothelial function during the loading phase and those on skin lesions in patients with psoriasis.

METHODS

We evaluated endothelial function with reactive hyperemia-peripheral arterial tonometry index (RHI) in 15 patients with psoriasis before the first and third infusions of infliximab. Patients were stratified into two groups; those who maintained Psoriasis Area and Severity Index (PASI) 75 response for more than 6 months (defined as responders) and the others (defined as nonresponders).

RESULTS

Six weeks after the initiation of infliximab (before the third infusion), PASI scores were significantly improved compared with baseline, while RHI values were not altered in the whole patient group. However, when the responders and the nonresponders were analyzed separately, RHI values tended to be decreased before the third infusion compared with baseline in the nonresponders, while being unchanged in the responders. Importantly, the difference in ∆RHI reached a statistical significance between the two groups, and the cutoff value (mean - 2 standard deviation of RHI values in the responders) identified the nonresponders with 67% of sensitivity and 100% of specificity.

CONCLUSIONS

The decrease in RHI values before the third infusion may serve as a predictor for the long-term unfavorable effect of infliximab on psoriatic skin lesions.

Rapid alteration of serum interleukin-6 levels may predict the reactivity of i.v. cyclophosphamide pulse therapy in systemic sclerosis-associated interstitial lung disease

Systemic sclerosis (SSc) is an autoimmune disorder characterized by excessive extracellular matrix deposition. Although SSc-associated interstitial lung disease (ILD) is one of the most important complications as a cause of death in SSc, prediction factors of treatment reactivity in SSc-ILD are still unclear. To assess relationships between interleukin (IL)-6 and reactivity to treatment, we measured serum IL-6 levels in 23 of active SSc-ILD patients under i.v. cyclophosphamide (IVCY) therapy and 20 of stabilized SSc-ILD, using the high-sensitivity enzyme-linked immunoassay system. Serum IL-6 levels in active SSc-ILD patients were significantly higher than those in stabilized SSc-ILD patients. Among active SSc-ILD patients, baseline serum IL-6 levels were not significantly different between IVCY responders and non-responders. Meanwhile, serum IL-6 levels after three IVCY doses out of a total of six were decreased in responders but not in non-responders. Regarding changes of parameters by the three doses of a total of six of IVCY, change in serum IL-6 levels correlated inversely with that in values of pulmonary function test. Thus, the rapid decrease in serum IL-6 levels during a couple of doses may predict the efficacy of IVCY therapy against SSc-ILD.

Serum interleukin-34 levels in patients with systemic sclerosis: Clinical association with interstitial lung disease

Interleukin (IL)-34 is a hematopoietic cytokine promoting proliferation and differentiation of macrophages. Because abnormal activation of macrophages is involved in the development of systemic sclerosis (SSc), we investigated serum IL-34 levels in patients with SSc. Serum IL-34 levels were significantly increased in diffuse cutaneous SSc compared with limited cutaneous SSc and healthy controls, while there were no significant differences between limited cutaneous SSc and healthy controls. In addition, SSc patients with increased serum IL-34 levels more often had interstitial lung disease (ILD) than those with normal levels. Moreover, in SSc patients, serum IL-34 levels negatively correlated with the percentage of predicted vital capacity, while they positively correlated with ground-glass opacity score and fibrotic score on chest computed tomography. Collectively, increased serum IL-34 levels were associated with greater frequency and severity of ILD in SSc patients. Serum IL-34 levels may be a useful serological marker for SSc-associated ILD.