Skin Signs of Rheumatoid Arthritis and its Therapy-Induced Cutaneous Side Effects

Isoquercitrin attenuates the osteoclast-mediated bone loss in rheumatoid arthritis via the Nrf2/ROS/NF-κB pathway

An excess of osteoclastogenesis significantly contributes to the development of rheumatoid arthritis (RA). Activation of the nuclear factor erythroid-2 related factor 2 (Nrf2) and nuclear factor kappa B (NF-κB) ligand (RANKL)-induced reactive oxygen species (ROS)-to-NF-κB signaling cascade are important mechanisms regulating osteoclastogenesis; however, whether Nrf2 is involved in RANKL-induced NF-κB activation is controversial. Isoquercitrin, a natural flavonoid compound, has been shown to have Nrf2-dependent antioxidant effects inprevious studies. We sought to verify whether isoquercitrin could modulate RANKL-induced NF-κB activation by activating Nrf2, thereby affecting osteoclastogenesis. Tartrate-resistant acid phosphatase staining, F-actin ring staining and resorption pit assay suggested that isoquercitrin significantly inhibited osteoclastogenesis and osteolytic function. Mitosox staining showed that RANKL-induced ROS generation was significantly inhibited by isoquercitrin from day 3 of the osteoclast differentiation cycle. Quantitative real-time PCR, Western blot, and immunofluorescence indicated that isoquercitrin activated the Nrf2 signaling pathway and inhibited NF-κB expression. And when we used the Nrf2-specific inhibitor ML385, the inhibition of NF-κB by isoquercitrin disappeared. Moreover, we found that Nrf2 is not uninvolved in RANKL-induced NF-κB activation and may be related to the timing of ROS regulation. When we limited isoquercitrin administration to 2 days, Nrf2 remained activated and the inhibition of NF-κB disappeared. In vivo experiments suggested that isoquercitrin attenuated RA modeling-induced bone loss. Overall, isoquercitrin-activated Nrf2 blocked the RANKL-induced ROS-to-NF-κB signaling cascade response, thereby inhibiting osteoclastogenesis and bone loss. These findings provide new ideas for the treatment of RA.

Signaling pathways in rheumatoid arthritis: implications for targeted therapy

Rheumatoid arthritis (RA) is an incurable systemic autoimmune disease. Disease progression leads to joint deformity and associated loss of function, which significantly impacts the quality of life for sufferers and adds to losses in the labor force. In the past few decades, RA has attracted increased attention from researchers, the abnormal signaling pathways in RA are a very important research field in the diagnosis and treatment of RA, which provides important evidence for understanding this complex disease and developing novel RA-linked intervention targets. The current review intends to provide a comprehensive overview of RA, including a general introduction to the disease, historical events, epidemiology, risk factors, and pathological process, highlight the primary research progress of the disease and various signaling pathways and molecular mechanisms, including genetic factors, epigenetic factors, summarize the most recent developments in identifying novel signaling pathways in RA and new inhibitors for treating RA. therapeutic interventions including approved drugs, clinical drugs, pre-clinical drugs, and cutting-edge therapeutic technologies. These developments will hopefully drive progress in new strategically targeted therapies and hope to provide novel ideas for RA treatment options in the future.

Huangqi Guizhi Wuwu Decoction Improves Arthritis and Pathological Damage of Heart and Lung in TNF-Tg Mice

Background: Huangqi Guizhi Wuwu Decoction (HGWD) is a traditional and effective Chinese medicine compound decoction for the treatment of rheumatoid arthritis (RA). However, there is few research on the treatment of rheumatoid cardiopulmonary complications. The present study was to study whether HGWD can alleviate the pathological changes caused by rheumatoid arthritis and cardiopulmonary complications.

Methods: Five 3-month-old TNF-Tg mice were treated with HGWD (9.1 g/kg) once a day or the same dose of normal saline lasted for 8 weeks, and wild-type littermates of the same age were used as a negative control, and methotrexate (MTX) was intraperitoneally administered as a positive control. After the treatment, pathological staining was performed on the mouse ankle joints, heart, and lungs.

Result: It was found that HGWD reduced the inflammation of the ankle joint synovium in TNF-Tg mice, and reduced myocardial hypertrophy, inflammatory infiltration and fibrosis of heart, as well as lung inflammation and fibrosis. Immunohistochemical staining with anti-TNF-α antibody showed that HGWD reduced the expression of TNF-α in the heart of TNF-Tg mice.

Conclusion: In conclusion, HGWD alleviates joint inflammation in TNF-Tg mice and reduces the pathological changes of the heart and lungs.

Urticaria and increased risk of rheumatoid arthritis: a two-sample Mendelian randomisation study in European population

BACKGROUND

In recent years, a growing body of observational studies suggest that urticaria is associated with a higher risk of rheumatoid arthritis (RA). However, the causal association between urticaria and RA remains unknown.

OBJECTIVE

To investigate the causal relationship of urticaria and RA in European populations by Mendelian randomisation (MR) approach.

METHODS

We conducted two-sample MR analyses. Eleven single-nucleotide polymorphisms associated with urticaria were used as instrumental variables. The summary data on urticaria were derived from FinnGen Data Freeze 2. The summary data on RA were obtained from a published meta-analysis using European samples. Four MR methods were applied to the MR estimates. Three heterogeneity tests, including Cochran's Q test, single variant analysis, and leave-one-out variant analysis, were used. The pleiotropy and horizontal pleiotropy among instrumental variables were assessed with MR-Egger regression intercept, MR pleiotropy residual sum and outlier global test, and PhenoScanner.

RESULTS

The MR analysis suggested that urticaria was causally associated with RA (odds ratio = 1.114, 95% confidence interval = 1.024-1.211, p = .011). No genetic pleiotropy or horizontal pleiotropy was revealed by MR-Egger regression intercept and MR pleiotropy residual sum and outlier global test. The sensitivity analysis results were relatively robust.

CONCLUSIONS

The MR analysis suggested there was sufficient evidence to indicate urticaria is the cause of RA.

CLIC1 Expression in Skin Biopsies from Patients With Rheumatoid and Psoriatic Arthritis as a Potential Tool to Predict Therapy Response

BACKGROUND/AIM

Chloride intracellular channel protein 1 (CLIC1) activates inflammasomes in rheumatoid (RA) and psoriatic (PsA) arthritis. We studied CLIC1 expression in RA and PsA patients' skin with vasculitis and its variability depending on the therapy used.

MATERIALS AND METHODS

CLIC1 immunoexpression was evaluated in the vascular (CLIC1-V) and stromal (CLIC1-S) compartments of the RA and PsA skin biopsies of patients treated with methotrexate (MTX), leflunomid (LFN), corticotherapy (CT), or biological therapies.

RESULTS

MTX significantly reduced CLIC1-S expression (p=0.016), whereas LFN decreased CLIC1-V (p<0.001). LFN therapy duration also correlated with CLIC1-V (p<0.001). CT decreased CLIC1-S expression (p=0.006). CLIC1-S expression persisted in skin biopsies despite of erythrocyte sedimentation rate (ESR, p=0.018) and C reactive protein (CRP, p=0.0026) normalisation. For PsA, CLIC1-S expression significantly related to MTX (p<0.022). Both CLIC1-S (p<0.001) and CLIC1-V (p=0.007) decreased by biological therapies in RA.

CONCLUSION

CLIC1 expression is strongly influenced by the therapy used. Our data strongly support the extensive evaluation of CLIC1 in RA as a potential marker of inflammation and tool to predict therapy response.

Cutaneous manifestations are frequent and diverse among patients with rheumatoid arthritis and impact their quality of life: a cross-sectional study in a cohort of patients with recent-onset disease

INTRODUCTION/OBJECTIVES

Cutaneous involvement is often overlooked in rheumatoid arthritis (RA). We described cutaneous findings in outpatients attending a recent-onset cohort and identified factors associated with skin involvement and reduced (R) dermatological quality of life (DQoL).

METHODS

Skin and rheumatological examinations were performed in 122 patients. DQoL was assessed through the Dermatology Life Quality Index (DLQI). Skin findings were classified as RA-specific and RA-nonspecific. Multiple regression analysis identified factors associated to skin involvement and RDQoL (DLQI score > 1).

RESULTS

Patients were middle-aged females (91%), with a 1-year mean disease activity score in 28 joints as 2.0 (interquartile range: 1.5-2.6). There were 94 (77%) patients in whom at least one cutaneous finding was observed: 17 (13.1%) had RA-specific findings (all were rheumatoid nodules) and 91 (96.8%) had at least one RA-nonspecific finding, further classified into skin diseases (35.2%), hair diseases (20.9%), and skin-related signs (76.9%, among whom 94.3% had xerosis). Age (odds ratio [OR]: 1.054, 95% confidence interval [CI]: 1.015-1.094) and skin-health concerns (OR: 5.657, 95% CI: 1.771-18.070) were associated with cutaneous involvement, whereas increased age and DLQI score were associated with a higher number of skin findings/patient. There were 29 patients (24.2%) with RDQoL, which were associated with the Short Form-36 emotional component (OR: 0.955, 95% CI: 0.923-0.988) and the number of skin findings/patient (OR 2.873, 95% CI 1.723-4.791). Pruritus and hair diseases were the individual categories associated with RDQoL.

CONCLUSIONS

Cutaneous manifestations are frequent in RA patients and have the potential to impact the emotional component of health-related quality of life. Key Points • Up to 77% of the RA patients with substantial follow-up, from a recent-onset disease cohort, had cutaneous manifestations; these were primarily RA-nonspecific findings, whereas 13.1% had RA-specific findings. • Skin-health concerns and age were associated with cutaneous involvement; meanwhile, increased age and Dermatology Life Quality Index (DLQI) score were associated with a higher number of cutaneous findings/patient. • Reduced dermatological quality of life (RDQoL) was documented in one in four patients and was associated with the SF-36 emotional component and the number of cutaneous findings/patient.

Endothelial Dysfunction and Extra-Articular Neurological Manifestations in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic, systemic, inflammatory autoimmune disease that affects about 1% of the global population, with a female–male ratio of 3:1. RA preferably affects the joints, with consequent joint swelling and deformities followed by ankylosis. However, evidence has accumulated showing that patients suffering from RA can also develop extra-articular manifestations, including cardiovascular disease states, neuropathies, and multiorgan dysfunction. In particular, peripheral nerve disorders showed a consistent impact in the course of the disease (prevalence about 20%) mostly associated to vasculitis of the nerve vessels leading to vascular ischemia, axonal degeneration, and neuronal demyelination. The pathophysiological basis of this RA-associated microvascular disease, which leads to impairment of assonal functionality, is still to be better clarified. However, endothelial dysfunction and alterations of the so-called brain-nerve barrier (BNB) seem to play a fundamental role. This review aims to assess the potential mechanisms underlying the impairment of endothelial cell functionality in the development of RA and to identify the role of dysfunctional endothelium as a causative mechanism of extra-articular manifestation of RA. On the other hand, the potential impact of lifestyle and nutritional interventions targeting the maintenance of endothelial cell integrity in patients with RA will be discussed as a potential option when approaching therapeutic solutions in the course of the disease.

Influence factors of extra-articular manifestations in rheumatoid arthritis

Background and objective

Extra-articular manifestations (EAMs) are serious outcomes or complications of rheumatoid arthritis (RA) with increasing mortality and morbidity. The purpose was to explore the factors influencing EAMs, tissue-specific/systemic EAMs, and the concurrence of several EAMs.

Patients and methods

In total, 519 inpatients with RA were enrolled. The clinical characteristics, laboratory parameters, and medications of RA patients and the details of EAMs were recorded carefully. Differences between groups were examined by a Chi-square test, independent samples t test, one-way analysis of variance, Mann-Whitney U test, and Kruskal-Wallis H test. Binary and ordinal logistic regression analyses were performed to determine the relationship between influential factors and EAMs, tissue-specific/systemic EAMs, and the concurrence of several EAMs.

Results

The morbidity of EAMs was 44.70%. Male sex, age, and traditional Chinese medicine (TCM) were independent influential factors of EAMs, and a number of statistically significant influence factors were found in the multivariate analysis of tissue-specific/systemic EAMs. Finally, age, CRP levels, number of RA-affected types of joints, and TCM were the factors that independently influenced the concurrence of several EAMs.

Conclusion

Influential factors identified in this study could be recommended in clinical work, which is hopeful to decrease the morbidity and mortality of EAMs in RA.

Case for diagnosis. Subcutaneous nodules in the plantar region

The authors report a case of mobile and painful nodules on the bilateral plantar surface of a female patient referred by the rheumatology service, where she was being followed-up for rheumatoid arthritis. A nodule excision was performed for differential diagnosis and symptom relief; the histopathological analysis was compatible with a rheumatoid nodule. Although rheumatoid nodules are a common manifestation of rheumatoid arthritis, exclusive plantar involvement is seldom described in the literature.

Tanshinone IIA Suppresses Proliferation and Inflammatory Cytokine Production of Synovial Fibroblasts from Rheumatoid Arthritis Patients Induced by TNF-α and Attenuates the Inflammatory Response in AIA Mice

Rheumatoid arthritis (RA) is a chronic and progressive autoimmune disease in which activated RA fibroblast-1ike synoviocytes (RA-FLSs) are one of the main factors responsible for inducing morbidity. Previous reports have shown that RA-FLSs have proliferative features similar to cancer cells, in addition to causing cartilage erosion that eventually causes joint damage. Thus, new therapeutic strategies and drugs that can effectively contain the abnormal hyperplasia of RA-FLSs and restrain RA development are necessary for the treatment of RA. Tanshinone IIA (Tan IIA), one of the main phytochemicals isolated from Salvia miltiorrhiza Bunge, is capable of promoting RA-FLS apoptosis and inhibiting arthritis in an AIA mouse model. In addition, RA patients treated at our clinic with Tan IIA showed significant improvements in their clinical symptoms. However, the details of the molecular mechanism by which Tan IIA effects RA are unknown. To clarify this mechanism, we evaluated the antiproliferative and inhibitory effects of proinflammatory factor production caused by Tan IIA to RA-FLSs. We demonstrated that Tan IIA can restrict the proliferation, migration, and invasion of RA-FLSs in a time- and dose-dependent manner. Moreover, Tan IIA effectively suppressed the increase in mRNA expression of some matrix metalloproteinases and proinflammatory factors induced by TNF-α in RA-FLSs, resulting in inflammatory reactivity inhibition and blocking the destruction of the knee joint. Through the integration of network pharmacology analyses with the experimental data obtained, it is revealed that the effects of Tan IIA on RA can be attributed to its influence on different signaling pathways, including MAPK, AKT/mTOR, HIF-1, and NF-kB. Taken together, these data suggest that the compound Tan IIA has great therapeutic potential for RA treatment.

Rheumatoid neutrophilic dermatitis

Rheumatoid neutrophilic dermatitis is a rare extra-articular manifestation of rheumatoid arthritis, both seropositive and seronegative for rheumatoid factor. The condition most often presents as symmetric erythematous papules, nodules, plaques, and urticaria-like lesions in patients with severe, long-lasting rheumatoid arthritis. We report a case of a 65-year-old man with well-controlled rheumatoid arthritis, who developed rheumatoid neutrophilic dermatitis on the right lower leg. The biopsy of skin lesions revealed an intense, neutrophilic dermal infiltrate, microabscesses, and leukocytoclasis without vasculitis. The patient responded well to pulses of intravenous methylprednisolone. We present this patient due to the rarity of the disease and atypical unilateral manifestation involving the flexural surfaces of the lower leg.

Collagen triple helix repeat containing-1: a novel biomarker associated with disease activity in Systemic lupus erythematosus

OBJECTIVE

The objective of this article is to investigate whether the aberrant expression of collagen triple helix repeat containing-1 (CTHRC1) from patients with systemic lupus erythematosus (SLE) could contribute to the pathogenesis of lupus.

METHODS

We divided SLE patients into active groups (Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) score ≥ 6) and inactive groups (SLEDAI score < 6). Serum concentrations of CTHRC1, interferon alpha, interleukin (IL)-28A and IL-28B were determined using an enzyme-linked immunosorbent assay in a group of 40 patients with SLE. Results were compared with those from 23 healthy controls.

RESULTS

Serum CTHRC1 protein levels were higher in patients with SLE compared with healthy controls. Patients with active disease displayed higher CTHRC1 levels compared with those with inactive disease as well. There was a positive association between serum CTHRC1 levels and SLEDAI and erythrocyte sedimentation rate, and a negative correlation with complement 3 and 4. Moreover, serum CTHRC1 levels were higher in SLE patients with arthritis and anemia compared with patients without the above-mentioned manifestations.

CONCLUSIONS

These findings indicate CTHRC1 probably plays an important part in the pathogenesis of SLE, and is positively associated with disease activity, while it also likely refers to the development of arthritis and anemia in SLE. Therefore, CTHRC1 may provide a novel research target and shed new light on the pathogenesis and therapy of SLE.

Mucocutaneous Manifestations in Patients with Rheumatoid Arthritis: A Cross-sectional Study from Eastern India

BACKGROUND

Cutaneous manifestations are fairly common in rheumatoid arthritis (RA) and they can help in early diagnosis, prompt treatment, and hence reduced morbidity from the disease.

AIMS

The objective of the present study was to find out the different patterns of dermatoses in a group of patients with RA from Eastern India.

METHODOLOGY

Consecutive patients fulfilling the American Rheumatism Association 1987 revised criteria for the classification of RA and who had different dermatoses were included in this cross-sectional study done over a period of 8 years in a tertiary care hospital in Eastern India. Thorough clinical examination and appropriate laboratory investigations were performed as needed. Data were recorded in a predesigned schedule, and appropriate statistical analysis was done.

RESULTS

We studied 111 evaluable patients with an age range of 19-71 years and a female to male ratio of 7:1. The mean disease duration of RA was 6.5 years. Cutaneous infections as a group was the most common mucocutaneous manifestation (34.2%) followed by xerosis including ichthyotic skin changes (27%), pigmented purpuric dermatoses (14.4%), leg ulcer (9.9%), periungual telangiectasia (9.9%), rheumatoid nodules (RNs) (8.1%), purpura and ecchymoses (7.2%), small vessel vasculitis in (7.2%), corn and callosities (6.3%), palmar erythema (4.5%), and neutrophilic dermatosis (4.5%). Raynaud's phenomenon was found in 3.6% patients and panniculitis in (3.6%) patients. Rheumatoid factor (RF) and anti-cyclic citrullinated peptides antibody were positive in 74.8% and 88.3% patients, respectively. No statistically significant difference of incidence of leg ulcer, small vessel vasculitis, RN, or Raynaud's phenomenon could be noted between RF positive and negative groups.

LIMITATIONS

Being an institution-based study, the study findings may not reflect the true situation in the community which remained a limitation of this study.

CONCLUSION

While some of the features of this study were analogous to Western data, other features showed discordance which may be due to ethnic variations among the patients with RA.

Denosumab: targeting the RANKL pathway to treat rheumatoid arthritis

INTRODUCTION

Rheumatoid arthritis (RA) is a chronic inflammatory disorder characterized by focal pathologic bone resorption due to excessive activity of osteoclasts (OC). Receptor activator of nuclear factor kappa B ligand (RANKL) is essential for the proliferation, differentiation, and survival of OC. Denosumab (DMab) is a humanized monoclonal antibody that binds to RANKL with high affinity and blocks its subsequent association with its receptor RANK on the surface of OC precursors. Area covered: The authors review the molecular and cellular mechanisms underlying therapeutic applications of DMab, provide recent highlights on pharmacology, efficacy and safety of DMab, and discuss the potential of DMab as a novel therapeutic option for the treatment of rheumatoid arthritis. Expert opinion: Clinical results suggest that DMab is efficient both in systemic and articular bone loss in RA with limited side effects. Diminished bone erosion activity was also noted in RA patients on corticosteroids and bisphosphonates. Combination of DMab with an anti-TNF agent was not associated with increased infection rates. Collectively, these data indicate that DMab, in combination with methotrexate and possibly other conventional synthetic Disease Modifying Anti-Rheumatic Drugs (csDMARDs), is an effective, safe and cost-effective option for the treatment of RA.