Prostaglandin E2 and IL-23 interconnects STAT3 and RoRγ pathways to initiate Th17 CD4+ T-cell development during rheumatoid arthritis

BACKGROUND

The chronic inflammation associated with rheumatoid arthritis (RA) leads to focal and systemic bone erosion of the joints resulting in a crippling disability. Recent reports indicate an increase in the incidence of RA in the coming years, placing a significant burden on healthcare resources. The incidence of RA is observed to be increasing with age and a significant proportion of those new cases will be aggressively erosive.

FINDINGS

The altered physiology, due to immune disturbances, contributes towards RA pathogenesis. The imbalance of inflammatory cytokines and non-cytokine immune modulators such as prostaglandin E2 (PGE2) and IL-23-induced pathogenic IL-17, plays a crucial role in persistent inflammation and bone degradation during RA. However, the molecular mechanism of IL-23, a key cytokine, and PGE2 in the development and perpetuation of IL-17 producing effector Th17 cells is poorly understood.

CONCLUSION

This review focuses on research findings that provide insight into the contribution of PGE2 and IL-23 during the development of pathogenic Th17 cells. We also highlight the key transcriptional factors required for Th17 development and therapeutic strategies to disrupt the interaction between IL-23 and IL-17 to prevent the end-organ damage in RA.

Assessment of 3-month changes in bone microstructure under anti-TNFα therapy in patients with rheumatoid arthritis using high-resolution peripheral quantitative computed tomography (HR-pQCT)

Background

Although one study showed minimal progression of erosions in patients with rheumatoid arthritis (RA) one year after TNFα inhibition therapy, no studies have investigated very early bone changes after initiation of anti-TNFα treatment. We investigated the effects of 3-month anti-TNFα treatment on bone erosion progression and bone microarchitecture in RA patients using high-resolution peripheral quantitative computed tomography (HR-pQCT).

Methods

Patients with RA (n = 27) (17 in the anti-TNFα and 10 in the MTX-only group) underwent assessment of disease activity score in 28 joints (DAS-28), radiographs, 3-T magnetic resonance imaging (MRI) and HR-pQCT of metacarpophalangeal and wrist joints at baseline and 3 months. HR-pQCT-derived erosion volume, joint volume/width and bone microarchitecture were computed and joint destruction was assessed using Sharp and RAMRIS scorings on radiographs and MRI, respectively.

Results

Overall, 73 erosions were identified by HR-pQCT at baseline. Over 3 months, the anti-TNFα group had decreased mean erosion volume; increased erosion volume was observed in one clinical non-responder. The MTX-only group in contrast, trended toward increasing erosion volume despite low disease activity. In the anti-TNFα group, joint-space width and volume of MCP joints decreased significantly and was positively correlated with erosion volume changes (R² = 0.311, p = 0.013; R² = 0.527, p = 0.003, respectively). In addition, erosion volume changes were significantly negatively correlated with changes in trabecular bone mineral density (R² = 0.353, p = 0.020) in this group. We observed significant correlation between percentage change in erosion volume and change in DAS-28 erythrocyte sedimentation rate and C-reactive protein CRP scores (R² = 0.558, p < 0.001; R² = 0.745, p < 0.001, respectively) in all patients.

Conclusions

Using HR-pQCT, our data suggest that anti-TNFα treatment prevents erosion progression and deterioration of bone microarchitecture within the first 3 months of treatment, one patient not responding to treatment, had significant progression of bone erosions within this short time period. Patients with low disease activity scores (<3.2) can have continuous HR-pQCT-detectable progression of erosive disease with MTX treatment only. HR-pQCT can be a sensitive, powerful tool to quantify bone changes and monitor RA treatment short term (such as 3 months).

Methods for segmentation of rheumatoid arthritis bone erosions in high-resolution peripheral quantitative computed tomography (HR-pQCT)

OBJECTIVE

The comparison between different techniques to quantify the 3-dimensional size of inflammatory bone erosions in rheumatoid arthritis(RA) patients.

METHODS

Anti-cyclic citrullinated peptide antibody(ACPA) positive RA patients received high-resolution peripheral quantitative computed tomography (HR-pQCT) scans of the metacarpophalangeal joints (MCP). Erosions were measured by three different segmentation techniques: (1) manual method with calculation by half-ellipsoid formula, (2) semi-automated modified Evaluation Script for Erosions (mESE), and (3) semi-automated Medical Image Analysis Framework (MIAF) software. Bland & Altman plots were used to describe agreement between methods. Furthermore, shape of erosions was classified as regular or irregular and then compared to the sphericity obtained by MIAF.

RESULTS

A total of 76 erosions from 65 RA patients (46 females/19 males), median age 57 years, median disease duration 6.1 years and median disease activity score 28 of 2.8 units were analyzed. While mESE and MIAF showed good agreement in the measurement of erosion size, the manual method with calculation by half-ellipsoid formula underestimated erosions size, particularly with larger erosions. Accurate segmentation is particularly important in larger erosions, which are irregularly shaped. In all three segmentation techniques irregular erosions were larger in size than regular erosions (MIAF: 19.7 vs. 3.4mm³; mESE: 15.5 vs. 2.3mm³; manual = 7.2 vs. 1.52mm³; all p < 0.001). In accordance, sphericity of erosions measured by MIAF significantly decreased with their size (p < 0.001).

CONCLUSION

MIAF and mESE allow segmentation of inflammatory bone erosions in RA patients with excellent inter reader reliability. They allow calculating erosion volume independent of erosion shape and therefore provide an attractive tool to quantify structural damage in individual joints of RA patients.

C2 Bone Erosion Secondary to Iatrogenic Pseudomeningocele: A Case Report and Description of a Novel Surgical Technique

BACKGROUND

Pseudomeningoceles are a rare cause of bone erosions. Development of such erosions in the C2 vertebral body and the odontoid process can lead to life-threatening instability. Treatment options to regain stability include atlantoaxial and occipitocervical fusion. For patients with a history of Chiari decompression and large C2 lesions, common fusion techniques are not always feasible. In addition, fusion surgery sacrifices physiologic motion and is therefore a disabling procedure, especially for young and active patients.

CASE DESCRIPTION

We report a novel combined open operative and subsequent minimal invasive filling technique of several instable osteolytic/cystic areas within the C2 vertebra of a 28-year-old woman. The underlying cause for the lesions was a pseudomeningocele communicating with the vertebral body. This was an incidental finding 15 years after foramen magnum decompression with C1 and partial C2 laminectomy for Chiari malformation. Novel treatment included open posterior surgery with total laminectomy of the remaining C2 arch and refilling the odontoid with viscous beta tricalcium phosphate and polymethylmethacrylate bone cement. Postoperative 6- and 12-month follow-up computed tomography imaging showed a stable incorporation of the filling.

CONCLUSIONS

Life-threatening fractures at the occipitocervical junction are rare and often are due to high-impact trauma. Osteolytic changes at those bone compartments are a potential cause for pathologic fractures during normal daily activities. In this case, increased pressure on the bone due to a pseudomeningocele resulted in slow bone loss without symptoms. A novel combined technique of bone filling was applied successfully to stabilize the C2 vertebral bone.

1,25(OH)2 vitamin D(3) contributes to osteoclast-like trans-differentiation of malignant plasma cells

1,25-dihydroxyvitamin D (1,25(OH)₂D) exerts pleiotropic effects including bone turnover and immune system regulation. It inhibits both T and B cell proliferation while decreasing the secretion of inflammatory cytokines and immunoglobulins. 1,25(OH)₂D also modulates monocyte-macrophage and osteoclast (OC) maturation. Since we have previously described that malignant plasma cells may trans-differentiate towards the myeloid lineage participating to skeletal devastation in multiple myeloma (MM), we here evaluated in vitro the role of 1,25(OH)₂D in this lineage switch. We investigated the gene and protein expression of vitamin D receptor (VDR) in MM cell lines. Thus, after cell treatment with 1,25(OH)₂D, we analyzed their morphology and the expression of myeloid and OC markers. Finally, we assessed their bone resorption property on calcium phosphate slices. All MM cells expressed VDR in nuclear and perinuclear sites. Treatment with 1,25(OH)₂D altered their morphology from round to fusiform, while inducing paxillin focalization. 1,25(OH)₂D administration also up-regulated myeloid and OC genes, including C/EBPα, RANK, M-CSFR and V-ATPase, whose promoters contain potential 1,25(OH)₂D responsive elements. Finally, 1,25(OH)₂D increased MM cell capability to generate pits of erosion on calcium phosphate discs. This data suggest that myeloma cells may undergo a functional trans-differentiation into OCs and, under appropriate experimental conditions, 1,25(OH)₂D triggers this lineage switch.

Articular Ultrasound in Asymptomatic Volunteers: Identification of the Worst Measures of Synovial Hypertrophy, Synovial Blood Flow and Joint Damage Among Small-, Medium- and Large-Sized Joints

Articular ultrasound of 6500 joint recesses was performed for the purpose of identifying which joint had the highest measurements among small-sized (SSJ), medium-sized (MSJ) and large-sized (LSJ) joints. Quantitative measurements of synovial hypertrophy (QSR) and semiquantitative measurements of synovial hypertrophy (SSH), power Doppler (SPD) and bone erosion (SBE) (score: 0-3) were made. Higher measurements (p < 0.01) of QSR were obtained in the second metatarsophalangeal joint (MTP), talonavicular joint, and hip. The highest SSH scores (2/3) were obtained in the second MTP, talonavicular joint, hip and knee; the highest SPD scores (1/2/3) in the first MTP, second MTP, dorsal second metacarpophalangeal (MCP) and radiocarpal recesses; and the highest SBE scores (2/3) in the radiocarpal, ulnocarpal and posterior recesses of the glenohumeral joint. In conclusion, higher measurements of synovial hypertrophy were found in the first and second MTPs (SSJ), talonavicular recess (MSJ) and hip (LSJ). Synovial blood flow was frequent in the first MTP and radiocarpal recess. Bone erosion stood out only in the glenohumeral joint.

TLRs, future potential therapeutic targets for RA

Toll like receptors (TLR)s have a central role in regulating innate immunity and in the last decade studies have begun to reveal their significance in potentiating autoimmune diseases such as rheumatoid arthritis (RA). Earlier investigations have highlighted the importance of TLR2 and TLR4 function in RA pathogenesis. In this review, we discuss the newer data that indicate roles for TLR5 and TLR7 in RA and its preclinical models. We evaluate the pathogenicity of TLRs in RA myeloid cells, synovial tissue fibroblasts, T cells, osteoclast progenitor cells and endothelial cells. These observations establish that ligation of TLRs can transform RA myeloid cells into M1 macrophages and that the inflammatory factors secreted from M1 and RA synovial tissue fibroblasts participate in TH-17 cell development. From the investigations conducted in RA preclinical models, we conclude that TLR-mediated inflammation can result in osteoclastic bone erosion by interconnecting the myeloid and TH-17 cell response to joint vascularization. In light of emerging unique aspects of TLR function, we summarize the novel approaches that are being tested to impair TLR activation in RA patients.

Osteonecrosis of the femoral head associated with pigmented villonodular synovitis

A 23-year-old Japanese woman with no history of corticosteroid intake or alcohol abuse presented with a 10-month history of left hip pain without any antecedent trauma. An anteroposterior radiograph performed 10 months after the onset of pain showed slight joint space narrowing and bone erosions surrounded by sclerotic lesions in both the acetabular roof and femoral neck. Magnetic resonance images of the left hip showed a feature of osteonecrosis of the femoral head and a mass with villus proliferation extending from the posterior intertrochanteric area to the anteromedial aspect of the femoral neck. In addition, the left quadratus femoris muscle, which is generally located just above the nutrient vessels of the femoral head, was not detected. Based on these findings, the patient was diagnosed with osteonecrosis of the femoral head caused by impairment of the nutrient vessels from invasion of the pigmented villonodular synovitis. She underwent radical synovectomy of the left hip 16 months after the onset of pain, and her hip pain improved after the surgery.

Unusual Presentation of Hydatidosis - Neck Lump Causing Costo-Vertebral Erosion

INTRODUCTION

Hydatid disease caused by larval stage of Echinococcus has been recognized endemically in many countries. Liver and lungs are the most commonly affected organs. Involvement of the head and neck region is rare and bony erosion due to hydatidosis is even rarer.

CASE REPORT

We report a case of a 17-year-old girl from a poor socio-economic background who presented with a right sided supraclavicular lump, which after surgical excision and histopathological examination was diagnosed as hydatid cyst of neck.

CONCLUSION

Because of its rarity in the neck region, primary diagnosis of hydatid cyst is overlooked and usually not included in the differential diagnosis of cystic neck swellings. A high index of suspicion is necessary to diagnose hydatid disease in an unusual location even in endemic areas.

A descriptive, cross-sectional study characterizing bone erosions in rheumatoid arthritis and gout by ultrasound

The aim of this study is to characterize bone erosions in metatarsal heads (MTH) in rheumatoid arthritis (RA) and gout by grayscale ultrasound. In a descriptive, cross-sectional study, we evaluated 40 patients with RA and 40 with gout, both diagnosed according to the American College of Rheumatology/European League Against Rheumatism criteria, respectively. All patients had bone erosion demonstrated by ultrasound, which was used, following OMERACT criteria, to describe the shape, size, number, border definition, overhanging margin, topography (intra- or extra-articular), and distribution (over dorsal, medial, lateral, or plantar aspect) of the lesions in the MTH. Descriptive statistics were used and a concordance exercise between two ultrasonographers blinded to the diagnosis was performed. Bone erosions in RA were observed most frequently at the plantar and lateral aspect of the fifth MTH, round in 96 %, small-sized (2.43 ± 0.9 mm), intra-articular (100 %), and single (75 %). Few bone erosions had a well-defined border an overhanging margin while in gout were found most frequently in the medial and dorsal aspect of the first MTH, single in 71 %, intra-articular in 100 %, and of median size (4.0 ± 2.3). For shape, 51 % was round and 49 % was oval. A well-defined border was present in 39 %, and an overhanging margin in 62 %. Inter-rater reliability kappa was excellent (0.81, 95 % CI 0.56-1.00). Some characteristics of bone erosions in RA, including shape, size, ill-defined border, and localization in the fifth MTH could distinguish the lesions from gout. Grayscale US has excellent reliability to describe bone erosions in RA and gout.

Equol suppresses inflammatory response and bone erosion due to rheumatoid arthritis in mice

Rheumatoid arthritis (RA) is a chronic and systemic autoimmune inflammatory disease. Typical pathological findings of RA include persistent synovitis and bone degradation in the peripheral joints. Equol, a metabolite of the major soybean isoflavone daidzein, shows superior bioactivity than other isoflavones. We investigated the effects of equol administration on inflammatory response and bone erosion in mice with collagen-induced arthritis (CIA). The severity of arthritis symptoms was significantly low in the equol-administered CIA mice. In addition, equol administration improved the CIA-induced bone mineral density decline. In the inflamed area of CIA mice, equol administration suppressed the expression of interleukin-6 and its receptor. Furthermore, equol reduced the expression of genes associated with bone formation inhibition, osteoclast and immature osteoblast specificity and cartilage destruction. These results suggest that equol suppresses RA development and RA-induced bone erosion by regulating inflammation and bone metabolism.

Detection and measurement of rheumatoid bone and joint lesions of fingers by tomosynthesis: a phantom study for reconstruction filter setting optimization

Rheumatoid arthritis (RA) is a systemic disease that is caused by autoimmunity. RA causes synovial proliferation, which may result in bone erosion and joint space narrowing in the affected joint. Tomosynthesis is a promising modality which may detect early bone lesions such as small bone erosion and slight joint space narrowing. Nevertheless, so far, the optimal reconstruction filter for detection of early bone lesions of fingers on tomosynthesis has not yet been known. Our purpose in this study was to determine an optimal reconstruction filter setting by using a bone phantom. We obtained images of a cylindrical phantom with holes simulating bone erosions (diameters of 0.6, 0.8, 1.0, 1.2, and 1.4 mm) and joint spaces by aligning two phantoms (space widths from 0.5 to 5.0 mm with 0.5 mm intervals), examining six reconstruction filters by using tomosynthesis. We carried out an accuracy test of the bone erosion size and joint space width, done by one radiological technologist, and a test to assess the visibility of bone erosion, done by five radiological technologists. No statistically significant difference was observed in the measured bone erosion size and joint space width among all of the reconstruction filters. In the visibility assessment test, reconstruction filters of Thickness+- and Thickness-- were among the best statistically in all characteristics except the signal-to-noise ratio. The Thickness+- and Thickness-- reconstruction filter may be optimal for evaluation of RA bone lesions of small joints in tomosynthesis.

Automated Breast Volume Scanner, a new automated ultrasonic device, is useful to examine joint injuries in patients with rheumatoid arthritis

OBJECTIVE

To explore the clinical application of automated scanning of wrist and finger joints by an Automated Breast Volume Scanner (ABVS) in patients with rheumatoid arthritis (RA).

METHODS

A total of 140 metacarpophalangeal (MCP) joints and 28 wrist joints from the 14 active RA patients were examined by both an ABVS system (the ACUSON S2000) from dorsal sites and by conventional ultrasonography (US) from multiple directions on the same day. We used a semiquantitative scale from 0 to 3 of synovial hypertrophy and the presence of bone erosion by grayscale for both methods; the efficacy of the two methods for identifying synovial hypertrophy and bone erosion were evaluated by kappa coefficient.

RESULTS

The scanning time of the ABVS was 2 min per patient and that of conventional US was 15 min per patient. The kappa coefficients of synovial hypertrophy in the MCP joints were 0.60 and 0.79 in wrist joints. These values were increased in the joints where synovial hypertrophy was moderate to severe (scores greater than 2). The kappa coefficients for the presence of bone erosion in the MCP joints were 0.74 and 0.93 in wrist joints.

CONCLUSION

The present data showed a substantial agreement between ABVS and conventional US for assessments of the synovial hypertrophy and bone erosion of wrist and finger joints in patients with RA. Since ABVS can scan the wrist and finger joints automatically in a short time, ABVS is a helpful new ultrasonic method to examine joint injuries in patients with RA.

Treatment with anti-C5aR mAb leads to early-onset clinical and mechanistic effects in the murine delayed-type hypersensitivity arthritis model

Blockade of the complement cascade at the C5a/C5a receptor (C5aR)-axis is believed to be an attractive treatment avenue in rheumatoid arthritis (RA). However, the effects of such interventions during the early phases of arthritis remain to be clarified. In this study we use the murine delayed-type hypersensitivity arthritis (DTHA) model to study the very early effects of a blocking, non-depleting anti-C5aR mAb on joint inflammation with treatment synchronised with disease onset, an approach not previously described. The DTHA model is a single-paw inflammatory arthritis model characterised by synchronised and rapid disease onset driven by T-cells, immune complexes and neutrophils. We show that a reduction in paw swelling, bone erosion, cartilage destruction, synovitis and new bone formation is apparent as little as 60 h after administration of a single dose of a blocking, non-depleting anti-mouse C5aR mAb. Importantly, infiltration of neutrophils into the joint and synovium is also reduced following a single dose, demonstrating that C5aR signalling during the early stage of arthritis regulates neutrophil infiltration and activation. Furthermore, the number of T-cells in circulation and in the draining popliteal lymph node is also reduced following a single dose of anti-C5aR, suggesting that modulation of the C5a/C5aR axis results in effects on the T cell compartment in inflammatory arthritis. In summary, these data demonstrate that blockade of C5aR leads to rapid and significant effects on arthritic disease development in a DTHA model strengthening the rationale of C5aR-blockade as a treatment strategy for RA, especially during the early stages of arthritis flare.

Erosion in the occipital bone caused by the fixation instrument used for posterior atlantoaxial fusion -report of 4 cases

Introduction

Conventionally, posterior C1-C2 fusion has been performed using a sublaminar wiring technique with a structural bone graft. Subsequent advent of newer fixation devices, such as the C1 lateral mass screw and C1 hook, has achieved more solid fixation with improved surgical outcome; however, in these fixation systems, the protruding end of the metal implant above the level of the atlas may result in a complication due to contact with the surrounding structures.

Case description

Two men and two women whose ages at the time of surgery ranged from 14 to 72 years. A supralaminar hook was used as a fixation device for C1 in two cases, whereas a lateral mass screw (Tan’s method) and an atlas claw hook were employed for one each of the remaining 2 cases. We retrospectively reviewed the clinical features and postoperative course of these patients using the clinical records. Moreover, we measured the protruding height of the instrument above the atlas as well as the Redlund-Johnell (R-J) value on postoperative radiographs. All patients complained of crepitus and/or pain on neck extension. Erosion in the occipital bone was detected on multiplanar reconstruction computed tomography (MPR-CT), whereas plain radiographs failed to reveal the bony change. In those cases, protruding instruments used for C1 fixation contacted the occipital bone resulting in an erosive change at the impingement point. We removed the implant in all four cases after confirmation of solid bony union.

Discussion and evaluation

Two of the four patients complained of occipital crepitus alone without pain. The management options for this condition may be controversial; however, progression of bony erosion may result in perforation of the occipital bone. This may possibly be associated with the serious complication of cerebrospinal fluid leakage. Considering this potential sequela, we removed the implants from all our reported cases after confirmation of solid bony union.

Conclusions

We treated four cases that developed erosion in the occipital bone after posterior spinal instrumentation was performed for upper cervical lesions including C1. MPR-CT was useful in detecting the erosive changes in the occipital bone.

Sonographic cutoff values for detection of abnormalities in small, medium and large joints: a comparative study between patients with rheumatoid arthritis and healthy volunteers

To determine ultrasound measurements indicative of abnormalities in small, medium and large joints, we conducted a cross-sectional study comparing 60 patients with rheumatoid arthritis (RA) and 78 healthy volunteers. A MyLab 60 ultrasound machine (Esaote) and a linear multifrequency probe were used. Quantitative measurements of synovial recesses and semiquantitative measurements of synovial hyperplasia, power Doppler and bone erosion (scores = 0-3) were performed. The cutoff values for synovial recesses indicating RA (receiver operating characteristic curve, area under the curve >0.800) were found to be (radiocarpal) 3.78 mm and (ulnocarpal) 3.07 mm. Those measurements with the greatest chance of indicating RA (logistic regression analysis expressed as odds ratios [ORs]) were (p < 0.001) measurements of synovial hyperplasia (ulnocarpal, OR = 100, and radiocarpal, OR = 70); synovial power Doppler (radiocarpal, OR = 66); synovial bone erosion (radiocarpal, OR = 324); fifth metatarsophalangeal joint (OR = 100); and second metacarpophalangeal joint (OR = 92). We concluded that for both quantitative and semiquantitative ultrasound measurements, radiocarpal abnormalities increase the chance of detecting RA.

Extradural dermoid cyst located in the lateral sphenoid ridge

Dermoid cysts are rare congenital tumors that occur primarily at the midline at a characteristic intradural location. However, dermoid cysts located at extradural and lateral regions have been rarely reported until now. In the present study, the authors demonstrate the unusual instance of an intracranial extradural dermoid cyst at the lateral sphenoid ridge. A 53-year-old woman admitted because of progressive headache and dizziness. The patient had no neurologic deficits, and magnetic resonance imaging with no contrast enhancement revealed a mass at the right sphenoid ridge. The mass was accompanied with sphenoid bone erosion visible on computed tomography. The patient underwent right pterional craniotomy, and the tumor including the capsule was totally resected. Presence of a dermoid cyst was confirmed with histopathological examination. The patient had no complications during the postoperative period. This study suggests that dermoid cyst should be considered for differential diagnosis of extradural and lateral intracranial masses.