Linking angiogenesis to bone destruction in arthritis

Effectiveness of Genicular Artery Embolization for Reducing Synovitis as Assessed by Contrast-Enhanced MR Imaging in Knee Osteoarthritis: A Pilot Study

PURPOSE

To investigate the impact of genicular artery embolization (GAE) on synovitis in knee osteoarthritis (OA) using contrast-enhanced magnetic resonance (MR) imaging and to assess its predictive role in pain response.

MATERIALS AND METHODS

A single-center retrospective analysis was conducted using contrast-enhanced MR imaging on 33 patients treated with GAE for knee OA between December 2022 and March 2023. MR assessments before the procedure and at 3 months after embolization were utilized in a semiquantitative scoring system for synovitis severity and distribution analysis. Pain and function through Western Ontario and McMaster Universities Osteoarthritis Index and visual analog scale scores were also assessed.

RESULTS

Significant synovitis reduction was noted after GAE, particularly in parapatellar and periligamentous areas. Synovial contrast enhancement scores significantly decreased from 5.1 (SD ± 2.0) to 2.9 (SD ± 2.0) at 3 months (P < .001), with a moderate negative correlation between synovial enhancement scores and pain levels (P = .005).

CONCLUSIONS

GAE significantly reduced synovitis in knee OA, evidenced by contrast-enhanced MR imaging. The correlation between preprocedural synovial contrast enhancement scores and pain relief after the procedure, although promising, requires careful interpretation because of the complex factors affecting pain in knee OA.

Monitoring of patients with rheumatoid arthritis by indocyanine green (ICG)-enhanced fluorescence optical imaging treated with anti-TNFα therapy

BACKGROUND

Fluorescence optical imaging (FOI) enables visualisation of inflammation in both hands in rheumatoid arthritis (RA).

OBJECTIVE

To investigate the usefulness of FOI in treatment monitoring under anti-TNFα therapy with certolizumab pegol (CZP) in patients with RA in comparison to clinical and laboratory outcome parameters.

METHODS

CZP-naïve patients with RA were eligible for this open-label study with an observational period of 52 weeks. Disease activity was monitored by the clinical score DAS28, tender/swollen joint count (TJC-28/SJC-28) and laboratory outcomes for systemic inflammation (CRP and ESR). FOI results were analysed in three different phases (P1-3) and PrimaVistaMode (PVM) by the FOI activity score (FOIAS).

RESULTS

Twenty-eight RA patients (median age 52.5 years, 26 females, thirteen with a history of other biologic therapy) were included. DAS28 (CRP) decreased from moderate disease activity at baseline (median 4.6, IQR 1.8) to low disease activity at week (w)52 (median 2.7, IQR 2.1; p < 0.001). Statistically significant decreases could also be demonstrated for SJC-28 and TJC-28. CRP/ESR were reduced numerically from baseline to w52. FOIAS in P1 (early phase) showed a continuous decrease of enhancement during the course of treatment period: from baseline (median 1.5, IQR 9.3) over w6 (median 1.0, IQR 3.0; p = 0.069), w12 (median 0.5, IQR 3.0; p = 0.171), w24 (n = 27, median 0.0, IQR 3.0; p = 0.004), until w52 (n = 18, median 0.0, IQR 2.8; p = 0.091), which could not be presented for FOIAS in P2, P3 and PVM.

CONCLUSION

FOI in P1 appears to be a valuable tool for fast and easy monitoring of treatment response to certolizumab in a clinical setting.

Geniculate Artery Embolization: Role in Knee Hemarthrosis and Osteoarthritis

Roughly 37% of Americans 60 years of age and older experience chronic pain due to osteoarthritis (OA) of the knee. After conservative treatment (pharmacologic, physical therapy, and joint injections) fails, patients often require total knee arthroplasty to alleviate pain and regain knee function. Given the high economic burden of surgery paired with its invasive nature, many patients with this degenerative joint disease seek alternative treatment. Moreover, many patients with severe knee OA who also have comorbidities that preclude surgery-most often morbid obesity-are left without options. Geniculate artery embolization (GAE) is a minimally invasive intra-arterial intervention that was originally developed for the treatment of knee hemarthrosis that has recently been adapted for symptomatic knee OA. Through selective embolization of geniculate branches corresponding to the site of knee pain, GAE inhibits the neovascularity that contributes to the catabolic and inflammatory drive of OA. Preliminary trials over the past decade have demonstrated promising clinical results, including decreased pain and improved function and quality of life after treatment. Given such success, GAE provides another minimally invasive treatment option for knee OA to patients who feel reluctant to undergo or are ineligible for surgery. The authors review the radiographic manifestations and current standard of treatment of OA and hemarthrosis of the knee. Procedural technique, embolic selection, and clinical evidence for GAE in the treatment of OA and hemarthrosis of the knee are also explored. The online slide presentation from the RSNA Annual Meeting is available for this article. ^©RSNA, 2021.

Genicular Artery Embolization for the Treatment of Symptomatic Knee Osteoarthritis

Genicular artery embolization (GAE) is a novel therapy to treat patients with symptomatic knee osteoarthritis (OA) by reducing synovial arterial hypervascularity. This study evaluates the safety and efficacy of GAE for the treatment of symptomatic knee OA.

Methods

A prospective, single-center, open-label U.S. Food and Drug Administration-approved investigational device exemption study was conducted. Patients enrolled in the study were 40 to 80 years old, with moderate or severe knee OA (Kellgren-Lawrence grade 2, 3, or 4), who previously had failure of conservative therapy. Baseline pain (visual analog scale [VAS]) and symptom scores (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC]) were assessed. After femoral arterial access was achieved, GAE of 1, 2, or 3 genicular arteries supplying the location of the subject's pain, as determined by digital subtraction angiography and cone-beam computed tomography, was performed using 100-μm particles. Adverse events and symptoms scores were assessed at 1 week, 1 month, 3 months, 6 months, and 1 year after GAE.

Results

Over a 10-month period, 40 subjects were enrolled. The median age was 69 years (range, 49 to 80 years). The median body mass index was 29 kg/m² (range, 19 to 44 kg/m²). Knee OA severity was grade 2 in 18% of the patients, grade 3 in 43%, and grade 4 in 40%. Technical success was achieved in 100% of the subjects. Transient skin discoloration and transient mild knee pain after the procedure were common and expected. Treatment-related adverse events included a groin hematoma requiring overnight observation in 1 subject, self-resolving focal skin ulceration in 7 subjects, and an asymptomatic small bone infarct on magnetic resonance imaging at 3 months in 2 subjects. The WOMAC total and VAS pain scores decreased by 61% and 67% at 12 months from a median baseline of 52 (of 96) and 8 (of 10), respectively. Twenty-seven patients (68%) had a reduction of ≥50% in both WOMAC total and VAS pain scores.

Conclusions

This prospective trial demonstrates that GAE is effective and durable in reducing pain symptoms from moderate or severe knee OA that is refractory to other conservative therapy, with an acceptable safety profile.

Level of Evidence

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Fluorescence optical imaging in patients with active rheumatoid arthritis: a comparison with ultrasound and an association with biomarkers

Objectives: This study compared indocyanine green (ICG)-enhanced fluorescence optical imaging (FOI) and musculoskeletal ultrasound (MSUS), and explored the significance of the FOI findings based on the association between the FOI and MSUS findings and serum biomarkers in patients with rheumatoid arthritis (RA). The study also explored the association between the FOI findings and patients' joint destruction at the joint-area level.Method: We enrolled 50 consecutive patients with active RA from among the patients hospitalized from May 2014 to March 2016 at Nagasaki University Hospital, Japan. FOI images were acquired with the Xiralite^® fluorescence imaging system and compared with the patients' clinical examination results and MSUS findings. On the same day, the patients' clinical disease activity and levels of serum biomarkers (including vascular endothelial growth factor) were obtained.Results: Although the FOI detected synovitis with high sensitivity, the frequency of positive findings and the diagnostic performance with MSUS as the reference standard for FOI differed considerably among the phases of FOI as well as among the affected joint regions. The FOI scores were positively correlated with clinical disease activity, MSUS scores, and serum biomarkers. The severity of FOI-proven synovitis was associated with the presence of MSUS-proven bone erosion.Conclusion: FOI is effective for detecting joint inflammation in RA patients, with high accuracy. The severity of the FOI score was closely associated with the joint destruction at the joint-area level. However, the significance of positive FOI findings differed depending on not only the phase of FOI but also the affected joint regions.

Development of semiquantitative ultrasound scoring system to assess cartilage in rheumatoid arthritis

OBJECTIVES

To develop and test the reliability of a new semiquantitative scoring system for the assessment of cartilage changes by ultrasound in a web-based exercise as well as a patient exercise of patients with RA.

METHODS

A taskforce of the Outcome Measures in Rheumatology Ultrasound Working Group performed a systematic literature review on the US assessment of cartilage in RA, followed by a Delphi survey on cartilage changes and a new semiquantitative US scoring system, and finally a web-based exercise as well as a patient exercise. For the web-based exercise, taskforce members scored a dataset of anonymized static images of MCP joints in RA patients and healthy controls, which also contained duplicate images. Subsequently, 12 taskforce members used the same US to score cartilage in MCP and proximal interphalangeal joints of six patients with RA in in a patient reliability exercise. Percentage agreement and prevalence of lesions were calculated, as intrareader reliability was assessed by weighted kappa and interreader reliability by Light's kappa.

RESULTS

The three-grade semiquantitative scoring system demonstrated excellent intrareader reliability (kappa: 0.87 and 0.83) in the web-based exercise and the patient exercise, respectively. Interreader reliability was good in the web-based exercise (kappa: 0.64) and moderate (kappa: 0.48) in the patient exercise.

CONCLUSION

Our study demonstrates that ultrasound is a reliable tool for evaluating cartilage changes in the MCP joints of patients with RA and supports further development of a new reliable semiquantitative ultrasound scoring system for evaluating cartilage involvement in RA.

Prediction of therapeutic responses with ultrasonography in RA patients treated with an anti-TNF drug: a retrospective cohort study

OBJECTIVE

Ultrasound (US) is more sensitive and reliable than a clinical examination, and is better correlated with the disease activity in rheumatoid arthritis (RA). We conducted the present study to assess the value of US as a screening tool to predict therapeutic responses in RA patients treated with anti-tumor necrosis factor (TNF) drugs.

METHODS

We retrospectively analyzed the cases of 86 consecutive RA patients who were classified by their DAS28-CRP scores at the 54th week. We assessed two US findings (i.e., the synovial hypertrophy index [SHI] and synovial vascularization) by grey-scale imaging and the Doppler synovitis index (DSI).

RESULTS

When we applied cut-off points determined by a ROC curve analysis, patients with a lower total SHI (≤34) or DSI (≤7) at baseline were significantly more likely to reach remission (44 patients, 51.2%) as shown by the DAS28-CRP at 54 weeks. On the basis of these cut-off values, we dichotomized all variables and performed a logistic regression analysis using the 54-weeks data; the only predictive factors of remission with anti-TNF therapy were the patients' baseline DAS28-CRP ≤2.7 as low disease activity/remission, and the SHI.

CONCLUSION

An ultrasound assessment would be a highly useful predictor of the achievement of clinical remission.

uPA-derived peptide, Å6 is involved in the suppression of lipopolysaccaride-promoted inflammatory osteoclastogenesis and the resultant bone loss

Introduction

Chronic inflammatory diseases such as rheumatoid arthritis and periodontitis frequently cause bone destruction. Inflammation‐induced bone loss results from the increase of bone‐resorbing osteoclasts. Recently, we demonstrated that urokinase type plasminogen activator (uPA) suppressed lipopolysaccaride (LPS)‐inflammatory osteoclastogenesis through the adenosine monophosphate‐activated protein kinase (AMPK) pathway, whereas its receptor (uPAR) promoted that through the Akt pathway.

Methods

We investigated the effects of uPA‐derived peptide (Å6) in the LPS‐induced inflammatory osteoclastogenesis and bone destruction.

Results

We found that Å6 attenuated inflammatory osteoclastogenesis and bone loss induced by LPS in mice. We also showed that Å6 attenuated the LPS‐promoted inflammatory osteoclastogenesis by inactivation of NF‐κB in RAW264.7 mouse monocyte/macrophage lineage cells. Furthermore, we showed that Å6 attenuated the Akt phosphorylation, and promoted the AMPK phosphorylation.

Conclusion

Å6 is involved in the suppression of LPS‐promoted inflammatory osteoclastgensis and bone destruction by regulating the AMPK and Akt pathways. These findings provide a basis for clinical strategies to improve the bone loss caused by inflammatory diseases.

High-Resolution US of Rheumatologic Diseases

For the past 15 years, high-resolution ultrasonography (US) is being routinely and increasingly used for initial evaluation and treatment follow-up of rheumatologic diseases. This imaging technique is performed by using high-frequency linear transducers and has proved to be a powerful diagnostic tool in evaluation of articular erosions, simple and complex joint and bursal effusions, tendon sheath effusions, and synovitis, with results comparable to those of magnetic resonance imaging, excluding detection of bone marrow edema. Crystal deposition diseases including gouty arthropathy and calcium pyrophosphate deposition disease (CPPD) have characteristic appearances at US, enabling differentiation between these two diseases and from inflammatory arthropathies. Enthesopathy, which frequently accompanies psoriatic and reactive arthritis, also has a characteristic appearance at high-resolution US, distinguishing these two entities from other inflammatory and metabolic arthropathies. The presence of Doppler signal in examined joints, bursae, and tendon sheaths indicates active synovitis. Microbubble echo contrast agents augment detection of tissue vascularity and may act in the future as a drug delivery vehicle. Frequently, joint, tendon sheath, and bursal fluid aspirations and therapeutic injections are performed under US guidance. The authors describe the high-resolution US technique including gray-scale, color or power Doppler, and contrast agent-enhanced US that is used in evaluation of rheumatologic diseases of the wrist and hand and the ankle and foot in their routine clinical practice. This article demonstrates imaging findings of normal joints, rheumatoid arthritis, gouty arthritis, CPPD, psoriatic and reactive arthritis, and osteoarthritis.

How does a cadaver model work for testing ultrasound diagnostic capability for rheumatic-like tendon damage?

To establish whether a cadaver model can serve as an effective surrogate for the detection of tendon damage characteristic of rheumatoid arthritis (RA). In addition, we evaluated intraobserver and interobserver agreement in the grading of RA-like tendon tears shown by US, as well as the concordance between the US findings and the surgically induced lesions in the cadaver model. RA-like tendon damage was surgically induced in the tibialis anterior tendon (TAT) and tibialis posterior tendon (TPT) of ten ankle/foot fresh-frozen cadaveric specimens. Of the 20 tendons examined, six were randomly assigned a surgically induced partial tear; six a complete tear; and eight left undamaged. Three rheumatologists, experts in musculoskeletal US, assessed from 1 to 5 the quality of US imaging of the cadaveric models on a Likert scale. Tendons were then categorized as having either no damage, (0); partial tear, (1); or complete tear (2). All 20 tendons were blindly and independently evaluated twice, over two rounds, by each of the three observers. Overall, technical performance was satisfactory for all items in the two rounds (all values over 2.9 in a Likert scale 1-5). Intraobserver and interobserver agreement for US grading of tendon damage was good (mean κ values 0.62 and 0.71, respectively), with greater reliability found in the TAT than the TPT. Concordance between US findings and experimental tendon lesions was acceptable (70-100 %), again greater for the TAT than for the TPT. A cadaver model with surgically created tendon damage can be useful in evaluating US metric properties of RA tendon lesions.

Lapatinib ameliorates experimental arthritis in rats

Epidermal growth factor receptor (EGFR) and its ligands are commonly expressed by synovial cells. The aim of the present study was to detect the potential effect of lapatinib an inhibitor of EGFR tyrosine kinases on collagen-induced arthritis. Thirty Wistar albino female rats were randomized into three groups. Arthritis was induced by intradermal injection of chicken type II collagen with incomplete Freund's adjuvant. Serum TNF-α, IL-17, and malondialdehyde (MDA) levels were analyzed. Tissue superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx) activities, and nuclear factor erythroid 2-related factor-2 (Nrf2) and heme oxgenase-1 (HO-1) expressions were determined. TNF-α, IL-17 and MDA levels, and Nrf2 and HO-1 expressions were lower in lapatinib-treated (30 mg/kg/day) group compared to sham group, while SOD, catalase, and GPx activities were higher (p < 0.05). Moreover, lapatinib ameliorated perisynovial inflammation and cartilage-bone destruction (p < 0.001). In conclusion, EGFR may have prominent pathogenic role and lapatinib may be an effective therapeutic option for arthritis.

Near-infrared Fluorescence Optical Imaging in Early Rheumatoid Arthritis: A Comparison to Magnetic Resonance Imaging and Ultrasonography

OBJECTIVE

Near-infrared fluorescence optical imaging (FOI) is a novel imaging technology in the detection and evaluation of different arthritides. FOI was validated in comparison to magnetic resonance imaging (MRI), greyscale ultrasonography (GSUS), and power Doppler ultrasonography (PDUS) in patients with early rheumatoid arthritis (RA).

METHODS

Hands of 31 patients with early RA were examined by FOI, MRI, and US. In each modality, synovitis of the wrist, metacarpophalangeal joints (MCP) 2-5, and proximal interphalangeal joints (PIP) 2-5 were scored on a 4-point scale (0-3). Sensitivity and specificity of FOI were analyzed in comparison to MRI and US as reference methods, differentiating between 3 phases of FOI enhancement (P1-3). Intraclass correlation coefficients (ICC) were calculated to evaluate the agreement of FOI with MRI and US.

RESULTS

A total of 279 joints (31 wrists, 124 MCP and 124 PIP joints) were evaluated. With MRI as the reference method, overall sensitivity/specificity of FOI was 0.81/0.00, 0.49/0.84, and 0.86/0.38 for wrist, MCP, and PIP joints, respectively. Under application of PDUS as reference, sensitivity was even higher, while specificity turned out to be low, except for MCP joints (0.88/0.15, 0.81/0.76, and 1.00/0.27, respectively). P2 appears to be the most sensitive FOI phase, while P1 showed the highest specificity. The best agreement of FOI was shown for PDUS, especially with regard to MCP and PIP joints (ICC of 0.57 and 0.53, respectively), while correlation with MRI was slightly lower.

CONCLUSION

FOI remains an interesting diagnostic tool for patients with early RA, although this study revealed limitations concerning the detection of synovitis. Further research is needed to evaluate its full diagnostic potential in rheumatic diseases.

Quantitative assessment of synovitis in patients with rheumatoid arthritis using fluorescence optical imaging

Introduction

To prospectively evaluate quantitative assessment of fluorescence optical imaging (FOI) for differentiation of synovitic from non-synovitic joints in patients suffering from rheumatoid arthritis (RA).

Methods

FOI of the hands was performed in patients with active RA, and a stratified quantitative fluorescence readout (FLRO) of 3 phases (1-120 s; 121-240 s; 241-360 s) was generated for 5 individual joints of the clinical predominant hand (carpal joint, metacarpophalangeal and proximal interphalangeal joints of digits II & III). To dissect the effect of the overall perfusion of the hand from the perfusion due to synovitis, a fluorescence ratio (FLRA) was additionally calculated, dividing each FLRO by the readout of the eponychium of digit II. The mean FLRO and FLRA were compared between joints with absent vs. present synovitis determined by clinical examination, grayscale, color Doppler ultrasonography, or magnetic resonance imaging (MRI).

Results

The analysis for 90 individual joints from 18 patients yielded FLRO ranging from 4.4 to 49.0 × 10³, and FLRAs ranging from 0.37 to 2.27. Overall, the analyses based on the FLRA revealed a higher discrimination than the analyses related to the FLRO, demonstrating most significant differences in phases 2 and 3. A sensitivity of 26/39 (67%) and a specificity of 31/40 (77%) were calculated for FLRA of phase 3 using a cut-off value of more than 1.2 to detect MRI-confirmed synovitis with FOI.

Conclusions

FOI has a potential for visualizing synovitis in subjects with RA. For adequate FOI interpretation, quantitative analysis should be based on the novel FLRA calculated for phases 2 and 3.

Does ultrasound-scored synovitis depend on the pharmacokinetics of subcutaneous anti-TNF agents in patients with rheumatoid arthritis?

OBJECTIVE

The aim of this study was to investigate the influence of the pharmacokinetics of s.c. anti-TNF agents on the grade of US-detected synovitis in RA patients.

METHODS

Fifty RA patients were prospectively recruited from the Biologic Therapy Unit of our hospital. Inclusion criteria were being in treatment with s.c. anti-TNF agents and having had neither changes in therapy nor local corticosteroid injections in the previous 3 months. Patients underwent clinical, laboratory [28-joint DAS (DAS28) and Simplified Disease Activity Index (SDAI)] and US assessment at two time points, i.e. at peak plasma drug concentration and at trough plasma drug concentration. US assessments were performed blindly to the anti-TNF agent, the administration time and the clinical and laboratory data. Twenty-eight joints were investigated for the presence and grade (0-3) of B-mode synovitis and synovial power Doppler signal. Global indices for B-mode synovitis (BSI) and Doppler synovitis (DSI) were calculated for 12 joints and for wrist-hand-ankle-foot joints. B-mode US remission was defined as a BSI <1 and Doppler US remission as a DSI <1.

RESULTS

There were no significant differences between the clinical, laboratory and B-mode and Doppler US parameters at peak time and trough time (P = 0.132-0.986). There were no significant differences between the proportion of patients with active disease and those in remission according to DAS28, SDAI, B-mode US and Doppler US at peak time and trough time assessments (P = 0.070-1).

CONCLUSION

Our results suggested that s.c. anti-TNF pharmacokinetics do not significantly influence US-scored synovitis in RA patients.

Histamine synergistically promotes bFGF-induced angiogenesis by enhancing VEGF production via H1 receptor

Histamine, a major mediator present in mast cells that is released into the extracellular milieu upon degranulation, is well known to possess a wide range of biological activities in several classic physiological and pathological processes. However, whether and how it participates in angiogenesis remains obscure. In the present study, we observed its direct and synergistic action with basic fibroblast growth factor (bFGF), an important inducer of angiogenesis, on in vitro angiogenesis models of endothelial cells. Data showed that histamine (0.1, 1, 10 µM) itself was absent of direct effects on the processes of angiogenesis, including the proliferation, migration, and tube formation of endothelial cells. Nevertheless, it could concentration-dependently enhance bFGF-induced angiogenesis as well as production of vascular endothelial growth factor (VEGF) from endothelial cells. The synergistic effect of histamine on VEGF production could be reversed by pretreatments with diphenhydramine (H1-receptor antagonist), SB203580 (selective p38 mitogen-activated protein kinase (MAPK) inhibitor) and L-NAME (nitric oxide synthase (NOS) inhibitor), but not with cimetidine (H2-receptor antagonist) and indomethacin (cyclooxygenase (COX) inhibitor). Moreover, histamine could augment bFGF-incuced phosphorylation and degradation of IκBα, a key factor accounting for the activation and translocation of nuclear factor κB (NF-κB) in endothelial cells. These findings indicated that histamine was able to synergistically augment bFGF-induced angiogenesis, and this action was linked to VEGF production through H1-receptor and the activation of endothelial nitric oxide synthase (eNOS), p38 MAPK, and IκBα in endothelial cells.

Three-dimensional Volumetric Ultrasound: A Valid Method for Blinded Assessment of Response to Therapy in Rheumatoid Arthritis

Objective.

To assess the responsiveness and repeatability of volumetric power Doppler ultrasound (PDUS) evaluation of synovitis and bone erosions in rheumatoid arthritis (RA).

Methods.

Twenty-three patients with RA (19 women, mean age 52.7 ± 12.6 yrs, mean disease duration 10.1 ± 8.6 yrs) were prospectively enrolled. All patients were beginning therapy with rituximab because of disease activity despite therapy with synthetic disease-modifying antirheumatic drugs and tumor necrosis factor-blocking agents. Patients underwent clinical, laboratory, and volumetric PDUS examination at baseline, 6 months, and 12 months. Ten centers participated in the study. Four centers recruited the patients and performed the volumetric acquisitions of PDUS images, while the remaining 6 centers assessed the PDUS volumes, blinded to the identity of patients and date of the visits. The most symptomatic hand and foot were scored for B-mode synovitis, synovial PD signal, and bone erosions. The repeatability of the volumetric PDUS assessment was investigated.

Results.

An overall improvement in clinical and PDUS measurements was found at the followup assessments. The mean indexes for synovial PD signal and bone erosions and the number of sites with abnormalities decreased significantly throughout the followup (p < 0.05). The intraacquisition, intrareader reliability was excellent for all PDUS measurements (intraclass correlation coefficients > 0.9).

Conclusion.

The results of our pilot study suggest that volumetric PDUS can be responsive and repeatable in multicenter cohort studies of RA. This technique may minimize assessment biases and reduce acquisition variability in open-label and observational studies.

Reliability of a consensus-based ultrasound score for tenosynovitis in rheumatoid arthritis

OBJECTIVE

To produce consensus-based scoring systems for ultrasound (US) tenosynovitis and to assess the intraobserver and interobserver reliability of these scoring systems in rheumatoid arthritis (RA).

METHODS

We undertook a Delphi process on US-defined tenosynovitis and US scoring system of tenosynovitis in RA among 35 rheumatologists, experts in musculoskeletal US (MSUS), from 16 countries. Then, we assessed the intraobserver and interobserver reliability of US in scoring tenosynovitis on B-mode and with a power Doppler (PD) technique. Ten patients with RA with symptoms in the hands or feet were recruited. Ten rheumatologists expert in MSUS blindly, independently and consecutively scored for tenosynovitis in B-mode and PD mode three wrist extensor compartments, two finger flexor tendons and two ankle tendons of each patient in two rounds in a blinded fashion. Intraobserver reliability was assessed by Cohen's κ. Interobserver reliability was assessed by Light's κ. Weighted κ coefficients with absolute weighting were computed for B-mode and PD signal.

RESULTS

Four-grade semiquantitative scoring systems were agreed upon for scoring tenosynovitis in B-mode and for scoring pathological peritendinous Doppler signal within the synovial sheath. The intraobserver reliability for tenosynovitis scoring on B-mode and PD mode was good (κ value 0.72 for B-mode; κ value 0.78 for PD mode). Interobserver reliability assessment showed good κ values for PD tenosynovitis scoring (first round, 0.64; second round, 0.65) and moderate κ values for B-mode tenosynovitis scoring (first round, 0.47; second round, 0.45).

CONCLUSIONS

US appears to be a reproducible tool for evaluating and monitoring tenosynovitis in RA.

TIMP2 deficient mice develop accelerated osteoarthritis via promotion of angiogenesis upon destabilization of the medial meniscus

Vascular invasion into the normally avascular articular surface is a hallmark of advanced osteoarthritis (OA). In this study, we demonstrated that the expression of tissue inhibitor of metalloproteinases-2 (TIMP2), an anti-angiogenic factor, was present at high levels in normal articular chondrocytes, and was drastically decreased shortly after destabilization of the medial meniscus (DMM). We also investigated the anti-angiogenic properties of TIMP2 via knockout. We hypothesized that the loss of TIMP2 could accelerate osteoarthritis development via promotion of angiogenesis. Loss of TIMP2 led to increased periarticular vascular formation 1 month post DMM, compared to wild-type mice, and did so without altering the expression pattern of matrix metalloproteinases and vascular endothelial growth factors. The increased vascularization eventually resulted in a severe degeneration of the articular surface by 4 months post DMM. Our findings suggest that reduction of TIMP2 levels and increased angiogenesis are possible primary events in OA progression. Inhibiting or delaying angiogenesis by TIMP2 expression or other anti-angiogenic therapies could improve OA prevention and treatment.

Inflammation assessment in patients with arthritis using a novel in vivo fluorescence optical imaging technology

BACKGROUND

Indocyanine green (ICG)-enhanced fluorescence optical imaging (FOI) is an established technology for imaging of inflammation in animal models. In experimental models of arthritis, FOI findings corresponded to histologically proven synovitis. This is the first comparative study of FOI with other imaging modalities in humans with arthritis.

METHODS

252 FOI examinations (Xiralite system, mivenion GmbH, Berlin, Germany; ICG bolus of 0.1 mg/kg/body weight, sequence of 360 images, one image per second) were compared with clinical examination (CE), ultrasonography (US) and MRI of patients with arthritis of the hands.

RESULTS

In an FOI sequence, three phases could be distinguished (P1-P3). With MRI as reference, FOI had a sensitivity of 76% and a specificity of 54%, while the specificity of phase 1 was 94%. FOI had agreement rates up to 88% versus CE, 64% versus greyscale US, 88% versus power Doppler US and 83% versus MRI, depending on the compared phase and parameter. FOI showed a higher rate of positive results compared to CE, US and MRI. In individual patients, FOI correlated significantly (p<0.05) with disease activity (Disease Activity Score 28, r=0.41), US (r=0.40) and RAMRIS (Rheumatoid Arthritis MRI Score) (r=0.56). FOI was normal in 97.8% of joints of controls.

CONCLUSION

ICG-enhanced FOI is a new technology offering sensitive imaging detection of inflammatory changes in subjects with arthritis. FOI was more sensitive than CE and had good agreement with CE, US in power Doppler mode and MRI, while showing more positive results than these. An adequate interpretation of an FOI sequence requires a separate evaluation of all phases. For the detection of synovitis and tenosynovitis, FOI appears to be as informative as 1.5 T MRI and US.

A systematic literature review of US definitions, scoring systems and validity according to the OMERACT filter for tendon lesion in RA and other inflammatory joint diseases

OBJECTIVE

To present the published data concerning the US assessment of tendon lesions as well as the US metric properties investigated in inflammatory arthritis.

METHODS

A systematic literature search of PubMed, Embase and the Cochrane Library was performed. Selection criteria were original articles in the English language reporting US, Doppler, tenosynovitis and other tendon lesions in patients with RA and other inflammatory arthritis. Data extraction focused on the definition and quantification of US-detected tenosynovitis and other tendon abnormalities and the metric properties of US according to the OMERACT filter for evaluating the above tendon lesions.

RESULTS

Thirty-three of 192 identified articles were included in the review. Most articles were case series (42%) or case-control (33%) studies describing hand and/or foot tenosynovitis in RA patients. The majority of older articles used only B-mode, whereas the most recent studies have incorporated Doppler mode. Definition of tenosynovitis or other tendon lesion was provided in 70% of the evaluated studies. Most of the studies (61%) used a binary score for evaluating tendon abnormalities. Concerning the OMERACT filter, 24 (73%) articles dealt with construct validity. The comparator most commonly used was clinical assessment and MRI. There were few studies assessing criterion validity. Some studies evaluated reliability (36%), responsiveness (21%) and feasibility (12%).

CONCLUSION

US seems a promising tool for evaluating inflammatory tendon lesions. However, further validation is necessary for implementation in clinical practice and trials.

Dynamic contrast-enhanced 3-T magnetic resonance imaging: a method for quantifying disease activity in early polyarthritis

OBJECTIVE

To determine whether measurement of synovial enhancement and thickness quantification parameters with 3.0-Tesla magnetic resonance imaging (3-T MRI) can reliably quantify disease activity in patients with early polyarthritis.

MATERIALS AND METHODS

Eighteen patients (16 women, 2 men; mean age 46 years) with early polyarthritis with less than 12 months of symptoms were included. MRI examination using 3-T device was performed by a new approach including both wrists and hands simultaneously in the examination field-of-view. MRI scoring of disease activity included quantification of synovial enhancement with simple measurements such as rate of early enhancement (REE; REE(57) = S(57)/S(200), where S(57) and S(200) are the signal intensities 57 s and 200 s after gadolinium injection) and rate of relative enhancement (RE; RE = S(200) - S(0)). Both wrists and hands were scored according to the Rheumatoid Arthritis MRI Scoring System (RAMRIS) for synovitis. Disease activity was clinically assessed by the 28-joint Disease Activity Score (DAS28).

RESULTS

DAS28 score was strongly correlated with RE (r = 0.8331, p < 0.0001), REE (r = 0.8112, p < 0.0001), and RAMRIS score for synovitis (r = 0.7659, p < 0.0002). An REE score above 0.778 accurately identified patients with clinically active disease (sensitivity 92%; specificity 67%; p < 0.05). A statistically significant difference was observed in the RE, REE, and RAMRIS scores for synovitis between patients with active and inactive disease (p < 0.05).

CONCLUSIONS

Our findings support the use of 3-T dynamic contrast-enhanced MRI for precise quantification of disease activity and for discriminating active disease from inactive disease in early polyarthritis.

Functionalized STAT1 siRNA nanoparticles regress rheumatoid arthritis in a mouse model

AIM

To develop and characterize an RGD peptide functionalized poly(lactide-co-glycolytic) acid (PLGA) nanosystem to deliver a STAT1 siRNA to joint tissues in a mouse model of rheumatoid arthritis.

METHODS

RGD-PLGA polymer was synthesized and used in preparing functionalized nanoparticles loaded with either tracking material or siRNA. The properties of the nanoparticles and stability of siRNA after encapsulation was assessed. Nanoparticle distribution was determined both noninvasively and based on analysis of dissected organs from arthritic and healthy mice. Arthritic mice were treated with weekly doses of STAT1 siRNA-loaded nanoparticles or controls. Clinical disease was assessed. Paws of arthritic mice were sectioned for histology or processed for RNA. STAT1, Mrc-1, and IL-10 mRNA abundance was determined by quantitative PCR.

RESULTS

Nanoparticles protected the siRNA from serum degradation. The presence of RGD peptide on the nanoparticles increased paw tissue uptake in arthritic mice. Furthermore, RGD functionalization increased lung delivery of nanoparticles in arthritic mice but not in control mice. Disease regressed in the STAT1 siRNA-treated animals and progressed in all control groups. STAT1 mRNA levels were decreased in paws of treated animals, while Mrc-1 and IL-10 mRNA levels were increased.

CONCLUSION

RGD functionalized PLGA nanoparticles encapsulating STAT1-targeted siRNAs are efficacious in the treatment of established arthritis, possibly through a selective inhibition of macrophage and dendritic cell activation.

Using magnetic resonance angiography to measure abnormal synovial blood vessels in early inflammatory arthritis: a new imaging biomarker?

OBJECTIVE

To ascertain whether magnetic resonance angiography (MRA) can reliably detect synovial neovascularization in subjects with early inflammatory arthritis.

METHODS

Subjects with 6 weeks to 6 months of clinical evidence of inflammatory hand arthritis had a radiograph, power Doppler ultrasound (PDU) scan, magnetic resonance imaging (MRI), and contrast enhanced MRA performed on the more symptomatic hand. Ultrasound examination of the wrist and 2nd-5th metacarpophalangeal (MCP) joints was scored for erosions, synovial thickening, and synovial blood flow. MRI were assessed using the OMERACT Rheumatoid Arthritis MRI Score (RAMRIS). MRA was used to assess the number of abnormal vessels in the 2nd-5th MCP and in the wrist.

RESULTS

Of 30 subjects, 66.7% showed abnormal vasculature on MRA in the MCP and/or wrist; mean number of abnormal vessels was 5.24 (range 0-22). Number of abnormal vessels on MRA was strongly correlated with degree of blood flow seen in the corresponding area on PDU (r = 0.79, p <or= 0.0001). The number of abnormal vessels was highly correlated with MRI MCP synovitis scores (r = 0.69, p <or= 0.0001), MRI wrist synovitis scores (r = 0.73, p <or= 0.0001), and ultrasound synovitis scores (r = 0.68, p <or= 0.0001).

CONCLUSION

In this cross-sectional pilot study, MRA identified abnormal vessels in patients with early inflammatory arthritis. This is the first report of MRA visualizing abnormal vessels in this patient population. If the degree of neovascularization in early inflammatory arthritis predicts disease course, MRA evidence of abnormal vessels could be a new imaging biomarker.

Targeting histone deacetylase activity in rheumatoid arthritis and asthma as prototypes of inflammatory disease: should we keep our HATs on?

Cellular activation, proliferation and survival in chronic inflammatory diseases is regulated not only by engagement of signal trans-duction pathways that modulate transcription factors required for these processes, but also by epigenetic regulation of transcription factor access to gene promoter regions. Histone acetyl trans-ferases coordinate the recruitment and activation of transcription factors with conformational changes in histones that allow gene promoter exposure. Histone deacetylases (HDACs) counteract histone acetyl transferase activity through the targeting of both histones as well as nonhistone signal transduction proteins important in inflammation. Numerous studies have indicated that depressed HDAC activity in patients with inflammatory airway diseases may contribute to local proinflammatory cytokine production and diminish patient responses to corticosteroid treatment. Recent observations that HDAC activity is depressed in rheumatoid arthritis patient synovial tissue have predicted that strategies restoring HDAC function may be therapeutic in this disease as well. Pharmacological inhibitors of HDAC activity, however, have demonstrated potent therapeutic effects in animal models of arthritis and other chronic inflammatory diseases. In the present review we assess and reconcile these outwardly paradoxical study results to provide a working model for how alterations in HDAC activity may contribute to pathology in rheumatoid arthritis, and highlight key questions to be answered in the preclinical evaluation of compounds modulating these enzymes.

Analysis of vascular gene expression in arthritic synovium by laser-mediated microdissection

OBJECTIVE

In rheumatoid arthritis (RA), formation of new blood vessels is necessary to meet the nutritional and oxygen requirements of actively proliferating synovial tissue. The aim of this study was to analyze the specific synovial vascular expression profiles of several angiogenesis-related genes as well as CD82 in RA compared with osteoarthritis (OA), using laser-mediated microdissection (LMM).

METHODS

LMM and subsequent real-time polymerase chain reaction were used in combination with immunohistochemical analysis for area-specific analysis of messenger RNA (mRNA) and protein expression of vascular endothelial growth factor (VEGF), VEGF receptor 1 (VEGFR-1), VEGFR-2, hypoxia-inducible factor 1alpha (HIF-1alpha), HIF-2alpha, platelet-derived growth factor receptor alpha (PDGFRalpha), PDGFRbeta, inhibitor of DNA binding/differentiation 2 (Id2), and CD82 in RA and OA synovial microvasculature and synovial lining.

RESULTS

Expression of Id2 mRNA was significantly lower in RA synovial vessels compared with OA synovial vessels (P=0.0011), whereas expression of VEGFR-1 was significantly higher in RA (P=0.0433). No differences were observed for the other parameters. At the protein level, no statistically significant differences were observed for any parameter, although Id2 levels were 2.5-fold lower in RA (P=0.0952). However, the number of synovial blood vessels and the number of VEGFR-2-expressing blood vessels were significantly higher in RA compared with OA.

CONCLUSION

Our results underscore the importance of area-specific gene expression analysis in studying the pathogenesis of RA and support LMM as a robust tool for this purpose. Of note, our results indicate that previously described differences between RA and OA in the expression of angiogenic molecules are attributable to higher total numbers of synovial and vascular cells expressing these molecules in RA rather than higher expression levels in the individual cells.

Longitudinal power Doppler ultrasonographic assessment of joint inflammatory activity in early rheumatoid arthritis: Predictive value in disease activity and radiologic progression

OBJECTIVE

To evaluate the sensitivity to change of power Doppler ultrasound (PDUS) assessment of joint inflammation and the predictive value of PDUS parameters in disease activity and radiologic outcome in patients with early rheumatoid arthritis (RA).

METHODS

Forty-two patients with early RA who started therapy with disease-modifying antirheumatic drugs underwent blinded sequential clinical, laboratory, and ultrasound assessment at baseline, 3 months, 6 months, and 1 year and radiographic assessment at baseline and 1 year. For each patient, 28-joint Disease Activity Score (DAS28) was recorded at each visit. The presence of synovitis was investigated in 28 joints using gray-scale ultrasonography and intraarticular power Doppler signal. Active synovitis was defined as intraarticular synovitis detected with power Doppler signal. The ultrasound joint count for active synovitis and an overall joint index for power Doppler signal were calculated. Sensitivity to change of PDUS variables was assessed by estimating the smallest detectable difference (SDD) from the intraobserver variability.

RESULTS

The SDD for ultrasound joint count for active synovitis and ultrasound joint index for power Doppler signal was lower than mean changes from baseline to 3 months, 6 months, and 1 year. Time-integrated values of PDUS parameters demonstrated a highly significant correlation with DAS28 after 1 year (r = 0.63, P < 0.001) and a stronger correlation with radiographic progression (r = 0.59-0.66, P < 0.001) than clinical and laboratory parameters (r < 0.5).

CONCLUSION

PDUS is a sensitive and reliable method for longitudinal assessment of inflammatory activity in early RA. PDUS findings may have a predictive value in disease activity and radiographic outcome.

Three-dimensional Doppler sonographic vascular imaging in regions with increased MR enhancement in inflamed wrists of patients with rheumatoid arthritis

OBJECTIVE

To compare three-dimensional (3D) power Doppler ultrasonography (PDUS) with contrast enhanced magnetic resonance imaging (MRI) in their capability to visualize synovial vascularity in inflamed wrists of patients with rheumatoid arthritis (RA).

METHODS

Nine patients with RA showing clinically active arthritis of the wrist as determined by tenderness and swelling were examined by contrast enhanced MRI and 3D PDUS. Vascularity close to and inside the joint capsule was visualized by conventional power Doppler mode. In a region with high Doppler signal intensity (=region of interest/ROI) a 3D blood vessel tree was obtained by a free-hand sweep. 3D images were evaluated with regard to the number of blood vessels in the intra- and peri-articular region. MRI examinations were performed using a 1.5 T Scanner. In MRI, time resolved coronal contrast enhanced T1-weighted sequences with fat suppression were acquired during an 8 min period to assess tissue enhancement. Relative enhancement was calculated and compared to 3D PDUS findings.

RESULTS

A 3D vascular tree consisting of peri- and intra-articular blood vessels could be demonstrated in the same anatomical ROI in which an increased gadolinium enhancement was measured by MRI in all examined RA patients. The number of penetrating vessels into the joint capsule, the number of intra-articular vessels and a semiquantitative estimation of the strength of blood flow were used to generate a 3D score for the intensity of synovial vascularity.

CONCLUSION

When compared with clinical symptoms and the gold standard dynamic MRI, 3D PDUS is a reliable imaging technique for assessing synovial vascularity in inflamed wrists of RA patients.

Growth hormone, VEGF and FGF: involvement in rheumatoid arthritis

Adult rheumatoid arthritis (RA), a systemic autoimmune disorder of unknown etiology, is characterized by dysfunctional cellular and humoral immunity, enhanced migration and attachment of peripheral macrophages and pro-inflammatory leukocytes to the synovium and articular cartilage of diarthrodial joints. The progressive destruction of cartilage and bone in RA is a result of elevated pro-inflammatory cytokine gene expression, synovial neovascularization, proteinase-mediated dissolution of articular cartilage matrix and osteoclast-mediated subchondral bone resorption. Juvenile chronic arthritis (JCA) is disease with manifestations similar to adult RA that occurs in childhood. JCA usually causes precocious joint destruction and often also presents with evidence of growth plate anomalies and reduced stature. Three proteins play an integral role in both adult RA and JCA. These are somatotropin (also called pituitary growth hormone (GH)), vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF). GH is responsible for regulating long bone growth and skeletal maturation through its capacity to stimulate insulin-like growth factor-I (IGF-1) synthesis by hepatocytes. Mechanisms responsible for growth plate disturbances and short stature in children with JCA include deficient GH production, GH-insensitivity resulting from defects in the GH receptor, suppressed IGF-1 synthesis or neutralization of IGF-1 action by IGF-1 binding proteins (IGFBPs). In addition, GH has also been implicated in perpetuating inflammation and pain in adult RA. VEGF has been shown to be the critical angiogenesis factor responsible for vascular proliferation and blood vessel invasion of the synovial lining membrane in RA. Acidic FGF (FGF-1) and basic FGF (FGF-2) have also been implicated in aberrant synoviocyte proliferation (i.e. synovial hyperplasia) and apoptosis resistance in adult RA.

Common carotid intima-media thickness and von Willebrand factor serum levels in rheumatoid arthritis female patients without cardiovascular risk factors

High atherosclerosis prevalence was found in rheumatoid arthritis (RA), and the von Willebrand factor (vWF) was shown to be a marker for endothelial damage. The aim of this study was to evaluate the association of intima-media thickness of the left common carotid artery with vWF serum levels in rheumatoid arthritis patients without cardiovascular risk factors. We included 55 RA female patients, each with at least 5 years of duration of the disease, and 20 healthy female subjects as members of the control group. The vWF, cholesterol, triglycerides, and the immune variables-rheumatoid factor and reactive C protein-were evaluated. The media thickness and intima-media thickness (IMT) in patients and in the control subjects were assessed by Doppler ultrasound of the left common carotid artery. Although the ages for RA patients and healthy female controls were not different, the IMT of the left common carotid artery (IMT CCA) in rheumatoid arthritis patients was increased in comparison with healthy control measurements, the mean being 0.67 mm (SD 0.18) vs 0.58 mm (SD 0.10) with a p value 0.01. The vWF serum levels showed differences in RA patients from those in control patients, 145.6 (SD 30.08) vs 121.8 (SD 37.17), respectively, with p=0.007. A correlation was also found between vWF with IMT CCA in the RA patients: r=0.390 and p<0.05. We concluded that the measurements of the left common carotid artery intima-media thickness together with the von Willebrand factor serum levels could give valuable information about the artery status and the atherosclerosis process in early stages in patients with rheumatoid arthritis without cardiovascular risk factors.

Role of angiogenesis in inflammatory bowel disease

Several studies have shown alterations in vascular anatomy and physiology in inflammatory bowel disease (IBD). These findings, together with the observed upregulation of the mediators of angiogenesis in IBD patients, suggest that angiogenesis possibly contributes to the initiation and perpetuation of IBD. There is considerable evidence of an interrelationship between the mechanisms of angiogenesis and chronic inflammation in IBD. The increased expression of endothelial junction adhesion molecules found in IBD patients indicates the presence of active angiogenesis. Evidence that angiogenesis is involved in IBD was also obtained from animal models of colitis, most notably from studies of angiogenesis inhibition. Serum levels of vascular endothelial growth factor (VEGF) correlate with disease activity in human IBD and fall with the use of steroids, thalidomide, or infliximab. Pharmacological inhibition of angiogenesis, therefore, has the potential to be a therapeutic strategy in IBD. This review outlines the evidence that the rate of angiogenesis is increased in the inflamed intestine in IBD and proposes lines for future research in this field.

Modern biologics used in orthopaedic surgery

PURPOSE OF REVIEW

In this review we summarize some of the most recent research in the area of local bone regeneration. These innovations may be relevant in the orthopaedic treatment of patients with rheumatoid arthritis, or other inflammatory arthridities, as such patients often present with inadequate bone stock.

RECENT FINDINGS

Bone grafting remains the standard treatment for bone deficiency. Several new approaches, such as the use of concentrated blood products or osteoprogenitor cells in conjunction with grafts, have been developed but remain to be tested clinically. Experimental studies have elucidated important aspects of the biology of bone graft remodeling and osteoprogenitor cell differentiation. Materials that can serve as graft alternatives continue to be developed. Positive experimental findings have resulted from combinations of such materials with osteoprogenitor cells or osteoinductive factors such as bone morphogenetic proteins.

SUMMARY

While few studies to date have examined the specific use of these new strategies in the setting of rheumatoid arthritis, many hold promise for patients with rheumatoid arthritis and other inflammatory and metabolic conditions that affect bone quality and quantity.

Immunohistochemical analysis of hip arthritis in ankylosing spondylitis: Evaluation of the bone–cartilage interface and subchondral bone marrow

OBJECTIVE

Previous histopathologic and magnetic resonance imaging studies suggest that the subchondral bone marrow might be the primary site of inflammation in patients with ankylosing spondylitis (AS) and that this might be reflected by inflammation found in hip joints. The aim of this study was to conduct an immunohistologic assessment of the bone-cartilage interface and subchondral bone marrow in AS patients with hip arthritis.

METHODS

We collected femoral heads from patients with AS, osteoarthritis (OA), and rheumatoid arthritis (RA) who were undergoing hip replacement. The subchondral bone marrow and bone-cartilage interface were assessed immunohistochemically by evaluating infiltrating T cells, microvessel density, and osteoclasts. Areas of the femoral head surface with and without cartilage were assessed separately.

RESULTS

At sites with surface cartilage, we found subchondral infiltration of CD3+ T cell aggregates at significantly higher numbers in AS patients as compared with OA patients, but not RA patients. At sites of complete cartilage destruction, the frequency of CD3+ T cell aggregates was significantly reduced as compared with sites with cartilage on the surface in AS patients, but not in RA patients. Similar differences were found for CD4+ and CD8+ T cells. Only at sites with surface cartilage, but not those without, angiogenesis and osteoclastic foci in the subchondral bone marrow in AS patients were significantly increased as compared with RA patients and with OA patients.

CONCLUSION

These findings suggest that the subchondral bone marrow and bone-cartilage interface are primary sites of inflammation in AS and that cartilage might be necessary for the induction of inflammation.