Can Magnetic Resonance Imaging Differentiate Undifferentiated Arthritis Based on Knee Imaging?

The value of different involvement patterns of the knee "synovio-entheseal complex" in the differential diagnosis of spondyloarthritis, rheumatoid arthritis, and osteoarthritis: an MRI-based study

OBJECTIVES

To explore the different involvement patterns of the knee "synovio-entheseal complex (SEC)" on MRI in patients with spondyloarthritis (SPA), rheumatoid arthritis (RA), and osteoarthritis (OA).

METHODS

This study retrospectively included 120 patients (male:female, 55:65) with a mean age of 39.20 years diagnosed with SPA (n = 40), RA (n = 40), and OA (n = 40) at the First Central Hospital of Tianjin between January 2020 and May 2022. Six knee entheses were assessed by two musculoskeletal radiologists according to the SEC definition. Bone marrow lesions associated with entheses include bone marrow edema (BME) and bone erosion (BE), which were classified as entheseal or peri-entheseal based on their relationship to the entheses. Three groups (OA, RA, and SPA) were established to characterize the location of enthesitis and the different SEC involvement patterns. Inter-group and intra-group differences were analyzed using the ANOVA or chi-square tests, and the inter-class correlation coefficient (ICC) test was used to determine inter-reader agreement.

RESULTS

The study contained a total of 720 entheses. The SEC-based analysis revealed different involvement patterns in three groups. The OA group had the most abnormal signals in tendons/ligaments (p = 0.002). The RA group had considerably greater synovitis (p = 0.002). The majority of peri-entheseal BE was identified in the OA and RA groups (p = 0.003). Furthermore, entheseal BME in the SPA group was significantly different from those in the other two groups (p < 0.001).

CONCLUSIONS

SEC involvement patterns differed in SPA, RA, and OA, which is important for differential diagnosis. SEC should be used as a whole evaluation method in clinical practice.

KEY POINTS

• The "synovio-entheseal complex (SEC)" explained differences and characteristic alterations in the knee joint in patients with spondyloarthritis (SPA), rheumatoid arthritis (RA), and osteoarthritis (OA). • The various SEC involvement patterns are crucial for differentiating SPA, RA, and OA. • When "knee pain" is the only symptom, a detailed identification of characteristic alterations in the knee joint of SPA patients may help timely treatment and delay the structural damage.

The clinical utility of faecal calprotectin in patients with differentiated and undifferentiated spondyloarthritis: Relevance and clinical implications

OBJECTIVES

There is cumulative evidence in the literature supporting a potential role of faecal calprotectin (FCP) as a biomarker for gut inflammation in spondyloarthritis (SpA). However its relevance in undifferentiated SpA (USpA) is still uncertain. The aim of the current study is to assess the diagnostic significance of FCP levels in patients with differentiated and undifferentiated SpA.

MATERIAL AND METHODS

A total of 52 differentiated SpA, 33 USpA and 50 controls could be included. For all patients, clinical evaluation, routine laboratory investigations, FCP levels, and occult blood in stool were performed. When indicated imaging and/or endoscopies were performed.

RESULTS

The differentiated SpA patients were 12 (23.1%) with ankylosing spondylitis, 21 (40.4%) with psoriatic arthritis, 13 (25%) with ulcerative colitis, 5 (9.6%) with Crohn's disease (CD) and one (1.9%) with reactive arthritis. The mean FCP level in 85 patients correlated with CRP and ESR. Within the SpA group ulcerative colitis and Crohn's disease patients had increased FCP levels compared to other SpA subgroups and USpA patients (p<0.001). The mean FCP levelwas significantly higher in the SpA patients compared to USpA and controls (p<0.001).

CONCLUSIONS

Elevated FCP levels may identify patients who are most likely to have SpA already in the unclassified phase of the disease. Further studies in different series of patients are needed to evaluate the potential diagnostic and prognostic roles of FCP in both differentiated and undifferentiated phases of the disease.

The Clinical Utility of Faecal Calprotectin in Patients with Differentiated and Undifferentiated Spondyloarthritis: Relevance and Clinical Implications

OBJECTIVES

There is cumulative evidence in the literature supporting a potential role of faecal calprotectin (FCP) as a biomarker for gut inflammation in spondyloarthritis (SpA). However its relevance in undifferentiated SpA (USpA) is still uncertain. The aim of the current study is to assess the diagnostic significance of FCP levels in patients with differentiated and undifferentiated SpA.

MATERIAL AND METHODS

A total of 52 differentiated SpA, 33 USpA and 50 controls could be included. For all patients, clinical evaluation, routine laboratory investigations, FCP levels, and occult blood in stool were performed. When indicated imaging and/or endoscopies were performed.

RESULTS

The differentiated SpA patients were 12 (23.1%) with ankylosing spondylitis, 21 (40.4%) with psoriatic arthritis, 13 (25%) with ulcerative colitis, 5 (9.6%) with Crohn's disease (CD) and one (1.9%) with reactive arthritis. The mean FCP level in 85 patients correlated with CRP and ESR. Within the SpA group ulcerative colitis and Crohn's disease patients had increased FCP levels compared to other SpA subgroups and USpA patients (p<0.001). The mean FCP levelwas significantly higher in the SpA patients compared to USpA and controls (p<0.001).

CONCLUSIONS

Elevated FCP levels may identify patients who are most likely to have SpA already in the unclassified phase of the disease. Further studies in different series of patients are needed to evaluate the potential diagnostic and prognostic roles of FCP in both differentiated and undifferentiated phases of the disease.

Rheumatology in Egypt: back to the future

Medical knowledge in ancient Egypt had a remarkable reputation since rulers of other empires used to request the pharaoh to send them their best physician to treat their beloved ones. Many rheumatologic conditions as giant-cell arteritis, reactive arthritis and other forms of spondyloarthritis have been identified in ancient Egyptian materials. Rheumatologists in Egypt are enormously expanding and mastering the tools that aid them in enhancing the management of rheumatic diseases. More Egyptian rheumatologists are actively participating in the annual European League Against Rheumatism (EULAR) and American College of Rheumatology conferences and those attached to well known state of the art centers are increasing. EULAR certified Egyptian MSUS trainers are effectively performing regionally. This review throws light on the rheumatology practice in Egypt, its progress from ancient times passing through Egyptian medical healthcare services, education systems for rheumatologists, rheumatology associations, an overview on the spectrum of rheumatic diseases through publications in the field till future perspectives. Rheumatology in Egypt is an actively growing and dynamic specialty of medicine with considerable contributions to the world's literature. These days, persistent efforts are mandatory to raise the standard of clinical and basic research, to optimize clinical practice with regard to new biologics, to develop tailored and targeted therapies for the rheumatic diseases, and to meet the medical demands of the exponentially increasing Egyptian population. Opportunities and challenges discussed high-lighten future perspectives needed to boost the rheumatology practice in Egypt.

Monitoring total-body inflammation and damage in joints and entheses: the first follow-up study of whole-body magnetic resonance imaging in rheumatoid arthritis

OBJECTIVE

To investigate changes in whole-body magnetic resonance imaging (WBMRI) inflammatory and structural lesions in most joints and entheses in patients with rheumatoid arthritis (RA) treated with adalimumab.

METHODS

WBMRI was obtained at weeks 0, 6, 16, and 52 in a 52 week follow-up study of 37 RA patients starting treatment with adalimumab. Readability and reliability of WBMRI were investigated for 76 peripheral joints, 23 discovertebral units, the sacroiliac joints, and 33 entheses. Changes in WBMRI joint and entheses counts were investigated.

RESULTS

The readability of peripheral and axial joints was 82-100%, being less for elbows and small joints of the feet. For entheses, 72-100% were readable, except for entheses at the anterior chest wall, elbow, knee, and plantar fascia. The intrareader agreement was high for bone marrow oedema (BMO), bone erosion (80-100%), and enthesitis (77-100%), and slightly lower for synovitis and soft tissue inflammation (50-100%). All synovitis, BMO, and soft tissue inflammation counts decreased numerically during treatment. The 26-joint synovitis WBMRI count decreased significantly during the first 16 weeks for patients with a good European League Against Rheumatism (EULAR) response (from median 6 to 4, p < 0.05), but not for patients with a moderate or no EULAR response. There were no overall changes in structural lesions.

CONCLUSIONS

WBMRI allows simultaneous monitoring of most axial and peripheral joints and entheses in RA patients and can visualize a decrease in inflammatory counts during treatment. This first WBMRI follow-up study of patients with RA encourages further investigation of the usefulness of WBMRI in RA.

Chemical exchange saturation transfer MR imaging of articular cartilage glycosaminoglycans at 3 T: Accuracy of B0 Field Inhomogeneity corrections with gradient echo method

Glycosaminoglycan Chemical Exchange Saturation Transfer (gagCEST) is an important molecular MRI methodology developed to assess changes in cartilage GAG concentrations. The correction for B0 field inhomogeneity is technically crucial in gagCEST imaging. This study evaluates the accuracy of the B0 estimation determined by the dual gradient echo method and the effect on gagCEST measurements. The results were compared with those from the commonly used z-spectrum method. Eleven knee patients and three healthy volunteers were scanned. Dual gradient echo B0 maps with different ∆TE values (1, 2, 4, 8, and 10 ms) were acquired. The asymmetry of the magnetization transfer ratio at 1 ppm offset referred to the bulk water frequency, MTRasym(1 ppm), was used to quantify cartilage GAG levels. The B0 shifts for all knee patients using the z-spectrum and dual gradient echo methods are strongly correlated for all ∆TE values used (r = 0.997 to 0.786, corresponding to ∆TE = 10 to 1 ms). The corrected MTRasym(1 ppm) values using the z-spectrum method (1.34% ± 0.74%) highly agree only with those using the dual gradient echo methods with ∆TE = 10 ms (1.72% ± 0.80%; r = 0.924) and 8 ms (1.50% ± 0.82%; r = 0.712). The dual gradient echo method with longer ∆TE values (more than 8 ms) has an excellent correlation with the z-spectrum method for gagCEST imaging at 3T.

Imaging in psoriatic arthritis

Psoriatic arthritis (PsA), a chronic inflammatory arthritis associated with psoriasis, is often associated with significant inflammation and joint damage leading to a decrease in quality of life measures. Plain radiographs have traditionally been used to detect and estimate the extent of joint damage. Newer imaging modalities such as ultrasound and MRI however, have provided the ability to detect joint damage earlier and measure the extent of joint damage more accurately, than with radiographs. These imaging modalities also provide a sensitive means of assessing for the presence of and quantifying the amount of inflammation. Furthermore, these imaging modalities can help with the identification of enthesitis, tendonitis, and dactylitis, features that can help make a diagnosis of PsA. Additionally, MRI and scintigraphy can help in the early detection and assessment of sacroiliitis and axial disease. In addition to benefits with diagnosis and prognosis, recent advances in imaging techniques have led to their increased use in the assessment of efficacy of novel therapies for psoriatic arthritis. Imaging modalities therefore allow for early detection, assessment of joint inflammation and joint damage as well as in the estimation of disease activity of PsA and thereby enable the clinician to treat PsA early, adequately, and safely.

The critical role of interleukin-23 in spondyloarthropathy

The spondyloarthropathies represent highly enigmatic conditions and although their clinical features, anatomical distribution of disease and genetic predisposing factors have been known for some time, a unified concept of the basic pathobiology underlying these illnesses has remained undefined. Recently progress has been made because numerous independent studies have converged upon IL-23 as a central cytokine in spondyloarthropathy and the mechanism and sites of action of this cytokine have now become much clearer. These findings enable the rational design of therapeutic strategies which it is hoped will profoundly modify the progression of these diseases. We will review the anatomical sites affected and the evidence for the importance of IL-23 in these conditions, before drawing these lines of investigation together to propose a model for the unified understanding of spondyloarthropathy.

Knee enthesitis and synovitis on magnetic resonance imaging in patients with psoriasis without arthritic symptoms

OBJECTIVE

This case-control study was designed to evaluate magnetic resonance imaging (MRI) findings of knee joints in patients with psoriasis without clinical peripheral or axial joint involvement, and to correlate MRI findings with disease and demographic variables.

METHODS

In total 48 patients with psoriasis and no clinical evidence of synovitis or enthesitis in any peripheral or axial joints were enrolled. A random sample of 20 healthy subjects without knee or other joint complaints and matched for age and sex served as controls. All patients and controls underwent enhanced MRI studies of both knee joints, and MRI findings were compared.

RESULTS

Among 48 patients (96 knees), a total of 90 entheseal lesions were detected, with no enthesitis in 2 cases (6.3%). Signs of continuing inflammation bilaterally were frequently found: soft tissue edema (STE; n = 52), bone marrow edema (BME; n = 20), perientheseal BME (n = 3), cartilaginous erosions (n = 42), and bone erosions (n = 27). In controls, 2 (10%) subjects had BME and another 5 (25%) showed cartilaginous erosions. None showed evidence of enthesitis. Significant correlations were observed between the number of entheseal lesions of both knees vs STE (present vs absent; r = 0.314, p = 0.030) and STE (number of lesions; r = 0.351, p = 0.014). Enthesitis (unilateral vs bilateral) was significantly and positively correlated with STE (r = 0.304, p = 0.036), cartilaginous erosions (r = 0.304, p = 0.036), and villous projections (r = 0.347, p = 0.016).

CONCLUSION

Subclinical synovitis and enthesitis are frequently found in the knee joint of patients with psoriasis. These may be an early sign of psoriatic arthritis.

Enthesitis and Related Changes in the Knees in Seronegative Spondyloarthropathies and Skin Psoriasis: Magnetic Resonance Imaging Case-Control Study

Objective.

To describe enhanced magnetic resonance imaging (MRI) features and characteristic entheseal changes in the knees in patients with seronegative spondyloarthropathy (SpA).

Methods.

The 56 patients included 30 with psoriatic arthritis, 5 with ankylosing spondylitis, 5 with reactive arthritis, 5 with ulcerative colitis (UC), 5 with Crohn’s disease, and another 6 with skin psoriasis. Controls were 20 healthy subjects without knee complaints. MRI was performed in all participants, emphasizing entheseal sites.

Results.

Both knees were studied in 45 (80.3%) patients and one knee in 11 (19.6%). MRI showed evidence of bone marrow edema in 13 (23.2%) patients, cartilaginous erosions in 18 (32.1%), and bone erosions in 9 (16.1%). Enthesitis was found in medial collateral ligaments in 18 (32.1%), lateral collateral ligaments in 8 (14.3%), posterior cruciate ligaments in 3 (5.35%), patellar tendon in 18 (32.1%), biceps femoris insertion in 3 (5.35%), medial patellofemoral ligaments (MPFL) in 5 (8.9%), and lateral patellofemoral ligament in 1 patient (1.8%). In the UC and Crohn’s patients (n = 10), 2 had bone erosions and 5 had enthesitis. In the skin psoriasis group (n = 6), one had bone marrow edema; enthesitis was detected in 5 at the patellar tendon insertion and in one in the MPFL. Entheseal-related changes were absent in the controls.

Conclusion.

This is the first study showing entheseal-related changes in the knees in patients with inflammatory bowel disease or skin psoriasis without clinical arthritis. Enthesitis of the knee on MRI may be an early finding in SpA.

Prevalence and predictive value of anti-cyclic citrullinated protein antibodies for future development of rheumatoid arthritis in early undifferentiated arthritis

The aim of this study is to evaluate the prevalence and predictive value of anti-cyclic citrullinated protein (CCP) antibodies as a diagnostic marker for future development of rheumatoid arthritis (RA) in a cohort of patients presenting with undifferentiated arthritis (UA). The study comprised 69 patients (22 males and 47 females) presenting with UA, and 66 healthy subjects as control group. For all patients the following parameters were assessed: swollen joint count (SJC), tender joint count (TJC), and duration of morning stiffness in minutes. Baseline laboratory investigations included erythrocyte sedimentation rate (ESR) first hour, C-reactive protein (CRP), complete blood count, complete liver and kidney function tests, urine analysis, anti-nuclear antibodies, rheumatoid factor (RF), and anti-CCP antibodies. Positive correlations were observed between anti-CCP versus SJC, TJC (p = 0.001), duration of morning stiffness (p = 0.04), ESR first hour, and bone erosive changes (p = 0.001). Anti-CCP showed sensitivity of 57%, specificity of 37.9%, positive predictive value of 65.1%, and negative predictive value of 39.3%. Sensitivity and positive predictive values of anti-CCP are close to those observed for RF. In patients presenting with UA, anti-CCP antibodies may allow prediction of RA, thereby allowing early individualized therapeutic decisions.