Micro-structural bone changes in early rheumatoid arthritis persist over 1-year despite use of disease modifying anti-rheumatic drug therapy

Circulating Baseline CXCR3+Th2 and Th17 Cell Proportions Correlate With Trabecular Bone Loss After 48 Weeks of Biological Treatment in Early Rheumatoid Arthritis

OBJECTIVE

The high prevalence of osteoporosis in rheumatoid arthritis (RA) is due to inflammation that stimulates differentiation of osteoclasts, a process involving circulating monocytes and T cell-derived factors. The aim of this study was to evaluate relations between circulating monocytes, T cell subsets, and changes in bone characteristics before and after treatment with biological disease-modifying antirheumatic drugs (bDMARDs) in RA.

METHODS

Thirty patients with untreated early RA who met the American College of Rheumatology/EULAR 2010 criteria were included. Data were collected before and 48 weeks after treatment with methotrexate (MTX) together with one of three bDMARDs (abatacept, tocilizumab, or certolizumab pegol). Disease activity was measured using the Clinical Disease Activity Index, swollen or tender joint counts, C-reactive protein levels, and erythrocyte sedimentation rates. Proportions of monocyte and CD4+ T cell subsets in blood samples were analyzed by flow cytometry. Bone densitometry was performed using high-resolution peripheral quantitative computed tomography (HR-pQCT).

RESULTS

HR-pQCT revealed an overall decrease in cortical (P = 0.009) and trabecular (P = 0.034) bone mineral density, although a subset of patients showed no bone loss after 48 weeks of treatment. The overall bone loss was not associated with age, body mass index, sex, intraarticular glucocorticoid injections, or baseline disease activity. Loss of trabecular bone volume fraction correlated with high proportions of circulating CXCR3+Th2 cells (r = -0.38, P = 0.04) and CXCR3+Th17 cells (r = -0.36, P = 0.05) at baseline. Similarly, no loss of trabecular bone volume fraction correlated with high proportions of regulatory T cells (r = 0.4, P = 0.03) at baseline. However, the associations were not significant when corrected for confounders and multiple testing.

CONCLUSION

MTX together with bDMARDs efficiently reduce disease activity but only prevent bone loss in a subset of patients with RA after 48 weeks of treatment. The correlations of circulating baseline T helper cell and regulatory T cell populations with trabecular bone changes suggest a potential novel role for these cells in systemic bone homeostasis during early RA.

Complications After Open Reduction and Internal Fixation for Distal Radius Fractures in Patients With and Without Rheumatoid Arthritis

PURPOSE

Rheumatoid arthritis (RA) can have severe impact on patients' functional abilities and increase the risk of fragility fractures. Little is known about how patients with RA fare after operative management of distal radius fractures. The purpose of this study was to compare postoperative complications after surgical fixation in patients with RA and controls, hypothesizing that patients with RA would have higher levels of postoperative complications.

METHODS

Patients were identified using Current Procedural Terminology and International Classification of Diseases, Ninth and Tenth Revision, codes for open treatment of distal radius fractures and RA at 3 level 1 trauma centers over a 5-year period (2015-2019). Chart abstraction provided details regarding injuries and treatment. Age- and sex-matched controls were identified in a 2:1 ratio. Postoperative complications were classified according to the Clavien-Dindo-Sink classification system and divided into early (less than 90 days) and late groups.

RESULTS

Sixty-four patients (21 with RA and 43 controls) were included. The patients were predominantly women, with a mean age of 62 years and a mean Charlson comorbidity index of 2.1. The RA medications at the time of injury included conventional synthetic disease-modifying antirheumatic drugs (5/21), biologic disease-modifying antirheumatic drugs (5/21), or chronic oral prednisone (6/21). Rheumatoid medications, except hydroxychloroquine, were withheld for 2-3 weeks after surgery. Rheumatoid patients were significantly more likely to sustain a complication compared with the control group, although this was no longer significant on adjusted analysis. Class I complications were the most common. The incidence of early versus late complications was similar between the groups. A high rate of early return to surgery for fixation failure occurred in the RA group compared with none in the control group.

CONCLUSIONS

Patients with RA undergoing operative management of distal radius fractures are at risk of postoperative complications, particularly fracture fixation failure, necessitating return to the operative room. High levels of pain, stiffness, and mechanical symptoms were noted in the RA group.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic IV.

Image Registration in Longitudinal Bone Assessment Using Computed Tomography

PURPOSE OF REVIEW

Rigid image registration is an important image processing tool for the assessment of musculoskeletal chronic disease. In this paper, we critically review applications of rigid image registration in terms of similarity measurement methods over the past three years (2019-2022) in the context of monitoring longitudinal changes to bone microstructure and mechanical properties using computed tomography. This review identifies critical assumptions and trade-offs underlying different similarity measurement methods used in image registration and demonstrates the effect of using different similarity measures on registration outcomes.

RECENT FINDINGS

Image registration has been used in recent studies for: correcting positional shifts between longitudinal scans to quantify changes to bone microstructural and mechanical properties over time, developing registration-based workflows for longitudinal assessment of bone properties in pre-clinical and clinical studies, and developing and validating registration techniques for longitudinal studies. In evaluating the recent literature, it was found that the assumptions at the root of different similarity measures used in rigid image registration are not always confirmed and reported. Each similarity measurement has its advantages and disadvantages, as well as underlying assumptions. Breaking these assumptions can lead to poor and inaccurate registration results. Thus, care must be taken with regards to the choice of similarity measurement and interpretation of results. We propose that understanding and verifying the assumptions of similarity measurements will enable more accurate and efficient quantitative assessments of structural changes over time.

Evaluation of the anti-RANKL monoclonal antibody in rheumatoid arthritis rats

Objectives: In this study, we aimed to investigate the therapeutic effect of anti-receptor activator of nuclear factor kappa-κB ligand (RANKL) monoclonal antibodies R748-1-1-1, R748-1-1-2 and R748-1-1-3 on rheumatoid arthritis (RA) in a rat model.

Materials and methods: Gene cloning, hybridoma technology, affinity purification, enzyme-linked immunosorbent assay, general observation, hematoxylin-eosin staining, X-ray, and many other experimental techniques were used in this study.

Results: Improved collagen-induced arthritis (CIA) modeling was successfully constructed. The RANKL gene was cloned and the anti-RANKL monoclonal antibody was prepared. Following treatment with the anti-RANKL monoclonal antibody, the soft tissue swelling of the hind paws, the joint thickening, the narrowed joint gap, and the blurred edge of the bone joint were improved. The pathological changes such as synovial hyperplasia of fibrous tissue, cartilage and bone destruction were significantly decreased in the anti-RANKL monoclonal antibody-treated CIA group. Compared to the normal control group and phosphate buffer saline (PBS)-treated CIA group, the expression of tumor necrosis factor-alpha (TNF-α) and interleukin-1 (IL-1) in antibody-treated CIA group, positive drug-treated CIA group, and IgG-treated CIA group were decreased (p<0.05).

Conclusion: The anti-RANKL monoclonal antibody can promote the therapeutic effect of RA rats, indicating that the anti-RANKL monoclonal antibody has a certain potential value and may be beneficial to the further study of the mechanism of RA treatment.

Lower hand grip in rheumatoid arthritis patients is associated with low finite element analysis using high resolution peripheral quantitative computed tomography scan of the 2nd metacarpophalangeal joint

AIM

To evaluate hand function by hand grip test in rheumatoid arthritis (RA) patients, and its association with bone erosions and the estimated bone strength (finite element - FE analysis) through the analysis of the 2nd metacarpal head of the dominant hand using high resolution peripheral quantitative computed tomography (HR-pQCT).

METHOD

Eighty-two female RA patients between 18-50 years old were selected. Demographic data, Health Questionnaire Assessment Disability Index (HAQ), Disease Activity Score of 28 joints (DAS)-28, simplified disease activity index (SDAI) and the hand grip test were set. The HR-pQCT scans of 2nd metacarpophalangeal joints of the dominant hand of all patients were performed according to SPECTRA group protocols. The images were used to assess bone erosions and FE analysis. The hand grip test was categorized in 2 groups and separately compared (< 18 vs ≥18 kgf). A logistic regression was performed using hand grip test <18 kgf as a dependent variable.

RESULTS

A significant difference was found between the 2 groups regarding HAQ, inflammatory markers (erythrocyte sedimentation rate, C-reactive protein), DAS-28, SDAI, total volume of erosion and bone strength parameter (FE analysis - Failure Load [F.Load]). The logistic regression analysis showed that the risk factors associated with hand grip test <18 kgf were higher SDAI (odds ratio [OR] 0.912; 95% CI 0.837-0.993) and lower values of bone strength parameter (F.Load) (OR 1.007; 95% CI 1.002-1.012).

CONCLUSION

Lower values of hand grip test were associated with higher disease activity score-SDAI and lower bone strength of 2nd metacarpal bone head of the dominant hand evaluated here through a FE analysis using HR-pQCT scan.

Bone erosion in the 2nd metacarpophalangeal head: association with its bone mineral density by HR-pQCT in rheumatoid arthritis patients

Background

Rheumatoid arthritis (RA) is a chronic autoimmune disease depicted by synovial inflammation leading to local and systemic bone loss. The aim of this study was to evaluate by a HR-pQCT (High Resolution Peripheral Quantitative Computed Tomography) study which parameters are associated with volume of bone erosions including bone mineral density (BMD) around erosions (VOI 1 to 4 = volume of interest), BMD of metacarpophalangeal (MCP) head, BMD of radius, presence of osteophytes and joint space width (JSW).

Methods

Fifty female RA patients (18–50 years) were enrolled in this study. Demographic and disease-specific data, laboratory inflammatory parameters and handgrip test were performed. All patients underwent HR-pQCT of 2nd and 3rd MCP joints and distal radius, according to established protocols. The volume of bone erosions was evaluated by MIAF (Medical Image Analysis Framework) software. Osteophytes were analyzed by manual method.

Results

The mean of age and disease duration were 40.0 ± 6.0 yrs. and 10.8 ± 4.8 yrs., respectively. According to DAS-28 (Disease Activity Score), 54% (27) of the sample were in remission. However, when SDAI (Simplified Disease Activity Index) was used, only 18% (9) were under remission. The mean of HAQ (Health Assessment Questionnaire), ESR (Erythrocyte sedimentation rate) and CRP (C reactive protein) were 0.9 ± 0.7, 13.9 ± 12.2 mm and 5.6 ± 7.5 mg/mL, respectively. Forty-six bone erosions (0.9 ± 1.2 erosion/patient) and 14 osteophytes (0.3 ± 0.7 osteophyte/patient) were found in 2nd MCP head. The median (IQR-Interquartile range) of volume of erosion and volume of osteophytes were 14.9 (5.7;35.9)mm³ and 3.1 (2.1, 4.3)mm³, respectively. The mean of JSW was 80.5 ± 34.2 mm³. The volume of bone erosions was negatively correlated with BMD of 2nd MCP head, VOI-4 and JSW; and it was positively correlated with osteophytes number. Regarding absence or presence of erosion in 2nd MCP head, a significant difference was found between BMD of MCP head, osteophyte number and JSW. Multiple linear regression analysis showed that only BMD of 2nd MCP head was independently associated with volume of bone erosions.

Conclusion

BMD of MCP head was independently associated with volume of bone erosion, suggesting that this parameter should be used to analyze and monitoring bone destruction, as well as to evaluate treatment response in RA patients.

High-Resolution Peripheral Quantitative Computed Tomography for Bone Evaluation in Inflammatory Rheumatic Disease

High resolution peripheral quantitative computed tomography (HR-pQCT) is a 3-dimensional imaging modality with superior sensitivity for bone changes and abnormalities. Recent advances have led to increased use of HR-pQCT in inflammatory arthritis to report quantitative volumetric measures of bone density, microstructure, local anabolic (e.g., osteophytes, enthesiophytes) and catabolic (e.g., erosions) bone changes and joint space width. These features may be useful for monitoring disease progression, response to therapy, and are responsive to differentiating between those with inflammatory arthritis conditions and healthy controls. We reviewed 69 publications utilizing HR-pQCT imaging of the metacarpophalangeal (MCP) and/or wrist joints to investigate arthritis conditions. Erosions are a marker of early inflammatory arthritis progression, and recent work has focused on improvement and application of techniques to sensitively identify erosions, as well as quantifying erosion volume changes longitudinally using manual, semi-automated and automated methods. As a research tool, HR-pQCT may be used to detect treatment effects through changes in erosion volume in as little as 3 months. Studies with 1-year follow-up have demonstrated progression or repair of erosions depending on the treatment strategy applied. HR-pQCT presents several advantages. Combined with advances in image processing and image registration, individual changes can be monitored with high sensitivity and reliability. Thus, a major strength of HR-pQCT is its applicability in instances where subtle changes are anticipated, such as early erosive progression in the presence of subclinical inflammation. HR-pQCT imaging results could ultimately impact decision making to uptake aggressive treatment strategies and prevent progression of joint damage. There are several potential areas where HR-pQCT evaluation of inflammatory arthritis still requires development. As a highly sensitive imaging technique, one of the major challenges has been motion artifacts; motion compensation algorithms should be implemented for HR-pQCT. New research developments will improve the current disadvantages including, wider availability of scanners, the field of view, as well as the versatility for measuring tissues other than only bone. The challenge remains to disseminate these analysis approaches for broader clinical use and in research.

Prospective Follow-Up of Cortical Interruptions, Bone Density, and Micro-structure Detected on HR-pQCT: A Study in Patients with Rheumatoid Arthritis and Healthy Subjects

OBJECTIVES

The purpose of the study was to prospectively investigate change (repair or progression) in the number, surface area and volume of cortical interruptions, bone density (vBMD) and micro-structural parameters assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT) in finger joints of patients with rheumatoid arthritis (RA) treated with synthetic disease modifying anti-rheumatic drugs (sDMARDs) and/or biologic DMARDs (bDMARDs) over a 1-year follow-up period, and in comparison with healthy subjects (HS).

METHODS

Thirty-two patients with RA (221 joints, 53% on bDMARDs) and 32 HS (117 joints) were assessed at baseline and after 1 year using semi-automatic analysis of HR-pQCT images. Mean changes (group level) and the proportion of joints (joint level) with changes beyond the least significant change were calculated.

RESULTS

At baseline, 530 interruptions were identified in patients, and 136 in HS. The mean of the interruption parameters did not significantly change in either group Mean vBMD decreased more in patients than in HS (- 4.4 versus - 1.1 mgHA/cm³, respectively). In patients versus HS, proportionally more joints showed repair in interruption volume (6.6% versus 1.7%, respectively) and loss of vBMD (26.7% versus 12.9%, respectively). In patients on sDMARDs versus patients on bDMARDs, proportionally more joints showed progression in the number of interruptions and loss of vBMD (6.1% versus 1.8% and 31.3% versus 17.2%, respectively).

CONCLUSIONS

HR-pQCT is able to quantify bone repair and progression. Cortical interruption-, vBMD-, and micro-structure were impaired in RA, of which vBMD and micro-structure further deteriorated, particularly in patients on sDMARDs.