A comparative MRI study of cartilage damage in gout versus rheumatoid arthritis

Associations of Changes in Knee Hyaline Cartilage Composition Measured With Dual-Energy Computed Tomography in Gout, Aging and Osteoarthritis

OBJECTIVE

To characterize dual-energy computed tomography (DECT) changes depicting hyaline cartilage changes in gout patients with and without osteoarthritis (OA) and in comparators without gout.

DESIGN

Patients with suspected crystal-associated arthropathy were enrolled and underwent bilateral DECT scans of the knees. Standardized regions of interest were defined in the femorotibial hyaline cartilage. Five DECT parameters were obtained: CT numbers in Hounsfield units (HU) at 80 and 140 kV, the electron density (Rho), the effective atomic number (Zeff), and the dual-energy index (DEI). Zones were compared between patients with gout, with and without knee OA, and between patients with gout and comparators without gout, after adjustment for confounders.

RESULTS

A total of 113 patients with gout (mean age 63.5 ± 14.3 years) and 15 comparators without gout (mean age 75.8 ± 11.5 years) were included, n = 65 (51%) had knee OA, and 466 zones of hyaline cartilage were analyzed. Older age was associated with lower attenuations at 80 kV (P < 0.01) and 140 kV (P < 0.01), and with Rho (P < 0.01). OA was characterized by lower attenuation at 140 kV (P = 0.03), but the lower Rho was nonsignificant after adjustment for confounders. In gout, hyaline cartilage exhibited lower Rho values (adjusted P = 0.04). Multivariable coefficients of association with Rho were -0.21 [-0.38;-0.04] (P = 0.014) for age, -4.15 [-9.0;0.7] (P = 0.093) for OA and 0.73 [-0.1;1.56] (P = 0.085) for monosodium urate volume.

CONCLUSION

Gout was associated with DECT-detected changes in cartilage composition, similar to those observed in older patients, with some similarities and some differences to those seen in OA. These results suggest the possibility of potential DECT biomarkers of OA.

Neutrophil extracellular traps induce the bone erosion of gout

OBJECTIVE

To investigate the relationships between monosodium urate (MSU) crystals -induced neutrophil extracellular traps (NETs) and bone erosion in gout.

METHODS

Animal models were used to study the relationship between NETs induced by MSU crystals and bone erosion. Neutrophils were treated with MSU crystals to induce NETs. The osteoblasts-like cells (OB) were then treated with NETs, and the supernatant was co-incubated with osteoclasts-like cells (OC). The NETs were digested with DNase, and the neutrophil elastase (NE) was inhibited with sivelestat sodium. Cell viability, mRNA, and protein expression were also assessed.

RESULTS

After treating OB with NETs, the cell viability decreased. Yet, after digesting the DNA and inhibiting NE, the viability was moderately improved. The expression level of osteoprotegerin (OPG) and alkaline phosphatase (ALP) was up-regulated, while the expression level of receptor activator of nuclear factor kappa-B ligand (RANKL) was down-regulated in the sivelestat sodium + MSU group compared with MSU group. The number of OC was significantly elevated. In contrast, the number of OB was not increased in the tibia after establishing the gout model. The supernatant obtained from OB was treated with NETs promoting OC differentiation. The expression level of receptor activator of nuclear factor kappa-B (RANK), tartrate-resistant acid phosphatase (TRAP), and cathepsin K (Cst K) was up-regulated in the MSU group compared with the normal control (NC) group.

CONCLUSION

NETs induced by MSU crystals could inhibit osteoblasts viability and enhance the activity of osteoclasts.

The Inhibition of Osteoblast Viability by Monosodium Urate Crystal-Stimulated Neutrophil-Derived Exosomes

Background and Objective

Bone erosion is common in patients with gout. The role of neutrophil-derived exosomes in gouty bone erosion remains elusive. This study aimed to investigate the functions of the neutrophil-derived exosomes in the development of bone erosion in gout.

Methods

Neutrophil-derived exosomes were collected and assessed by transmission electron microscopy and nanoparticle tracking analysis. Cell counting kit-8 assay was applied to evaluate cell viability, and cell apoptosis was assessed by flow cytometry. In addition, quantitative Real-time PCR and Western blotting were used to determine the expression levels of alkaline phosphatase (ALP), osteoprotegerin (OPG), and receptor activator of nuclear factor-κB ligand (RANKL). Neutrophil-derived exosomes were tagged with PKH67. The miRNA expression profiles of exosomes and human fetal osteoblasts (hFOB) were compared using high-throughput sequencing. Functional miRNAs transfected into hFOB after co-incubation with exosomes were selected and validated by preliminary qPCR.

Results

Neutrophil-derived exosomes were stimulated by monosodium urate (MSU). The exosomes could inhibit the viability of the hFOB, and the expression levels of ALP and OPG were down-regulated, while the expression level of RANKL was up-regulated. However, there was no significant difference in the viability of osteoclasts and the expression of nuclear factor of activated T cells 1. Exosomes were observed in the cytoplasm under a confocal microscopy, confirming that exosomes could be taken up by hFOB. In total, 2590 miRNAs were found, of which 47 miRNAs were differentially expressed. Among the delivered miRNAs, miR-1246 exhibited the highest level of differential expression. The viability of hFOB was reduced by miR-1246 mimics and increased by miR-1246 inhibitors. There was no significant difference in hFOB apoptosis rate between the miR-1246 mimic and miR-1246 inhibitor group. MiR-1246 overexpression decreased the expression levels of ALP and OPG, whereas increasing the expression level of RANKL. In contrast, miR-1246 inhibitor increased the expression levels of ALP and OPG, while decreasing the expression level of RANKL. Neutrophil-derived exosomes stimulated by MSU could increase the expression of miR-1246.

Conclusion

Neutrophil-derived exosomes stimulated by MSU could inhibit the viability of osteoblasts.

[Inflammatory changes of the hip joint]

Die Osteoarthrose ist die häufigste Ursache für den Hüftschmerz des Erwachsenen. Daher wird anderen Ursachen wie z. B. Entzündungen weniger Beachtung für den Gelenkschmerz in der Erstdiagnose geschenkt. Dieser Artikel gibt eine Übersicht von unterschiedlichen rheumatologischen Erkrankungen der Hüfte und deren Interpretation in der Bildgebung. Die Vor- und Nachteile der einzelnen bildgebenden Verfahren werden anhand der pathologischen Befunde für die rheumatologischen Erkrankungen erläutert.

Are Doctors the Best People to Manage Gout? Is There a Role for Nurses and Pharmacists?

PURPOSE OF REVIEW

To discuss alternate models of long-term gout management RECENT FINDINGS: Nurse-led care of gout appears to improve the uptake of and adherence to urate-lowering treatment in a research setting. Less impressive improvements were achieved with pharmacist-led remote management of gout; however, both strategies were more effective than usual primary care provider management of gout. Individualised education about gout, patient involvement in decision-making, and access to trained support in managing side-effects and gout flares can improve the uptake of fine and adherence to urate-lowering treatment. This may be best achieved with nurse-led care of gout. However, further research is required to evaluate if the model of nurse-led care of gout can be implemented in routine clinical practice and in different healthcare systems.