Biologic Treatment Is Associated With Better Bone Health in Patients With Psoriatic Arthritis

Psoriatic arthritis (PsA) can lead to structural damage, such as bone erosion and enthesophytes. Increasingly, the impact of PsA on systemic bone is also being recognized, particularly as manifested by fractures. A recent investigation assessed whether the use of disease-modifying antirheumatic drugs (DMARDs), including both methotrexate and biologics, impacted systemic bone structure.

Patients included in the study were part of the Erlangen Imaging Cohort, which prospectively assesses bone composition in patients with a variety of inflammatory diseases. In total, 165 patients with PsA were recruited and categorized into 3 groups: those treated with methotrexate only (n = 34); those treated with biologics only (n = 52), including adalimumab, infliximab, etanercept, certolizumab, golimumab, secukinumab, and ustekinumab; and patients who received no DMARDs (n = 79) over the last 6 months. A greater proportion of patients receiving biologics had received glucocorticoids, and for a longer duration than the other groups.

High-resolution peripheral quantitative computed tomography was performed on the distal radius of each patient’s dominant hand to assess volumetric bone density and cross-sectional bone area. Bone microstructure was also assessed.

Patients who took any DMARD were found to have higher total volumetric bone mineral density (vBMD) and trabecular vBMD than those who took no DMARDs. They also had better bone microstructure, lower trabecular separation, and higher cortical thickness.

Notably, methotrexate did not have an influence on bone microstructure or functional properties; patients who were taking biologics had higher total and trabecular vBMD compared with the no-DMARD group, as well as higher cortical thickness. Biomechanical properties of the bone were better in the biologic group than in the no-DMARD group.

Despite the fact that the group treated with biologics had longer duration and a higher proportion of corticosteroid use, they also exhibited better bone density and higher stiffness and failure load estimates than those who took no DMARDs, although the same was not observed for patients who took methotrexate versus the no-DMARD group.

Given that PsA is associated with increased fracture risk, neutralizing the key proinflammatory and bone-destructive mediators of the disease, conclude the authors, appears to be important to restoring bone health and limiting fracture risk for patients with PsA, and biologics appear to be associated with better bone structure and function for these patients.

Reference

Simon D, Kleyer A, Bayat S, et al. Effect of disease-modifying anti-rheumatic drugs on bone structure and strength in psoriatic arthritis patients [published online July 3, 2019]. Arthritis Res Ther. doi: 10.1186/s13075-019-1938-3.