Background/Purpose: Preclinical studies show that tsDMARDs such as baricitinib may be a therapeutic agent for bone anabolic effects by increasing osteoblast function in inflammatory conditions.[1] High-resolution CT imaging (HR-pQCT) allows the determination of volumetric, peripheral bone mineral density of trabecular and cortical bone in patients with rheumatic diseases in vivo with a resolution of 82 micrometers voxel size. [2] Recently introduced rendering techniques such as cinematic rendering, developed by Siemens Healthineers allow a fotorealistic- insight into the bone on microstructural level in vivo.(3)

To test whether HR-pQCT images, segmented by cinematic rendering depict changes in bone mineral density in patients treated with baricitinib.

Methods: Bone density measurements of two time points of the radial bone from patients with active rheumatoid arthritis who are part of an ongoing, prospective cohort (ethics 19_18B;324_16) receiving baricitinb were analyzed. Volumetric bone density (vBMD) of the entire radius (Dtotal) in mg/hydroxyapatite / cm³ was determined as well as the cortical (Dcort) and trabecular (Dtrab) part of the bone. The measurements were registered using the software supplied by the manufacturer Scanco to determine the percentage change of vBMD. Images were post-processed using cinematic rendering technique to visualize pathologies in detail.

Results: Clinical characteristics are shown in table 1. We included three patients as a proof of concept analysis. All patients showed an improvement in clinical scores. We were able to display bone microstructure using cinematic rendering technique in great detail (figure 1) proving the feasibility to visualize bone microstructure with cinematic rendering at two time points. Furthermore, our preliminary data regarding vBMD shows that anabolic effects were observed for trabecular bone in particular. One patient displayed an increase of 49%.

Conclusion: The preliminary data reported here underline the potential impact of tsDMARDs therapy on secondary peripheral osteoporosis in patients with rheumatoid arthritis. These observations led to a prospective clinical trial, investigating effects of tsDMARDS (baricitinib) on bone metabolism(EUDRA-CT 2018-001164-32).

1. Adam, S., N. Simon, U. Steffen, F.T. Andes, C. Scholtysek, D.I.H. Muller, D. Weidner, D. Andreev, A. Kleyer, S. Culemann, M. Hahn, G. Schett, G. Kronke, S. Frey, and A.J. Hueber, JAK inhibition increases bone mass in steady-state conditions and ameliorates pathological bone loss by stimulating osteoblast function. Sci Transl Med, 2020. 12(530).
2. Simon, D., A. Kleyer, F. Stemmler, C. Simon, A. Berlin, A.J. Hueber, J. Haschka, N. Renner, C. Figueiredo, W. Neuhuber, T. Buder, M. Englbrecht, J. Rech, K. Engelke, and G. Schett, Age- and Sex-Dependent Changes of Intra-articular Cortical and Trabecular Bone Structure and the Effects of Rheumatoid Arthritis. J Bone Miner Res, 2016.
3. https://www.siemens-healthineers.com/de/medical-imaging-it/advanced-visualization-solutions/syngovia-cinematic

Figure 1. High resolution CT images of the radius from patient 1 are visualized with Cinematic Rendering at two time points (figure 1a and figure 1b). * illustrates changes in trabecular bone.

« Back to ACR Convergence 2020

ACR Meeting Abstracts - https://acrabstracts.org/abstract/cinematic-rendering-enables-depiction-of-bone-anabolic-effects-in-patients-treated-with-baricitinib/