The Effect of TNF Inhibition on Bone Density and Fracture Risk and of IL17 Inhibition on Radiographic Progression and Bone Density in Patients with Axial Spondyloarthritis: a Systematic Literature Review.

PURPOSE OF REVIEW: Osteoporosis in axial spondyloarthritis may be modified by therapy. The purpose of this systematic review is to describe (i) the effect of TNFi on BMD, (ii) the effect of secukinumab on BMD, and (iii) the effect of secukinumab on radiographic disease progression in axSpA.

RECENT FINDINGS: We searched PubMed, Embase, and Cochrane using the following retrieval languages: spondyloarthritis, ankylosing spondylitis, TNF, IL-17, x-rays, and osteoporosis. Twenty-nine studies were included; 27 re: TNFi and BMD, and 2 re: IL-17 blockers and x-ray progression. TNFi over 2-4 years increased BMD of the lumbar spine (3.2-14.9%) and hip (2.26-4.7%) without reducing vertebral fractures. Secukinumab reduced radiographic progression; none (73%) and minimal (79%) at 4 years. No data on IL-17 blockade and bone were found. TNFi therapy improves bone density but not vertebral fracture rates. Secukinumab improves symptoms and may slow radiographic progression. Data is lacking regarding the effects of secukinumab on BMD and fractures. These are important questions which may impact the choice of therapy.