The Culprit in axSpA: Structural Damage or Disease Activity?

Global functioning of patients with axial spondyloarthritis (axSpA) is more strongly linked with measures of disease activity and function than with mobility and radiographic damage, according to study results published online ahead of print in Arthritis Care & Research.

“The results also suggest that global functioning is, in this cohort, not much dependent on the degree of structural damage in the axial skeleton,” wrote corresponding author David Kiefer, MD, of Ruhr University Bochum in Bochum, Germany, and study coauthors.

Researchers investigated the association between global functioning and clinical measures of disease activity, physical function, spinal mobility, and radiographic damage in 103 consecutive patients with radiographic and nonradiographic axSpA for the study. Tools assessed included the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), Bath Ankylosing Spondylitis Metrology Index (BASMI), Assessment of Spondyloarthritis International Society Health Index (ASAS HI), and range of motion and range of kinematics using Epionics SPINE, an electronic device for gauging axial mobility. Structural damage of the spine and sacroiliac joints was assessed by counting the number of syndesmophytes and by New York criteria for sacroiliitis grading.

ASAS HI scores were significantly associated with patient-reported BASDAI, BASFI, and back pain scores, according to the study. ASAS HI measures did not correlate, however, with range of motion, range of kinematics, or radiographic damage of the spine and sacroiliac joints.

The study found a weak correlation between ASAH HI and BASMI scores.

“Our data suggest that axSpA patients may find factors related to spinal mobility less relevant than others or may use coping strategies to overcome these limitations.”

Reference

Kiefer D, Braun J, Kiltz U, et al. Global functioning in axial spondyloarthritis is stronger associated with disease activity and function than with mobility and radiographic damage. Arthritis Care Res. Published online July 25, 2023. doi:10.1002/acr.25204