Scoring Spinal Fat Lesions May Show Treatment Efficacy in SpA

January 9, 2014

A new system for measuring the spinal fat lesions in axial spondyloarthritis appears to determine treatment outcomes as accurately as, and sooner than, current methods. This could make new drug trials much more informative.

Pedersen SJ, Zhao Z, Lambert RG, et al. The FAt Spondyloarthritis Spine Score (FASSS): development and validation of a new scoring method for the evaluation of fat lesions in the spine of patients with axial spondyloarthritis. Arthritis Res Ther. 2013 Dec 16;15(6):R216. [Epub ahead of print]

A new system for measuring the spinal fat lesions that commonly appear when inflammation abates in axial spondyloarthritis (SpA) appears to determine treatment outcomes as accurately as and sooner than current methods, according to a team of Canadian and Danish researchers.

In a small MRI study of 58 patients randomly chosen from a cohort with SpA, the new Fat SpA Spine Score (FASSS) system proved to be reliable in evaluating the type, size, and location of the spinal fat deposits. It was also good at predicting the emergence of syndesmophytes, new bone growth that may signal tissue repair in SpA.

The web-based FASSS system, developed by members of the Canada-Denmark MRI Working Group, measures the exact size of a specific type of fat deposit on the front and back corners of vertebral bodies in the central spine -- detecting even the smallest changes that may suggest improvement in SpA, within less than a year.

The FASSS scoring system proved consistent with excellent inter-reader reliability, even for pairs of MRI scans taken a year apart.

Most other scoring systems don’t measure the size and growth of these fat lesions and take a least two years to determine whether SpA has progressed or not, the researchers note. Especially because it is considered unethical to maintain randomization in trials of disease-modifying therapy for that long, they say, the discovery of fat changes that occur more quickly as well as a method to detect them presents an “exciting prospect.”