Axial spondyloarthritis: coming of age

Disease characteristics, pathogenesis, and treatment controversies of axial psoriatic arthritis

Axial psoriatic arthritis (axPsA) has considerable overlap with axial spondyloarthritis (axSpA) but has some unique features that sometimes preclude classification into axSpA. It has some clinical and radiographic differences compared to axSpA. Imaging typically shows asymmetric syndesmophytes, mainly in the cervical spine, with less frequent sacroiliitis. It more commonly presents later in life and is associated with less severe inflammatory back pain than axSpA. The interleukin (IL) IL-23/IL-17 axis is central to the pathogenesis of both diseases. However, the response to therapies targeting these cytokines has been different. IL-23 inhibitors are ineffective in axSpA but may be effective in psoriatic arthritis (PsA). Recent post hoc analyses of clinical trial data with IL-23 inhibitors in PsA have raised the possibility of their efficacy in axPsA and need evaluation in future clinical trials. Moreover, there is a need for classification criteria for axPsA and better tools to assess therapeutic response.

Have Therapeutics Enhanced Our Knowledge of Axial Spondyloarthritis?

PURPOSE OF REVIEW

An overview of how the treatment landscape of axial spondyloarthritis (axSpA) has shaped our understanding of the disease.

RECENT FINDINGS

Prior to the millennium, non-steroidal anti-inflammatory drugs (NSAIDs) were the only treatment for axSpA, yet only 30% of patients responded and many developed side effects. In 2003, the first biological disease-modifying drug (bDMARD) was licensed for axSpA which substantially improved outcomes in comparison to NSAIDs. In 2022, there are now several bDMARDs for axSpA; however, they too are not universally efficacious in treating axial inflammation and may have deleterious effects on extramusculoskeletal manifestations. Nevertheless, successful or not, each bDMARD gives invaluable insight into axSpA immunobiology. This review discusses how much we have learned from the use of bDMARDs in axSpA, how this has redefined our understanding of the disease, and how we might use this knowledge to develop new and better treatments for axSpA in the future.

Worse scores but similar patterns of disease activity: interpreting outcomes in women with axial spondyloarthropathy

OBJECTIVE

The aim of this study was to evaluate the impact of sex on disease activity in axial spondylitis (axSpA).

METHOD

Data were extracted from the Ankylosing Spondylitis Registry of Ireland (ASRI). In this cross-sectional study, patients were analysed on the basis of sex, with a series of comparison analyses performed.

RESULTS

Overall, 886 participants were enrolled in the ASRI [232 (26.2%) women, 644 (72.6%) men]. Females recorded significantly worse Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) (4.57 vs 3.83, p < 0.01) and Ankylosing Spondylitis Quality of Life questionnaire (ASQoL) (7.51 vs 6.12, p < 0.01) scores than males. There was a stronger correlation in the Bath Ankylosing Spondylitis Functional and Metrology Indices (BASFI and BASMI) in females (r_s = 0.619, p < 0.01) than in males (r_s = 0.572, p < 0.01). Analysis of factors in BASDAI revealed that the higher total scores in females compared to males were due not to any single component, but to worse scores in all six components of the BASDAI combined. Ranking of components by severity between sexes revealed identical ranking in four of the six components of the BASDAI.

CONCLUSIONS

Women with axSpA reported significantly worse disease activity, quality of life, and functional ability than men. However, the BASDAI capturedsimilar patterns of disease activity. Limitation of spinal mobility in women with axSpA corresponded to greater impairment in functional ability. Further evaluation of disease monitoring tools is required to ensure that disease activity is accurately captured in men and women with axSpA.