Relationship between spinal lesions related to axial spondyloarthritis and degenerative spinal lesions: 10-year follow-up of the DESIR cohort.

OBJECTIVE

This study aimed to investigate the relationship between spinal axial spondyloarthritis (axSpA)-related lesions and degenerative lesions (DLs) over 10 years (10Y).

METHODS

Whole spine MRI and cervical/lumbar spine radiographs at baseline/5Y/10Y from patients with axSpA from the DESIR cohort were assessed for axSpA-related lesions and DLs by three independent readers, different teams for the two lesion types. We used multilevel (patient and vertebra, considering consensus across readers), standard and time-lagged autoregressive generalized estimating equation (GEE) models. The relationship between syndesmophytes and the subsequent development of osteophytes/syndesmophytes in adjacent vertebrae on radiographs was analysed using a time-lagged autoregressive GEE model, after excluding vertebrae with both lesions. All models were adjusted for age, sex, HLA-B27 status, BMI, smoking and job type, and bDMARDs during follow-up.

RESULTS

Data from 326 patients (35 [S.D. = 9] years; 46% men) showed a significant association between axSpA-related lesions on MRI and the total number of DLs on MRI, though the effect sizes were small (β-coefficients: 0.07-0.17). On radiographs, paravertebral syndesmophytes were significantly associated with the total number of DLs (β-coefficient: 0.37; 95%CI: 0.26-0.48). However, these associations were not found in time-lagged autoregressive models. Syndesmophytes increased the risk of adjacent syndesmophyte [odds ratio (OR):6.92; 95%CI: 2.44-19.61], but not of osteophytes (OR: 1.05; 95%CI: 0.25-4.36).

CONCLUSION

Although significant associations were found between axSpA-related lesions and DLs at the same time point, no temporal relationship was observed. On radiographs, syndesmophytes increased the risk of syndesmophytes at adjacent levels, but there was no association with osteophyte development. AxSpA-related lesions and DLs coexist, but progress independently of each other.