gms | German Medical Science

Introduction: Previous studies showed that patients with non-radiographic and radiographic axial spondyloarthritis (nr- and r-axSpA) have similar disease burden and similar response to anti-inflammatory therapy given similar level of inflammatory activity. Only little is known, however, about long-term disease course in patients with early axSpA. The aim of the study was to investigate the long-term (up to 10 years) clinical course of patients with early axSpA.

Methods: In total, 525 patients with early axSpA (r-axSpA with symptom duration ≤10 years and nr-axSpA with symptom duration ≤5 years) from the German Spondyloarthritis Inception Cohort (GESPIC) were included. The final patient classification was based on central reading results in 458 patients with available pelvic X-rays, and on local rheumatologist judgement in 67 patients. A total of 251 patients were finally classified as r-axSpA and 274 as nr-axSpA. Clinical evaluation, which included disease activity (BASDAI, C-reactive protein – CRP, ASDAS) as well as therapy recording, was performed at baseline and every 6 months thereafter until year 2 and annually thereafter till year 10. Treatment was conducted at the discretion of the local rheumatologist.

Results: Since the cohort has started prior to introduction of TNF inhibitors (TNFi), only 2% patients received TNFi at baseline that increased to 23% at year 10 (15% in nr-axSpA and 31% in r-axSpA). The use of NSAIDs and csDMARDs decreased in both groups, while use of systemic steroids did not change substantially (9% at baseline, 8% at year 10). The proportion of patients with low disease activity according to BASDAI (<4) was higher in r-axSpA as compared to nr-axSpA at almost all time points, while the proportion of patients with low disease activity according to ASDAS (<2.1), as well as with ASDAS inactive disease (<1.3) was similar between nr-axSpA and r-axSpA. In the group of patients who completed year 10 (n=134 in total, 68 with nr-axSpA, 67 with r-axSpA) the same trends in therapy and disease activity were observed.

Conclusion: Patients with nr-axSpA and r-axSpA showed a similar disease course in terms of disease activity on the group level. The drop-out rate in this observational cohort was overall high, but comparable between groups. The lower proportion of patients with nr-axSpA being treated with TNFi might reflect a later introduction of TNFi for this indication.

Disclosures: None declared