Background TNFi drug survival is one of the valid outcome measure in rheumatological diseases. TNFi drug survival is not evaluated adequetly in non-radiographic axial spondyloarthritis (nr-axSpA).
Objectives Objective of this study was to compare TNFi drug survival in ankylosing spondylitis (AS) and (nr-axSpA).
Methods HÜR-BİO (Hacettepe University Rheumatology Biologic Registry) is a single center biological registry since 2005 in Turkey. Data collected includes demographic data, co-morbidities, smoking, switch ratio, magnetic resonance imaging (MRI), HLA-B27, baseline and follow-up disease activity parameters (such as BASDAI, BASFI, CRP, ESR, global VAS, swollen joint count and tender joint count). Patients with nr-axSpA were fulfilled ASAS classification criteria for axial SpA without meeting modified New York criteria for AS (1). Patients with psoriasis and inflammatory bowel disease were excluded from this study. If patients took TNFi drugs last 6 months, patient accepted as ongoing TNFi treatment. Kaplan-Meier plots and log rank tests were used to assess drug survival.
Results There were 630 AS and 102 nr-axSpA patients with TNFi in this database. In nr-axSpA group, 53 of 74 (71.6%) patients had HLA-B27 positivity, and 65 of 68 (95.6%) patients had sacroiliitis in MRI. Sixteen nr-axSpA patients had both HLA-B27 positivity and sacroiliitis in MRI. Mean age in AS and nr-axSpA were 41±11 vs 36±9 years, p<0.001. Mean disease duration in AS and nr-axSpA were 9.7±7.2 vs 4.4±3.1 years, p<0.001. AS patients were more frequently male 415/630 (65.8%) vs 47/102 (46.1%), p<0.001. Mean TNFi duration was higher in AS patients than nr-axSpA 34±31 vs 19±21 months, p<0.001. TNFi drugs in AS and nr-axSpA patients were adalimumab (23.1% vs 34.3%), etanercept (38.1% vs 35.3%), infliximab (34.4.% vs 24.5%) and golimumab (4.1% vs 5.9%), p>0.05. Patients with nr-axSpA and AS had similar TNFi switch ratio 26.6% vs 30.3%, p>0.05. Baseline CRP 3.70±7.24 vs 3.31±6.72 mg/dl, p>0.05 BASDAI score 5.6±1.8 vs 5.6±2.0, p>0.05 and BASFI score 4.4±2.6 vs 4.5±2.7, p>0.05 were similar in AS and nr-axSpA patients. However, baseline ESR (33±23 vs 21±20 mm/hour, p<0.001), tender joint counts (0.83±1.34 vs 0.29±0.96, p=0.006), and swollen joit counts (0.63±1.44 vs 0.58±0.27 p<0.001) were higher in nr-axSpA patients. At last visit, ESR (14±15 vs 10±11 mm/hour, p=0.007), CRP (1.28±2.15 vs 0.47±0.77 mg/dl, p=0.002), BASDAI score (2.4±2.0 vs 3.0±2.3 p=0.016), and BASFI score (2.7±2.3 vs 1.9±2.1 p=.0009) were statistically different in AS patients from nr-axSpA patients. Patients with nr-axSpA and AS patients had similar TNFi drug surival (log rank 0.65) (figure 1).
Conclusions In a randomized controlled trial, Ability-1 study (1), found that clinical activity and functional capacity were similar both AS and nr-axSpA patients. Our biological database confirmed mentioned study that BASDAI and BASFI similarly impaired in both diseases. Besides, we also demonstrated that TNFi drug survival was similar in AS and nr-axSpA.
Ann Rheum Dis 2013;72:815–822.
Disclosure of Interest None declared