TY - JOUR T1 - Ankylosing Spondylitis versus Nonradiographic Axial Spondyloarthritis: Comparison of Tumor Necrosis Factor Inhibitor Effectiveness and Effect of HLA-B27 Status. An Observational Cohort Study from the Nationwide DANBIO Registry JF - The Journal of Rheumatology JO - J Rheumatol SP - 59 LP - 69 DO - 10.3899/jrheum.160958 VL - 44 IS - 1 AU - Bente Glintborg AU - Inge J. Sørensen AU - Mikkel Østergaard AU - Lene Dreyer AU - Abdiweli A. Mohamoud AU - Niels S. Krogh AU - Oliver Hendricks AU - Lis S. Andersen AU - Johnny L. Raun AU - Marcin R. Kowalski AU - Laura Danielsen AU - Randi Pelck AU - Henrik Nordin AU - Jens K. Pedersen AU - Dorte G.A. Kraus AU - Susan R. Christensen AU - Inger M.J. Hansen AU - Jakob Esbesen AU - Annette Schlemmer AU - Anne G. Loft AU - Nabil al Chaer AU - Lone Salomonsen AU - Merete L. Hetland Y1 - 2017/01/01 UR - http://www.jrheum.org/content/44/1/59.abstract N2 - Objective. To compare baseline disease activity and treatment effectiveness in biologic-naive patients with nonradiographic axial spondyloarthritis (nr-axSpA) and ankylosing spondylitis (AS) who initiate tumor necrosis factor inhibitor (TNFi) treatment and to study the role of potential confounders (e.g., HLA-B27 status).Methods. Observational cohort study based on prospectively registered data in the nationwide DANBIO registry. We used Kaplan-Meier plots, Cox, and logistic regression analyses to study the effect of diagnosis (nr-axSpA vs AS) and potential confounders (sex/age/start yr/HLA-B27/disease duration/TNFi-type/smoking/baseline disease activity) on TNFi adherence and response [e.g., Bath Ankylosing Spondylitis Activity Index (BASDAI) 50%/20 mm].Results. The study included 1250 TNFi-naive patients with axSpA (29% nr-axSpA, 50% AS, 21% lacked radiographs of sacroiliac joints). Patients with nr-axSpA were more frequently women (50%/27%) and HLA-B27–negative (85/338 = 25%), compared to AS (81/476 = 17%; p < 0.01). At TNFi start patients with nr-axSpA had higher visual analog scale scores [median (quartiles)] for pain: 72 mm (55–84)/65 mm (48–77); global: 76 mm (62–88)/68 mm (50–80); fatigue: 74 mm (55–85)/67 mm (50–80); and BASDAI: 64 (54–77)/59 (46–71); all p < 0.01. However, patients with nr-axSpA had lower C-reactive protein: 7 mg/l (3–17)/11 mg/l (5–22); and BAS Metrology Index: 20 (10–40)/40 (20–50); all p < 0.01. Median (95% CI) treatment adherence was poorer in nr-axSpA than in AS: 1.59 years (1.15–2.02) versus 3.67 years (2.86–4.49), p < 0.0001; but only in univariate and not confounder-adjusted analyses (p > 0.05). Response rates were similar in AS and nr-axSpA (p > 0.05). HLA-B27 negativity was associated with poorer treatment adherence [HLA-B27 negative/positive, nr-axSpA: HR 1.74 (1.29–2.36), AS: HR 2.04 (1.53–2.71), both p < 0.0001]; and lower response rates (nr-axSpA: 18/61 = 30% vs 93/168 = 55%; AS: 17/59 = 29% vs 157/291 = 54%, both p < 0.05).Conclusion. In this nationwide cohort, patients with nr-axSpA had higher subjective disease activity at start of first TNFi treatment, but similar outcomes to patients with AS after confounder adjustment. HLA-B27 positivity was associated with better outcomes irrespective of axSpA subdiagnosis. ER -