TY - JOUR

T1 - Ankylosing Spondylitis versus Nonradiographic Axial Spondyloarthritis

T2 - Comparison of Tumor Necrosis Factor Inhibitor Effectiveness and Effect of HLA-B27 Status. An Observational Cohort Study from the Nationwide DANBIO Registry

AU - Glintborg, Bente

AU - Sørensen, Inge J

AU - Østergaard, Mikkel

AU - Dreyer, Lene

AU - Mohamoud, Abdiweli A

AU - Krogh, Niels S

AU - Hendricks, Oliver

AU - Andersen, Lis S

AU - Raun, Johnny L

AU - Kowalski, Marcin R

AU - Danielsen, Laura

AU - Pelck, Randi

AU - Nordin, Henrik

AU - Pedersen, J. K.

AU - Kraus, Dorte

AU - Christensen, Susan R

AU - Hansen, I M

AU - Esbesen, Jakob

AU - Schlemmer, Annette

AU - Loft, Anne G

AU - Al Chaer, Nabil

AU - Salomonsen, Lone

AU - Hetland, Merete L

PY - 2017/1

Y1 - 2017/1

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.

AB - 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.

KW - Adult

KW - Antirheumatic Agents

KW - Biological Products

KW - Cohort Studies

KW - Female

KW - HLA-B27 Antigen

KW - Humans

KW - Male

KW - Medication Adherence

KW - Middle Aged

KW - Registries

KW - Sacroiliac Joint

KW - Severity of Illness Index

KW - Spondylarthritis

KW - Spondylitis, Ankylosing

KW - Treatment Outcome

KW - Tumor Necrosis Factor-alpha

KW - Journal Article

KW - Observational Study

U2 - 10.3899/jrheum.160958

DO - 10.3899/jrheum.160958

M3 - Journal article

C2 - 27909080

VL - 44

SP - 59

EP - 69

JO - Journal of Rheumatology

JF - Journal of Rheumatology

SN - 0315-162X

IS - 1

ER -