Anne Gitte Rasmussen Loft

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

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  • Bente Glintborg, University of Copenhagen, Denmark
  • Inge J Sørensen, University of Copenhagen, Denmark
  • Mikkel Østergaard, University of Copenhagen, Denmark
  • Lene Dreyer, University of Copenhagen, Denmark
  • Abdiweli A Mohamoud, University of Copenhagen, Denmark
  • Niels S Krogh, ZiteLab ApS, Copenhagen, Denmark., Denmark
  • Oliver Hendricks, University of Copenhagen, Denmark
  • Lis S Andersen, Rønne Hospital, Denmark
  • Johnny L Raun, University of Southern Denmark, Denmark
  • Marcin R Kowalski, Aalborg University, Denmark
  • Laura Danielsen
  • ,
  • Randi Pelck, Zealand University Hospital, Denmark
  • Henrik Nordin, University of Copenhagen, Denmark
  • J. K. Pedersen, University of Southern Denmark, Denmark
  • Dorte Kraus
  • Susan R Christensen
  • I M Hansen, University of Southern Denmark, Denmark
  • Jakob Esbesen, Vejle Hospital, Denmark
  • Annette Schlemmer
  • Anne G Loft
  • Nabil Al Chaer, Slagelse Hospital, Denmark
  • Lone Salomonsen, Aarhus University Hospital, Denmark
  • Merete L Hetland, University of Copenhagen, Denmark

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.

Original languageEnglish
JournalJournal of Rheumatology
Pages (from-to)59-69
Number of pages11
Publication statusPublished - Jan 2017

    Research areas

  • Adult, Antirheumatic Agents, Biological Products, Cohort Studies, Female, HLA-B27 Antigen, Humans, Male, Medication Adherence, Middle Aged, Registries, Sacroiliac Joint, Severity of Illness Index, Spondylarthritis, Spondylitis, Ankylosing, Treatment Outcome, Tumor Necrosis Factor-alpha, Journal Article, Observational Study

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