Background:Bath Ankylosing Spondylitis Metrology Index (BASMI) is an instrument developed to assess spinal and hip mobility. The relationship between BASMI and disease activity is not always linear and, above all, the data that correlate the variation in BASMI values (ΔBASMI) with the variation in disease activity scores and response to treatment are not unanimous.Objectives:Explore the effect of biological disease-modifying antirheumatic drugs (bDMARD) in spine mobility (as assessed by BASMI) and the associations between ΔBASMI and disease activity.Methods:Observational retrospective study was performed including consecutive patients with the diagnosis of Spondyloarthritis (SpA) followed at our Rheumatology Department. Demographic, clinical, including Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), BASMI, Ankylosing Spondylitis Disease Activity Score with erythrocyte sedimentation rate and C-reactive protein (ASDAS ESR and ASDAS CRP, respectively), and laboratorial data were collected from our national database at baseline, 6 and 12 months after initiation of a bDMARD. The variation of each parameter was calculated as the difference between the levels recorded at 6 and 12 months and the reference level and presented in the form of Δ. Statistical analysis was performed using SPSS 23.0. Correlations between variables were studied using Spearman correlation analysis and comparison between groups was performed using Wilcoxon and Kruskal-Wallis tests.Results:Median age of patients (n=178) was 42 years old [34, 50], 92 (51.7%) were males with a median disease duration of 4.9 [1.0, 10.3] years. One hundred and twenty-six patients (70.8%) had Ankylosing Spondylitis, 15 (8.4%) Inflammatory Bowel Disease related SPA and 30 (16.9%) Undifferentiated SpA. Fifty four (30.3%) patients were taking glucocorticoids and regarding conventional synthetic disease-modifying anti-rheumatic drugs use before starting the bDMARD: Sulfasalazine (52, 29.2%), Methotrexate (31, 17.4%) and Leflunomide (3, 1.7%). Regarding the bDMARD, only one patient started Secukinumab and the others a Tumor necrosis factor inhibitor (TNFi) [Golimumab (n= 64, 36.0%), Adalimumab (n=36, 20.2%), Infliximab (n= 35, 19.7%), Etanercept (n= 32, 18.0%) and Certolizumab (n= 10, 5.6%)].The majority of the patients had very high disease activity at baseline (86.0%, n=153); median ESR was 29 mm/h [15, 47], median CRP was 13.7 mg/L, [6.60, 27.3], median ASDAS CRP was 7.6 [6.0, 9.0] and median BASMI was 8.0 [7-0, 9.0]. After 6 and 12 months of treatment, mean ESR, CRP, ASDAS-CRP and BASMI were significantly lower than mean baseline values (p<0.01), with median ASDAS-CRP at 12 months of 2.20 [1.50, 2.90] and median ΔBASMI of -4.10 [-5.50, -2.40].BASMI at baseline showed a moderate correlation with ASDAS CRP (r=0.468, p<0.01), BASDAI (r=0.496, p<0.01) and patient visual analogic scale (VAS) (r=0.563, p<0.01). No correlations were found between BASMI and CRP, ESR, physician VAS or the consumption of nonsteroidal anti inflammatory drugs at baseline.A significant positive correlation was found between ΔBASMI and ΔASDAS at 6 months and 12 months (r=0.243, p=0.02; r=0.286; p<0.01) and also between ΔBASMI and ΔBASDAI at 6 and 12 months (r=0.183, p=0.04; r=0.291, p=0.02). No correlations were found between ΔBASMI and ΔCRP or ΔESR. No differences were observed in ΔBASMI, regarding the bDMARD of choice.Conclusion:In our cohort, starting a bDMARD improved BASMI scores through a 12 month period and there was a correlation between the variation of BASMI and disease activity improvement. As such, a TNFi may retard the progression of spinal mobility dysfunction in SpA patients. We cannot draw conclusions regarding differences between TNFi and interleukin 17 inhibitors and further work is needed to clarify possible differences in their impact in improving spine mobility.Disclosure of Interests:Salomé Garcia: None declared, Bruno Miguel Fernandes: None declared, Sara Ganhão: None declared, Maria Rato: None declared, Filipe Pinheiro: None declared, Georgina Terroso: None declared, Miguel Bernardes Speakers bureau: Abbvie, Amgen, Biogen, Eli-Lilly, Glaxo-Smith-Kline, Pfizer, Janssen, Novartis, Lúcia Costa: None declared
Disease-modifying effect of etanercept versus sulphasalazine on spinal mobility in patients with ankylosing spondylitis
