Pos0991 predictors of Development of Advanced Spinal Ankylosis/Bamboo Spine in Axial Spondyloarthritis: Results From Real-Life Data

Abstract

BackgroundIn axial spondyloarthritis (axSpA), intervertebral ossification bridges of consecutive vertebrae may progress to advanced spinal ankylosis and bamboo spine over the years [1].ObjectivesTo identify demographic, clinical, disease activity and treatment factors associated with development of bamboo spine / advanced spinal ankylosis and bamboo spine-only in the Hacettepe University Rheumatology Biologic Registry (HUR-BIO) cohort.MethodsHUR-BIO is a prospective, single center database of biological disease-modifying antirheumatic drug (bDMARD) treatments. 770 patients on bDMARDs treatment had both lumbar and cervical lateral radiographies at the time of the data collection, and were included in the study. Bamboo spine was defined Bath Ankylosing Spondylitis Radiologic Index (BASRI)-spine grade 4 with a complete fusion of lumbar and cervical spines. Advanced spinal ankylosis was defined as the presence of at least two intervertebral adjacent bridges and/or fusion at the lumbar and/or cervical spine without bamboo spine. We analyzed the ensemble of variables by multivariable logistic regression to identify predictors associated with bamboo spine / advanced spinal disease, and bamboo spine-only.ResultsIn the study, there were 99 patients with advanced spinal ankylosis and 78 patients with bamboo spine. Older age (OR 1.12, 95% CI 1.07-1.17), male gender (OR 4.26, 95% CI 1.75-10.41), delay diagnosis ≥ 24 months (OR 2.7, 95% CI 1.27-5.74), obesity (OR 4.03, 95% CI 1.53-10.64), hip involvement (OR 4.94, 95% CI 1.94-12.6), smoking ≥ 10 package/year (OR 2.28, 95% CI 1.003-5.2) were significantly associated factors with bamboo spine / advanced spinal ankylosis. Similarly, older age (OR 1.17, 95% CI 1.09-1.3), male gender (OR 8.31, 95% CI 2.09-33.1), obesity (OR 5.15, 95% CI 1.25-21.27), hip involvement (OR 4.74, 95% CI 1.32-16.96) and smoking ≥ 10 package/year (OR 3.19, 95% CI 1.03-9.89) were showed statistical significance with bamboo spine (Table 1).Table 1.Predictors of Bamboo Spine and Advanced Spinal Ankyloses, and Bamboo Spine-onlyMultivariable ModelCovariatesBamboo Spine and Advanced Spinal AnkylosisBamboo SpineOR (95% CI)p-valueOR (95% CI)p-valueAge1.12 (1.07-1.17)<0.001*1.17 (1.09-1.3)<0.001*Male (vs female)4.26 (1.75-10.41)0.001*8.31 (2.09-33.1)0.003*Delay Diagnosis (≥ 24 months vs <24 months)2.7 (1.27-5.74)0.01*2.39 (0.85-6.71)0.09BMI0.019*0.074- 25 to < 30 (vs <25)2.05 (0.77-5.46)0.153.37 (0.84-13.6)0.087- ≥ 30 (vs <25)4.03 (1.53-10.64)0.005*5.15 (1.25-21.27)0.024*Hip involvement (present vs absent)4.94 (1.94-12.6)0.001*4.74 (1.32-16.96)0.017Smoking (≥ 10 package/year vs <10 package/year)2.28 (1.003-5.2)0.049*3.19 (1.03-9.89)0.044*Family History of SpA (First-degree; present vs absent)1.67 (0.61-4.57)0.322.82 (0.79-10.06)0.11Uveitis History (present vs absent)1.04 (0.39-2.74)0.941.19 (0.33-4.29)0.79Use SSZ (present vs absent)0.6 (0.17-2.07)0.422.09 (0.39-11.28)0.39Use Corticosteroids (present vs absent)0.69 (0.27-1.75)0.430.73 (0.18-2.97)0.66*p <0.05BMI: Body mass index; SpA: Spondyloarthritis; SSZ: SulfasalazineConclusionData on the predictors of development of advanced spinal ankylosis and bamboo spine are scarce. In this study, we showed that older age, male gender, delay in diagnosis, obesity, hip involvement and smoking are factors that predict the development of advanced spinal involvement in axSpA.References[1]Ostergaard M, Lambert RG. Imaging in ankylosing spondylitis. Ther Adv Musculoskelet Dis. 2012;4(4):301-11.Disclosure of InterestsNone declared