ANTI TNF THERAPY IN ANKYLOSING SPONDYLITIS – AN OBSERVATIONAL STUDY ASSESSING THE IMPACT OF SMOKING IN WHITE BRITISH AND INDIAN POPULATION

Background: Ankylosing spondylitis (AS) have heterogeneous clinical manifestations and diverse responses to antiTNF therapy according to ethnic origin.Previous study has shown that smoking has a detrimental effect on disease activity, functional impairment, inflammatory response and efficacy of treatment.1 There is clear dearth of evidence looking at the effect of smoking among Indian patients with AS.No previous study have explored the influence of smoking and antiTNF response among Indians and White British patients with AS.We have attempted to identify influence of smoking on the disease activity and anti TNF response in these two ethnic groups. Objectives: 1. To study the impact of smoking on the disease outcome and Anti TNF treatment responses among Indian (IND) and White British (WB). Methods: This is a retrospective observational study. We selected two groups of AS patients on antiTNF therapy, 125 in total, with 100 WB and 25 IND with a ratio of 4:1.Clinical, demographics and blood parameters including CRP and HLA B27,Disease outcome measures eg.BASDAI, BASFI and spinal VAS score prior to, 3 months and 12 months after initiation of antiTNF therapy were collected from biologics therapy database.Smokers from both ethnic groups had variable smoke exposure. Tukey's HSD test was used to compare the change in outcome measure from base line at 12 months for smokers and non-smokers among Indians and White British.Analysis of variance (ANOVA) was used to compare the differences in the groups at baseline and 12 months. Results: Total number of cases included in the study; (n=125) with 100 WB and 25 IND patients (ratio 4:1).It showed male predominance (68% in WB; 88% in IND).There was no significant association between HLA status, smoke exposure and anti TNF treatment response. Table 1. Treatment outcome Mean BASDAIMean BASFIMean SPINAL VASMean CRP Pre antiTNFPost antiTNF (12m)Pre antiTNFPost antiTNF (12m)Pre antiTNFPost antiTNF (12m)Pre antiTNFPost antiTNF (12m) Indian smoker7.45.26.95.297.95.216.29.2 Indian non smoker6.43.95.954.216.93.813.87.9 White British smoker7.034.287.14.47.44.512.86.4 White British non smoker5.92.96.33.17.13.110.55.7 P valuep=0.03p<0.05P=0.107p=0.43 Patients from both groups showed significant improvement of BASDAI,BASFI and spinal VAS scores following 12 months of treatment.Our study highlighted the negative impact of smoking on AS. Smokers from both ethnic groups showed poorer treatment response.Indian smokers demonstrated comparatively poorer response to anti TNF therapy BASDAI compared to White British cohort (p=0.03), BASFI (p<0.05) and Spinal VAS (p=0.107) (Table -1). We noticed improvement in the CRP levels following 12 months of antiTNF therapy among both ethnic groups,however there were no significant correlation between smoking and inflammatory response. Conclusions: 1. Smoking had a detrimental effect on Anti TNF response and disease outcome in both Ethnic group. 2. Indian smokers showed poor clinical outcome and treatment responses to anti TNF therapy. 3. There were no significant correlation observed between smoking and inflammatory responses within both ethnic groups. References: 1. Cigarette smoking has a dose dependent impact on progression of structural damage in the spine inpatients with axial spondyloarthritis: Results from the GErman SPondyloarthritis Inception Cohort (GESPIC)Citation:Annals of the Rheumatic Diseases, August 2013;1468-2060. Disclosure of Interest: None declared DOI: 10.1136/annrheumdis-2015-eular.6404Citation: Annals of the Rheumatic Diseases, volume 74, supplement 2, year 2015, page 276Session: Spondyloarthritis - treatment (Poster Presentations )