| Abstract
| - Background. Smoking has been associated with poor response to anti-tumour necrosis factor α (anti-TNFα) drugs in rheumatoid arthritis patients(1)(2) and has been identified as a predictor of poorer functional outcome in psoriatic arthritis (PsA) patients (3). The effect of smoking on treatment response and drug survival has not been specifically studied in PsA patients. Objectives. To evaluate if smoking in PsA patients affects treatment response and drug survival of first anti-TNFα therapy. Methods. The study included PsA patients (n=78) attending the rheumatology department at Gartnaval General Hospital, who had started their first anti-TNFα drug therapy. Patient-reported demographic data was recorded and patients with current or previous smoking exposure were categorised as “smokers” and those with no smoking exposure as “non-smokers”. Measurements of 76 joint swelling score, 78 joint tenderness score, global pain score, patient global visual analogue score (VAS), physician global, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and Health Assessment Questionnaire (HAQ) were recorded at baseline, 3 and 6 months and analysed using t-test and Fisher’s exact test where appropriate. Response to treatment was evaluated based on the EULAR Psoriatic Arthritis Response Criteria (PsARC). Drug survival was explored by noting if patients were still on their first anti-TNF at each follow-up. Results. 78 patients were studied (adalimumab n=41, etanercept n=35, infliximab n=2). Mean age was 47.65 years, 50% were female, and mean disease duration was 11.32 years. 54.05% (n=37) were smokers. There were no significant differences in baseline scores between smokers and non-smokers. At 3-month follow up (n=72), non-smokers were more likely to have achieved EULAR response (78.38% vs. 67.65%, P=0.4219) with non-smokers achieving a significantly larger decrease in patient global visual analogue score (63.70% vs. 34.35%, P=0.0016) and non-significantly larger improvements in all other measurements. At 6 months (n=58), non-smokers were again more likely to have achieved response (86.21% vs. 58.62%, P=0.0379) with non-significantly better improvements in all other measurements. There was a significant difference in drug survival; non-smokers were more likely to still be taking the drug at 6 months (79.21% vs. 41.38%, P=0.0067). Conclusions. Exposure (previous or current) to cigarette smoking emerged as a significant negative predictor of treatment response and drug survival at 6 month follow-up. References. Söderlin MK, Petersson IF, Geborek P. The effect of smoking on response and drug survival in rheumatoid arthritis patients treated with their first anti-TNF drug. Scandinavian journal of rheumatology2012;41(1):1-9. Hyrich KL, Watson KD, Silman a J, Symmons DPM. Predictors of response to anti-TNF-alpha therapy among patients with rheumatoid arthritis: results from the British Society for Rheumatology Biologics Register. Rheumatology. 2006;45(12):1558-65. Tillett W, Jadon D, Shaddick G, Cavill C, Korendowych E, De Vries CS, et al. Smoking and delay to diagnosis are associated with poorer functional outcome in psoriatic arthritis. Annals of the rheumatic diseases. 2013 [Epub ahead of print] Acknowledgements. Sister Janice France, RGN Kelvin Cheng, Medical Student Disclosure of Interest. None Declared
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