THU0585-HPR Impact on the Therapeutic Response to Anti-Tumor Necrosis Factor (ANTI-TNF) Agents of the Thickness of the Subcutaneous Tissue (SBC) in the Site of Injection Measured by Ultrasound

Background Anti-TNF drugs are administered either subcutaneously (SBC) or intravenously and this may determine their bioavailability. There are two major aspects regarding the SBC self-administration: the injection site and the injection technique. Thus, the appropriated patient training by a nurse is essential for appropriated self-administration of these agents. The SBC thickness might influence the correct distribution of the drug in the target tissue. Objectives To evaluate the relationship between the SBC thickness at the site of injection of anti-TNF agents and clinical response in patients with rheumatoid arthritis (RA) and spondyloarthropathies (SpA). Methods This prospective cross-sectional study included 117 patients, 59 (50.5%) with RA and 58 (49.5%) with SpA on SBC anti -TNF therapy for at least 6 months [(etanercept (47.9%), adalimumab (44.4%), golimumab (6%) or certolizumab (1.7%)]. Demographic variables, disease activity and site of self-injection were collected. SBC thickness measurement was performed in arms, abdomen and thighs by the same investigator using B-mode ultrasound. Clinical response to anti-TNF was assessed according to the Disease Activity Score (DAS) 28 C-reactive protein (CRP) for patients with RA and by Disease Activity Score (ASDAS) for patients with SpA. Results 82 (70%) of patients self-administered the anti-TNF in the abdomen, 23 (19.7%) in the thigh and 12 (10.3%) in the arm. SBC thickness was significantly higher in the abdomen (24.7±14.3) than in thighs (11.6±4.9) and arms (9.1±4.5) (p Conclusions SBC thickness of in the injection site measured by ultrasound may influence the bioavailability of anti-TNF agents and therefore it could impact on disease activity in patients with RA and SpA. Disclosure of Interest : T. Del Rio: None declared, E. Naredo Grant/research support: UCB and MSD, Consultant for: Abbvie, Roche Farma, Bristol-Myers Squibb, Pfizer, UCB, General Electric Healthcare, and Esaote, L. Valor: None declared, I. de la Torre: None declared, D. Hernandez: None declared, A. Lόpez: None declared, A. Beltran: None declared, L. Martinez: None declared, J. C. Nieto: None declared, C. Gonzalez: None declared, J. Lopez-Longo: None declared, I. Monteagudo Consultant for: Abbvie, Roche Farma, Bristol-Myers Squibb, Pfizer, UCB, General Electric Healthcare, and Esaote, M. Montoro: None declared, L. Carreno: None declared DOI 10.1136/annrheumdis-2014-eular.3211