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
Authors: T. Del Río, E. Naredo, L. Valor, I. de la Torre, D. Hernández, A. Lόpez, A. Beltran, L. Martinez, J.C. Nieto, C. Gonzalez, J. Lopez-Longo, I. Monteagudo, M. Montoro, L. Carreño
Journal: Annals of the Rheumatic Diseases (2014)

<h3>Background</h3> 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. <h3>Objectives</h3> 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). <h3>Methods</h3> 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. <h3>Results</h3> 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&lt;0.0005). Thirty-three (40.2%) patients that self-administered the anti-TNF in the abdomen, 4 (17.4%) in the thighs and 9 (75.0%) in the arms had criteria for disease activity. The injection site was statistically significantly associated with clinical activity (p=0.004). <h3>Conclusions</h3> 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. <h3>Disclosure of Interest</h3> : T. Del Río: 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. Hernández: 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. Carreño: None declared <h3>DOI</h3> 10.1136/annrheumdis-2014-eular.3211