TY - JOUR T1 - Anti-TNFα drug levels in patients with rheumatoid arthritis and spondyloarthritis JO - Reumatología Clínica (English Edition) T2 - AU - Meriño-Ibarra,Erardo AU - Manero Ruíz,Francisco Javier SN - 21735743 M3 - 10.1016/j.reumae.2021.06.003 DO - 10.1016/j.reumae.2021.06.003 UR - https://reumatologiaclinica.org/en-anti-tnf-drug-levels-in-patients-articulo-S217357432100215X AB - Background and objectivesKnowledge of the levels of anti-TNFa drugs can modify treatment in patients with rheumatoid arthritis (RA) and spondyloarthritis (SpA). ObjectivesTo compare the levels of anti-TNFa in patients with RA vs SpA, in different clinical situations. Materials and methodsA retrospective, observational study was conducted. Levels of anti-TNFa and the presence of anti-drug antibodies were measured in consecutively selected patients, using the ELISA technique. ResultsFifty-three, 73 and 78 patients treated with infliximab, adalimumab and etanercept were studied, respectively. The median drug levels in patients using standard doses were infliximab 2.2 µg/mL (1.4–5.2), adalimumab 4.9 µg/mL (0.8−8.9) and etanercept 3.1 µg/mL (2.3−4.4). There were no differences in drug levels according to disease activity but we found differences in etanercept and infliximab levels according to DMARD use. ConclusionsLevels of anti-TNFa drugs will change with DMARD treatment. ER -