[THE INPUT OF MEASURING INFLIXIMAB LEVELS AND LEVELS OF ANTIBODIES TO INFLIXIMAB IN THE MANAGEMENT OF PATIENTS WITH RHEUMATIC DISEASES].

Background: High levels of infliximab (IFX) directed antibodies (IFX-Ab) may result in significant reduction in IFX concentration and loss of drug efficacy.

Objectives: To assess the input of measuring serum IFX levels and levels of IFX-Ab in the management of rheumatic diseases.

Methods: Serum levels of IFX and anti-IFX-Ab were measured by ELISA (IFX-Abs were also identified by anti-human lambda chain Ab) and correlated to patients (responders and nonresponders) disease activity scores.