Drug monitoring in long-term treatment with adalimumab for juvenile idiopathic arthritis-associated uveitis

Objectives Assessing influence of anti-adalimumab (ADA) antibodies (AAA) on serum trough ADA levels and uveitis activity in long-term ADA treatment of juvenile idiopathic arthritis (JIA)-associated uveitis. Patients and interventions This prospective observational study included 20 patients from a single centre treated with ADA for active uveitis refractory to conventional disease-modifying antirheumatic drugs. AAA, serum ADA trough levels and uveitis activity were evaluated at regular intervals up to 6 years. Results AAA were detected in nine patients (45%). Permanent AAA in seven were associated with undetectable ADA trough levels and loss of response (LOR). Transient AAA were detected in four with measurable ADA trough levels and response of uveitis to treatment, followed in two by permanent AAA associated with LOR. Use of concomitant immunosuppression was significantly higher in patients without AAA (p<0.05). Conclusions AAA-associated LOR frequently occurs in long-term treatment with ADA for JIA-associated uveitis. Concomitant immunosuppressive therapy significantly reduces the risk of LOR due to AAA.