TY - JOUR T1 - Relationship between the clinical response to adalimumab treatment and serum levels of adalimumab and anti-adalimumab antibodies in patients with psoriatic arthritis JF - Annals of the Rheumatic Diseases JO - Ann Rheum Dis SP - 624 LP - 625 DO - 10.1136/ard.2009.108787 VL - 69 IS - 3 AU - A W R van Kuijk AU - M de Groot AU - S O Stapel AU - B A C Dijkmans AU - G J Wolbink AU - P P Tak Y1 - 2010/03/01 UR - http://ard.bmj.com/content/69/3/624.abstract N2 - While the majority of patients with psoriatic arthritis (PsA) respond well to treatment with adalimumab, some patients lose response.1 An explanation might be the development of antiadalimumab antibodies, which has been reported in rheumatoid arthritis.2 3 Therefore, we studied the incidence of antiadalimumab antibodies in PsA, and the relationship with serum adalimumab concentration and clinical response.Twenty-two patients with active PsA, fulfilling CASPAR classification criteria,4 started adalimumab treatment (table 1). The patients met the requirements of the Dutch consensus on initiation of tumour necrosis factor blocking therapy in PsA5 and were seen at baseline, and after 3 and 12 months. Serum samples were collected just before the next injection with adalimumab. The Disease Activity Score in 28 joints (DAS28), which has been shown to discriminate between active drug and placebo in clinical trials in … ER -