Factors associated with achievement of inactive disease in children with juvenile idiopathic arthritis treated with etanercept.

Objective: To evaluate the rate of inactive disease in children with juvenile idiopathic arthritis (JIA) treated with etanercept, and to identify clinical characteristics associated with attainment of inactive disease.

Methods: Clinical charts of patients who were given etanercept between January 2002 and January 2011 were evaluated retrospectively. For each patient, all visits from initiation of etanercept to the last followup evaluation in which the patient was still receiving etanercept were examined to establish whether the patient had reached the state of inactive disease and to identify the first visit in which inactive disease was documented. Clinical characteristics associated with achievement of inactive disease were determined through univariate analyses and Cox regression procedures.

Results: A total of 173 patients who received etanercept for a median of 2.2 years (range 0.5-10.5 yrs) were studied. Eighty-seven patients (50.3%) achieved inactive disease after a median of 0.6 years (range 0.1-2.5 yrs) of therapy. At last followup evaluation, 85 patients (49.1%) still had inactive disease and 70 (40.5%) were in clinical remission on medication. The probability of achievement of inactive disease after 6, 12, and 24 months of therapy was 24%, 46% and 57%, respectively. On Cox regression analysis, the attainment of inactive disease was associated with lack of wrist involvement and an age at disease onset < 3.6 years.

Conclusion: Around half of our patients with JIA treated with etanercept achieved a state of inactive disease. Children who lacked wrist involvement and were younger at disease onset had a greater likelihood of achieving inactive disease.