Background/Purpose:            

To avoid the progression of joint damage, early decision making is important in JIA patients who failed to achieve sustainable clinical remission by the 1^st biologic agents.  Therefore, we examined whether the scores of DAS 28 at 3 months after initiating the 1^st biologic therapy can predict subsequent sustainable remission with the 1^st biologic agents in the polyarticular JIA (pJIA) patients.

Methods:

pJIA patients who had started the 1^st biologic agents at the Kagoshima University Hospital were involved in this study. The patients were divided into two groups according to the subsequent efficacy of the 1^st biologic agents; patients who successfully maintained clinical remission with the 1^st biologic agents (remission group) and the patients who were eventually obliged to switch to the 2^nd biologic agents due to the lack of efficacy (switching group).

Results:

Scores of DAS28 of 14 pJIA patients involved in this study gradually improved after starting the 1^st biologic agents.  However, 6 of 14 patients (43%) failed to maintain their clinical remission and eventually switched to the 2^nd biologic agents at 9 months (median, range 6-18 months) after initiating the 1^st biologic agents (switching group).  The rest of 8 patients (57%) achieved sustainable clinical remission with the 1^st biologic agents (remission group).  

There were no significant differences between the two patients’ groups as to sex ratio, age at onset, disease duration at initiating biologics. However, Das28 score at 3 months of the 1^st biologic therapy was significantly higher in switching group (1.75±1.0) than that of remission group (3.8±0.87)(p=0.001) (Figure 1). The receiver operating characteristic (ROC) analysis revealed that the cut-off point of DAS28 to discriminate the two patients’ group was 2.37 (sensitivity 100%, specificity 88.9%).

Conclusion: Evaluating DAS28 at 3 month after initiating biologic therapy was useful in predicting subsequent sustainable clinical remission.  Patients with DAS28 >2.37 at 3 month after initiating the 1^st biologic agents should be considered to switch to the 2^nd biologic agents in the treatment of pJIA.