Background/Purpose: Systemic juvenile idiopathic arthritis (sJIA) should be considered as a polygenic autoinflammatory disease. Interleukin 1 (IL-1) has been shown to be a major mediator of the inflammatory cascade that underlies sJIA. Treatment with anakinra has been reported to be effective in a sizable portion of patients with sJIA. To assess clinical response rate and disease course in sJIA patients treated with anakinra. To evaluated whether the response to anakinra was related to baseline variables.

Methods: We reviewed 63 (30 F) consecutive patients with sJIA treated with anakinra for at least 6 months in our institution. Clinically inactive disease (CID) was defined according to Wallace criteria.

Results: The median age at the disease onset was 5.8 (IQR 2.7 –10.7) years. The median time from onset to received anakinra was 1.9 (IQR 0.7-5.8) months. Twenty-five of the 63 patients had been included in a previous study conducted by our group. At baseline fever was present in 59 patients (93.7%), rash in 51 (81%), 60/63 patients (95.2%) had evidence of active joints at baseline with a median number of 2 (IQR 1-4), range from 1 to 15. After 6 months of treatment 44 patients (69.8%) met criteria for inactive disease. Among 63 patients 19 (30.2%) received anakinra in monotherapy and 44 (69.8%) received anakinra with glucocorticoids. There were no statistically significant differences between the two groups for demographic, clinical and laboratory features. Fifteen of 19 (78.9%) patients treated with anakinra alone and 29/44 (65.9%) patients treated with anakinra and glucocorticoids met criteria for CID off glucocorticoids at 6 months (p=0.37). The only variable significantly related with the response was the short time from disease onset to receiving anakinra (p=0.0001). Based on the ROC curve, the cut-off of 3 months was the value with the best performance in term of sensitivity and specificity. Among the 63 patients 38 started anakinra ≤ 3 months and 25 ≥ 3 months. There were no statistically significant differences for demographic, clinical and laboratory features among patients who started anakinra in the first 3 months from disease onset compared to those that started anakinra after 3 months. At 6 months after beginning of anakinra treatment, 34/38 patients (89.5%) who started anakinra within 3 months from disease onset and 10/25 (40%) who started anakinra after 3 months from disease onset reached clinical inactive disease off glucocorticoids (p< 0.0001). Patients who started anakinra after the first 3 months from disease onset have a significantly higher risk of non-response (OR=5.7, 95% CI: 2.1-15.2).

Conclusion: According with several observations, anakinra is effective in a significant proportion of patients with sJIA. A possible approach to introduce IL-1 inhibitor, with or without concomitant glucocorticoids, early in the disease course taking advantage of a “window of opportunity” has been suggested. Our observation confirms that earlier treatment with anakinra is associated with a better short-term outcome. Moreover, our results show that beginning of treatment after two months of disease is correlated with a high risk of non-response.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/early-treatment-with-anakinra-in-systemic-juvenile-idiopathic-arthritis-2/