ESPE Abstracts

Systemic Juvenile Idiopathic Arthritis (sJIA) is a chronic autoinflammatory disease, with significant complications that can give short-term and long-term disability with reduced quality of life. Growth delay and short stature are described in >40% of cases, with a complex pathogenesis. Chronic inflammation, long-term corticosteroids treatment, hepatic involvement, malnutrition decrease IGF-1 and GH biological effects. Corticosteroids inhibit growth velocity, bone maturation, GH and IGF-1 synthesis and biological effects. Inflammatory cytokines increase IGF-1-receptor resistance and reduce osteogenesis. Children with an early disease onset and/or frequent relapses and/or a bad control of the disease, have a higher risk of short stature. Furthermore, the GnRH-gonadotropin-gonadic axis is often impaired in adolescents with sJIA who show a bad control of the disease, with a worsening of growth delay. Moreover, puberty failure is associated with a reduced bone mass peak with future bone fragility. We studied 25 patients (15 F, 10 M) (age 1-18 years), 22 treated with biological drugs (19 canakinumab; 4 tocilizumab; 1 anakinra; 1 sarilumab), 3 with corticosteroids in association with biological drugs. At the diagnosis, mean height in SDS was -0.03 (range: -3.37-1.68; Median: 0.2). At the last follow-up visit, still in treatment with biological drugs, the patients improved the mean height in SDS: 0.19 (range: -3.43-1.82; Median: 0.4). 2 patients with persistent active disease with low control by biological drugs, needed the association of corticosteroids with the anti-IL-1 beta antagonist (canakinumab): they showed a significantly low growth velocity (-3.3 SDS). Biological drugs improve growth velocity and puberty timing, inhibiting inflammatory cytokines and sparing corticosteroids. However, inhadequate growth persists especially in patients with a severe disease and/or in low responders or in patients with frequent relapses. An early window of opportunity for treatment with biological drugs shows a significant growth improvement. In our children growth was more compromised in younger children who needed the association of corticosteroids with biological drugs and a poor control of the disease. Many patients showed a reduced height in SDS at the diagnosis. However, most of them, improved height during the follow-up, because of an effective treatment strategy.

References:

1. Tibaldi J, et al. Development and initial validation of a composite disease activity score for systemic juvenile idiopathic arthritis. Rheumatology (Oxford). 2020;59(11):3505-3514.

2. Cavalli G, et al. Interleukin 1α: a comprehensive review on the role of IL-1α in the pathogenesis and treatment of autoimmune and inflammatory diseases. Autoimmun Rev. 2021 Mar;20(3):102763.