Influence of biologic therapy on growth in children with chronic inflammatory connective tissue diseases

OBJECTIVES: Connective tissue diseases (CTD) are a heterogeneous group of chronic inflammatory conditions. One of their complications in children is the inhibition of growth velocity. Due to direct inflammation within the musculoskeletal system as well as glucocorticoid therapy, this feature is the most essential and is mainly expressed in the course of juvenile spondyloarthropathies and juvenile idiopathic arthritis (JIA). Duration of the disease, but predominantly the activity of the inflammatory process, seems to have a significant impact on the abnormal growth profile in children. Effective biological therapy leads to improvement of the patient's clinical condition and also, through the extinction of disease activity and reduction of daily doses of glucocorticosteroids (GCS), it gradually accelerates and normalizes the growth rate in children with CTD. Our objective was to evaluate the impact of biological therapy on growth in children with chronic inflammatory CTD. MATERIAL AND METHODS: Data from 24 patients with CTD treated with tumor necrosis factor-α-blockers (etanercept, adalimumab, golimumab) and an interleukin-6 receptor blocker (tocilizumab) were reviewed at the time of disease onset, biological treatment initiation and at least 12 up to 24 months onwards. The rate of growth was correlated with the daily doses of GCS, and the type and duration of biological therapy. RESULTS: Patient median height, measured as the change in height standard deviation score, was 0.36 ±1.07 at disease onset and –0.13 ±1.02 at biologic therapy initiation. The growth velocity accelerated in 17 patients (70.1%) during the biological treatment. Mean height-SDS improvement between biological treatment initiation up to two years was 0.51 ±0.58. In 47% of patients daily doses of GCS were reduced to 0 mg/kg/day. CONCLUSIONS: In the treatment of CTD, biological agents restore growth velocity not only by inflammation inhibition, but also through limiting GCS daily doses.