Etanercept Treatment Improves Longitudinal Growth in Prepubertal Children with Juvenile Idiopathic Arthritis

PAOLA FERNANDEZ VOJVODICH, JES B. HANSEN, ULF ANDERSSON, LARS SÄVENDAHL, and STEFAN HAGELBERG

ABSTRACT.

Objective. Anti-tumor necrosis factor (TNF) therapy is known to decrease disease activity of juvenile idiopathic arthritis (JIA), but its effect on longitudinal growth in relation to puberty is not clear. We studied longitudinal growth in response to etanercept treatment in prepubertal and pubertal patients with JIA.

Methods. Out of 52 children treated with etanercept, we studied 20 prepubertal and 11 early/midpubertal patients adherent to treatment for at least 1 year. We collected data on growth and glucocorticoid medication and calculated each patient's height standard deviation score (SDS) in relation to the mid-parental height, the change of this value (ΔhSDS) from –1 to 0 and 0 to 1 year of treatment, and the change between the ΔhSDS values to assess growth improvement.

Results. In the prepubertal group, the relative height SDS (mean ± standard error of the mean) was –1.8 ± 0.2, –2.1 ± 0.3, and –1.9 ± 0.3, and in the pubertal group –1.1 ± 0.4, –1.3 ± 0.3, and –1.1 ± 0.3 at –1, 0, and +1 year of treatment, respectively. The ΔhSDS before etanercept was –0.3 ± 0.1 in prepubertal and –0.2 ± 0.2 in pubertal patients. Over the first year with etanercept, ΔhSDS was +0.2 ± 0.1 in prepubertal (p = 0.001 vs before etanercept; paired Student t-test) and +0.2 ± 0.1 in pubertal patients (p = 0.071). Nevertheless, most prepubertal (17/20) and pubertal (8/11) patients had improved growth (ΔhSDS) in response to etanercept treatment when analyzed individually. The need for intraarticular glucocorticoid injections was negatively correlated to the improved growth (p = 0.001).

Conclusion. TNF inhibition with etanercept improved growth in a majority of patients with JIA. Our data demonstrate that growth improvement with etanercept was independent of the pubertal growth spurt. (First Release Nov 15 2007; J Rheumatol 2007;34:2481-5)

Key Indexing Terms:

JUVENILE IDIOPATHIC ARTHRITIS
ETANERCEPT
GROWTH
PUBERTY

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From the Pediatric Endocrinology and Pediatric Rheumatology Units, Department of Woman and Child Health, Karolinska University Hospital, Stockholm, Sweden, and the Department of Epidemiology, Novo Nordisk A/S, Bagsvaerd, Denmark.

Supported by the Swedish Research Council, Stiftelsen Frimurare Barnhuset i Stockholm, and unrestricted grants from Novo Nordisk A/S, Denmark and Wyeth AB, Sweden.

P. Fernandez Vojvodich, BSc; L. Sävendahl, MD, PhD, Professor, Pediatric Endocrinology Unit; U. Andersson, MD, PhD, Professor; S. Hagelberg, MD, PhD, Pediatric Rheumatology Unit, Department of Woman and Child Health, Karolinska University Hospital; J.B. Hansen, MSc, PhD, Department of Epidemiology, Novo Nordisk A/S.

Address reprint requests to Dr. S. Hagelberg, Pediatric Rheumatology Unit Q1:02, Department of Woman and Child Health, Karolinska University Hospital, SE-171 76 Stockholm, Sweden. E-mail: Stefan.Hagelberg@karolinska.se

Accepted for publication August 27, 2007.

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