Diagnostic interest of acid-labile subunit measurement in relationship to other components of the IGF system in pediatric patients with growth or eating disorders

Objective: To analyze the possible utility of measuring acid-labile subunit (ALS) in some types of pathologies in which the IGF system is altered and to compare it with the clinical implications of measurements of other compo nents of this axis. Design and methods: We studied serum ALS concentrations in 20 children with normal variants of short stature (NVSS) at diagnosis and 24 with growth ho rmone deficiency (GHD), 18 obese patients and 18 girls with anorexia nervos a at diagnosis and during a follow-up period. Results: In patients with GHD and anexoria nervosa, mean ALS concentrations were significantly reduced, but there was a high percentage of overlap wit h control values. At diagnosis, ALS concentrations were normal in obese pat ients and children with NVSS. During follow-up, these values normalized in children with GHD who were treated with GH, tended to normalize in those wi th anexoria nervosa who showed weight gain, and did not change in obese chi ldren upon weight loss. However, ALS measurement was less accurate than tha t of IGF-I or IGF binding protein (IGFBP)-3 in diagnosis of GHD. The correl ations found between ALS and some IGF system components at diagnosis either decreased or were non-significant during follow-up of these clinical condi tions. Conclusion: ALS adds little information to that obtained with IGF-I and IGF BP-3 determinations.