Response to long-term growth hormone therapy in short children with reduced GH bioactivity.
OBJECTIVE
The aim of the present study was to investigate whether short children with normal growth hormone (GH) immunoreactivity, but reduced bioactivity (bioinactive GH) could benefit from rhGH treatment as GH deficient (GHD) patients.


METHODS
We evaluated 12 pre-pubertal children (8 M, 4 F), with GH deficiency-like phenotype showing normal serum GH peak levels (>10 ng/ml), measured by immunofluorimetric assay (IFMA-GH), in contrast with a reduced GH bioactivity (bio-GH), evaluated using the Nb(2) cells. We also evaluated 15 age-matched GHD pre-pubertal children (11 M, 4 F) with serum GH peak <5 ng/ml. Both groups were treated with rhGH therapy at the dose of 0.23 mg/kg/week s.c.


RESULTS
Serum bio-GH/IFMA-GH ratio at peak time for each patient during the provocative test was significantly lower in bioinactive GH than in GHD children (0.29 vs. 2.05, p = 0.00001). Recombinant human GH therapy induced a significant (p < 0.001) increase in growth rate in both groups during the first 2 years. In the third year of treatment, while growth rate in GHD children is maintained, in bioinactive GH patients it decreases remaining, however higher compared to the pre-treatment one.


CONCLUSIONS
Short rhGH therapy given to selected bioinactive GH children improve growth rate and might result in greater final adult height.
Travaglino
Paola
P
Department of Pediatrics, University of Pavia, Pavia, Italy.
Buzi
Fabio
F
Meazza
Cristina
C
Pagani
Sara
S
Tinelli
Carmine
C
Iughetti
Lorenzo
L
De Sanctis
Vincenzo
V
Aimaretti
Gianluca
G
Poddighe
Dimitri
D
Barberi
Salvatore
S
Bozzola
Mauro
M
D001827:Body Height / Q000187:drug effects; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004393:Dwarfism, Pituitary / Q000188:drug therapy*; D005260:Female; D006130:Growth Disorders / Q000378:metabolism; D013006:Growth Hormone / Q000378:metabolism* / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D011627:Puberty / Q000378:metabolism; D013995:Time
D013006:Growth Hormone