Five-year follow-up of growth hormone antibodies in growth hormone deficient children treated with recombinant human growth hormone.
OBJECTIVE
The aim was to investigate the long-term evolution of circulating growth hormone antibodies (GH-AB) during and after treatment with methionyl-recombinant human growth hormone (met-rhGH).


METHODS
The investigation was performed on serum samples of 46 growth hormone deficient children, treated for at least 12 months with met-rhGH. Twenty patients had never been treated with hGH (previously untreated patients, Group I). Twenty-six subjects were previously treated with pituitary extracted hGH (treated patients, Group II).


METHODS
Serum levels of GH-AB were measured by radioimmunoassay using charcoal precipitation of free ligand.


RESULTS
Fifteen patients (75%) of Group I and three patients (12%) of Group II developed GH-AB. In 15 GH-AB positive patients the antibodies became detectable during the first year of treatment with met-rhGH. In three patients, however, the GH-AB appeared during the second year. Once present, the GH-AB remained detectable throughout the period of treatment with met-rhGH. In six patients in whom treatment with met-rhGH was stopped, GH-AB levels decreased rapidly. In nine patients in whom treatment with met-rhGH was changed to rhGH, the levels of GH-AB decreased and ultimately became undetectable. In two patients GH-AB remained present during administration of rhGH. No effect of GH-AB on the growth-promoting effect of met-rhGH could be documented, either during the first or during the second year of treatment.


CONCLUSIONS
This study confirms the high immunogenicity of met-rhGH, especially in patients not treated earlier with hGH. Once present, the GH-AB remain detectable throughout the period of treatment with met-rhGH. After stopping met-rhGH treatment or changing to rhGH the GH-AB disappear rapidly in most patients. No effect of GH-AB on the growth-promoting effect of rhGH could be documented.
Massa
G
G
Department of Paediatrics, University of Leuven, Belgium.
Vanderschueren-Lodeweyckx
M
M
Bouillon
R
R
D000293:Adolescent; D000328:Adult; D001323:Autoantibodies / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006128:Growth / Q000187:drug effects; D006130:Growth Disorders / Q000188:drug therapy / Q000276:immunology*; D013006:Growth Hormone / Q000031:analogs & derivatives / Q000172:deficiency / Q000276:immunology* / Q000627:therapeutic use; D019382:Human Growth Hormone; D006801:Humans; D008297:Male; D011994:Recombinant Proteins / Q000627:therapeutic use
D001323:Autoantibodies; D011994:Recombinant Proteins; D019382:Human Growth Hormone; D013006:Growth Hormone