Effects of recombinant human growth hormone (rhGH) replacement therapy on detailed immunologic parameters in somatotropine--deficient paediatrics patients prior and after 6 months of rhGH treatment.

OBJECTIVE: This study aims at assessing how recombinant human growth hormone treatment of children and young people suffering from isolated growth hormone deficiency affects some selected parameters of the immune system: a percentage of lymphocytes, granulocytes, monocytes, concentrations of A, G, and M immunoglobulins, a percentage of T lymphocytes divided into subpopulations CD4 and CD8, a percentage of NK and B lymphocytes, and phagocytic activity of granulocytes and monocytes.

MATERIALS AND METHODS: The study comprised 30 children and young people aged 4.2-18 years with isolated growth hormone deficiency both prior to and 6 months after rhGH (recombinant human growth hormone) treatment with a dose of 0.093 IU/kg every 24 hr. The control group comprised 25 healthy children with normal height in the respective age bracket. Labelling was conducted by flow cytometry FACS manufactured by Becton-Dickinson using both labelled antibodies and PHAGOTEST® commercial kit (Orpegen). Concentrations of A, G and M immunoglobulins in blood serum were assessed by means of immunoturbidimetric method using COBAS (manufactured by Roche).

RESULTS: The lowest percentage of active granulocytes in PHAGOTEST® was found in a group examined prior to treatment compared to the control group. The percentage increased after 6 months of rhGH treatment to values comparable with the control group. Although mean concentrations of IgM and IgA after 6 months of treatment with rhGH significantly decreased in comparison with those determined prior to treatment, they still remained within the baseline norm. No significant differences in the phagocytic activity of monocytes, IgG concentration, % of NK lymphocytes, T lymphocytes divided into CD4 and CD8 lymphocytes, B lymphocytes and CD4/CD8 lymphocytic index were found. None of the patients exhibited any clinical symptoms of immune disorders.

CONCLUSION: rhGH treatment of patients with isolated growth hormone deficiency can have positive influence on the phagocytic activity of scavenger cells, mainly granulocytes, which in children with isolated growth hormone deficiency seems to be lower than in their health peers. Growth hormone treatment of children with isolated growth hormone deficiency does not significantly affect the activity of the immune system expressed by the phagocytic activity of monocytes, the percentage of B, T and NK lymphocytes and IgG concentration in blood serum.