Prednisone inhibits the efficacy of recombinant human growth hormone in pediatric renal transplant recipients.

To test the efficacy and toxicity of recombinant human growth hormone (rhGH, Protropin, Genentech), we reviewed our experience of its administration of rhGH to pediatric renal transplant recipients. Endogenous growth hormone (GH) levels were measured after stimulation with L-dopa and clonidine in growth retarded children whose height (ht) was greater than or equal to 2 standard deviations (SD) below the mean for age. Criteria for receiving rhGH were either subnormal GH levels (< 10 ng/ml) or a zero growth velocity over the preceding year despite normal GH levels after stimulation. The dose of rhGH administered subcutaneously was 0.1 mg/kg/day for 6 days/week. The efficacy of rhGH was evaluated using growth velocity index (GVI) and height standard deviation (Z) score. Catch-up growth was defined as an increase in Z score (delta Z) > or = 0.4. Twenty patients (17 with subnormal GH levels and 3 with normal GH levels but zero GVI) consented to rhGH treatment. Seventeen patients (14 males, 6 pubertal) have completed one year or more of rhGH therapy and are the subjects of this analysis. All 17 patients were receiving cyclosporine and 12 were receiving prednisone during rhGH therapy. Six of the 17 patients (35%) demonstrated catch-up growth (delta Z + 1.3 +/- 0.13). By regression analysis, the only factor noted to affect rhGH response was the concurrent use of prednisone. All five patients not receiving prednisone demonstrated catch-up growth compared to only 1 of 12 patients receiving prednisone (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)