Growth after discontinuation of recombinant human growth hormone therapy in children with chronic renal insufficiency. The Genentech Cooperative Study Group.

OBJECTIVES

The impact of a pause in treatment with recombinant human growth hormone (rhGH) during the course of chronic renal insufficiency (CRI) once target height (50th percentile for mid-parental height) is reached and the impact of cessation of rhGH treatment after successful renal transplantation were evaluated. Prepubertal patients with CRI included in a multicenter, randomized, double-blind, placebo-controlled trial who either reached target height or received a renal transplant, or both, were included in this report. Patients in the placebo group may have initiated pubertal development at the time rhGH treatment was begun.

STUDY DESIGN

Growth velocity (measured in centimeters per year) and standardized height score (SDS) in 22 patients who had a pause in rhGH therapy after attainment of target height were evaluated serially before and after the pause, and 30 patients, 4 of whom were also included in the pause group, who discontinued rhGH therapy at the time of transplantation were followed as long as 68 months after transplantation.

RESULTS

Six of twenty-two patients (two of whom subsequently underwent transplantation) continued with the pause in treatment for a mean (+/-SD) duration of 25.5 +/- 26.9 months (group 1), and 16 of 22 resumed rhGH therapy after pausing for a mean (+/-SD) of 9.0 +/- 4.6 months (group 2). The mean (+/-SD) growth velocity during the pause in group 1 was 5.1 +/- 1.8 cm/yr and in group 22.7 +/- 1.7 cm/yr. After reinstitution of rhGH in group 2, the mean (+/-SD) growth velocity increased to 7.2 +/- 1.7 cm/yr. The mean (+/-SD) height SDS in the 30 patients who discontinued rhGH therapy at the time of transplantation was -2.8 +/- 0.9 at baseline (initiation of rhGH therapy), -1.6 +/- 1.3 at the time of transplantation, and -1.7 +/- 1.2 at last follow-up. The mean (+/-SD) growth velocity was 5.1 +/- 4.7 cm/yr after transplantation, and the mean (+/-SD) delta (delta) height SDS was -0.07 +/- 0.5 at last follow-up.

CONCLUSIONS

A pause in rhGH treatment in children with CRI after attainment of target height leads to maintenance of height SDS in 27% and a marked reduction in growth velocity, requiring reinstitution of rhGH therapy, in 73%; discontinuing rhGH treatment at the time of transplantation does not result in substantive posttransplantation "catch down" growth.