FOLLOW-UP OF ANTIBODIES TO GROWTH-HORMONE IN 210 GROWTH HORMONE-DEFICIENT CHILDREN TREATED WITH DIFFERENT COMMERCIAL PREPARATIONS

The aim of the study was to evaluate the immunogenicity of different c ommercial recombinant-growth hormone preparations. The presence of ant ibodies to growth hormone was tested in 210 growth hormone-deficient c hildren at 6-month intervals during treatment for 6-66 months. The pat ients were treated with three preparations (groups A, B and C of 70 ca ses each) having the authentic growth hormone sequence. Groups A and B received hormone synthesized by the recombinant DNA technique in E. c oli, while the group C preparation was produced in a mammalian cell li ne. The preparations showed poor immunogenicity and antibodies were fo und as follows: 1.4% in patients of group A (1 case: binding capacity 0.2 mg/l and Ka 3.5 10(7) l M(-1)), 2.8% in patients of group B (2 cas es; case 1 binding capacity 0.7 mg/l and Ka 1.5 10(7) l M(-1); case 2 binding capacity 0.04 mg/l and Ka of 1.8 10(8) and 6.5 10(6) l M(-1)), and 8.5% in group C (6 cases; binding capacity from 0.4 to less than 0.02 mg/l, Ka from 1.6 10(7) to 3.8 10(8) l M(-1)). Only two patients of group C presented the antibodies in two subsequent examinations; in the other patients the positivity was found once. In all patients pos itive samples were found at intervals of 6-24 months after the start o f therapy. In all antibody-positive patients growth velocity presented no decrease at the time of antibody detection and was never different to that of negative patients. We conclude that the three commercial p reparations examined showed poor immunogenicity without clinical relev ance.