THE DETECTION of antibodies to human growth hormone (HGH) developing during long-term therapy with HGH has recently been reported by several investigators. Antibodies did not appear to interfere with the response to HGH in two patients reported by Trafford et al1 or in three patients reported by Roth et al.2 The growth-promoting effect appeared to be neutralized in the three patients of Prader et al3 and in the patient described by Parker et al.4 The short-term metabolic effects of HGH were inhibited in two of Prader's patients as measured by nitrogen balance studies. These findings suggest that antigenicity of HGH preparations in man may limit their therapeutic usefulness.
We have observed the development of antibodies to HGH in one of three patients receiving long-term therapy with Li HGH. This patient failed to show a growth response to HGH therapy. Immunological and biological studies of these anti-HGH