Intra-erythrocyte deposition of growth hormone in rheumatic diseases.

Standard radioimmunoassay was employed to quantify matched basal intra-erythrocyte growth hormone (GH) and serum GH levels from patients with osteoarthritis, diffuse idiopathic skeletal hyperostosis (DISH), gout, and Sjögren's syndrome and in a group of normal volunteers (control group). Basal intra-erythrocyte GH concentration was significantly higher ( P<0.05) than serum GH concentration in blood samples from patients with osteoarthritis and DISH but not from those with gout or Sjögren's syndrome. Regression analysis determined that basal serum GH levels did not correlate with age. While intra-erythrocyte GH levels exceeded serum GH levels in osteoarthritis and DISH, intra-erythrocyte GH was not a strong predictor of serum GH levels in osteoarthritis, DISH, or in the control group.