Galactosyl hydroxylysine in assessment of Paget's bone disease.

Urinary galactosyl hydroxylysine/creatinine ratio (GHL) was used to assess rates of bone collagen degradation and the activity of the pagetic lesion as well as for monitoring the rate and degree of suppression of bone resorption over 1 year in patients treated with 30 mg of intravenous pamidronate for 3 consecutive days. The clinical utility of GHL was compared with that of urinary hydroxyproline/creatinine and deoxypyridinoline/creatinine and with bone isoenzyme of serum alkaline phosphatase. The results suggest that GHL is a quantitative marker of the activity of Paget's bone disease. GHL is less sensitive than hydroxyproline, deoxypyridinolone and bone alkaline phosphatase in monitoring treatment of Paget's disease. The assay of GHL is easier, faster and less costly than that of hydroxyproline or deoxypyridinoline and it can be easily standardized.