Cathepsin activities and disease manifestations.

(A) The relation between clinical severity score index calculated according to Zimran et al41 and serum cathepsin K activity in 20 patients with untreated type I Gaucher disease; similar data were obtained for measurements of cathepsins B and S (see text). (B) Serial measurements of cathepsins B (i) and K (ii) in a 52-year-old man with osteoporosis due to Gaucher disease (N370S/84GG genotype), who was previously treated by splenectomy. The horizontal axis shows the time after starting 30 IU/kg/mo imiglucerase. At 6 months the patient experienced an episode of avascular necrosis of the femoral head, shown by the arrow. Cathepsin activities were determined retrospectively in stored sera routinely collected at clinical evaluations. The dotted lines represent the 95% upper confidence limits of serum cathepsin activities in 26 healthy control subjects.