Hematologic improvement in a patient with Gaucher disease on long-term enzyme replacement therapy: evidence for decreased splenic sequestration and improved red blood cell survival.

We describe here an investigation of the hematologic response of a child with Gaucher disease to a six-year therapeutic trial of human placental mannose-terminated glucocerebrosidase. While on enzyme replacement therapy, the patient's hemoglobin and platelet count significantly increased (6.9 g/dl to 12.2 g/dl, and 39,000/microliters to 74,000/microliters, respectively). Over the same time interval his absolute reticulocyte count decreased (88.1 x 10(3)/microliters to 31.5 x 10(3)/microliters). The patient's splenic volume decreased by over 60% (2108ml to 797ml) and his bone marrow demonstrated a dramatic clearing of Gaucher cell infiltration. Serum erythropoietin levels were at the lower range of normal at points in time when he was severely anemic and did not change with improvement in hemoglobin. Coincident with the improvement in the patient's hemoglobin, in vivo survival of autologous radiolabeled RBCs increased 34%. The improved hematopoietic profile appeared to result primarily from an increase in the in vivo survival of mature hematopoietic elements secondary to a decrease in splenic sequestration. Improved marrow function secondary to the clearing of Gaucher cell infiltrates may also play a role in his improved hematologic status.