Hematologic response in type I Gaucher's disease after enzyme replacement therapy.

Sir, Gaucher's disease is a sphingolipidosis characterized by recessive autosomal transmission. It is often accompanied by normochromic normocytic anemia which almost never requires transfusion therapy. Continued therapy using enzyme replacement is currently a treatment choice for this rare and as yet little studied disease. The neurologic and liver damage linked to metabolic abnormalities are particularly poor understood. 1-4 We monitored hemoglobin and reticulocyte behavior after 6 months of enzyme replacement therapy in 13 patients, age between 6 and 46 years, with type I non-neuropathic Gaucher's disease followed in our Institute. The patients were divided into two groups by age; one group of 7 patients aged between 6 and 18 years, the other group of 6 patients aged between 19 and 46 years (no longer pediatric, but continuing to reveice treatment at our Gaucher's Disease Center). Reticulocyte RNA was stained and examined under Argon light using a Dasit ® 3000 ana-lyzer. The reading is based on the principle of cyto-metric flow and provides, both quantitative (absolute and percentage values) and qualitative information on reticulocytes, breaking them down into three subgroups according to intensity of fluorescence and, therefore, state of maturity (high fluorescence-HFR, middle fluorescence-MFR, low fluorescence-LFR). Blood samples were stored with EDTA 2K and analyzed within two hours of being taken. The Wilcoxon test for paired data, before and after therapy, was used for statistical analysis. After 6 months of enzyme therapy the hematolog-ic findings of the first group (Table 1) had improved, with increased hemoglobin and MCHC and a reduction in both total reticulocytes and HFR; conversely, the number of LFR increased. In the second group, however, (Table 2), hemoglobin did not change significantly following therapy and the patients seemed Table 1. Variations of hematologic parameters before (1) and after 6 months (2) of enzyme replacement therapy in 7 young patients affected by Gaucher's disease type I with normal levels of serum ferritin. Reticulocytes RBC data Ferritin Pts. Total 1 Total 2 LFR 1 LFR 2 MFR 1 MFR 2 HFR 1 HFR 2 Hb 1 Hb 2 MCV 1 MCV 2 MCHC 1 MCHC 2 2 10 6 /µL % % % g/dl fL g/dL ng/mL Table 2. Variations of hematologic parameters before (1) and after 6 months (2) of enzyme replacement therapy in 6 older patients affected by Gaucher's disease type I with high levels of serum ferritin. Reticulocytes RBC data Ferritin Pts. Total 1 Total 2 LFR …