HYPOCHOLESTEROLEMIA IN HAIRY-CELL LEUKEMIA - A MARKER FOR PROLIFERATIVE ACTIVITY

Hypocholesterolemia is a well-documented phenomenon associated with a variety of hematological malignancies and nonmalignant disorders assoc iated with splenomegaly. To determine the incidence of hypocholesterol emia in patients with hairy cell leukemia (HCL), we measured the serum cholesterol levels before and after a single cycle of 2-chlorodeoxyad enosine (2-CdA) in 46 patients. The mean pre-treatment serum cholester ol level was 152.8 mg/dl (range, 60 to 293 mg/dl), The mean post-treat ment serum cholesterol level was 190.0 mg/dl, This was significantly h igher than the pre-treatment values (P < 0.0001). Twelve patients who had previously undergone splenectomy showed a similar response to trea tment, with a pre-treatment value of 180.0 mg/dl and a post-treatment value of 219.8 mg/dl (P < 0.0001), However, there was a significant di fference in the pre-treatment serum cholesterol levels in the nonsplen ectomized patients (143.0 mg/dl) compared to the splenectomized patien ts (180.0 mg/dl) (P < 0.03). The pre-treatment serum cholesterol did n ot correlate with the pre-treatment splenic index (correlation coeffic ient = -0.39, P < 0.065). Similarly, there was no correlation between the change in splenic index and the change in serum cholesterol level post-treatment. These findings suggest that hypocholesterolemia in HCL is related to tumor burden and not to splenomegaly alone. Since chole sterol is critical to hairy cell metabolism and structure, treatment s trategies interfering with cholesterol synthesis may be productive. (C ) 1997 Wiley-Liss, Inc.