Red cell distribution width (RDW) as a marker of disease activity in patients with hairy cell leukemia

Red cell distribution width (RDW) was examined in 18 patients with hairy cell leukemia (HCL) treated with 2-chlorodeoxyadenosine (2-CdA), in 5 patients treated with Interferon alpha (IFN-alpha) and in 9 patients subjected to splenectomy. Out of 18 patients treated with 2-CdA one patient was excluded of the study because of association of HCL with acquired sideroblastic anemia. In the remaining 17 patients the mean value of RDW before therapy was 18.8% (range 13.5% to 25.0%) and dropped after successful therapy after 6 to 12 months to the mean value of 13.6% (range 11.2% to 17.9%) and after 18 months to 13.4% (range 12.6% to 14.7%) (p = 0.00015 and p = 0.00049 respectively). The hemoglobin level increased from the mean value of 119 g/l (range 99 g/l to 157 g/l) before therapy to the mean value of 145.9 g/l (range 127 g/l to 172 g/l) after 6 to 12 months and after 18 months to 147.8 g/l (range 132 g/l to 168 g/l) (p = 0.000017 and p = 0.00036 respectively). The same trend was observed in the group of patients treated with IFN-alfa. The RDW decreased from the mean value of 21.3% (range 18.8% to 28.7%) to the mean value of 15.3% (range 12.4% to 16.7%), (p = 0.031). The hemoglobin level increased in this group of patients from the mean value of 115 g/l (range 98 g/l to 127 g/l) to the mean value of 136 g/l (range 127 g/l to 146 g/l) (p = 0.031). In 9 patients in complete hematologic remission 34 to 293 months after splenectomy the mean value of RDW was 13.9% (range 13.0% to 15.5%).

Increased RDW in HCL is associated with active disease and is reversible after successful therapy. This phenomenon has not been reported in the literature yet. Preliminary results show that the increase of RDW may be due to the dyserythropoiesis.