Serum interleukin-1 beta levels correlate with neoplastic bulk in hairy cell leukemia

Interleukin-1 alpha (IL-1 alpha), interleukin-1 beta (IL-1 beta) and soluble IL-2 receptor (sIL-2R) serum levels were evaluated in 24 hairy cell leukemia (HCL) patients. Of these, three patients were studied at the time of diagnosis, 12 in relapse after interferon (IFN) therapy, eight with a partial response after IFN and one with a complete response after 2-deoxycoformycin (DCF) therapy. Statistically significant differences were observed in the serum levels of IL-1 beta and sIL-2R between HCL patients and controls. These were 400.3 pg per 0.1 ml (range 23.2-990) and 64.3 pg per 0.1 ml (20-115) for IL-1 beta and 4667.2 U/ml (488-7800) and 424.3 U/ml (188-666) for sIL-2R, respectively. In contrast, IL-1 alpha measurements showed no statistical differences between the two groups. A significant increase of sIL-2R (p = 0.01) and IL-1 beta (p = 0.03) serum levels was observed in patients studied at the time of diagnosis or in relapse compared to those in partial or complete remission. IL-1 beta serum levels directly correlated with sIL-2R (p less than 0.0001) and with hairy cell (HC) bone marrow infiltration, expressed by the HC index (p = 0.003). The comparison of IL-1 beta serum levels of HCL patients with those detected among 149 patients grouped according to diagnosis (Hodgkin's disease = 17, non-Hodgkin's lymphomas = 57, acute non-lymphoid leukemia = 46, and acute lymphoid leukemia = 29) indicate that HCL patients showed the highest IL-1 beta serum level increase, indicating that IL-1 beta could be used as a specific clinical marker of this disease.